opinions on retaining a seedling

[shoy]

Here in Georgia W. Radler's Brite Eyes has been an outstanding rose. Lots of research indicates resistance to a particular strain of black spot. The same research shows that it doesn't always pass along that resistance to offspring.

I have an OP seedling out of Brite Eyes that is all yellow with about 15 petals. It starts out great guns and then gets infected with black spot (here in zone 8b, central GA), recovers, and puts on another show. The yellow fades but no more than lots of other yellows here. Is there some genetic reason to believe that crosses might one day pass along the resistance found in Brite Eyes?

Stephen

[roseseek]

I doubt it. If this seedling doesn't express that trait, what makes you think is possesses it to pass on? Do any selfs of it remain cleaner?

[david zlesak]

I doubt it too.... The resistance is dominant. Brite Eyes has only one copy of that dominant allele across its 4 sets of chromosomes and just a portion of its seedlings inherit it. There is a race of black spot that can overcome Brite Eyes, but most all the races in our collection don't. If your BE in the same garden looks healthy yet suggesting the resistance is holding and this seedling breaks down, the seedling likely didn't inherit the allele unfortunately. It is a very pretty seedling and may be interesting to backcross with Brite Eyes or use with other parents that have different black spot resistance genes. It sounds like it has pretty good horizontal resistance that allows it to not get too much black spot in order to have strength to rebuild and flower again during the season. The yellow flower color is beautiful!