SEGREGATION ANALYSIS OF ISOZYME MARKERS ON ISOLATED MICROSPORE-DERIVED EMBRYOS IN BRASSICA-NAPUS L

The segregation of isozyme genetic markers was studied on embryos arising from isolated microspore cultures in five rapeseed F1 hybrid genotypes. Out of the ten isozyme genes considered, five (Aco-1, Aco-3, Lap-1, Pgm-3, Tpi-1) did not segregate according to expected Mendelian ratios in at least two Fl crosses. F2 plants, generated from the same hybrids, included in the analysis, were free of segregation distortions. Linkage analysis between each segregating enzyme locus in each progeny revealed independence between these markers. In this paper, the results of the linkage analysis as well as the origins of the distortions are discussed. The existence of androgenic embryogenesis genes may be responsible for the abnormal segregations of the five isozyme genes.