辽宁省辣椒疫霉菌生理小种的生物学特性及生物制剂对辣椒疫病的防效
Biological characteristics of physiological race in soilborne plant pathogen Phytophthora capsici and biological agents control on pepper blight in Liaoning Province

为了明确辽宁省辣椒疫霉菌Phytophthora capsici优势小种的生物学特性及生物制剂对辣椒疫病的影响，于2013-2014年在辽宁省辣椒种植区采集样品，采用组织分离法获得33个分离物，对分离物进行单孢子囊纯化鉴定，采用单基因鉴别寄主技术鉴定生理小种，研究了不同培养条件对优势小种生长发育的影响，并测定了生物制剂对辣椒疫病的防效。结果表明，菌株Pc-2、Pc-5和Pc-6等23株菌株为3号生理小种，占分离物总数的69.7%；菌株Pc-2在9种供试培养基上均可生长，菌丝生长最适培养基为燕麦片培养基，最适pH为9，温度为28℃；番茄培养基、pH为10和光暗交替有利于其形成孢子囊；pH为7、温度为5℃以及全光照处理是游动孢子释放的最佳条件；游动孢子萌发受酸碱度和光照的影响均不明显，28℃是其萌发的最适温度；在先灌药后接种处理中肃克对辽椒12号疫病的防效为78.2%。研究表明，3号生理小种为辽宁省辣椒疫霉菌的优势小种，低温促进游动孢子的释放，肃克防效优于其它生物制剂。
In order to clarify the biological characteristics of dominant race of soilborne plant pathogen Phytophthora capsici and effects of biological agents on pepper Phytophthora blight, samples were collected from pepper plant regions in Liaoning Province in 2013-2014. The 33 pathogen isolates were acquired with tissue isolation method and the isolates were identified as P. capsici after being subcultured and single zoosporangium purification. Physiological races were identified by single gene differentials. The growth and development of dominant race at different conditions were studied, and control efficiency of biological agents to pepper Phytophthora blight was evaluated by plot experiment. The results showed that 23 isolates, including strains Pc-2, Pc-5 and Pc-6 were race 3, which accounted for 69.7% of the total isolates. The strain Pc-2 could grow under nine kinds of media, with the optimal condition at pH 9, 28℃ and oat meal agar. The largest sporangia formation was at pH 10, alternating light and dark, and tomato agar. The optimal zoospore release was at pH 7, 5℃ and full light. Zoospores germination of P. capsici could not be significantly influenced by light and pH, and the optimal zoospores germination was at 28℃. Control efficiency by Suke to Liaojiao 12 was 78.2% on the treatment of first bio-fungicides then inoculation in field trial. The results indicated that dominate race in Liaoning Province was race 3, and low temperature could accelerate zoospores germination. The control effect of Suke was better than that of other treatments.