大豆疫霉对甲霜灵敏感性的遗传与变异

Inheritance and Variation of Sensitivity to Metalaxyl in Phytophthora Sojae

通过平板法,在含甲霜灵1.0μg·mL-1的CAM平板上测定了分离于不同地区的5个大豆疫霉菌和以Ps411-4为亲本的无性后代、有性后代对甲霜灵敏感性的遗传。结果表明:分离自不同地域的菌株对甲霜灵的敏感性存在差异,供试菌株对甲霜灵的敏感性在无性单孢后代无显著变异,而在50个自交有性后代中,上述浓度对其菌丝生长的抑制率分布范围为70.2%～96.8%,与亲本有极显著差异,其中5株高于亲本,4株低于亲本,41株与亲本相似。表明大豆疫霉对甲霜灵的敏感性同样在无性后代稳定遗传而在有性后代发生变异。结果提示,供试大豆疫霉菌株中上述性状可能由细胞核杂合基因控制。

This paper was to investigate the inheritance and variation of sensitivity to metalaxyl in Phytophthora sojae; Five Phytophthora sojae strains of Ps411 , Ps126, Ps223, Hs6, PsSD isolated from different regions and asexual and sexual progenies of Ps411-4 were used and their sensitivity to metalaxyl was evaluated by the ratio of the growth rates on carrot agar medium amended with 1.0 μg · mL^-1 metalaxyl to the growth rates on the same medium without metalaxyl. The sensitivity of P. sojae to metalaxyl varied with their origins. The sensitivity of P. sojae to metalaxyl also steadily inherited in three successive zoospore progenies but showed obvious variation in first generation. In 50 single-oospore descendants,the restraint rate of metalaxyl to hypha ranged 70.2% -96.8%, with 5 higher,4 lower, and 41 similar to parent. Results indicate the sensitivity of P. sojae to metalaxyl inherited steadily in zoospor progenies while varied obviously in single- oospore generation, and the character of P. sojae could be controlled by nuclear heterozygous genes.