OPEN-POLLINATED, HYBRIDS, HEIRLOOMS AND GMOS (for those of you -- the gardeners AND THE CHEFS -- who havent read my Garden Guru page): Im posting this again because I keep seeing others post on this subject and not everyone has it quite right. This is a complex subject (and a long one, so bear with me), to say the least, so I need to back-up into the basics with some definitions. And then a second part to follow. “O. P.” is the commonly understood anagram for “open pollinated.” “OP” seeds are a result of either natural pollination processes (the birds and the bees and the butterflies and a gazillion others) or human selection for specific traits, which are then reselected in every crop. These traits are relatively fixed, within a range of variability. Ordinarily, open-pollinated seeds are not referred to as cultivars (nor varieties) as there is still some variability. The word “strain.” instead, fits this concept. Open-pollinated vegetable strains reproduce themselves in one of two ways: (1) cross-pollination between two plants via wind, insects or water or (2) self-pollination between male and female flower parts contained within the same flower or among separate flowers on the same plant. So long as plants of an OP variety are kept isolated from different plants with which they can cross, they will produce seed that will “come true to type” or , as amateur gardeners like to say, “true from seed.” In other words, the plants in the following generation will resemble the parent plants — of sorts. “F-1 hybrid” (technically written as F1, with the 1 in subscript format) stands for “first filial generation” or what comes from the combination of genes from two distinct parents (the “crossing”). Not important here but interesting: if that first generation ever produces a second generation, by the way, those are F-2 and a third is F-3 and so on. In the past, the word “hybrid” was used by biologists for those creatures that came from the crossing of two distinct species. The longer, more accurate term for this was “interspecific hybrid.” Many vegetables are exactly this, happening either naturally or , more often, done under the auspices of early human civilizations. Corn may be the best known example of this. We would hardly recognize its parents as corn; in fact, it isn’t positively known what its parents were (good theories exist). Many squash, cabbage relatives, cucumbers, potatoes and tomatoes also are interspecific hybrids. In the broadest sense, nearly all vegetables are hybrids in this sense. Most vegetables as we know them are “man-made” or at least “man modified.” (And yes, women had a lot to do with it, too. ) But today, the word “hybrid” when it comes to flowers and vegetables as far as gardeners are concerned, has a narrower definition. The contemporary word here is more a legal term, one of commerce and detailed documentation. An “F-1 hybrid” is made by crossing two different parent cultivars (the better name for “variety”, by the way) of the same species. To advertise and sell a vegetable cultivar as an F-1 hybrid, the parents must be known and named, and the pollination process controlled. The offspring of such pollination crossing produce a new, uniform seed cultivar with specific characteristics from both parents. For example, breeders may choose to cross two tomato parents to make an F-1 hybrid that exhibits the known early maturity of one parent with a known specific disease resistance of the other. The unique characteristics of an F-1 hybrid are very uniform only in the first generation of seed, so seed saved from F-1 plants, to produce an F-2 generation, will not come true if replanted. A remixing and regression of genetics makes for undependable and usually not-so-desirable outward characteristics. This, along with the high price of F-1 seeds, is what bothers home garden seed savers the most. To produce consistent F-1 hybrids, the original cross must be repeated each season. Most new vegetable cultivars are F-1 hybrids. “What’s the big difference?” as far as gardeners and vegetable eaters are concerned. Which is better? “Hybrids” or “O. P. “? Here’s a comparison of key attributes: Vigor In hybrids, there is something called “hybrid vigor.” The offspring of two different plant varieties often exhibit this increased SYNERGISTIC vitality, known technically as heterosis. Some hybridized vegetables seem to gain more hybrid vigor than others. Broccoli and sweet corn are good examples of this. For other plants, such as squash, melons, cucumbers and tomatoes, the difference between hybrid and OP vigor is generally less noticeable. But among the best open-pollinated strains, there is a certain vitality, which involves complex combinations of genes. Mostly, this is significant in locally-selected vegetables because of their adaptation to the local weather, soils, pests, and diseases. (Pay special attention to this very last note; it’s an important piece of the concept called “heirloom. “) Disease Resistance When it comes to disease resistance, hybrids can offer superior pest and disease resistances, especially in the case of vegetables such as tomatoes. There are, however, many modern OP varieties that have impressive disease resistance. The Marketmore series of cucumbers is one example. Cost Hybrid seeds are invariably more expensive than open-pollinated seeds. The price difference has to do with, among other things — the costs of research in creating hybrids and maintaining breeding lines. — the costs of manual labor for the pollinating. Yep, it’s all done by hand. — Also, a company that develops a hybrid can charge a little more for the seed because the firm has exclusivity and because it is difficult or impossible for gardeners to save seed from an F-1 hybrid. Taste (the BIG one) First, the question of hybrid versus OP flavor is strictly a matter of personal preference. Taste IS highly subjective, after all. What we grow up eating is what becomes our preferred taste. I grew up in an Italian household where grandfather Ambrogio planted a vegetable garden. The tomatoes were grown from seed from Italy and they were absolutely perfectly delicious. Many years later when I became a judge for All-America selections and a “celebrity” judge for way too many blind tomato tastings, I was introduced to all the well-known “heirloom” tomato strains. While others who knew these tomatoes described the flavors as “what a tomato should taste like”, I found the flavors truly odd and somewhat off-putting. Second, we need to make a distinction between OPs and the hybrids that have been developed specifically for home-garden use and those earmarked for large-scale growers. Breeders who specialize in vegetables for factory farms and food processors tend to focus on qualities other than flavor, including and especially shipping ability. Almost any home-garden grown vegetable — whether hybrid or OP — will almost certainly taste better than something that has been trucked to your supermarket from hundreds of miles away. Third, although commercial hybrid vegetables have not been bred with top flavor as a priority in the USA, some hybrids from Europe, where flavor has been more commonly a commercial breeding goal, are quite delicious. Finally, after all that is said, breeders simply cannot manipulate complex characteristics such as flavor as easily as they can size and shape and ripening dates. There are many genes involved in a flavor profile. Maintenance Hybrid seed is also known as “high response” seed, meaning they respond very well to extra water, fertilizer, and pesticides. It also means that these seeds require extra fertilizers, herbicides, pesticides and lots of water to achieve their high yields. Open pollinated strains grow well without high inputs because they have been selected under “natural” conditions (back to “vigor” and back to the true concept of “heirloom”). NEXT PART (to come) -- HEIRLOOMS
Posted on: Sat, 09 Aug 2014 18:52:46 +0000
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