- Hybrids & Heirlooms
- What Is a Hybrid Plant?
- How Are Hybrid Plants Made?
- What Is an F1 Hybrid?
- Are Hybrid Plants the Same as Genetically Modified Plants?
- Hybrid vs. Open Pollinated vs. Heirloom
- Hybrid Plants Advantages and Disadvantages
- Advantages of Hybrid Plants
- Disadvantages of Hybrid Plants
- Should I Buy Hybrid or Heirloom Plants and Seeds?
- The first seed
- The upside of seeds
- What is the Seed?
- Types of Seeds
- Solved Question for You
- Hybrid varieties
- How Corn Hybrids are Developed
- Be Inspired Blog – California
- What does “F1” Mean?
- A beginner’s guide to… F1 slang
- Learn About F1 Hybrid Seeds
- What are F1 Hybrid Seeds?
- Why Use F1 Hybrid Seeds?
How experts define heirlooms can vary, but typically they are at least 50 years old, and are often pre-WWII varieties. Most heirlooms come from seed that has been handed down for generations in a particular region or area, hand-selected by gardeners for a special trait. Others may have been developed by a university a long time ago (again, at least 50 years), in the early days of commercial breeding. All heirloom vegetables are open-pollinated, which means they’re pollinated by insects or wind without human intervention. In addition, they tend to remain stable in their characteristics from one year to the next.
Many gardeners agree that most heirloom varieties boast greater flavor than that found in hybrids, especially among tomatoes. Bonnie’s heirloom tomato varieties are clearly marked on the plant trays.
While hybrid plants typically yield a crop that is uniform in both appearance and timing, heirloom vegetables may produce a “mixed bag” harvest. The harvest may come in less predictably, and fruit size can vary greatly even on the same plant.
Despite their sometimes odd looks and quirky ways, heirlooms bring lots to the table (literally!). The Amish heirloom tomato Pink Brandywine, for example, yields fruit with an unbeatable flavor in shades reminiscent of a glass of Cabernet. Arkansas Traveler, a Southern favorite, originated in Northwest Arkansas prior to 1900 and gradually found its way across the South to North Carolina. Offering some resistance to cracking and disease, this beauty yields delicious tomatoes under typical Southern summer conditions–high heat, high humidity, and drought.
Hybrids & Heirlooms
As you review seed catalogs and make selections, you may be confronted with the terms hybrid, open pollinated, and heirloom. Knowing what these mean will help you know more about the plant and what to expect.
Crossing specific parent plants produces a hybrid seed (plant) by means of controlled pollination. These hybrid seeds are often called “F1” or “F1 hybrids.” The terms “hybrid” and “F1” are strictly defined in the seed industry and, when used in seed catalogs, do not apply to plants crossed in the wild.
Some people think of a hybrid as blending two different plants, like mixing a red flowered plant and white flowered plant to get a pink flowered offspring. Unfortunately, the laws of genetics prevent it from being that easy. Most hybridized plants require the cross breeding of carefully chosen parent plants. The resulting seed will produce plants with very specific characteristics. Hybrid plants are very consistent from plant to plant and year to year. Hybrids carry a combination of traits from the parent plants.
Based on desirable traits, breeders select specific male and female parent plants. The plants selected to be the female seed-bearing partner have their pollen bearing anthers removed. They receive pollen only from those plants selected as their partners. By controlling the pollination, the resulting offspring will have identifiable genetic characteristics from both parents.
Producing hybrid seed is more time consuming and expensive because the plants must be hand pollinated. In addition, plant breeders may work for years to find the right combination of desirable traits they are looking for in a plant.
The breeder of the F1 hybrid variety can be the exclusive source of that variety. Only the breeder knows exactly what two parent plants are needed to produce the seed. Other breeders can try to duplicate a hybrid, but only the first breeder knows the exact combination used. Of course, it is through the process of trying to breed new and better varieties that unexpected new ones are found.
Not every F1 hybrid is a winner. The All America Selections program and other trial gardens are ways that new varieties are tested side by side to see what, if any, improvements have taken place in a certain type of flower or vegetable. Before a variety reaches the market, seed companies perform their own trials, and many hybrids end up in the compost pile, never to be seen again.
The extra work needed to produce hybrid varieties usually means higher cost. Are they worth the price? Consider the advantages and disadvantages of hybrids. Hybrids possess wider adaptability to environmental stress and are more uniform from plant to plant than non-hybrids. Other benefits of hybrids may be earlier flowers, higher yields, improved disease resistance, or other characteristics. Many hybrids are better, more consistent garden performers.
The extra vitality in hybrid plants is called “hybrid vigor.” More plants survive the seedling stage, grow larger and stronger than non-hybrids, and have higher yields. Improved disease and insect resistance means fewer pesticides have to be used in the garden.
The primary disadvantage of hybrids is the seeds cannot be saved from year to year. Seeds saved from hybrid plants usually will not produce the same plant the following year because most varieties are not self-sustaining. Offspring of hybrids usually show an unpredictable mixture of characteristics from the grandparent plants instead of being similar to the parent.
Some gardeners feel that the taste of hybrid vegetables does not equal that of heirloom varieties. But taste is so subjective that there does not seem to be a fair test to compare hybrids developed for the home garden to heirlooms. Burpees Big Boy, Celebrity, and Early Girl tomatoes, Sweet Success cucumber, and Premium Crop broccoli are examples of F1 hybrids that have been popular for years.
Open-pollinated, also known as heirloom or standard, plants are varieties that have stable traits from one generation to the next. Open pollinated plants are fairly similar to each other but not as uniform as hybrids. Because most were originally chosen for only one or two specific characteristics, individual plants of older heirloom varieties may differ greatly in size, shape, or other traits.
Open pollinated varieties are usually grown in fields where they self and cross-pollinate. Wind and insects carry the pollen from one plant to another. Plants that cross-pollinate must be isolated from other plants of different varieties so they will produce seed that is “true to type.” Beans, lettuce, peas, and tomatoes are self-pollinating so they are easier to continue year to year without having to isolate them from other varieties of plants.
Genetic “drift” can occur over a period of time. Plants that deviate too far from the accepted standard are removed from commercial nursery fields of open pollinated varieties. Likewise, home gardeners should destroy highly unusual plants if you are trying to preserve an open pollinated variety. Removal of these rogue plants prevents them from pollinating other plants and producing too much variation.
The advantage of open pollinated seeds is that the home gardener from year to year and generation to generation may continue heirloom plants by careful seed saving. Open pollinated plants provide a larger gene pool for future breeding. Well known open pollinated varieties include Kentucky Wonder pole bean, Scarlet Nantes carrot, Black Beauty eggplant, Black Seeded Simpson lettuce, California Wonder pepper, and Brandywine and Roma tomatoes.
As a gardener you may choose hybrids, heirlooms, or a combination of both types for the garden. Compare the characteristics of each variety with the qualities you want in a plant. Select varieties that are best for your garden.
February – March 2001: Hybrids & Heirlooms | Put the Right Plant In the Right Place | Windbreaks Can Help Save On Energy Costs | Apple Scab & Black Knot
What Is a Hybrid Plant?
A hybrid plant is a plant grown from the seed produced by cross-pollinating two distinct parent plants of different varieties. This process of controlled pollination creates a new, third variety that will hopefully have a combination of the desirable traits of each of the parent plants.
Some widely known examples of hybrid plants are Early Girl, Big Boy and Celebrity tomatoes.
How Are Hybrid Plants Made?
To create a hybrid plant, a grower first chooses two parent plants that have desirable traits. Then, they cross-pollinate these two varieties through controlled pollination. This means that they prevent open pollination and self-pollination (processes that happen in nature) by protecting their female plant from outside pollination and manually pollinating the female plant with pollen from the male plant.
The grower then harvests the seed produced by this controlled pollination and plants it to grow the new variety. The new variety is then assessed to see if it has the desirable traits from each parent that the grower was hoping to combine. For example, the grower may have chosen one parent plant from a variety that is disease resistant but has small fruit and the other parent plant from a variety that has large fruits but is prone to disease. The hope is that the new variety they create will have the positive traits of the parent plants. In this case, that would be a plant that is disease resistant and produces large fruit.
If the new variety does not have these traits, then the grower must start over and continue to experiment until they get the desired traits. Once they find the parent combination that produces the desired results, they will continue to do that cross each year to get seeds they can plant or sell.
What Is an F1 Hybrid?
An F1 hybrid is the first generation of a hybrid plant that is the offspring of two distinct parent plants of different varieties. The parent plants are bred through controlled cross-pollination to create a new, third variety of plant. This new variety is an F1 hybrid.
Are Hybrid Plants the Same as Genetically Modified Plants?
It is important to note that hybrid plants are not the same as genetically modified (GM) plants. Hybridization under controlled pollination is still a natural process and similar to what occurs naturally with open-pollinated plants. Genetically modified plants are “created in a lab using highly complex technology, such as gene splicing. These high-tech GM varieties can include genes from several species – a phenomenon that almost never occurs in nature.” (Mother Earth News)
Some genetically modified plants even contain genes from completely different kingdoms. For example, scientists may splice in genetic material from bacteria in order to create a plant more resistant to a particular disease or pest.
With little longitudinal information on how genetically modified plants behave over time, there is a lot of controversy over whether or not genetically modified plants are safe. This is not a concern with hybrid plants, where growers simply manage the natural reproduction process to create desirable traits.
Hybrid vs. Open Pollinated vs. Heirloom
Hybrid plants are propagated through controlled pollination in which the grower selects parent plants with specific traits and purposefully breeds those parent plants to create a hybrid plant.
It is essentially the same, natural process of reproduction that occurs in open pollination, except the grower controls the reproduction process by selecting the parent plants and preventing open pollination – instead of allowing nature to take its course.
Open pollination is what occurs naturally in your backyard garden or commercial fields or in the wild. This process occurs when pollinators – bats, bees, butterflies, birds, wind – complete the pollination process. Open pollination generally increases biodiversity, but the resulting plants may have traits that vary significantly; whereas, the controlled pollination of hybrid plants results in specific, expected traits.
Heirloom plants, which are also called heritage plants or standards, are open-pollinated or self-pollinated and are grown from seeds passed down in families or communities over the generations. Most gardeners and growers assert that an open-pollinated variety must be at least 50 years old to be considered an heirloom. Others define heirlooms by the ability to trace the provenance of the seeds back through the generations.
Hybrid Plants Advantages and Disadvantages
We have all walked through a farmers market or the produce section at our local grocery store and seen one bin of tomatoes that are nearly identical in size, shape and color next to another bin filled with tomatoes that are small, large, round, lumpy, orange, red, multicolored, and completely unique. The first bin with the nearly identical tomatoes will be from hybrid seeds that provide that uniformity of color, size and shape. The second bin of tomatoes that completely lack uniformity are heirloom varieties grown from open-pollinated seeds.
Whether you should choose hybrid seeds and plants, or open-pollinated and heirloom seeds and plants depends on your preferences and goals. Many gardeners plant both heirlooms and hybrid plants in their gardens. Both types of seeds have advantages and disadvantages, so we will address those here to help you decide which type is best for you.
Advantages of Hybrid Plants
- Hybrids have more uniform characteristics when compared to open-pollinated plants.
- Hybrids can be bred to have specific, desirable traits, such as larger harvests, disease resistance or a longer blooming period.
- Disease-resistant hybrids may mean fewer chemicals are needed to ensure survival.
- Hybrid seeds allow commercial growers to produce uniform plants, flowers, fruits, or vegetables, which makes them more attractive to consumers.
- Home gardeners often prefer hybrid seeds for uniformity in their flowerbeds.
- Hybrid plants often grow faster and are more vigorous (known as “hybrid vigor”).
- Hybrid plants are often bred to thrive in less-than-ideal conditions, such as drought conditions.
Disadvantages of Hybrid Plants
- Growing hybrid plants limits biodiversity and contributes to a continued loss of variety.
- New hybrid seeds must be produced or purchased every year.
- Unlike heirloom and other open-pollinated plants, seeds from hybrids cannot be saved to plant in your garden from one year to the next or to be passed down to your children.
- The seeds of hybrid plants do not breed true and produce unpredictable traits (if they grow at all). For example, the offspring may have just the traits of one grandparent or may have completely unexpected traits.
- Hybrid seeds are more expensive to produce and more expensive for growers to purchase.
- The yield from the offspring of hybrid plants is significantly reduced, which is another reason you must purchase new hybrid seeds each year.
- Many gardeners believe that fruits and vegetables from hybrids lack the flavor found in heirloom varieties.
Should I Buy Hybrid or Heirloom Plants and Seeds?
The answer to this depends on your preference and goals. If your goal is to fill your flowerbed with uniform plants that you can predict will be similar in size and bloom color, hybrids are the way to go. If you rely on your vegetable garden to produce a bountiful harvest to preserve for winter, hybrids may, again, be the answer. You should also choose hybrids if you prefer fruits and vegetables with a uniform appearance that resembles what you would purchase at your local grocer.
If you want to save money by saving seeds from your garden to plant the following year, go with heirloom varieties. You should also choose heirloom seeds and plants if you want to support biodiversity or if you prefer more flavorful produce.
Curious Kids is a series for children of all ages, where The Conversation asks experts to answer questions from kids. All questions are welcome: find out how to enter at the bottom of this article.
Where did the first seed come from? – Alice, age six, Beverley, UK
Hi Alice. This is a clever question. As I’m sure you know, plants use seeds to spread their young and make new plants. But plants haven’t always used seeds to do this. Seeds came together bit-by-bit over a really long time, as plants evolved.
To understand how this happened, you need to know that all living things change slowly over time, to get better at surviving in their environment – this process is called evolution.
Here’s how it works: when a living thing has a feature which works well, it will be able to live longer and have more young. These young will probably have similar features, thanks to their parents.
Plants started using seeds to spread their young somewhere between 385m and 365m years ago. Before seeds existed, plants had other ways of doing this.
Spores on the leaves of a fern. .
Back then, most plants used spores. Some plants today, such as algae, mosses and ferns, still do. You might have spotted the tiny brownish dots on the underside of fern leaves – these are spores.
Spores are different from seeds in a few ways. A spore is made of just one part – a single cell – while a seed contains many cells, each with different jobs to do.
Another difference is that spores only have one parent plant, while seeds have two.
This means that, after a seed starts sprouting, it can grow into a plant, just like its parents.
But spores have to work a bit harder: once they’ve travelled away from their parent plant, they grow into a little green plate of cells, which scientists call a “gametophyte”. Then, two gametophytes must join together, before they can grow into a plant.
It’s easier for gametophytes to join together when its wet – and that’s why plants that use spores usually need to grow in wet places.
For example, horsetails are a very ancient type of plant, which like to grow along lakes, rivers and ponds: they have very strange spores with four “legs” which help them to move and travel further away.
The first seed
Scientists believe that an extinct seed fern, called Elksinia polymorpha, was the first plant to use seeds.
This plant had cup-like features, called “cupules”, that would protect the developing seed. These cupules grew along the plant’s branches.
Today, plants with seeds do things a little differently. There are two main types: “angiosperms” and “gymnosperms”.
Angiosperms are flowering plants – their seeds develop inside of fruit, like apples, tomatoes or even rose hips or holly berries.
The seeds of gymnosperm and angiosperm plants.
Gymnosperms, such as pine trees, grow their seeds inside a hard cone.
The upside of seeds
Seeds have evolved because they are better at helping plants to survive than spores are. For example, seeds contain a food source to help the new plant grow.
They also have a hard coat, which helps them to live longer in different conditions: this means plants with seeds can life in lots of different places, from hot, dry deserts to cool, rainy places.
Seeds are so good at helping plants to spread their young that most plant species on Earth today use seeds.
Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question – along with your name, age and town or city where you live – to [email protected] Send as many questions as you want! We won’t be able to answer every question, but we’ll do our best.
More Curious Kids articles, written by academic experts:
Why do spiders have hairy legs? – Audrey, age five, Melbourne, Australia
Why do we have different seasons at specific times of the year? – Shrey, age nine, Mumbai, India
How is water made? – Clara, age eight, Canberra, Australia
You, of course, hate the seed when you are savouring your favourite watermelon. However, are you aware that without the seeds, you can’t get to eat and enjoy that fruit at all? Seeds are important for plants in more ways than you can actually imagine! In this chapter, we will look at the types of seed and study about their characteristics in more detail.
What is the Seed?
A seed is a basic part of any plant. The ovules after fertilization, develop into seeds. A seed is made up of a seed coat and an embryo. The embryo is made up of a radicle, an embryonal axis and one (wheat, maize) or two cotyledons (gram and pea). A seed is found inside a fruit which converts into a new plant when we plant it. Hence, the seed is the most important part.
Let us now look at the different types of seeds and study their characteristics.
Types of Seeds
A Seed is primarily of two types. The two types are:
- Monocotyledonous Seed
- Dicotyledonous Seed
Let us now study about these types of seeds in brief.
Structure of a Monocotyledonous Seed
A Monocotyledonous seed, as the name suggests, has only one cotyledon. There is only one outer layering of the seed coat. A seed has the following parts:
- Seed Coat: In the seed of cereals such as maize, the seed coat is membranous and generally fused with the fruit wall, called Hull.
- Endosperm: The endosperm is bulky and stores food. Generally, monocotyledonous seeds are endospermic but some as in orchids are non-endospermic.
- Aleuron layer: The outer covering of endosperm separates the embryo by a proteinous layer called aleurone layer.
- Embryo: The embryo is small and situated in a groove at one end of the endosperm.
- Scutellum: This is one large and shield-shaped cotyledon.
- Embryonal axis: Plumule and radicle are the two ends.
- Coleoptile and coleorhiza: The plumule and radicle are enclosed in sheaths. They are coleoptile and coleorhiza.
Learn more about the Morphology of Flower here.
Structure of a Dicotyledonous Seed
Unlike monocotyledonous seed, a dicotyledonous seed, as the name suggests, has two cotyledons. It has the following parts:
- Seed coat: This is the outermost covering of a seed. The seed coat has two layers, the outer testa and the inner tegmen.
- Hilum: The hilum is a scar on the seed coat through which the developing seed was attached to the fruit.
- Micropyle: It is a small pore present above the hilum.
- Embryo: It consists of an embryonal axis and two cotyledons.
- Cotyledons: These are often fleshy and full of reserve food materials.
- Radicle and plumule: They are present at the two ends of the embryonal axis.
- Endosperm: In some seeds such as castor, the endosperm formed as a result of double fertilisation, is a food storing tissue. In plants such as bean, gram and pea, the endosperm is not present in the matured seed. They are known as non-endospermous.
Solved Question for You
Question: What are the types of mature seeds?
Solution: We know two types of mature seeds. These are:
- Non-albuminous – These seeds do not contain any residual endosperm to store the food. Example: pea, groundnut.
- Albuminous – These seeds consist of an endosperm to function as a storage for the food. Example: wheat, maize.
Share with friends
The outstanding example of the exploitation of hybrid vigour through the use of F1 hybrid varieties has been with corn (maize). The production of a hybrid corn variety involves three steps: (1) the selection of superior plants; (2) selfing for several generations to produce a series of inbred lines, which although different from each other are each pure-breeding and highly uniform; and (3) crossing selected inbred lines. During the inbreeding process the vigour of the lines decreases drastically, usually to less than half that of field-pollinated varieties. Vigour is restored, however, when any two unrelated inbred lines are crossed, and in some cases the F1 hybrids between inbred lines are much superior to open-pollinated varieties. An important consequence of the homozygosity of the inbred lines is that the hybrid between any two inbreds will always be the same. Once the inbreds that give the best hybrids have been identified, any desired amount of hybrid seed can be produced.
Pollination in corn (maize) is by wind, which blows pollen from the tassels to the styles (silks) that protrude from the tops of the ears. Thus controlled cross-pollination on a field scale can be accomplished economically by interplanting two or three rows of the seed parent inbred with one row of the pollinator inbred and detasselling the former before it sheds pollen. In practice most hybrid corn is produced from “double crosses,” in which four inbred lines are first crossed in pairs (A × B and C × D) and then the two F1 hybrids are crossed again (A × B) × (C × D). The double-cross procedure has the advantage that the commercial F1 seed is produced on the highly productive single cross A × B rather than on a poor-yielding inbred, thus reducing seed costs. In recent years cytoplasmic male sterility, described earlier, has been used to eliminate detasselling of the seed parent, thus providing further economies in producing hybrid seed.
Much of the hybrid vigour exhibited by F1 hybrid varieties is lost in the next generation. Consequently, seed from hybrid varieties is not used for planting stock but the farmer purchases new seed each year from seed companies.
Perhaps no other development in the biological sciences has had greater impact on increasing the quantity of food supplies available to the world’s population than has the development of hybrid corn (maize). Hybrid varieties in other crops, made possible through the use of male sterility, have also been dramatically successful and it seems likely that use of hybrid varieties will continue to expand in the future.
How Corn Hybrids are Developed
There are five major steps in the development of a commercial corn hybrid:
1) selection and development of appropriate source germplasm
2) development of superior inbreds
3) testing of inbreds in experimental hybrid combinations
4) identification of a superior hybrid combination
5) multi-location testing of the pre-commercial hybrid
Finally, extensive seed production and marketing of all new hybrids is required.
To understand how a new hybrid is developed, a basic knowledge of corn pollination and breeding processes is required. The corn plant has separate male and female flowering parts (Fig. 1). The tassel is the male flower and produces pollen; the ear is the female flower. A typical hybrid corn ear consists of several hundred kernels attached to the cob or rachis and surrounded by a group of modified leaves called the husk. Each kernel starts as an ovule and has its own silk which grows out of the husk at the top of the ear.
When the tassel is fully emerged from the upper leaf sheath, pollen-shed will begin, usually from the middle of the central spike of the tassel and then spreading out over the whole tassel. Pollen grains are produced in anthers which open up under appropriate weather conditions. Pollen, which is only viable for 18-24 hours, is very light and can be carried considerable distances by the wind. Pollen shed from the tassel usually begins 2-3 days before silk emergence and can continue for several days thereafter, but will stop when the tassel is too wet or too dry.
The silks are covered with fine, sticky hairs that catch and anchor pollen grains. Within minutes after landing on the silks, the pollen grain germinates and a pollen tube grows down the silk to fertilize the ovule or potential kernel. This usually takes 12 to 28 hours. Under good conditions, all silks will emerge and be ready for pollination within 3 to 5 days. Unfavourable environmental conditions during pollination can have a great impact on grain yield. Since there is usually more than enough pollen (a given tassel can produce up to 5 million pollen grains), problems generally occur when there is poor synchronization between silk emergence and pollen shedding.
Corn with its separate male and female flowering parts is a naturally cross-pollinating plant. This means that ovules can be pollinated by pollen from neighbouring plants. Therefore, care must be taken in a breeding program to ensure that pollen from the appropriate tassel fertilizes ovules on the appropriate ear. This is usually achieved by hand-pollinating. As soon as ear shoots are visible in the leaf axils of a plant, a small paper ‘shoot-bag’ is placed over the shoots; this allows the ear to continue growing and the silks to emerge but prevents any pollen from falling on the silks (Fig.2).
When pollen shed begins, a paper bag is placed over the tassel and stapled at the base of the tassel to trap the pollen. The next day the tassel bag containing pollen is removed and quickly placed over the silks of a covered ear after removing the protective shoot-bag (Fig. 3). The tassel bag is pulled around the stalk, stapled and shaken so that the pollen grains fall on the silks (Fig. 4). A plant is ‘selffertilized’ (also referred to as selfing or inbreeding) when the pollen from a tassel is placed on the silks of the ear of the same plant (Fig. 5). A plant is ‘crossfertilized’ or ‘crossed’ when the pollen from a tassel is placed on the silks of a different plant. Of the millions of hand pollinations made by corn breeders, only a handful result in a superior inbred that will be used in a commercial hybrid.
| Fig. 3 Transferring pollen from tassels of male parent
to silks of female parent.
|Fig. 4 Maintaining inbred lines.|
Between 1850 and 1910, North American corn breeders developed higher yielding corn varieties by open-pollination. In this procedure, plants were allowed to shed pollen without covering silks, resulting in a mix of cross and self pollinated kernels on each ear. The best plants would be selected and their ears (usually the largest ones in the field) would be kept to use as seed the next year. The resulting populations were gradually improved for agronomic traits, but were very variable in plant height, ear height, maturity, etc., due to the random cross-pollinations.
In the 1920’s, the concept of hybrid vigour (heterosis) was discovered. If corn plants are self-pollinated for six or more generations, the plants become smaller and less vigorous due to inbreeding depression, but their traits become more uniform. At every generation, selection can be made for specific traits such as pest resistance, plant or ear type, ear size, etc. This repeated inbreeding produces an ‘inbred’ line of corn. We can save breeding time by getting two generations per year using winter nurseries in warmer climates.
An inbred is genetically uniform for all traits and will always breed true to form. Hybrid vigour occurs when we crosspollinate two inbred lines from different unrelated backgrounds (Fig. 6). The offspring of such a cross will have a larger-yielding ear and will be a more robust plant. It is also uniform for most traits. There are many theories to explain hybrid vigour, but this phenomenon is still not well understood. Note that if an ear of hybrid corn is self-pollinated, the resulting progeny will be variable in yield as well as in other traits. This is why farmers must buy their hybrid corn seed each year and should not plant the seed from a field of hybrid.
Development of inbreds takes about 75% of the effort in a corn breeding program. Most of the effort is spent evaluating inbreds by crossing to another inbred, which is called a tester, to see if it will produce a desirable hybrid. The process is called evaluating the combining ability of the inbred. The cross is called a testcross. The field performance of this testcross is extensively evaluated in replicated multi-location trials. Inbreds with superior testcross performance are advanced to the next generation. If we could select at the inbred level, i.e. if the performance of the inbred on its own could predict the performance of the hybrid testcross, we could considerably reduce expenses. In fact, this can be done for some traits such as earliness, plant height and some disease resistance but, unfortunately, not for yield. It is important to note that the seed sold to farmers is produced on small inbred plants. Therefore, besides having good combining ability, an inbred line must be easy to maintain and to cross in order to keep seed costs down.
The inbred lines used for commercial hybrids must be maintained by hand-pollination, a painstaking process (Fig. 4). For production of hybrid seed, inbred seed is planted in fields isolated from other corn by at least 200 m (600 ft). Hybrid seed is produced by planting the ‘female’ and ‘male’ inbred lines together in a field (Fig. 7).
The choice of which inbred to designate female and which to designate male depends on the ear and tassel characteristics of each; usually the female has higher yield and the male has better pollen production. The ratio of female to male rows varies among seed companies. Differential planting dates can be used to ensure synchronization between male and female flowering.
Female rows are detasseled mechanically or by hand shortly after the tassels have emerged from the uppermost leaf sheath and before they begin to shed pollen (Fig 8). This ensures that all pollen is from the male parent. Commercial seed-corn fields are normally harvested by a picker-husker and the husked ears are sorted to remove off-type ears. The ears are dried and shelled and the seed is cleaned and graded by size. Finally, germination is tested and the seed is treated with a fungicide before packaging.
Today, 80% of corn seed grown in North America is single-cross hybrid as described above. The remaining 20% of hybrids are double, three-way and modified (related-line parents) crosses. Three-way cross hybrids have only one inbred parent and are somewhat cheaper to produce.
We are often asked the question, “What are hybrid seeds exactly?” The easiest way to provide a hybrid seed definition is to first understand what is not a hybrid seed. You may notice that some plants mature earlier than others of the same strain, or may have a slightly different colour. This is a clear indication that they are open pollinated. If you grow their seed next year, you will pretty much get the same plant you had the previous year. This is a great, cost-effective way for you to select plants that do well in your garden.
However, uniformity in disease resistance, date of maturity, and all physical qualities is necessary for most market gardeners and useful for home gardeners with very limited space. This uniformity is ensured by growing hybrid seed.
A hybrid is created by crossing two unique parents. Crossing involves taking the pollen from the male and transferring it to the female. The first generation of offspring from this cross all look and act the same. They also show what’s known as hybrid vigour: these plants come out stronger than their parents. But you can’t plant their seed in order to raise these plants the following year. The seed collected from a hybrid plant will either resemble one of the parents, or be sterile. Throughout this website we have indicated whether the seed is hybrid or open pollinated.
We at West Coast Seeds feel there are benefits to growing both open-pollinated and hybrid seeds. We endeavour to provide both types of seeds for all the crops that we offer. With the understanding of the benefits and disadvantages of both hybrid and open-pollinated varieties, you – our customer – can choose which type of seed you want to grow.
Can a hybrid seed also be CERTIFIED ORGANIC?
The answer is Yes!
Hybrid, offspring of parents that differ in genetically determined traits. The parents may be of different species, genera, or (rarely) families. The term hybrid, therefore, has a wider application than the terms mongrel or crossbreed, which usually refer to animals or plants resulting from a cross between two races, breeds, strains, or varieties of the same species. There are many species hybrids in nature (in ducks, oaks, blackberries, etc.), and, although naturally occurring hybrids between two genera have been noted, most of these latter result from human intervention.
Because of basic biological incompatibilities, sterile hybrids (those incapable of producing living young) such as the mule (a hybrid between a jackass and a mare) commonly result from crosses between species. Some interspecific hybrids, however, are fertile and true breeding. These hybrids can be sources for the formation of new species. Many economically or aesthetically important cultivated plants (bananas, coffee, peanuts, dahlias, roses, bread wheats, alfalfa, etc.) have originated through natural hybridization or hybridization induced by chemical means, temperature changes, or irradiation.
The process of hybridization is important biologically because it increases the genetic variety (number of different gene combinations) within a species, which is necessary for evolution to occur. If climatic or habitat conditions change, individuals with certain combinations may be eliminated, but others with different combinations will survive. In this way, the appearance or behaviour of a species gradually may be altered. Such natural hybridization, which is widespread among certain species, makes the identification and enumeration of species very difficult.
Be Inspired Blog – California
Posted on: July 28, 2017
If you’re new to gardening or if you’re an experienced gardener, you’ve probably heard about hybrid plants and may have questions about them.
Keep reading to learn about hybrid plants from The Spruce, how plants are hybridized, the different types and much more; are you ready to learn?
What Are Hybrid Plants?
A hybrid plant is the result of cross pollinating two different plant varieties and growing the seed the mix produces. The plant that grows from that seed combination is called a hybrid. Commercial cross planting is done to get some type of valued attribute of each initial variety into the offspring. Hybrids might be developed for disease resistance, size of plant, flower, or fruit, increased flowering, color, taste or any reason a plant might be considered special. Today, many modern plants sold are hybrids.
How are Plants Hybridized?
For the initial crossing, pollen from one plant is transferred to the flower of another variety. Before doing so, the breeder must decide which plant they want to use as the female (the pistil) and which they want to take pollen from (the stamen, male parts).
The pistil is then pollinated manually, with the pollen. To prevent the plants from self-pollinating, all the stamens must be removed from the plants that are going to be pollinated. The fruits that form because of this cross pollination are harvested and the seeds are kept.
Finding the preferred result can take years of testing. First time hybrid plants are grown the following year and the plants they produce are checked out. If they meet expectations, the cross will be repeated and the seeds will be distributed the following year. If the results aren’t quite right, the breeder must try again. The breeder who first creates a hybrid owns the rights to it, which is why they can be more expensive than non-hybrids, or open pollinated, plants. Breeders guard the parentage of their hybrids closely.
What Happens When You Plant Seeds from Hybrid Plants?
Remember, because hybrids are a cross between varieties, the seed produced by hybrids will not grow true to seed. Seeds grown from a hybrid could exhibit traits of one or both parent plants or be something totally surprising. Other times, the seed is sterile and does not grow at all.
Are Hybrid Plants Unnatural?
Most hybrid plants are manmade crosses, but hybridization is possible in nature. Two plants close to each other of different species can be cross pollinated by insects or the wind and the resulting seed simply falls on the soil and grows into a hybrid. Few of the flowers and vegetables we grow today are in their original wild form.
6 Popular Hybrid Plants
Now that you know a little more about hybrid plants, let’s look at some of the most popular and successful crosses.
- Hybrid Lilies
Hybrid lilies are classified as Asiatic hybrids and Oriental hybrids. Oriental hybrid lilies have large 6 to 8 inch, fragrant, pink, red, purple or white flowers. The flowers of the Asiatic hybrids are smaller and typically have no fragrance. The flowers come in bright shades of yellow, gold, rose, pink, white and orange. The Asiatic lilies naturally flower from late spring to early summer while the Oriental lilies naturally bloom during late summer. Hybrid lilies can easily be grown as potted plants when grown in the right medium with proper light and watering. Lilies are likely to develop leaf scorch from the fluoride found in most growing mediums. Hence, care should be taken that the medium does not contain superphosphate or perlite. The soil pH for Asiatic hybrids should be 6.5 and between 6.5 to 6.8 for the Oriental hybrids.
- Sweet Corn
Much of U.S. corn grown are hybrid types. The characteristics of these varieties have made it easier for home gardeners to grow and they are sweeter than previous crops. Grow sweet corn in larger gardens in rows for successful pollination and subsequent ear development. Plant the seeds in deep, rich, well-drained soil and in an area that receives full sun. Sow the seeds about two weeks after the last frost occurs. Harvest the ears only during the short milk stage, when punctured kernels emit juices that are milky in color.
Olympia is a hybrid of spinach, which is preferred due to its superior growth. The leaves are dark green and thick and the growth is upright. Olympia is a highly-recommended option for spring, summer, fall and overwintering. The hybrid spinach is highly resistant to bolting under high summer temperatures and long days. Olympia spinach is ready to harvest after about 48 days. The spinach can be sowed as soon as the soil is at about 40 degrees Fahrenheit and the seeds start germinating within one to two weeks.
- Stargazer Lilies
These oriental hybrids feature vibrant blooms that measure up to 8 inches in diameter, are very fragrant and come in red, purple, pink and white hues. They grow strongly during the summer and bloom in late summer. Plants are often marketed in the spring and can easily be grown as potted plants. For best results, plant bulbs in the fall or spring at three times the depth of their length. Water it regularly as the plant starts to grow and deadhead spent flowers to direct energy back to the bulb for next season’s growth.
- Meyer Lemon Trees
Meyer lemons, originally from China, are a cross between a true lemon tree and mandarin orange tree. The fruit is much sweeter than traditional lemons, which makes this variety a favorite of gardeners and chefs alike. Meyer lemon trees can be grown outside in climates warmer than zone 8, or can be grown in pots that are brought indoors during cooler months. Buy trees that are 2 to 3 years old and plant them in soil that is sandy, well-draining and slightly acidic. Keep the soil consistently moist but not too soggy.
- Argemone Mexicana
This hybrid poppy is found in Mexico and now widely planted in many parts of the world. An extremely hardy plant, it is tolerant of drought and poor soil, often being the only cover on new road cuttings or verges. It has bright yellow latex, and though poisonous to grazing animals, is rarely eaten, but has been used medicinally by many people including those in its native area, the Natives of the western US and parts of Mexico. Mexicana seeds contain 22–36% of a pale yellow non-edible oil, called argemone oil or katkar oil, which contains the toxic alkaloid sanguinarine and dihydrosanguinarine. It has been isolated from the whole plant of Argemone mexicana.
Hybrid plants are the new normal when done by a breeder, but they can be created organically in nature. Were you surprised by any of the popular hybrid plants listed above? Did you know some of them were even hybrids? Check out our other blog posts for more information on gardening, and visit our locations page to find a store near you!
About SummerWinds Nursery: SummerWinds Garden Centers is a leading high-end retailer of garden and nursery products. Headquartered in Boise, Idaho, SummerWinds operates retail nurseries in the greater Phoenix, Arizona area, and in Silicon Valley, California, making it one of the largest independent retail nursery companies in the west. SummerWinds appeals to both the serious and casual gardeners, with a broad selection of premium gardening products and a friendly and knowledgeable staff. www.summerwindsnursery.com.
- Abbott R, Albach D, Ansell S, Arntzen JW, Baird SJE, Bierne N, Boughman J, Brelsford A, Buerkle CA, Buggs R, et al. (2013) Hybridization and speciation. J Evol Biol 26: 229–246
- Alexander DH, Novembre J, Lange K. (2009) Fast model-based estimation of ancestry in unrelated individuals. Genome Res 19: 1655–1664
- Anderson E. (1948) Hybridization of the habitat. Evolution 2: 1–9
- Anderson E. (1949) Introgressive Hybridization. John Wiley & Sons, New York
- Anderson E. (1953) Introgressive hybridization. Biol Rev Camb Philos Soc 28: 280–307
- Anderson E, Hubricht L. (1938) Hybridization in Tradescantia. III. The evidence for introgressive hybridization. Am J Bot 25: 396–402
- Anderson E, Stebbins GL. (1954) Hybridization as an evolutionary stimulus. Evolution 8: 378–388
- Arnold ML. (2006) Evolution through Genetic Exchange. Oxford University Press, Oxford
- Bapteste E, van Iersel L, Janke A, Kelchner S, Kelk S, McInerney JO, Morrison DA, Nakhleh L, Steel M, Stougie L, et al. (2013) Networks: expanding evolutionary thinking. Trends Genet 29: 439–441
- Barbash DA, Awadalla P, Tarone AM. (2004) Functional divergence caused by ancient positive selection of a Drosophila hybrid incompatibility locus. PLoS Biol 2: e142.
- Barker MS, Arrigo N, Baniaga AE, Li Z, Levin DA. (2016) On the relative abundance of autopolyploids and allopolyploids. New Phytol 210: 391–398
- Blair WF. (1955) Mating call and stage of speciation in the Microhyla olivacea–M. carolinensis complex. Evolution 9: 469–480
- Buerkle CA, Morris RJ, Asmussen MA, Rieseberg LH. (2000) The likelihood of homoploid hybrid speciation. Heredity 84: 441–451
- Buerkle CA, Wolf DE, Rieseberg LH. (2003) The origin and extinction of species through hybridization. In Population Viability in Plants. Springer, Berlin, pp 117–141
- Butlin R. (1987) Speciation by reinforcement. Trends Ecol Evol 2: 8–13
- Chapman MA, Burke JM. (2007) Genetic divergence and hybrid speciation. Evolution 61: 1773–1780
- Chen ZJ. (2013) Genomic and epigenetic insights into the molecular bases of heterosis. Nat Rev Genet 14: 471–482
- Cockayne L. (1923) Hybridism in the New Zealand flora. New Phytol 22: 105–127
- Combes MC, Cenci A, Baraille H, Bertrand B, Lashermes P. (2012) Homeologous gene expression in response to growing temperature in a recent allopolyploid (Coffea arabica L.). J Hered 103: 36–46
- Crow JF. (1948) Alternative hypotheses of hybrid vigor. Genetics 33: 477–487
- Cruickshank TE, Hahn MW. (2014) Reanalysis suggests that genomic islands of speciation are due to reduced diversity, not reduced gene flow. Mol Ecol 23: 3133–3157
- Dannemann M, Andrés AM, Kelso J. (2016) Introgression of Neandertal- and Denisovan-like haplotypes contributes to adaptive variation in human Toll-like receptors. Am J Hum Genet 98: 22–33
- Darwin C. (1876) The Effects of Cross and Self Fertilisation in the Vegetable Kingdom. John Murray, London
- deVicente MC, Tanksley SD. (1993) QTL analysis of transgressive segregation in an interspecific tomato cross. Genetics 134: 585–596
- Dittrich-Reed DR, Fitzpatrick BM. (2013) Transgressive hybrids as hopeful monsters. Evol Biol 40: 310–315
- Dobzhansky T. (1940) Speciation as a stage in evolutionary divergence. Am Nat 74: 312–321
- Dobzhansky T, Ehrman L, Pavlovsky O, Spassky B. (1964) The superspecies Drosophila paulistorum. Proc Natl Acad Sci USA 51: 3–9
- Dobzhansky T, Koller PC. (1938) An experimental study of sexual isolation in Drosophila. Biol Zentralblatt 58: 589–607
- Dong S, Adams KL. (2011) Differential contributions to the transcriptome of duplicated genes in response to abiotic stresses in natural and synthetic polyploids. New Phytol 190: 1045–1057
- Durand EY, Patterson N, Reich D, Slatkin M. (2011) Testing for ancient admixture between closely related populations. Mol Biol Evol 28: 2239–2252
- Du Rietz GE. (1930) The Fundamental Units of Biological Taxonomy. Svensk Botaniska Foreningen, Uppsala, Sweden
- East EM. (1936) Heterosis. Genetics 21: 375–397
- Eaton DAR, Ree RH. (2013) Inferring phylogeny and introgression using RADseq data: an example from flowering plants (Pedicularis: Orobanchaceae). Syst Biol 62: 689–706
- Ellstrand NC, Meirmans P, Rong J, Bartsch D, Ghosh A, de Jong TJ, Haccou P, Lu BR, Snow AA, Stewart CN, et al. (2013) Introgression of crop alleles into wild or weedy populations. Annu Rev Ecol Evol Syst 44: 325–345
- Falush D, Stephens M, Pritchard JK. (2003) Inference of population structure using multilocus genotype data: linked loci and correlated allele frequencies. Genetics 164: 1567–1587
- Falush D, van Dorp L, Lawson D. (2016) A tutorial on how (not) to over-interpret STRUCTURE/ADMIXTURE bar plots. bioRxiv 66431
- Felsenstein J. (1981) Skepticism towards Santa Rosalia, or why are there so few kinds of animals? Evolution 35: 124–138
- Flint-Garcia SA, Buckler ES, Tiffin P, Ersoz E, Springer NM. (2009) Heterosis is prevalent for multiple traits in diverse maize germplasm. PLoS ONE 4: e7433.
- Focke WO. (1881) Die Pflanzen-Mischling. Borntraeger, Berlin
- Gaeta RT, Pires JC, Iniguez-Luy F, Leon E, Osborn TC. (2007) Genomic changes in resynthesized Brassica napus and their effect on gene expression and phenotype. Plant Cell 19: 3403–3417
- Geraldes A, Farzaneh N, Grassa CJ, McKown AD, Guy RD, Mansfield SD, Douglas CJ, Cronk QCB. (2014) Landscape genomics of Populus trichocarpa: the role of hybridization, limited gene flow, and natural selection in shaping patterns of population structure. Evolution 68: 3260–3280
- Gompert Z, Buerkle CA. (2013) Analyses of genetic ancestry enable key insights for molecular ecology. Mol Ecol 22: 5278–5294
- Grant V. (1958) The regulation of recombination in plants. Cold Spring Harb Symp Quant Biol 23: 337–363
- Grant V. (1966) The selective origin of incompatibility barriers in the plant genus Gilia. Am Nat 100: 99–118
- Grant V. (1975) Genetics of Flowering Plants. Columbia University Press, New York
- Grant V. (1981) Plant Speciation, Ed 2 Columbia University Press, New York
- Gravel S. (2012) Population genetics models of local ancestry. Genetics 191: 607–619
- Greaves IK, Gonzalez-Bayon R, Wang L, Zhu A, Liu PC, Groszmann M, Peacock WJ, Dennis ES. (2015) Epigenetic changes in hybrids. Plant Physiol 168: 1197–1205
- Green RE, Krause J, Briggs AW, Maricic T, Stenzel U, Kircher M, Patterson N, Li H, Zhai W, Fritz MHY, et al. (2010) A draft sequence of the Neandertal genome. Science 328: 710–722
- Gross BL, Kane NC, Lexer C, Ludwig F, Rosenthal DM, Donovan LA, Rieseberg LH. (2004) Reconstructing the origin of Helianthus deserticola: survival and selection on the desert floor. Am Nat 164: 145–156
- Groszmann M, Greaves IK, Fujimoto R, Peacock WJ, Dennis ES. (2013) The role of epigenetics in hybrid vigour. Trends Genet 29: 684–690
- Hagedoorn AL, Hagedoorn-Vorstheuvel La Brand AC. (1921) The Relative Value of the Processes Causing Evolution. Martinus Nijhoff, The Hague, The Netherlands
- Hagiwara WE, Onishi K, Takamure I, Sano Y. (2006) Transgressive segregation due to linked QTLs for grain characteristics of rice. Euphytica 150: 27–35
- Hahn MW, Nakhleh L. (2016) Irrational exuberance for resolved species trees. Evolution 70: 7–17
- Harris K, Nielsen R. (2013) Inferring demographic history from a spectrum of shared haplotype lengths. PLoS Genet 9: e1003521.
- Harrison RG. (1990) Hybrid zones: windows on evolutionary process. Oxford Surv Evol Biol 7: 69–128
- Heiser CB. (1951) Hybridization in the annual sunflowers: Helianthus annuus × H. debilis var. cucumerifolius. Evolution 5: 42–51
- Hey J, Nielsen R. (2004) Multilocus methods for estimating population sizes, migration rates and divergence time, with applications to the divergence of Drosophila pseudoobscura and D. persimilis. Genetics 167: 747–760
- Hopkins R. (2013) Reinforcement in plants. New Phytol 197: 1095–1103
- Hopkins R, Guerrero RF, Rausher MD, Kirkpatrick M. (2014) Strong reinforcing selection in a Texas wildflower. Curr Biol 24: 1995–1999
- Hopkins R, Rausher MD. (2011) Identification of two genes causing reinforcement in the Texas wildflower Phlox drummondii. Nature 469: 411–414
- Hopkins R, Rausher MD. (2012) Pollinator-mediated selection on flower color allele drives reinforcement. Science 335: 1090–1092
- Howard DJ. (1993) Reinforcement: origin, dynamics, and fate of an evolutionary hypothesis. In Harrison RG, editor. , ed, Hybrid Zones and the Evolutionary Process. Oxford University Press, New York, pp 46–69
- Hufford MB, Lubinksy P, Pyhäjärvi T, Devengenzo MT, Ellstrand NC, Ross-Ibarra J. (2013) The genomic signature of crop-wild introgression in maize. PLoS Genet 9: e1003477.
- Jones DF. (1917) Dominance of linked factors as a means of accounting for heterosis. Proc Natl Acad Sci USA 3: 310–312
- Kaeppler S. (2012) Heterosis: many genes, many mechanisms—end the search for an undiscovered unifying theory. ISRN Bot 2012: 1–12
- Kiær LP, Felber F, Flavell A, Guadagnuolo R, Guiatti D, Hauser TP, Olivieri AM, Scotti I, Syed N, Vischi M, et al. (2009) Spontaneous gene flow and population structure in wild and cultivated chicory, Cichorium intybus L. Genet Resour Crop Evol 56: 405–419
- Kirkpatrick M. (2000) Reinforcement and divergence under assortative mating. Proc Biol Sci 267: 1649–1655
- Kirkpatrick M, Servedio MR. (1999) The reinforcement of mating preferences on an island. Genetics 151: 865–884
- Kölreuter JG. (1766) Vorläufige nachricht von einigen das geschlecht der pflanzen betreffenden versuchen und beobachtungen, nebst fortsetzungen 1, 2 und 3 (1761-1766). Wilhelm Engelmann, Leipzig, Germany
- Krieger U, Lippman ZB, Zamir D. (2010) The flowering gene SINGLE FLOWER TRUSS drives heterosis for yield in tomato. Nat Genet 42: 459–463
- Kulathinal RJ, Stevison LS, Noor MAF. (2009) The genomics of speciation in Drosophila: diversity, divergence, and introgression estimated using low-coverage genome sequencing. PLoS Genet 5: e1000550.
- Kwit C, Moon HS, Warwick SI, Stewart CN Jr. (2011) Transgene introgression in crop relatives: molecular evidence and mitigation strategies. Trends Biotechnol 29: 284–293
- Lai Z, Nakazato T, Salmaso M, Burke JM, Tang S, Knapp SJ, Rieseberg LH. (2005) Extensive chromosomal repatterning and the evolution of sterility barriers in hybrid sunflower species. Genetics 171: 291–303
- Leducq JB, Nielly-Thibault L, Charron G, Eberlein C, Verta JP, Samani P, Sylvester K, Hittinger CT, Bell G, Landry CR. (2016) Speciation driven by hybridization and chromosomal plasticity in a wild yeast. Nat Microbiol 1: 15003.
- Levin DA, editor. , editor (1979) Hybridization: An Evolutionary Perspective. Dowden, Hutchinson & Ross, Stroudsberg, PA
- Levin DA, Francisco-Ortega J, Jansen RK. (1996) Hybridization and the extinction of rare plant species. Conserv Biol 10: 10–16
- Levin DA, Kerster HW. (1967) Natural selection for reproductive isolation in Phlox. Evolution 21: 679–687
- Lexer C, Welch ME, Durphy JL, Rieseberg LH. (2003) Natural selection for salt tolerance quantitative trait loci (QTLs) in wild sunflower hybrids: implications for the origin of Helianthus paradoxus, a diploid hybrid species. Mol Ecol 12: 1225–1235
- Linnaeus C. (1760) Disquisitio de sexu plantarum Amoenitates Acad 10: 100–131
- Liou LW, Price TD. (1994) Speciation by reinforcement of premating isolation. Evolution 48: 1451–1459
- Littlejohn MJ, Loftus-Hills JJ. (1968) An experimental evaluation of premating isolation in the Hyla ewingi complex (Anura: Hylidae). Evolution 22: 659–663
- Liu Y, Nyunoya T, Leng S, Belinsky SA, Tesfaigzi Y, Bruse S. (2013) Softwares and methods for estimating genetic ancestry in human populations. Hum Genomics 7: 1.
- Lotsy JP. (1916) Evolution by Means of Hybridization. Martinus Nijhoff, The Hague, The Netherlands
- Lukhtanov VA, Shapoval NA, Anokhin BA, Saifitdinova AF, Kuznetsova VG. (2015) Homoploid hybrid speciation and genome evolution via chromosome sorting. Proc Biol Sci 282: 20150157.
- Madlung A. (2013) Polyploidy and its effect on evolutionary success: old questions revisited with new tools. Heredity (Edinb) 110: 99–104
- Mailund T, Halager AE, Westergaard M, Dutheil JY, Munch K, Andersen LN, Lunter G, Prüfer K, Scally A, Hobolth A, et al. (2012) A new isolation with migration model along complete genomes infers very different divergence processes among closely related great ape species. PLoS Genet 8: e1003125.
- Mallet J. (2005) Hybridization as an invasion of the genome. Trends Ecol Evol 20: 229–237
- Mallet J, Besansky N, Hahn MW. (2016) How reticulated are species? BioEssays 38: 140–149
- Mao D, Liu T, Xu C, Li X, Xing Y. (2011) Epistasis and complementary gene action adequately account for the genetic bases of transgressive segregation of kilo-grain weight in rice. Euphytica 180: 261–271
- Marsden-Jones EM. (1930) The genetics of Geum intermedium Willd. Haud Ehrh., and its back-crosses. J Genet 23: 377–395
- Mavárez J, Salazar CA, Bermingham E, Salcedo C, Jiggins CD, Linares M. (2006) Speciation by hybridization in Heliconius butterflies. Nature 441: 868–871
- Mayr E. (1942) Systematics and the origin of species from the viewpoint of a zoologist. Columbia University Press, New York
- Mayr E. (1986) Joseph Gottlieb Kölreuter’s contributions to biology. Osiris 2: 135–176
- McNeilly T, Antonovics J. (1968) Evolution in closely adjacent plant populations. IV. Barriers to gene flow. Heredity 23: 205–218
- Müntzing A. (1930) Outlines to a genetic monograph for the genus Galeopsis: with special reference to the nature and inheritance of partial sterility. Hereditas 13: 185–341
- Ng DWK, Lu J, Chen ZJ. (2012) Big roles for small RNAs in polyploidy, hybrid vigor, and hybrid incompatibility. Curr Opin Plant Biol 15: 154–161
- Nielsen R, Wakeley J. (2001) Distinguishing migration from isolation: a Markov chain Monte Carlo approach. Genetics 158: 885–896
- Nilsson-Ehle H. (1911) Kreuzungsuntersuchungen an hafer und weizen. Lunds Univ Areskripft 7: 1–84
- Nosil P, Funk DJ, Ortiz-Barrientos D. (2009) Divergent selection and heterogeneous genomic divergence. Mol Ecol 18: 375–402
- Ortíz-Barrientos D, Noor MAF. (2005) Evidence for a one-allele assortative mating locus. Science 310: 1467.
- Pardo-Diaz C, Salazar C, Baxter SW, Merot C, Figueiredo-Ready W, Joron M, McMillan WO, Jiggins CD. (2012) Adaptive introgression across species boundaries in Heliconius butterflies. PLoS Genet 8: e1002752.
- Paşaniuc B, Sankararaman S, Kimmel G, Halperin E. (2009) Inference of Locus-Specific Ancestry in Closely Related Populations. Oxford University Press, Oxford, pp i213–i221
- Paterniani E. (1969) Selection for reproductive isolation between two populations of maize, Zea mays L. Evolution 23: 534–547
- Payseur BA, Rieseberg LH. (2016) A genomic perspective on hybridization and speciation. Mol Ecol 25: 2337–2360
- Pease JB, Haak DC, Hahn MW, Moyle LC. (2016) Phylogenomics reveals three sources of adaptive variation during a rapid radiation. PLoS Biol 14: e1002379.
- Pease JB, Hahn MW. (2015) Detection and polarization of introgression in a five-taxon phylogeny. Syst Biol 64: 651–662
- Pool JE, Nielsen R. (2009) Inference of historical changes in migration rate from the lengths of migrant tracts. Genetics 181: 711–719
- Porras-Hurtado L, Ruiz Y, Santos C, Phillips C, Carracedo A, Lareu MV. (2013) An overview of STRUCTURE: applications, parameter settings, and supporting software. Front Genet 4: 98.
- Presgraves DC, Stephan W. (2007) Pervasive adaptive evolution among interactors of the Drosophila hybrid inviability gene, Nup96. Mol Biol Evol 24: 306–314
- Price AL, Tandon A, Patterson N, Barnes KC, Rafaels N, Ruczinski I, Beaty TH, Mathias R, Reich D, Myers S. (2009) Sensitive detection of chromosomal segments of distinct ancestry in admixed populations. PLoS Genet 5: e1000519.
- Pritchard JK, Stephens M, Donnelly P. (2000) Inference of population structure using multilocus genotype data. Genetics 155: 945–959
- Racimo F, Sankararaman S, Nielsen R, Huerta-Sánchez E. (2015) Evidence for archaic adaptive introgression in humans. Nat Rev Genet 16: 359–371
- Ramsey J, Schemske DW. (1998) Pathways, mechanisms, and rates of polyploid formation in flowering plants. Annu Rev Ecol Syst 29: 467–501
- Rieseberg LH. (2006) Hybrid speciation in wild sunflowers. Ann Mo Bot Gard 93: 34–48
- Rieseberg LH, Archer MA, Wayne RK. (1999) Transgressive segregation, adaptation and speciation. Heredity 83: 363–372
- Rieseberg LH, Carney SE. (1998) Plant hybridization. New Phytol 140: 599–624
- Rieseberg LH, Ellstrand NC, Arnold M. (1993) What can molecular and morphological markers tell us about plant hybridization? CRC Crit Rev Plant Sci 12: 213–241
- Rieseberg LH, Kim SC, Randell RA, Whitney KD, Gross BL, Lexer C, Clay K. (2007) Hybridization and the colonization of novel habitats by annual sunflowers. Genetica 129: 149–165
- Rieseberg LH, Raymond O, Rosenthal DM, Lai Z, Livingstone K, Nakazato T, Durphy JL, Schwarzbach AE, Donovan LA, Lexer C. (2003a) Major ecological transitions in wild sunflowers facilitated by hybridization. Science 301: 1211–1216
- Rieseberg LH, Sinervo B, Linder CR, Ungerer MC, Arias DM. (1996) Role of gene interactions in hybrid speciation: evidence from ancient and experimental hybrids. Science 272: 741–745
- Rieseberg LH, Widmer A, Arntz AM, Burke JM. (2003b) The genetic architecture necessary for transgressive segregation is common in both natural and domesticated populations. Philos Trans R Soc Lond B Biol Sci 358: 1141–1147
- Rosenthal DM, Rieseberg LH, Donovan LA. (2005) Re-creating ancient hybrid species’ complex phenotypes from early-generation synthetic hybrids: three examples using wild sunflowers. Am Nat 166: 26–41
- Rosenzweig BK, Pease JB, Besansky NJ, Hahn MW. (2016) Powerful methods for detecting introgressed regions from population genomic data. Mol Ecol 25: 2387–2397
- Ru D, Mao K, Zhang L, Wang X, Lu Z, Sun Y. (2016) Genomic evidence for polyphyletic origins and interlineage gene flow within complex taxa: a case study of Picea brachytyla in the Qinghai-Tibet Plateau. Mol Ecol 25: 2373–2386
- Saether SA, Saetre GP, Borge T, Wiley C, Svedin N, Andersson G, Veen T, Haavie J, Servedio MR, Bures S, et al. (2007) Sex chromosome-linked species recognition and evolution of reproductive isolation in flycatchers. Science 318: 95–97
- Sankararaman S, Sridhar S, Kimmel G, Halperin E. (2008) Estimating local ancestry in admixed populations. Am J Hum Genet 82: 290–303
- Scascitelli M, Whitney KD, Randell RA, King M, Buerkle CA, Rieseberg LH. (2010) Genome scan of hybridizing sunflowers from Texas (Helianthus annuus and H. debilis) reveals asymmetric patterns of introgression and small islands of genomic differentiation. Mol Ecol 19: 521–541
- Schumer M, Cui R, Boussau B, Walter R, Rosenthal G, Andolfatto P. (2013) An evaluation of the hybrid speciation hypothesis for Xiphophorus clemenciae based on whole genome sequences. Evolution 67: 1155–1168
- Schumer M, Cui R, Rosenthal GG, Andolfatto P. (2015) Reproductive isolation of hybrid populations driven by genetic incompatibilities. PLoS Genet 11: e1005041.
- Schumer M, Rosenthal GG, Andolfatto P. (2014) How common is homoploid hybrid speciation? Evolution 68: 1553–1560
- Servedio MR. (2009) The role of linkage disequilibrium in the evolution of premating isolation. Heredity 102: 51–56
- Servedio MR, Kirkpatrick M. (1997) The effects of gene flow on reinforcement. Evolution 51: 1764–1772
- Servedio MR, Noor M. (2003) The role of reinforcement in speciation: theory and data. Annu Rev Ecol Evol Syst 34: 339–364
- Shang L, Wang Y, Cai S, Wang X, Li Y, Abduweli A, Hua J. (2015) Partial dominance, overdominance, epistasis and QTL by environment interactions contribute to heterosis in two upland cotton hybrids. G3 (Bethesda) 6: 499–507
- Shen G, Zhan W, Chen H, Xing Y. (2014) Dominance and epistasis are the main contributors to heterosis for plant height in rice. Plant Sci 215-216: 11–18
- Shen H, He H, Li J, Chen W, Wang X, Guo L, Peng Z, He G, Zhong S, Qi Y, et al. (2012) Genome-wide analysis of DNA methylation and gene expression changes in two Arabidopsis ecotypes and their reciprocal hybrids. Plant Cell 24: 875–892
- Shivaprasad PV, Dunn RM, Santos BA, Bassett A, Baulcombe DC. (2012) Extraordinary transgressive phenotypes of hybrid tomato are influenced by epigenetics and small silencing RNAs. EMBO J 31: 257–266
- Shull GH. (1908) The composition of a field of maize. J Hered Os 4: 296–301
- Shull GH. (1911) The genotypes of maize. Am Nat 45: 234–252
- Smadja CM, Loire E, Caminade P, Thoma M, Latour Y, Roux C, Thoss M, Penn DJ, Ganem G, Boursot P. (2015) Seeking signatures of reinforcement at the genetic level: a hitchhiking mapping and candidate gene approach in the house mouse. Mol Ecol 24: 4222–4237
- Smith JE. (1804) Flora Britannica, Vol. 3. J Taylor, London
- Snow AA, Pilson D, Rieseberg LH, Paulsen MJ, Pleskac N, Reagon MR, Wolf DE, Selbo SM. (2003) A Bt transgene reduces herbivory and enhances fecundity in wild sunflowers. Ecol Appl 13: 279–286
- Solís-Lemus C, Ané C. (2016) Inferring phylogenetic networks with maximum pseudolikelihood under incomplete lineage sorting. PLoS Genet 12: 1509.06075v1
- Soltis DE, Visger CJ, Soltis PS. (2014) The polyploidy revolution then…and now: Stebbins revisited. Am J Bot 101: 1057–1078
- Soltis PS, Soltis DE. (2009) The role of hybridization in plant speciation. Annu Rev Plant Biol 60: 561–588
- Sousa V, Hey J. (2013) Understanding the origin of species with genome-scale data: modelling gene flow. Nat Rev Genet 14: 404–414
- Stebbins GL., Jr (1947) Types of polyploids: their classification and significance. Adv Genet 1: 403–429
- Stebbins GL. (1950) Variation and Evolution in Plants. Columbia University Press, New York
- Stebbins GL. (1959) The role of hybridization in evolution. Proc Am Philos Soc 103: 231–251
- Stelkens R, Seehausen O. (2009) Genetic distance between species predicts novel trait expression in their hybrids. Evolution 63: 884–897
- Suarez-Gonzalez A, Hefer CA, Christe C, Corea O, Lexer C, Cronk QCB, Douglas CJ. (2016) Genomic and functional approaches reveal a case of adaptive introgression from Populus balsamifera (balsam poplar) in P. trichocarpa (black cottonwood). Mol Ecol 25: 2427–2442
- Sweigart AL, Flagel LE. (2015) Evidence of natural selection acting on a polymorphic hybrid incompatibility locus in Mimulus. Genetics 199: 543–554
- Tang J, Yan J, Ma X, Teng W, Wu W, Dai J, Dhillon BS, Melchinger AE, Li J. (2010) Dissection of the genetic basis of heterosis in an elite maize hybrid by QTL mapping in an immortalized F2 population. Theor Appl Genet 120: 333–340
- Tang S, Presgraves DC. (2009) Evolution of the Drosophila nuclear pore complex results in multiple hybrid incompatibilities. Science 323: 779–782
- Than C, Ruths D, Nakhleh L. (2008) PhyloNet: a software package for analyzing and reconstructing reticulate evolutionary relationships. BMC Bioinformatics 9: 322.
- Todesco M, Pascual MA, Owens GL, Ostevik KL, Moyers BT, Hübner S, Heredia SM, Hahn MA, Caseys C, Bock DG, et al. (2016) Hybridization and extinction. Evol Appl 9: 892–908
- Vähä JP, Primmer CR. (2006) Efficiency of model-based Bayesian methods for detecting hybrid individuals under different hybridization scenarios and with different numbers of loci. Mol Ecol 15: 63–72
- Vallejo-Marín M, Hiscock SJ. (2016) Hybridization and hybrid speciation under global change. New Phytol 211: 1170–1187
- Wallace AR. (1889) Darwinism: An Exposition of the Theory of Natural Selection with Some of Its Applications. Macmillan, London
- Wang L, Greaves IK, Groszmann M, Wu LM, Dennis ES, Peacock WJ. (2015) Hybrid mimics and hybrid vigor in Arabidopsis. Proc Natl Acad Sci USA 112: E4959–E4967
- Warschefsky E, Penmetsa RV, Cook DR, von Wettberg EJB. (2014) Back to the wilds: tapping evolutionary adaptations for resilient crops through systematic hybridization with crop wild relatives. Am J Bot 101: 1791–1800
- Wen D, Yu Y, Hahn MW, Nakhleh L. (2016) Reticulate evolutionary history and extensive introgression in mosquito species revealed by phylogenetic network analysis. Mol Ecol 25: 2361–2372
- Whalen M. (1978) Reproductive character displacement and floral diversity in Solanum section Androceras. Syst Bot 3: 77–86
- Whitney KD, Broman KW, Kane NC, Hovick SM, Randell RA, Rieseberg LH. (2015) Quantitative trait locus mapping identifies candidate alleles involved in adaptive introgression and range expansion in a wild sunflower. Mol Ecol 24: 2194–2211
- Whitney KD, Randell RA, Rieseberg LH. (2010) Adaptive introgression of abiotic tolerance traits in the sunflower Helianthus annuus. New Phytol 187: 230–239
- Wiegand KM. (1935) A taxonomist’s experience with hybrids in the wild. Science 81: 161–166
- Winge O. (1917) The chromosomes: their numbers and general importance. Comptes Rendus des Trav du Lab Carlesb 13: 131–175
- Yakimowski SB, Rieseberg LH. (2014) The role of homoploid hybridization in evolution: a century of studies synthesizing genetics and ecology. Am J Bot 101: 1247–1258
- Yang X, Xia H, Wang W, Wang F, Su J, Snow AA, Lu BR. (2011) Transgenes for insect resistance reduce herbivory and enhance fecundity in advanced generations of crop-weed hybrids of rice. Evol Appl 4: 672–684
- Zhou G, Chen Y, Yao W, Zhang C, Xie W, Hua J, Xing Y, Xiao J, Zhang Q. (2012) Genetic composition of yield heterosis in an elite rice hybrid. Proc Natl Acad Sci USA 109: 15847–15852
- Zhou R, Moshgabadi N, Adams KL. (2011) Extensive changes to alternative splicing patterns following allopolyploidy in natural and resynthesized polyploids. Proc Natl Acad Sci USA 108: 16122–16127
- Zirkle C. (1934) More records of plant hybridization before Koelreuter. J Hered 25: 3–18
What does “F1” Mean?
Posted By Mandy Peterson on 10/17/2018 in Breeding
When it comes to designer dogs, this is definitely one of the most common questions that people ask.
If you are looking for a new puppy and hear someone say “She is an F1 Goldendoodle”, you may be wondering what that means and if it’s bad if you just get a regular Goldendoodle instead of a fancy F1 Goldendoodle?
Well, the preface F1 actually refers to the generation of a designer dog and the breed of its parents- but at the end of the day they are all still Goldendoodles (or Labradoodles, Cockapoos, Bernedoodles, etc.)
What about F1b, F2, or F3? How do F1 and F1b Labradoodle puppies differ? Or if you are looking at a litter of Maltipoos and the breeder says they are F2, what exactly does that mean? Keep reading!
This can all seem very confusing at first but luckily, it is actually quite simple!
In order to produce a designer dog, you need two different breeds of *purebred dogs. We will use a Golden Retriever and a Poodle for our examples, but it can be any two different breeds of purebred dogs.
*This is a very important clarification because what makes a “Designer Dog” differ from mixed breeds is the fact that it is an intentionally bred dog. These generational prefaces, while a bit confusing, are very important in distinguishing that your pup is in fact a designer dog, with a direct genealogy line that starts with two purebred parents, and has been tracked properly by a breeder.
F1 = (First Generation) The offspring of a Golden Retriever/Poodle pairing. The puppy is 50% Golden Retriever and 50% Poodle.
As first generation hybrids, F1 Goldendoodles have the added health benefits attributed to what is known as *hybrid vigor. However, if one of the purebred parents sheds (like a Golden Retriever in this case), F1’s are known to shed more and be the least hypoallergenic. It is also hardest to predict the size, coat type, or appearance of a first generation (F1) hybrid because the puppies have an equal chance of inheriting traits from either parent.
*Hybrid Vigor: A phenomenon that usually occurs when the first cross between two unrelated purebred lines is healthier and grows better than either parent line.
F1b = (First Generation Backcrossed) The offspring of an F1 Goldendoodle backcrossed (or paired) with one of the original purebred breeds. F1 Goldendoodle X Poodle = F1b puppy. The puppy will be 75% Poodle and 25% Golden Retriever.
The purpose of a first generation backcross (F1b) is generally to breed towards more desirable traits such as a smaller size or nonshedding and allergy friendliness.
Although there is less hybrid vigor in an F1b crossing than in an F1, the first generation backcross still is close enough in the breeding tree to benefit from vigor. With each successive generation, vigor will be lost.
F2 = (Second Generation) The offspring of two F1 Goldendoodle parents. The puppy is technically still 50% Golden Retriever and 50% Poodle but is genetically the most varied generation possible.
The high variation is due to the fact that there are now traits from 2 different Golden Retrievers and 2 Poodles and dominant and recessive genes can create a very diverse litter. (For example: In these litters it is possible to have a “straight coat” Goldendoodle that looks very similar to a Golden Retriever.)
F2s are not as common as F1 or F1b litters because they are so genetically unpredicatble. When breeding on, most breeders breed a backcross instead, as the puppies are more predictable and work well for people with allergies.
F2b= The offspring of an F1 Goldendoodle and an F1b Goldendoodle. Although three generations in the making, F2bs are still considered second generation dogs.
There is less vigor in this generation than the first, but the second generation backcross still is close enough in the breeding tree to the original hybrid to benefit from some hybrid vigor. With each successive generation vigor will be lost.
F1bb= The offspring of an F1b backcrossed (or paired) with one of the original purebred breeds. In this case, an F1b Goldendoodle paired with a Poodle.
This increases the percentage of Poodle in the mix (87.5%) compared to your traditional F1b and is best for people with major allergy concerns. The traits of F1bb pups are highly predictable and will strongly take after the Poodle parent.
F3 = (Third Generation or Multi-gen) A breeding between F1b to F1b or F2 to F2 or any combination of higher generation Doodles.
To save on too many confusing letters and numbers, anything F3 and above is often referred to as Multi-generational to denote that there are multiple generations of Doodles involved.
Double Doodle = The offspring of breeding two different designer dogs together. For example: F1 Goldendoodle X F1 Labradoodle = Double Doodle. The puppy will be 50% Poodle, 25% Golden Retriever and 25% Labrador Retriever.
Double Doodles come in a variety of sizes, colors, coat types, and temperaments. Because the genes of multiple breeds have to be considered, their traits are hardest to predict and can vary greatly even within the same litter.
Double doodles benefit from hybrid vigor and tend to be healthier than either parent line.
We hope that this helped answer any questions you might have had about generation prefaces. Hopefully you now have a better idea of what generation of designer dog will work best for you! Each one is very different and for that reason it is important to know what generation of designer dog you are getting and who its parents are. It is best to get your pup from a breeder that has registered their dogs and litters and who has also kept careful track of each litter and their genealogy.
Once you have established which breed (and generation!) of designer dog that will be the best fit for you, the next thing you need to decide is WHERE you will find your sweet puppy. Being picky about who your breeder is and where your pup is coming from is probably the single most important thing you can do before bringing a new dog into the family. If you have questions or want to learn more about how to pick a breeder, take a minute to read this blog post: How to Spot a Reputable Breeder. You can also search for trusted Designer Dogs of America breeders and browse the puppies for sale page HERE.
When you find the perfect dog for you, don’t forget to make it official and register them with Designer Dogs of America- the only database specifically built to help the breeders and owners of Designer Dogs across the country!
And because we want to be with you through every step of the journey, consider joining our community on Facebook and Instagram- a place to connect with other breeders and designer dog owners, ask questions, learn, and show off your sweet furry family member! ❤️
Author InformationMandy Peterson Author URL: https://www.designerdogsofamerica.com/united-states/salem/goldendoodle-breeder/our-puppy-amour
A beginner’s guide to… F1 slang
A new F1 season means a new set of fans ready to immerse themselves in the technicolour, sensory overload-y glory that is Formula 1 (we’re biased, we know). But with F1 being the technical, jargon-laden sport that it is, it can sometimes be hard for a newbie to work out what the hell the drivers, team bosses and commentators are talking about half the time. So to help new fans get themselves up to speed, we decided to produce a guide to some of the most commonly used pieces of F1 slang, and what they mean – and here it is!
What is it: When a driver, struggling to get past another car, pits early in a bid to get a performance advantage from fresh tyres that will hopefully put them ahead when their rival then pits.
Use it in a sentence: “He’s going to try to use the undercut to get ahead”
Not to be confused with: A haircut popular with hipsters the world over.
What are they: Small pieces of rubber that are shredded from the tyres during cornering, which build up off the racing line. Running onto them mid-race can be treacherous as they prevent the tyre making proper contact with the road, thereby reducing grip. Driving over them after the chequered flag, however, is a nifty tactic the drivers use to try and make sure their cars aren’t underweight at the race end.
Use it in a sentence: “I got onto the marbles in the hairpin, went a bit wide and got the tyres dirty”
Not to be confused with: Lots of small glass balls on the track. That would be dangerous.
Check out our beginner’s guide to F1 cliches
DIRTY AIR/CLEAN AIR
What is it: ‘Dirty air’ is created by the odd vortices of air spinning off the back of a leading car and reducing the efficient airflow over the wings of the following one, giving it a performance disadvantage by reducing downforce. Clean air is when a car is out on its own, with a nice, undisturbed airflow passing over its wings, providing good downforce.
Use it in a sentence: “I tried to get past but I was stuck in his dirty air. But once he pitted and I got some clean air, I could start to put in some decent laps”
Not to be confused with: A gastric problem.
What is it: Quite simply, it’s when the underside of the car hits the track. It’s usually caused by bumps in the track or a sudden rise or crest, à la Eau Rouge. The act of bottoming was made more spectacular, if you’ll pardon the expression, by the introduction of titanium skid blocks in 2015, which throw off a shower of sparks when the cars’ undersides hit the deck.
Use it in a sentence: “The car had a good balance, although on my qualifying lap, it was bottoming and I lost some time”
Not to be confused with: Anything involving the gluteus maximus.
Learn About F1 Hybrid Seeds
Much is written in today’s gardening community about the desirability of heirloom plant varieties over F1 plants. What are F1 hybrid seeds? How did they come about and what are their strengths and weaknesses in the home garden of today?
What are F1 Hybrid Seeds?
What are F1 hybrid seeds? F1 hybrid seeds refers to the selective breeding of a plant by cross pollinating two different parent plants. In genetics, the term is an abbreviation for Filial 1 – literally “first children.” It is sometimes written as F1, but the terms mean the same.
Hybridization has been around for a while now. Gregor Mendel, an Augustinian monk, first recorded his results in cross breeding peas in the 19th century. He took two different but both pure (homozygous or same gene) strains and cross-pollinated them by hand. He noted that the plants grown from the resulting F1 seeds were of a heterozygous or different gene make up.
These new F1 plants carried the characteristics that were dominant in each parent, but were identical to neither. The peas were the first documented F1 plants and from Mendel’s experiments, the field of genetics was born.
Don’t plants cross pollinate in the wild? Of course they do. F1 hybrids can occur naturally if conditions are right. Peppermint, for example, is the result of a natural cross between two other mint varieties. However, the F1 hybrid seeds that you find packaged on the seed rack at your local garden center are different from wild crossed seeds in that their resultant plants are created by controlled pollination. Since the parent species are fertile, one can pollinate the other to produce these peppermint seeds.
And the peppermint we just mentioned? It’s perpetuated through the regrowth of its root system and not through seeds. The plants are sterile and can’t propagate through normal genetic reproduction, which is another common characteristic of F1 plants. Most are either sterile or their seeds don’t breed true, and yes, in some cases, seed companies do this with genetic engineering so that their F1 plant refinements can’t be stolen and replicated.
Why Use F1 Hybrid Seeds?
So what are F1 hybrid seeds used for and are they better than the heirloom varieties we hear so much about? The use of F1 plants really blossomed when people began to do more vegetable shopping in grocery store chains than in their own backyards. Plant breeders sought more uniform color and size, looked for more definite harvest deadlines and durability in shipping.
Today, plants are developed with a specific purpose in mind and not all of those reasons are about commerce. Some F1 seeds may mature faster and flower earlier, making the plant more suitable for shorter growing seasons. There might be higher yields from certain F1 seeds that will result in larger crops from smaller acreage. One of the most important accomplishments of hybridization is disease resistance.
There is also something called hybrid vigor. Plants grown from F1 hybrid seeds tend to grow stronger and have greater survival rates than their homozygous relatives. These plants need fewer pesticides and other chemical treatments to survive and that’s good for the environment.
There are, however, a few downsides to using F1 hybrid seeds. F1 seeds are often more expensive because they cost more to produce. All that hand pollination doesn’t come cheap, nor does the laboratory testing these plants undergo. F1 seeds can’t be harvested by the thrifty gardener for use the following year. Some gardeners feel that the flavor has been sacrificed to uniformity and those gardeners might be right, but others might disagree when they taste that first sweet taste of summer in a tomato that ripens weeks ahead of the heirlooms.
So, what are F1 hybrid seeds? F1 seeds are useful additions to the home garden. They have their strengths and weaknesses just as Grandma’s heirloom plants do. Gardeners shouldn’t rely on fad or fancy but should try a range of selections, regardless of the source, until they find those varieties best suited to their gardening needs.