Thread: Some
View Single Post
Old November 9, 2009   #5
carolyn137
Moderator Emeritus
 
carolyn137's Avatar
 
Join Date: Jan 2006
Location: Upstate NY, zone 4b/5a
Posts: 21,169
Default

I had asked Jeffery his definitionm of landrace and this is what he posted elsewhere:


By landrace, I mean a variety that:

a) Has a lot of genetic variation, but is recognizable by certain typical traits,

b) Is widely grown in a particular region, and has a long history there (100-200 generations or more),

c) Has never undergone an intensive program of artificial selection.
By landrace, I mean a variety that:

a) Has a lot of genetic variation, but is recognizable by certain typical traits,

b) Is widely grown in a particular region, and has a long history there (100-200 generations or more),

c) Has never undergone an intensive program of artificial selection.

,,, to which one person posted.....doesn't that rule out tomatoes on all three counts?

To which I tend to agree.

Lots of DNA analyses have shown the lack of genetic diversity ( variation) and much has been said about tomatoes being in a genetic bottleneck and that outcrossomg with other tomato species should be looked at more closely.

Tomatoes aren't grown widely in one particular region, they're grown in many countries around the world with no specific limitation on varieties said to be from this or that area. I'm not sure how to comment on the 100-200 generation number b'c I don't know exactly how to equate it with a tomato generation time, which, if looked at directly, could mean a couple of generations in one year depending on where grown,

As regards the last comment, it's been estimated that about 95% of all OP varieties arose from natural cross pollination and genetic stabilization to the OP state and the remaining 5% would be from mutation of an existing variety.

http://en.wikipedia.org/wiki/Landrace

Above is just one of many discussions about landraces.There are many more to be found via Google. I was going to link to that Ethiopian Wheat example I've mentioned several times but decided to go with just the above.
__________________
Carolyn
carolyn137 is offline   Reply With Quote