Genetic Variability within and among Wintering Populations of Brant

through the induction of meiosislike pair-ing and recombination of chromosomes in somatic tissue, be responsible for some of the somaclonal variation often reported in such studies.6 Presumably, natural selec-tion would favor cells carrying superior recombinations and would occasionally produce chimeras or entire regenerated plants with an altered genotype. Our fail-ure to observe somaclonal variants among dozens of regenerated sorghum plants can be explained by the low frequency of so-matic pairing and separation of chromo-somes in our material or by a selective disadvantage of recombinant cells result-ing from such processes. Somatic pairing and recombination of chromosomes per se, however, do not explain the novel na-ture of many somaclonal variants or in-dicate why such variants frequently can-not be recovered in sexual propagation