Enzymatic comparison and mortality of Beauveria bassiana against cabbage caterpillar Pieris brassicae LINN.
Enzymatic comparison and mortality of Beauveria bassiana against cabbage caterpillar Pieris brassicae LINN.
复制标题
DOI：
10.1016/j.bjm.2016.08.004
复制
发表时间：
2017-07
期刊：
影响因子：
--
通讯作者：
Joshi N
中科院分区：
文献类型：
--
作者：
Dhawan M;Joshi N
球孢白僵菌(Beauveria Bassiana)是一种昆虫病原真菌，是防治主要经济作物害虫的替代生防剂。菜青虫是十字花科一种新出现的害虫。因此，在本研究中，球孢白僵菌的真菌分离物，即球孢白僵菌。测定了MTCC 2028、MTCC 4495、MTCC 6291和NBAII-11对菜青虫3龄幼虫的毒力。其中，球孢杆菌MTCC 4495菌株在较高孢子浓度(109孢子/ml)下的死亡率最高(86.66%)，较低浓度(107孢子/ml)的球孢杆菌MTCC 6291菌株的最低死亡率(30.00%)。对分离菌株的胞外角质层降解酶活性进行了测定。不同真菌菌株之间的酶分泌模式和酶活性水平均存在差异。球孢杆菌MTCC 4495的平均几丁质酶活性最高，为0.51U/ml，最高酶活为1.12U/ml，最高酶活为1.36U/ml。球孢杆菌MTCC 6291的几丁质酶和蛋白酶活性最低，分别为0.37和0.91U/ml。球孢杆菌NBAII-11的平均脂肪酶活性最低(1.04U/ml)。我们的研究表明，球孢杆菌MTCC 4495是对白菜疫霉菌致病作用最强的菌株，也记录了最大的胞外酶活性，这表明胞外酶可能在球孢杆菌对白菜疫霉菌的致病中起作用。
Beauveria bassiana, an entomopathogenic fungus, is the alternative biocontrol agent exploited against major economic crop pests. Pieris brassicae L. is an emerging pest of the Brassicaceae family. Therefore, in the present study, fungal isolates of Beauveria bassiana, viz. MTCC 2028, MTCC 4495, MTCC 6291, and NBAII-11, were evaluated for their virulence against third instar larvae of P. brassicae. Among all these fungal isolates, maximum mortality (86.66%) was recorded in B. bassiana MTCC 4495 at higher concentration of spores (109 conidia/ml), and the minimum mortality (30.00%) was recorded in B. bassiana MTCC 6291 at a lower concentration (107 conidia/ml) after ten days of treatment. The extracellular cuticle-degrading enzyme activities of fungal isolates were measured. Variability was observed both in the pattern of enzyme secretion and the level of enzyme activities among various fungal isolates. B. bassiana MTCC 4495 recorded the maximum mean chitinase (0.51 U/ml), protease (1.12 U/ml), and lipase activities (1.36 U/ml). The minimum mean chitinase and protease activities (0.37 and 0.91 U/ml, respectively) were recorded in B. bassiana MTCC 6291. The minimum mean lipase activity (1.04 U/ml) was recorded in B. bassiana NBAII-11. Our studies revealed B. bassiana MTCC 4495 as the most pathogenic isolate against P. brassicae, which also recorded maximum extracellular enzyme activities, suggesting the possible roles of extracellular enzymes in the pathogenicity of B. bassiana against P. brassicae.