Population Dynamics of Open-pollinated Maize Synthetics under Non-random Fertilization Conditions

Abstract

With the exception of natural populations in higher plants cross-pollinated crops, such as maize, sorghum, rye sugarbeet, buckwheat and rapeseed, have no complete homozygous genotypes in a population unless either artificial isolation from other genotypes or controlled pollination in applied. Through open-pollination, in contrast, every population appears to be able to preserve its heterozygosity to some extent. The theoretical genetic basis accounting for this phenomenon is related to the random mating population theory including the some premises (Falconer 1960). In the past decade, on the other hand, it has been pointed out that this ideal population could not actually be obtained in cross-pollinated crops (Hartl 1975, Harding 1975, Jain 1975, Clegg et al. 1978, Yamada 1982). In these reports it was emphasized, that either at the sporophyte or at the gametophyte stages random fertilization was not possible and that this fact could not be overlooked.