[Genetic analysis of isozyme loci of intraspecific hybrid in Auricularia auricula].
摘要
Monokaryon strains H2 and J3 were respectively developed from the cultivated strains He-1 and Ju-1 of Auricularia auricula through protoplasted monokaryon technique. Dicaryon strain H2J3 was bred through crossbreeding of H2 and J3 as parents. Fifty-two F1 monokaryon strains were obtained from the fruitbodies of dicaryon H2J3 of A. auricula by the single-spore isolation and culture. All the tested strains, parent monokaryon strains (H2,J3) and fifty-two F1 monokaryon strains, were cultured in liquid Complete Yeast Medium(CYM) for twenty days, and the mycelia of tested strains were respectively analysed by polyacrylamide gel electrophoresis. Bian Y B et al. have reported the results of isozyme zymogram polymorphisms of cultured strains including He-1 and Ju-1, and the specific expression of esterase genes on the different stages of mycelial development in A. auricula. The same named methods of isozyme loci and alleles suggested by Gottlieb (1973) were used in this study. The relative fitness of allele segregation and theoretical expected ratio was examined by the contingency chi 2 test. The linkage relationship was assessed according to the method suggested by Rudin and Ekberg (1978). The isozyme analysis of tested strains showed that the isozymes of esterase (EST), malate dehydrogenase(MDH) and formate dehydrogenase(FDH) of A. auricula were respectively controlled by 7, 5 and 4 polymorphic loci. The isozyme bands which were controlled by EST-3, EST-4, MDH-3 and MDH-4 loci were stably expressed in the parental strains and most tested F1 monokaryon strains. Genetic analysis was impossible for these four loci. The relative fitness between allele observed value and theoretical expected value was further examined by means of contingency chi 2 at 1% level, the result indicated that significant difference existed from the chi 2 value of MDH-5 and FDH-1 in 7 polymorphic loci of EST, MDH and FDH, and denied the hypothesis in which the isozyme bands controlled by MDH-5 and FDH