ABSTRACT

Multiple alleles were constantly detected in Alternaria solani isolates by simple sequence repeat (SSR) analysis, and sectors were also observed in their subcultures. These preliminary results and observations point to a possible parasexual cycle in A. solani. In this study, codominant SSR markers were used as molecular markers on the chromosomes of A. solani and single-conidium subculture was used to simulate the mitosis process of A. solani in nature. The number of alleles at locus As-95236 changed from 2 to 1 as a molecular marker for haploidy of parasexuality of A. solani. Fifty monosporic F1 strains were tested. The results showed that two parent strains lost allele with a haploid probability of 38%. For F2 strains, the results showed that all four F1 strains lost allele with a haploid probability of 75%. Since sexual recombination of A. solani has not been found so far, the allele lost in the subcultures of A. solani isolates provides molecular evidence for the existence of parasexual reproduction in A. solani.

摘要

通过简单序列重复 (SSR) 分析，在黑链格孢菌分离株中不断检测到多个等位基因，并且在其亚培养物中也观察到了扇区。这些初步结果和观察表明，A. solani可能存在准性循环。本研究采用共显性SSR标记作为A. solani染色体上的分子标记，并采用单分生孢子传代模拟A. solani在自然界中的有丝分裂过程。位点 As-95236 等位基因的数量从 2 变为 1，作为A. solani副性交单倍体的分子标记. 测试了五十个单孢子 F1 菌株。结果表明，两个亲本菌株以38%的单倍体概率丢失了等位基因。对于 F2 菌株，结果显示所有 4 个 F1 菌株均以 75% 的单倍体概率丢失等位基因。由于性别重组A.菌尚未发现迄今，在亚文化失去了等位基因A.菌菌株提供parasexual再现中存在的分子证据A.菌。