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Subject: Market Farming
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- From: "William H Shoemaker" <wshoemak AT illinois.edu>
- To: "'Market Farming'" <market-farming AT lists.ibiblio.org>
- Subject: Re: [Market-farming] hybrid vs. selection
- Date: Mon, 7 Feb 2011 08:19:21 -0600
That is a pretty good set of definitions
but I’d like to add some details in case anyone is interested, especially
if they save seed. If you save seeds of heirloom varieties,
it’s very important that they not be crossed with other varieties of the
same crop which may be nearby. That can happen quite naturally, which is why
they say in the open-pollinated definition that there should be isolation, or
distance, between varieties if the variety is to be maintained accurately. The
reason is that pollen from a different variety reaching a flower of an heirloom
or open-pollinated variety will change the genetic profile of the seed, meaning
the seed won’t be the same variety any more. Like children, they’ll
be similar, but will have characteristics of the pollen source as well as the
maternal plant (the original variety). The rule of thumb with self-pollinating
crops like tomatoes, peppers, snap beans, etc., is that there will be at least
5% “outcrossing” or natural movement of pollen from plant-to-plant
if they are nearby. This is facilitated by air movement, but even more-so by
bees. If you watch insects visiting tomatoes or snap beans you’ll see
lots of native pollinators, even honeybees, visiting the flowers. While they do
that they move pollen from plant to plant, facilitating the crossing of
varieties. If you are saving seed you can diminish the risk by simply covering
the flowers with a paper bag or something similar before they open and securing
them from “wild” pollen. Let them self-pollinate under cover, then
after several days have passed and the flower naturally drops its petals, the
cover can be removed, the baby fruit tagged and allowed to mature before seed
harvest. The resulting seed will be true to the maternal parent genetics. Do
this on multiple plants to maintain the diversity within the genetics of the
variety and mix the seed from different heirloom or open-pollinated parents.
You can also cover a whole block of plants with reemay or another fine-textured
fabric and it will do a pretty good job too. Isolating your plants, perhaps in
a greenhouse, will effectively do the same thing. Its important to know that hybrids are not
the same as GMOs but they are much more manipulated as varieties by breeders.
With most hybrids their parents have gone through a number of generations of “inbreeding”,
where the plants that are selected for specific traits are crossed with
themselves. This refines the set of genes to a smaller, more controlled and
defined set of genes in each subsequent generation. After about 10 generations
these individual inbreds are very unique, often with some poor traits but each
having a very concentrated set of valuable traits that are based on specific
genes, such as verticillium wilt resistance, or yellow fruit color. When these
finished inbreds are crossed, hybrids result. These hybrids have the full
complement of positive traits of each inbred parent. Like the High Mowing
definitions page said, when you save seed from these hybrids, the offspring
begin to “revert”, or become less like the hybrid parent and often
exhibit traits similar to the inbred parents of the hybrid. Some of those
traits can be poor. And some of the “recessive” genes that are
valuable in the hybrid disappear, making those plants less valuable than the
hybrid parent. Seed companies like hybrids because they control the production
of the hybrid seed because they are the only ones who have the inbred parents. GMO’s are totally different than standard
hybrids, though many GMO’s are created with hybrids. GMOs could be
created with open-pollinated and heirloom varieties as well. What makes the GMOs
different is that they were created by mechanically inserting a gene into the
plant that could not be inserted naturally. There are many versions of this
technique but essentially they all involve the placement of a gene, or manipulation
of a gene, such that the result would not be found in nature. I really believe,
like Stewart Brand, that this technique can be incredibly valuable and do much
good. The problem is that the potential for selfish gain or other irresponsible
behavior drives some of those who use the technique. There is a real moral
dilemma involved in the power of this technique and until we have thoroughly
vetted the issue and placed reasonable limitations on the use of this
technique, there will be public backlash against it. Like many areas of
science, we have put tools in the hands of people who care less about their
impact on society than on their ability to accumulate wealth at others’
expense. Bill William H. Shoemaker Sr. Research Specialist, Food Crops 630-584-7254, FAX-584-4610 The following link to the
"definitions" page at High Mowing Organic Seeds might be helpful for
folks wanting simple definitions of hybrid, heirloom, OP, etc. On Sun, Feb 6, 2011 at 9:38 AM, Vern and Amy <vaspencer AT sisna.com>
wrote: Don, |
-
[Market-farming] hybrid vs. selection,
Vern and Amy, 02/06/2011
-
Re: [Market-farming] hybrid vs. selection,
Darren Young, 02/06/2011
-
Re: [Market-farming] hybrid vs. selection,
stonecirclefarm tds.net, 02/06/2011
-
Re: [Market-farming] hybrid vs. selection,
William H Shoemaker, 02/07/2011
-
Re: [Market-farming] hybrid vs. selection,
Wiediger, Alison, 02/07/2011
-
Re: [Market-farming] hybrid vs. selection,
Vern and Amy, 02/08/2011
- Re: [Market-farming] hybrid vs. selection, Wiediger, Alison, 02/08/2011
-
Re: [Market-farming] hybrid vs. selection,
Road's End Farm, 02/08/2011
- Re: [Market-farming] hybrid vs. selection, William H Shoemaker, 02/08/2011
- Re: [Market-farming] hybrid vs. selection, Road's End Farm, 02/08/2011
- Re: [Market-farming] hybrid vs. selection, William H Shoemaker, 02/08/2011
-
Re: [Market-farming] hybrid vs. selection,
Vern and Amy, 02/08/2011
-
Re: [Market-farming] hybrid vs. selection,
Wiediger, Alison, 02/07/2011
-
Re: [Market-farming] hybrid vs. selection,
William H Shoemaker, 02/07/2011
- Re: [Market-farming] hybrid vs. selection, Vern and Amy, 02/08/2011
-
Re: [Market-farming] hybrid vs. selection,
stonecirclefarm tds.net, 02/06/2011
-
Re: [Market-farming] hybrid vs. selection,
Darren Young, 02/06/2011
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