Healthy soil and sustainable growing

[Pete Vukovich <pvukovic1@yahoo.com>]

My understanding is that a hybrid is just a cross between homozygous (true breeding) parents - the resulting offspring are F1 hybrids.

Its possible to create seeds from different alleles (eg related but different species)  which cannot produce fertile offspring - these days they appear to call these 'lethal hybrids'. Viable F1 hybrids must be recrossed each generation to maintain the desired traits, back crossing or self pollinating them produces an F2 plant which is likely to maintain the trait , but whose hybridized children will likely not. What most seed companies sell are F2 hybrids, supposedly cheaper to produce than the original F1's since you can just take a bunch of F1's and let them cross within a population without selective/hand pollination.

http://www.genetics.org/cgi/content/abstract/181/4/1545

I know my understanding of this stuff is primitive, though I suspect in spite of hundreds of years of work on it the science is primitive particularly in plants. Crossing two plants doesn't tell you that the offspring must have a specific allele (genetic type), having a specific allele doesn't tell you what the phenotype (_expression_) will be - just a rough statistical estimate depending on the number of ways genes can express a phenotype.
This doesn't even begin to take into account epigenetics (gene masking based on a combination of environmental or genetic influences), or gene-gene interactions.


--- On Sun, 2/7/10, Emery Mitchamore <emitch@att.net> wrote:

From: Emery Mitchamore <emitch@att.net>
Subject: Re: [Livingontheland] hybrids
To: "Healthy soil and sustainable growing" <livingontheland@lists.ibiblio.org>
Date: Sunday, February 7, 2010, 6:57 PM

This  note caused me to realize that I don't understand the difference between hybrids that don't produce viable seeds, those whose viable seeds don't reproduce the characteristics of the parents, and the products of (often many generations of), cross-breeding, such as mentioned below, that DO reproduce the desirable characteristics of their parents.  Can anyone explain this to a non-botanist?

On Feb 7, 2010, at 5:17 PM, Lynn Montgomery wrote:

The below is from this year's Native Seeds/SEARCH catalogue. I hope this clears up some of the questions and prejudices about hybrids. If you live in the SW region this is the best place to get really old native seed varieties. A lot of these will grow elsewhere, for those who like to experiement.

www.nativeseeds.org

About the seeds we steward...

Is our seed “hybrid”?

No and yes. No, our seeds are not “hybrid” in the sense of

being produced through controlled pollination — often with

highly inbred lines — by modern plant breeders, typically for

large-scale high-input agricultural production systems.

However, hybridization — the crossing of genetically distinct

parents, both within and between populations, varieties, and

species — has been important in the evolution of crop

diversity. It is a natural process, resulting from open-pollination,

and one that farmers have often used to their

advantage. Thus, hybridization is likely reflected in the genetic

make-up of much of our seed, making them “hybrids.”

The seeds we offer in our catalog and store were all

originally collected from subsistence and small-scale farmers

and gardeners. These are the food crops that have sustained

traditional communities for centuries. They have been selected

and nourished by farmers over generations, becoming adapted

to local environmental conditions and cropping systems, and

their individual flavors, odors, and textures have infused local

culinary and ceremonial practices. They are the result of much

open-pollination, hybridization, and subsequent selection

(both natural and human-imposed). We celebrate this

diversity!

To Grow a garden is to believe in tomorrow
- Eleanor Roosevelt

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E. E. "Mitch"  Mitchamore

www.hillcountrynatives.biz

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