高产多糖和麦角甾醇姬松茸菌株的诱变选育

^(60)Co-γMutation Breeding and SCoT Analysis of Agaricus blazei Strains with High Polysaccharide and Ergosterol Yield

为获得可用于发酵高产活性物质的优良姬松茸菌株,利用150~601 Gy的^(60)Co-γ射线对姬松茸(Agaricus blazei)原生质体进行辐照诱变,以菌丝生长速度、菌丝体生物量、多糖以及麦角甾醇产量为指标筛选优良再生菌株,并基于SCoT多态性分子标记对再生菌株进行遗传多样性分析。结果表明:经过筛选获得生长速度优于出发菌株的再生菌株9个;对液体发酵菌丝体中多糖和麦角甾醇含量测定,确定其中最优的诱变菌株为150-2,其多糖和麦角甾醇产量分别是出发菌株的1.96和2.97倍;基于SCoT分子标记分析表明9个菌株的DNA均有所改变,同一剂量下诱变菌株的基因突变呈现出不定向性,但多糖和麦角甾醇产量提高幅度大的正向突变株显示出较高的遗传相似性,在聚类树中属于同一分支。本研究结果为利用辐照诱变技术提高姬松茸活性物质含量奠定了基础。

In order to obtain superior Agaricus blazei Murrill strains to be used in fermentation of active substances,^(60)Co-γray at 150-601 Gy was used to irradiate protoplasts of A.blazei.The resultant mutant strains were screened in terms of mycelial growth rate,mycelium biomass,intracellular polysaccharide(IPS)yield and ergosterol yield.In addition,the genetic diversity of the mutant strains was analyzed by start codon targeted(SCoT)polymorphism DNA markers.The results showed that nine mutant strains had a greater mycelial growth rate than the control.Among them,150-2 had the highest IPS and ergosterol yields in liquid fermentation,and its IPS and ergosterol yields were 1.96 and 2.97 times of that of JSR3,respectively.The SCoT molecular marker analysis of the nine selected mutants showed that mutagenesis at the same^(60)Co-γdose resulted in undirected DNA mutations,and the mutants with significantly increased IPS and ergosterol yields clustered within the same clade of the dendrogram.This study provides a reference for improving active substance content in A.blazei by mutagenesis.