棉花黄萎病菌低致病力突变体的表型分析及致病相关基因克隆

 本研究通过对菌核型强致病力菌株Vd080产生的800个T-DNA插入突变体进行致病力测定，筛选得到31株致病力极显著降低的突变体，并对其进行了生物学性状分析。分子验证结果表明，这些低致病力突变体均为阳性，且有25株的T-DNA为单拷贝插入。与野生型菌株Vd080相比，这25株低致病力突变体菌落形态变异丰富，除了8株与野生型菌株形态一致的菌核型突变体外，还有3株黄色菌丝型，2株白色菌丝型和12株中间型突变体。此外，多数突变体的生长速率、产孢量和粗毒素产量都发生了显著变化，且各生理指标之间并无明显相关性。借助TAIL-PCR技术和VdLs.17的基因组数据库，进一步获得了这25株单拷贝插入低致病力突变体T-DNA的侧翼序列，并从Vd080中成功克隆得到了影响黄萎病菌致病力的相关基因。

Phenotypic analysis of low virulent Verticillium dahliae mutants on cotton and cloning of pathogenicity related genes

800 T-DNA inserted mutants of high virulent Verticillium dahliae strain Vd080 producing microsclerotia were conducted pathogenicity tests. Among them, the virulence of 31 mutants exhibited significant reduction, and their biological characteristics was analyzed. The results of molecular identification showed that all the low virulent mutants were positive and 25 mutants had single T-DNA inserted. Compared with the wild type strainVd080, the mutant colonies showed diverse variation. Among them, 8 mutants were similar with wild type producing microsclerotia, there were also 3 yellow mycelia, 2 white mycelia and 12 intermediate strains. Furthermore, the growth rate, spore yield and crude toxin of most strains changed significantly, but the correlation among these physiological indicators was not significant. With the aid of TAIL-PCR technique and VdLs.17 genome database, the flanking sequences of the 25 single T-DNA inserted low virulent mutants were obtained, and the pathogenicity related genes were successfully cloned.