摘要
筛选对草地贪夜蛾高毒力Bt菌株,对于开发绿色高效防治草地贪夜蛾新产品具有重要意义。本研究从自行筛选的对夜蛾科害虫高毒力的Bt菌株资源中,选取9株菌株进行草地贪夜蛾室内毒力测定,并对高毒力菌株进行杀虫基因分析;选取室内毒力测定活性最高的3株菌株进行田间小区药效试验。结果表明,9株Bt菌株在药后7 d对草地贪夜蛾初孵幼虫均表现出显著的毒杀效果,LC50范围在0.07~3.38μg/g,其中毒力最高的3个菌株分别是KN50、KN11和KNR8,LC50分别为0.07、0.23和0.43μg/g,表现非常显著的致死效果;对KN50、KN11和KNR8等6种高毒力的Bt菌株的杀虫基因分析发现,他们都含有vip3Aa、cry2Ab、cry1Ac、cry1Ia杀虫基因。KN50、KN11和KNR8菌株的32000IU/mg制剂在田间对草地贪夜蛾表现出不同程度防效,其防效高低与室内毒力结果一致,其中KN50药后7 d防效最高,在200和400 g/667 m2下对1~3龄幼虫防效分别可达86.09%和95.22%,对不同龄期幼虫混发的防效为72.61%和86.59%。因此KN50、KN11和KNR8这3个菌株能作为备选高效菌株用于防治草地贪夜蛾新产品开发,为实现草地贪夜蛾的绿色防控、化学农药合理减替提供重要保障。
To screen Bt strains with high virulence against Spodoptera frugiperda is crucial for the development of green and efficient IPM of S.frugiperda.In this study,nine Bt strains with high toxicity to Noctuidae,isolated by our company,were tested for their virulence against S.frugiperda in laboratory,and analyzed the insecticidal genes.Three of the highest virulent strains were further tested in field trial for their control efficacies against S.frugiperda.The results indicated that nine Bt strains showed prominent insecticidal activity against neonate of S.frugiperda at 7 days post treatment.The LC50 ranged from 0.07 to 3.38μg/g.The three highest virulent strains were KN50,KN11 and KNR8,with LC50 of 0.07,0.23 and 0.43μg/g,respectively,showing very remarkable efficacy.Insecticidal gene analysis results demonstrated that six highly virulent Bt strains contained the same four insecticidal genes-vip3Aa,cry2Ab,cry1Ac and cry1Ia.Field trial results showed that the control efficacies of KN50,KN11 and KNR8 with 32000 IU/mg were significantly different,but were consistent with laboratory results.KN50 showed the highest insecticidal efficacy at 7 days post treatment,which was 86.09%and 95.22%for 200 g/667 m2 and 400 g/667 m2,respectively,against the first to third instar larvae,and 72.61%and 86.59%against larval populations of mixed instars.Therefore,the KN50,KN11 and KNR8 strains represent candidates for new product development to replace chemical pesticides and achieve green control S.frugiperdar.
作者
刘华梅
胡虓
王应龙
杨普云
束长龙
朱晓明
张杰
孙刚忠
张晓明
李青
LIU Huamei;HU Xiao;WANG Yinglong;YANG Puyun;SHU Changlong;ZHU Xiaoming;ZHANG Jie;SUN Gangzhong;ZHANG Xiaoming;LI Qing(Wuhan Kernel Bio-tech Co.,Ltd,Wuhan 430074,China;State Key Laboratory for Biology of Plant Diseases and Insect Pests/Institute of Plant Protection,Chinese Academy of Agricultural Sciences,Beijing 100193,China;National Agro-Tech Extension and Service Center,Beijing 100125,China)
出处
《中国生物防治学报》
CSCD
北大核心
2019年第5期721-728,共8页
Chinese Journal of Biological Control
基金
国家重点研发计划(2017YFD0201204)
关键词
草地贪夜蛾
苏云金杆菌
毒力测定
杀虫基因
田间防效
Spodoptera frugiperda
Bacillus thuringiensis
bioassay
insecticidal gene analysis
field control efficacy
