甘蔗梢腐病原菌的鉴定及其室内毒力测定

Identification and Toxicity Indoor of the Pathogens Causing Pokkah Boeng Disease of Sugarcane

由镰刀菌引起的甘蔗梢腐病,是甘蔗生产过程中一种常见病害。更为重要的是,甘蔗梢腐病株中常含有串珠镰刀菌类水溶性毒素,对人畜禽均有毒害作用,严重威胁食品安全及人类和动物的健康。本文针对从海南岛不同甘蔗种植区采集甘蔗梢腐病的典型病斑,对其分离和单孢纯化及鉴定。继而从中挑选了分别来自不同蔗区的4个有效单孢菌株,进而选择了6种常用杀菌剂,于室内对它们分别进行了毒力测定。进一步分别求得不同杀菌剂对相应菌株的剂量反应回归方程,各药剂对相应菌株的抑制中浓度EC50、EC75及相关系数r值等。试验结果表明:多菌灵、灭病威、正品甲津托3种药剂对甘蔗梢腐病菌毒力较强,尤以多菌灵为最佳,其EC50为1.77～2.51μg/mL。菌核净的次之。比较而言,百菌清和代森锰锌2种药剂效果均不如前者的,特别是代森锰锌,其EC50为62.5～227.63μg/mL。

Pokkah boeng is caused by the fungus Fusarium moniliforme and/or Fusarium moniliforme var. subglutinans. The disease is present in most, and it may cause serious yield losses in commercial plantings. Additionally, some strains produce significant quantities of secondary metabolites, for mycotoxins such as moniliformin. In this study, isolates collected from Hainan provinces were identified based on the morphological characteristics, and 4 single spore isolates were tested toxicity by the 6 fungicides indoor. The result showed： used Carbendazim, carbendazim sulphur, and Meroif^TM their effects were the better to the others, especially Carbendazim, their ECs0 were 1.77-2.51 μg/mL o The effects of dimethachlon were better, too. But the rest of chlorothalonil, mancozeb showed badly, especially mancozeb, their EC50 were 62.5 -227.63 μg/mL .