North American Fruit Explorers mailing list at ibiblio

[Rob Halgren <halgren@msu.edu>]

> Ginda, Does this mean they are examining sequences after each successful
> fertilization, or that they are using some Genetic Engineering concepts and
> practices to achieve this end? In relation to wild breeding populations, an 
> item
> which has not been addressed is hand pollination in breeding has many 
> downsides.
> Natural flower structure differs from flower to flower, with some flowers 
> being
> unable to fertilize under normal conditions. ie insect/wind. Various parts can
> have flaws only revealed under a microscope. By hand pollinating the number of
> these types of flowers is likely to increase, debilitating the plant in future
> generations. This has been recognized first with vegetable 
> breeding/preservation,

	It isn't at all difficult to examine all the seedlings for the presence 
of the genetic marker they are selecting for.  A few grams of tissue, 
some reagents, and a thermocycler are all you need.  It is cheap, too. 
Or at least it is now.  If I recall, they are using standard breeding 
techniques, and selecting the seedlings to grow to breeding size.  If 
they did that right, they could raise a large number of otherwise 
genetically diverse trees to breeding size.

> > I still wonder whether the Chestnut will ever be more than functionally 
> > extinct,
> > since its habitat niche has been filled by other species in the last 50+ 
> > years.
        
	For example the Green Ash, which has been almost exterminated  by 
emerald ash borers in SE Michigan?  You won't find an ash bigger than a 
few inches in diameter in a large portion of the state - the ones that 
the borers didn't get the state is cutting down to prevent the spread of 
the critter.  I'm not sure they are succeeding.  So, since a lot of 
those ash trees were planted to replace american chestnut and elm, it 
seems only fitting to replace them with blight resistant chestnut.  I'm 
not too worried about our 'natural' forests in michigan - most of them 
are a)managed, and b)pretty diverse.  I'm sure that blight resistant 
chestnut would be planted in these managed woodlots, it will spread from 
there (assuming there are any unmanaged woodlots by then).

	Of course at some point people will get smart and start planting a 
diverse arrangment of street trees.  I lost 5 large elms last year to 
dutch elm disease (or something like it - could have been another 
pathogen) - because 40 years ago someone thought it would be nice to 
have every shade tree in the yard the same species.  Now if he had 
planted two or three species I might still have some trees.  I still 
have a box-elder, but nuclear winter wouldn't kill those.  My inlaws 
live in an older subdivision where every other street was planted in 
blocks - so some streets have just been completely denuded of ash trees, 
which they are replacing with maples, of course.  Exploding maple 
disease will take care of that in 10 years, probably.

	I am a magnet for plant pests.  When I lived in Chicago it was my 
neighborhood that was decimated by asian long-horned beetles.  Very few 
trees left standing, after the city went through with its containment 
strategy.  I've been to California a few times in the last couple years, 
but I'm not taking credit for sudden oak death (not yet, anyway).

Rob (good year for big strawberries.  Too much water though - big isn't 
necessarily tasty)

--
Robert G. Halgren, Ph.D.
Bioinformatics Specialist
GTSF - Michigan State University
http://genomics.msu.edu
(517) 353-7236    -   halgren@msu.edu