玉米链格孢病菌生物学特性及防治药剂离体活性筛选

Biological Characteristics and Screening of Fungicides of Maize Alternaria tenuis Nees

为了满足生产中对玉米链格孢叶斑病进行防治以及抗病育种的需要,采用菌丝生长速率法对玉米链格孢叶枯病病原菌的生物学特性和室内药剂筛选进行研究,结果表明:不同的营养、温度、p H值等条件对菌丝生长和产孢量有显著影响。病菌生长最适碳、氮源分别为乳糖和蛋白胨,30℃、p H值为6的条件下生长最好;最适产孢碳源为麦芽糖,最适氮源为蛋白胨,最适产孢温度和p H值与最适生长条件基本一致。光照对菌丝生长没有明显影响,但连续光照却明显有利于产孢过程。病菌菌丝的致死温度为60℃,10min;孢子致死温度52℃,10min。药剂室内毒力试验结果表明:异菌脲对病菌的毒力作用最强,EC50值仅为0.365 mg·L-1;霜·锰锌、咪鲜胺锰盐等药剂对玉米链格孢病菌也具有较好的抑制效果。

In order to meet the needs of preventing the disease of maize alternaria leaf spot and breeding, In this paper, the mycelial growth rate method was used to study the biological characteristics of maize leaf blight pathogen Alternaria and fungicide screening. The results showed that nutrition, temperature and pH had significant effects on mycelia growth and sporulation of the pathogen. The suitable carbon and nitrogen sources for mycelia growth were lactose and peptone, respectively. The proper temperature was 30℃and the optimal pH was 6.0. The optimal carbon source of sporulation was maltose, nitrogen source was peptone, respectively. The optimal spore production temperature and pH were indentical with the optimal growth conditions. Light had no significant effect on mycelial growth, but continuous illumination was obviously beneficial to spore production. The lethal temperature of hypha and spore production was 60 ℃, 10 min and 52℃, 10 min, respectively. The virulence results showed that iprodione was the most virulence, EC50 value of 0.365 mg·L^-1. In addition, sadofan, prochloraz-manganese and several fungicides had inhibitory action for the mycelia growth.