辣椒炭疽病拮抗内生菌的分离鉴定及防效试验

Isolationandidentificationof antagonistic endophytic bacteria incapsicumand the control efficiency oncapsicum anthracnose

采用组织分离法,从湖南衡阳地区辣椒炭疽病频发田块的健康果实中筛选具有抗炭疽病活性的内生细菌,从100株内生菌中筛选获得1株对辣椒炭疽病菌具有较强拮抗效果的菌株C3,该菌株在平板对峙试验中的抑菌带宽为16.5 mm,抑菌率达到80.26%;结合生理生化特性测定和分子鉴定结果,确定其为贝莱斯芽孢杆菌(Bacillus velezensis)。在果实针刺试验中,菌液浓度为10^(7)cfu/mL时病斑最小;菌液浓度为10^(7)cfu/mL、每株喷施50 mL的盆栽防效达到90.67%;将菌液浓度降至10^(6)cfu/mL时盆栽防效仍有68.64%;菌液浓度为10^(7)cfu/mL时田间防效达到48.71%,与400 mg/L吡唑醚菌酯对照组的防效(54.18%)接近。

By tissue separation,endophytic bacteria with anti-anthrax activity were screened from healthy capsicum fruits in Hengyang area of Hunan Province,and one strain named C3 with strong antagonistic effect against anthrax in capsicum was selected from 100 endophytic strains.The inhibition bandwidth of strain C3aganist the pathogen of capsicum anthracnose in theconfrontation test on a plate was 16.5 mm,and the inhibition rate reached 80.26%.Based on physiological-biochemical and molecular identification,strain C3 was identified as Bacillus velezensis.The lesion was the smallestwhen strain C3 was applied atbacterial concentration of 1.0×10^(7)cfu/mL in fruitinfection test.In the indoor pot experiment,the control effectagainst anthracnose reached 90.67%whenspraying 50 mL/per plant with strain C3 bacterial solutionat a concentration of1.0×10^(7)cfu/mL,andthe control effect was still 68.64%withbacterial solution at a concentration of 1.0×10^(6)cfu/mL.Field plot experiments showed that the control effectreached 48.71%when spraying 2 L in each plotwith strain C3 bacterial solution at a concentration of 1.0×10^(7)cfu/mL,which was close to that(54.18%)of chemical control with 400 mg/L pyraclostrobin.