The Effect of Genotype on Levels of Pseudocompatibility and the Production of Improved Varieties inBrassica Oleracea

Publisher Website
Google Scholar
Abstract
Summary Genotypes of Brussels sprout (Brassica oleracea var. gemmifera) and of kale (Brassica oleracea var. acephala), involving homozygous and heterozygous combinations of the S alleles S2, S5, S7, S15, S22, S29, S36, S39, S45, S46 and S61 were used to study the effect of genotype on levels of pseudocompatibility. Pseudocompatibility in Brassica oleracea is affected not only by environmental factors but also genetic factors. Different dominance levels are known to exist amongst the S alleles, and it seems clear that those alleles low in the dominance series (e.g. S5, S16 and S15) are more subject to pseudocompatibility than those alleles high in the dominance series (e.g. S22 and S29). Variation in the level of pseudo-compatibility within an S genotype has been shown here to depend on the genetic background in which the S genes operate. “Competitive interaction” is described for two combinations of S alleles in pollen. An unexpected pattern of compatibility was found involving certain alleles, e.g. S15 and S5. In such allele combinations pollen from the heterozygote (S5·15) was less successful on self pollination than on pollination of the homozygotes (S5·5 and S15·15). The significance of pseudocompatibility in Brassica breeding is discussed and possible alternatives to F1 hybrid breeding considered.