@prism Re: Post 639
Me too. I was just going to hybridize some Irises, simple cross polination. Yeah right!
Wham! Diploid, Tetraploid, Hexaploid, Polyploid.
It means different varieties within the same species have different numbers of chromosome.
Humans are diploid, 2 complete sets of chromosomes, one from each parent.
Plants can be polyploid, Tetraploid, 4 sets chromosomes, Hexaploid 6 sets of chromosomes.
Hybridizing polyploidal plants get complicated as it is difficult to cross breed the polyploids (Tetraploid with Hexaploid, for example)
As I noted earlier, simple cross pollination of Polyploid plants, Diploid, Tetraploids, Hexaploids results in mostly sterile seeds or very weak plants because of the problems of matching all those chromosomes.
This is now greatly facilitated by irradiation which was replaced by chemical colchicine.
It became easy, abt 1920-1930 to hybridize the polyploids using those tools
It revolutionized plant breeding, resulting in an explosion of new variations.
But for me, without access to radiation equipment or colchicine, it meant I had to know the Ploidal state of the Iris I was attempting to cross and the problems associated with same. Applied genetics.