Question about SSE requests... - Page 2

Ruby · May 3, 2007

This is kind of off-topic, but I was just re-reading this and I'm kind of wondering about it:

Quote:

And then we get back to genetic diversity. This is a topic that makes me scratch my head. I'm sure you already know that tomatoes have perfect flowers which are self-pollinating and each tomato is identical or nearly identical to the parent if no crossing takes place.

People get so upset if they have a crossed seed -- they want the REAL Cherokee Purple or the REAL Brandywine (Sudduth's). Yet, over and over I have read that you should grow several plants and save seed from the different plants and mix the seeds together to "maintain genetic diversity."

Anyway, I'm sure I'm about to get smacked upside the head with a biology book and/or lesson.

Anyone know the biology behind this? In theory, shouldn't all these "stable" varieties be inbred to the point that, if you ensured there was no pollen contamination going on, you would get the exact same plant every time? Growing more than one plant seems like it would be insurance just in case something happened to the other plants. Is there a lot of genetic variation going on within a variety?

**carolyn137** · May 4, 2007

Is there a lot of genetic variation going on within a variety?

****

Not a lot of genetic variation but some.

Trained eyes can see the differences in internode length, and other traits, and I think all of us who plant more than one plant/variety have seen that some plants bear fruits earlier or later than others, all other variables staying the same.

I will never save seeds from just one or two fruits, rather, I try to always have more than one plant of each variety and so while saving seed from MANY fruits from one plant is OK, saving seed from many fruits from several plants is even better.

The guidelines suggest planting out 8 plants/variety and saving seed from the inner four.

Now that doesn't make that much sense to me b'c nada is said about the closeness of varieties in adjacent rows.

I'm one of many who used to grow so many varieties per season that there was no way I could bag blossoms, so I relied on minimal geographic isolation and for my purposes that worked pretty darn well.

In summary, yes, there is genetic diversity within a variety, no, most folks aren't trained to see it, but some trait differences are rather obvious and if there's too much deviation from the known and described traits then the variety isn't that variety anymore or becomes a strain of that variety, which just means that the variety can be IDed as being that variety but has some traits that might be different from the original.

Yellow Brandywine ( Platfoot), Mortgage Lifter ( Estler) or Mortgage Lifter ( Mullens), Brandywine ( Sudduth/Quisenberry) are examples of strains. And there are very very few strains of varieties that have been recognized.

feldon30 · May 4, 2007

No diversity = bad
A little diversity = good
Too much diversity = bad

Got it. I think.

**carolyn137** · May 4, 2007

Quote:

Originally Posted by feldon30

No diversity = bad
A little diversity = good
Too much diversity = bad

Got it. I think.

As in the GOOD ( a little diversity), the BAD ( no diversity) and the UGLY ( too much diversity)?

Where am I remembering that from?

May 4, 2007	#17
carolyn137 Moderator Emeritus Join Date: Jan 2006 Location: Upstate NY, zone 4b/5a Posts: 21,169	Is there a lot of genetic variation going on within a variety? **** Not a lot of genetic variation but some. Trained eyes can see the differences in internode length, and other traits, and I think all of us who plant more than one plant/variety have seen that some plants bear fruits earlier or later than others, all other variables staying the same. I will never save seeds from just one or two fruits, rather, I try to always have more than one plant of each variety and so while saving seed from MANY fruits from one plant is OK, saving seed from many fruits from several plants is even better. The guidelines suggest planting out 8 plants/variety and saving seed from the inner four. Now that doesn't make that much sense to me b'c nada is said about the closeness of varieties in adjacent rows. I'm one of many who used to grow so many varieties per season that there was no way I could bag blossoms, so I relied on minimal geographic isolation and for my purposes that worked pretty darn well. In summary, yes, there is genetic diversity within a variety, no, most folks aren't trained to see it, but some trait differences are rather obvious and if there's too much deviation from the known and described traits then the variety isn't that variety anymore or becomes a strain of that variety, which just means that the variety can be IDed as being that variety but has some traits that might be different from the original. Yellow Brandywine ( Platfoot), Mortgage Lifter ( Estler) or Mortgage Lifter ( Mullens), Brandywine ( Sudduth/Quisenberry) are examples of strains. And there are very very few strains of varieties that have been recognized. __________________ Carolyn

May 4, 2007	#18
feldon30 Tomatovillian™ Join Date: May 2006 Location: Rock Hill, SC Posts: 5,346	No diversity = bad A little diversity = good Too much diversity = bad Got it. I think.