几种不同来源的苎麻疫霉菌在棉花上的致病力测定

用菌丝块创伤接种测定分离自棉苗、棉铃、苎麻和构树上的苎麻疫霉菌对棉花致病力，结果表明来源于不同寄主的苎麻疫霉菌对棉苗和棉铃的致病力存在明显的分化。来自棉花（棉苗和棉铃）的菌株致病力较强，来自苎麻和构树的菌株对棉苗和棉铃的致病力较弱。来自棉花上的不同苎麻疫霉菌株对棉苗的致病力存在一定的差异，但对棉铃的致病力差异不明显。

Pathogenicity Test of Phytophthora boehmeriae Sawada from Different Hosts on Cotton

The pathogenicity of Phytophthora boehmeriae Sawada obtained from cotton seedling, cotton boll, ramie (Boehmeria nivea) and common papermulberry (Broussonetia papyrifera) was tested by wound inoculation with culture disc on cotton. The significant difference of pathogenesis was observed in the isolates from the host plants showing above. The pathogenicity of the isolates from cotton was stronger than those from ramie and common papermulberry. Some differences of pathogenicity of different cotton isolotes were observed on cotton seedlings, but not on cotton bolls.