苏云金芽胞杆菌JQ23的表型鉴定及对韭菜迟眼蕈蚊的防治效果

The Phenotype Determination of Bacillus thuringiensis JQ23 and Its Control Efficiency against Bradysia odoriphaga

韭菜迟眼蕈蚊是韭菜生产上的重要害虫,实验室从河南省采集的土样中分离获得1株对韭菜迟眼蕈蚊幼虫高毒力的Bt新菌株JQ23。经Biolog GENⅢ细菌鉴定系统分析菌株JQ23为苏云金芽胞杆菌,相似率为0.596;通过室内生物活性测定,明确菌株JQ23对韭菜迟眼蕈蚊2龄幼虫72 h的LC50值为8.38×10^6芽胞/mL;经室内盆栽防治试验结果表明,菌株JQ23在1×10^7芽胞/mL浓度下,采用滴灌法连续用药3次,间隔7 d,对韭菜迟眼蕈蚊的防治效果达到86.28%;经春季田间小区试验,再次验证菌株JQ23在1×10^8芽胞/m L浓度下,采用滴灌法连续用药3次,间隔7～10 d,对韭菜迟眼蕈蚊的防治效果达到66.75%。由此可见,菌株JQ23能够有效地控制韭菜迟眼蕈蚊的虫口数量,减少作物的受害率,达到较好的防治效果。

Bradysia odoriphaga is an important pest of Chinese chive production. A new Bacillus thuringiensis strain JQ23 was isolated from the soil collected from Henan province by antibiotic method. GEN Ⅲ Biolog bacterial identification system showed that JQ23 strain can use 13 kinds of carbon sources, and is sensitive to 9 chemical substances, Bioassay showed that JQ23 strain was of high insecticidal activity against B. odoriphaga, with 72 h LCs0 of 8.3804×106 spore/mL against 2nd instars of B. odoriphaga. The pot tests showed that, continuous dripping application of JQ23 at 1× 107 spore / mL for three times at intervals of 7 d, the final control reached 86.28%. In field plot experiment in spring, continuous dripping application of JQ23 at 1 ×108 spore/mL for three times at intervals of 7--10 d, the final control was 66.75%. These results show that the JQ23 strain can achieve an effective control orB. odoriphaga.