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[nafex] Re: Are your plants working for you? AKA, Ruthless culling



Ed Fackler wrote:
>>>>>>
     With apple, and probably many other fruit species, the so-called
"genetic variation
being lost" is a gross misnomer for the following reason(s), or so it
appears to
me.  When the apple left the origin, it did so primarily by seed 
either by
man or animal.
Somewhere very early in the process, perhaps in as little as 1-2000 
years,
the more tasty ones
were preferred and those incredibly few "genes" moved via the silk 
route to
modern
hybridization (in Great Britian in the 1700s).
     Since then, with the notable exception of M. floribunda 821 crab 
(the
most effective or active
ventura (scab) resistant gene), most apple varieties available today
(including most antiques)
possess incredibly few gene variations due simply to centuries of
inbreeding.
>>>>>>
I agree with some points:

Isn't true that most orchards until the recent era were seed 
propagated?  That would have retained significant variation.  Some 
new variation may have occurred in the "selected" stock.

As to the amount of inbreeding that exists in apples I'm not sure.  I 
have read that for grain and many other breeding programs, inbreeding 
with the occasional out-cross is the preferred way to develop a 
variety.  But for fruit breeding, inbreeding is not preferred as the 
homozygous (alike genes) in the same location makes for for a weak 
plant (especially in apple).  Is this because they are already inbred 
Or is it resistant to inbreeding?

I would propose that definitely not every Fameuse, Delicious, 
Jonathan descendant/cross be preserved, but those varieties that 
either is known to have a unique heritage, or didn't figure in most 
modern breeding programs should be preserved (and only some of the 
best of those).  

I think someone suggested our clonal repositories as a safety net for 
varieties.  I think that they do a good job and do provide a some 
degree of safety, but that they are also subject to the vagaries of 
govermental funding.

Chris Mauchline
SE PA, zone 6


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