Analysis of self-incompatibility interactions in 30 resynthesized Brassica napus lines. I. Fluorescence microscopic studies.

Thirty Brassica napus lines have been developed through interspecific hybridization of B. oleracea and B. campestris lines with defined S-allele constitutions. These lines, which represent 29 different S-allele combinations, were tested in a diallel of test-pollinations to determine the activity of the introgressed S-alleles and intergenomic dominance relationships. Some consistent trends were observed: B. oleracea S-alleles high in the dominance series (e.g. S8, S14, S29) were always active in the resynthesized B. napus lines, whereas recessive S-alleles (S2, S15) lost their activity in some test combinations. The B. campestris S-alleles were active in most cases, although 2 alleles were partially inactivated by the recessive B. oleracea allele S15.