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Old July 17, 2016   #9
bower
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Join Date: Feb 2012
Location: Newfoundland, Canada
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Interesting to note that the alliums are outcrossing by nature - flowers don't mature male and female parts at the same time, to ensure at minimum an outcross with another flower in the same umbel. They suffer from inbreeding depression if the population is too small. So healthy seeded alliums contain a fair degree of heterozygosity.

This makes me think, there is a reasonable chance that the Walking Onions have some degree of heterozygosity so that the seed would indeed produce diverse offspring as opposed to a 'selfed' result identical to the parent. The fact they reproduce clonally doesn't mean that the genome of the plant is entirely homozygous - and would be unlikely to some extent, given that alliums are mandatory outcrossers.

Put another way, if you had a Sungold F1 that was propagated by cuttings for generations, you would still get diverse results by growing the true seeds from the plant. While an Indian Stripe OP propagated clonally would still produce plants identical to the parent from true seeds, except for a possible random mutation eg PL.

In the case of garlic, it is possible that the low true seed viability is due to insufficient genetic diversity and heterozygosity - maybe presence of multiple loci/ alleles that are detrimental or fatal when homozygous. Possibly all garlic originated from a small founder population, (or a few small isolated founder populations) and that clonal reproduction is nature's way of overcoming the genetic obstacles to forming viable seed, rather than the effect of human selection. After a long time and many disparate strains grown out the genetic diversity has been increased by small random mutations, so you now have a better chance of viable seed by crossing different varieties which have diverged genetically over a long time.
In the case of the Walking Onions, only way to find out is by growing out the seeds. Great project! Please keep us posted.
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