ISSR标记在黑木耳单核体遗传分析中的应用

采用原生质体单核化和单孢分离法分别获得黑木耳Auricularia auricula栽培菌株新科5号两个亲本单核体(T1、T2)和33个F1代孢子单核体。从73条ISSR引物中筛选出13条可区分两个亲本单核体(T1、T2)的引物,对新科5号及F1代孢子单核体进行扩增,共扩增出70条带,其中63条在供试菌株间表现出多态性,多态位点百分率为90.0%。根据扩增结果采用软件NTsys2.10e计算菌株间的遗传相似系数并进行聚类分析,36个菌株间的遗传相似系数(GS值)的变化范围为0.2500～0.8382,其中T1和T2之间的GS值最小,遗传相似程度最低;F1代33个孢子单核体中24个与T1聚为一类,其余9个与T2聚为另一类,但并非严格按照交配型进行归类。试验表明黑木耳子实体上各个担子在减数分裂中染色体交换极具多样性,F1代孢子单核体表现出偏向其中一个亲本的现象,ISSR标记在黑木耳杂交育种中具有潜在的应用价值。

Application of ISSR marker in the genetics analysis of monokaryons from Auricularia auricula

Two parent monokaryons (T1, T2) and thirty-three of F1 sporulated monokaryons have been developed from cultivated strain XinKe 5 of Auricularia auricula by protoplast monokaryonization and single-spore isolation technique. Seventy-three ISSR primers were screened and thirteen which could differentiate T1 and T2 effectively were selected to amplify strain XinKe 5 and F1 sporulated monokaryons. A total of seventy fragments were amplified, among them sixty-three (accounting for 90.0% of the total) were polymorphic. Genetic similarity coefficient matrix (GS) among thirty-six strains ranged from 0.2500 for the lowest similarity coefficient between parent monokaryotic strains T1 and T2 to 0.8382 for the greatest extent of similarity. The ISSR dendrogram based on the similarity coefficient matrix was constructed by using NTsys 2.10e software. Tested strains could be classified into 2 major groups: T1 and twenty-four of F1 sporulated monokaryons fell into same group, while T2 and the rest of F1 sporulated monokaryons fell into the other group. Monokaryons were notclassified strictly based on mating types. The results showed that chromosome crossing-over in each basidia of fruitbody was complex and polymorphic during meiosis, and the most of F1 sporulated monokaryons resembled parental monokaryon T1. The potential applications of ISSR marker were discussed in cross breeding of Auricularia auricula.