香菇交配型因子次级重组体的鉴定

Identification of Secondary Recombinants for Mating Type Factors in Lentinula edodes

对13个香菇菌株的担孢子后代进行了交配型分析,其中8个菌株非亲和反应与亲和反应之比与预期的3∶1的比例无显著差异。另外5个菌株非亲和反应与亲和反应之比不符合3∶1,其中4个菌株在0.05显著水平的X2值仅略高于理论值,而另一菌株HL01具有特殊的表现,其单核体132个随机配对的非亲和反应与亲和反应之比为82∶50,X2值显著偏离3∶1的临界值。用4个标准测试菌株鉴定了来自HL01同一子实体的189个孢子单核体的交配型,在189个单核体中,161个单核体归于4种正常交配型(A1B1,A2B2,A1B2,A2B1)之一。而另外28个可能源于次级重组的单核体可分成另外4个类群。通过以所有可能的组合进行配对杂交,进一步分析了28个单核体的交配型。结果表明,次级重组同时在A因子和B因子中发生,重组值分别为8.5%和11.6%。A因子至少由2个亚基组成而B因子可能由不止2个亚基组成。随后的出菇试验表明,至少含有1个重组体的所有可亲和配对均具有结实能力。

Analysis of mating type was carried out for basidispore progeny of thirteen strains of Lentimda edodes. Of 13 Strains the proportion of incompatibility to compatibility reactions for progeny from eight of the strains did not differ significantly from the expected 3 ： 1 radio. The proportions for the five others were not consistent with 3 ： 1. Among them, the actual chi-squared values of four strains were just slightly higher than the threshold chi-squared value at 5% significance, and strain HL01 was found with an exceptional phenotype. The proportion of incompatibility to compatibility of 132 random pairings of monokaryons derived from this dikaryon was 82：50. This value differs significantly （Chi-squared = 11 ） from the expected 3 ： 1 ratio. The mating types of 189 spore monokaryons derived from the same sporocarp of HL01 were identified using four standard tester strains. Of 189 monokaryons, 161 monokaryons could be classified into one of four normal mating types （A1B1, A2B2, A1B2 and A2B1）, and the other 28 monokaryons that probably arose from secondary recombination could be classified into another four groups. By crossing in all pairwise combinations, the mating type of 28 monokaryons was further analyzed. The results indicated that secondary recombination occurred in both A and B factors, at frequencies of 8.5% and 11.6%, respectively. Factor A is composed of at least two subloci while B factor may be composed of more than two subloci. The subsequent fruiting test revealed that all the compatible pairs which contained at least one of the recombinants had the ability to produce fruiting body.