Hybrid vigor in pepper seedlings

Early Scarlet, radish, sprout

Hybrid vigor, or heterosis, is a poorly understood process from a genetic standpoint, but it’s one that plant breeders exploit quite successfully.  Simply put, they cross two varieties of a plant, then grow out the children called the F1 generation.  If the cross is successful, it produces a hybrid plant which has superior characteristics to both of its parents, and often has stronger vigor — growing larger and faster than either parent.  If you’ve ever had a mystery squash take over your compost pile and look like Audrey II, that was hybridization at work.

Hybrids are developed to have better yield, flavor, resistance to a particular pest or disease, and/or better performance in a certain climate.  In many ways, this is similar to the reasons heirloom varieties are developed.  Grandma’s special zucchini from years of saving seeds is a variety which performs uniquely well in her garden, but may do poorly in yours 100 miles away.  (Or not.)  Regional favorites, like banana peppers here in the South, do so well throughout the region that they become hugely popular and are often sold as commercial transplants.  Most people don’t think of these as heirlooms, but they still are.  And all heirlooms or newer open pollinated varieties start out as a hybrid cross.

Hybrids or “F1” cultivars are common in catalogs.  These are not “genetically modified” any more than a mixed breed dog is, they are just crosses that are commercially produced in order to sell the children for seed.  While you can’t save the next F2 generation for seed and expect them to reproduce true, sometimes hybrids are just the ticket for a vegetable that doesn’t want to do well for you.

I grow sweet peppers, bell or lamuyo, from hybrid.  The open pollinated varieties simply don’t do well for me.  However, hot peppers do.  This year my pepper crop includes the African-American heirloom Fish Pepper with it’s lovely foliage and mildly hot taste, and experimenting with the new Islander F1 bell which is purple in it’s “green” stage.

Here’s the comparison of seedlings at the same age of development and grown under the same conditions:

Fish Pepper seedling

Fish Pepper seedling

Islander F1 seedling

Islander F1 seedling

The Fish Pepper will grow up just fine, but the hybrid is nearly ready for planting. Unfortunately, the weather is not, so the hybrids will just have to wait a bit longer.

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Heirlooms, open pollinated, hybrids, oh my!

Many seed catalogs are filled with glossy pages advertising rare and expensive heirloom varieties, and then there are other seed catalogs which tout the superiority of their hybrids.  Which is correct?  Well, both.

First, hybrids are not GMOs, which is a common misconception, and we’ll discuss GMOs in a future post.  Hybrids seeds are the product of a cross between varieties of the same species. If you mate a poodle and a pit bull, you get puppies which are mutts.  Those first generation (“F1”) puppies may have some characteristic you want (like a hybrid seed).  If you breed the F1 mutts, you have no idea what the puppies will end up looking or acting like, but they are still dogs.  This is why when you grow hybrid seeds, you don’t save the seeds of your crop to plant the next year.

All varieties were at some point a hybrid.  If a variety of a crop consistently produces true from one generation to the next, it is considered stable and open pollinated.  If you save these seeds, the next generation will almost certainly look, taste and grow like the previous one.  You can breed your own vegetable varieties if you want to spend the time and attention on it.

An heirloom variety is simply an open pollinated variety which has been around for a long time.  Sometimes they are referred to as old fashioned varieties; sometimes they are the product of “modern” breeding from pioneers like Luther Burbank that have withstood the test of time.  More rarely, they may be called landraces, but that is usually a term applied to corn and connotates a micro-variety which is highly adapted to a small area but wasn’t formally bred.  If you save the same seeds from your garden for a few decades, you will likely evolve a landrace strain which is highly adapted to your specific garden and habits.

So why would anyone choose a hybrid if they can’t save seeds from it?  One, the crossed strain may have some highly desired characteristic, like resistance to a particular disease.  Two, heterosis, or hybrid vigor.  Hybrids often have a physiological vigor absent in open pollinated varieties: in short, they grow faster, are more robust and produce more fruit.  While all hybrids will not exhibit heterosis, if a hybrid seed is being marketed, it probably does, or at least does not have the opposite to heterosis, outbreeding depression.

Heirlooms, on the other hand, tend to have a range of genetic expression you don’t see in modern hybrids.  When people go to the grocery store, they expect pumpkins to be orange and globular with a stem on top, tomatoes to be red and round and corn to be yellow or white.  But all three have the genetic material to come in an astonishing array of shapes and colors and patterns.  Some people choose heirlooms for appearance.

Heirlooms are also generally the product of generations of specialized breeding, so a variety tends to be very good at growing in one particular kind of condition.  On the flip side, that means that lovely yellow tomato you are eyeballing in the catalog may be a complete bust at your home.  Unless you are experimenting, your best bet is to choose heirloom varieties which are traditional to your area.

So… which should you choose?  It really depends on your needs.  I am a strong advocate of growing open pollinated varieties (not necessarily heirlooms) and saving seeds, but I include a few hybrids in my normal choices.  For example, I grow Hakeuri turnips from Johnny’s because they produce an outstanding tasting salad turnip… and I don’t like turnips.

I suggest you start with the varieties the old-timers and experienced gardeners grow in your area, especially if they are old fashioned favorites that have proven themselves for decades.  Most gardeners will be happy to talk your leg off about their garden, so don’t be shy to ask!  These are not necessarily the varieties you see marketed as transplants or on seed racks in the big box stores.  If you don’t have gardeners to talk to yet, a farmer’s co-op or a local nursery that has been in business for a long time may be able to help.  Your local Cooperative Extension Office can also probably provide some guidance.

(By Nicole Castle)