crossing the ploidy boundary
continued from another thread....
some context for anyone who wasn't following it..
The discussion was around crossing tetrapoloid daylilies, such as Ed Murray, that will occasionally set viable seed with diploids in order to produce natural tetraploids without the use of chemical conversions (such as colchicine).
The question was asked "Why?"
Well, the reasons I am looking into this avenue intially are that first, I have a breeding goal that combines a trait only found in diploids today with a trait only found in tetraploids today. I have small children at home and do not want to have the dangerous chemicals around. So doing a conversion attempt myself is out. I could find someone to attempt the conversion for me- and may follow that route in parallel to exploring natural crosses across the ploidy boundary.
But, secondly, on a broader view, today's tetraploid daylilies are the result of a small segment of the diploid gene pool having been chemically converted by hybridizers who selected from the current hybrids of the day.
With other plants, such as bearded iris, where the conversion to tetraploidy began much earlier, more of the original gene pool was preserved in the conversions. This is because the conversions were initially done through dedication of a group of hybridizers in the early 1920s who took the time to cross breed the diploid species plants with naturally occuring tetraploid species- thus transferring a larger set of the original gene pool to tetraploid. Today nearly all modern bearded iris are tetraploid. The only time a hybridizer has to worry about ploidy mis-match is when they are working with species or historics.
Does it take longer, yes. Will it result in negative traits being added back in, yes, in the short term. The earliest work in tetraploid conversions resulted in lots of mud & lots of infertility issues. Still, the long term the merits of a broader gene pool, IMHO, probably outweigh those detriments.
Just food for thought. Other viewpoints, comments & opinions?