感染星天牛幼虫高致病力金龟子绿僵菌菌株的筛选

摘要

Colony growth rates and sporulation of 6 strains of Metarhizium anisopliae and their virulence to Anoplophora chinensis larvae were investigated in laboratory.Results showed that colony growth rates and sporulation of different strains were significantly different.Colony growth rates of the strains MaYTTR04 and MaZPTR01 were relatively higher than those of other strains,with colony diameters of 6.3 cm and 5.9 cm on PPDA plate at 15 days after inoculation,respectively.Sporulation of these two strains was 2.0×10^8 spores ·cm ^-2 and 1.1×10^8 spores· cm^- 2,significantly higher than that of other strains.Bioassay results showed that virulence of different M.anisopliae strains against to A.chinensis larvae was significantly different,with mortalities ranged from 40% to 96.7% at 20 days after inoculation.Mortalities of the larvae inoculated with MaZPTR01and MaYTTR04 were 96.7% and 93.3%,respectively,much higher than those inoculated with other strains.The cadaver rates of larvae inoculated with these two strains were 86.7% and 80%,respectively,significantly higher than those of other strains.The median lethal time（LT50） of MaZPTR01and MaYTTR04 was 5.71 d and 5.80 d,respectively.The results showed that the two M.anisopliae strains,MaZPTR01and MaYTTR04,had high virulence against to A.chinensis larvae,and also were excellent at growth performance.Therefore,these two strains can be the potential candidate in A.chinensis control.%室内测定了6株金龟子绿僵菌菌株的菌落生长速率、产孢量及其对星天牛幼虫的致病力。结果表明：不同菌株生长速率和产孢量存在显著差异,在PPDA培养基上,菌株MaYTTR04和MaZPTR01的菌落生长较快,培养15 d后,菌落直径分别为6.3 cm和5.9 cm;产孢量以菌株MaYTTR04最大,MaZPTR01其次,分别为2.0×10^8孢子·cm^-2和1.1×10^8孢子·cm^-2,显著高于其他菌株。生物测定结果表明,不同绿僵菌菌株对星天牛幼虫的致病力差异显著,接种20 d后,星天牛幼虫累积死亡率在40%～96.7%之间;菌株MaZPTR01和MaYTTR04对星天牛幼虫致死率分别达到96.7%和93.3%;僵虫率也高,分别达到86.7%和80%;致死中时（LT50）短,分别为5.71 d和5.80 d。研究结果表明,菌株MaZPTR01和MaYTTR04对星天牛幼虫致病力较强,同时具备良好的生产性能,故可作为优良菌株用于星天牛的防治。