咖啡炭疽病菌致病性测定及其拮抗菌筛选

Pathogenicity and Screening of Antagonistic Bacteria of Coffee An-thrax

炭疽病是咖啡的一种常见病害,对咖啡果实的产量和质量造成严重损失,开展引起咖啡炭疽病的病原菌致病性及其生物学特性研究,并筛选有效的拮抗菌,将为咖啡炭疽病的生物防治提供参考依据。对实验室分离并保存的4株咖啡炭疽病病原Wyq1(Colletotrichum siamense)、Yyq1(C. fructicola)、Xbd1(C. gloeosporioides)、Hb1(C.theobromicola)孢子悬浮液进行致病性测定,并选择致病力最强的菌株进行后续试验;通过平板培养法测定病原菌的生物学特性,采用平板对峙法对病原菌进行拮抗菌筛选。致病性测定结果显示,4株菌株均可侵染健康咖啡叶片,且在4株病原菌中菌株Xbd1的致病力最强;对菌株Xbd1的生物学特性测定结果表明,营养生长最适培养基为马铃薯葡萄糖琼脂培养基(PDA),最适氮源为胰蛋白胨,最适碳源为葡萄糖,最适温度为28℃,最适pH为7,不同光照对其营养生长的差异不显著。室内拮抗菌筛选中有5株拮抗效果较好,分别是枯草芽孢杆菌(Bacillus subtilis)MC4-2、特基拉芽孢杆菌(B. tequilensis)D5-8、贝莱斯芽孢杆菌(B. velezensis)MC2-1、弯曲芽孢杆菌(B. flexus)ZLSY3和解淀粉芽孢杆菌(B. amyloliticus)GJ7,其中拮抗效果最好的是枯草芽孢杆菌MC4-2,抑制率达57.8%。通过咖啡炭疽病病原菌致病性测定及其拮抗菌筛选,明确了该病原菌的致病性,筛选得到的5株拮抗菌的拮抗效果均较好,为炭疽病的防治及其生防菌剂的开发奠定基础。

Anthracnose is a common disease of coffee,which causes serious loss to the yield and quality of coffee fruit.The research on pathogenicity and biological characteristics of the pathogenic bacteria causing coffee anthracnose and screening of effective antagonists would provide reference for the biological control of coffee anthracnose.Four coffee anthracnose pathogens Wyq1(Colletotrichum siamense),Yyq1(C.fructicola),Xbd1(C.gloeosporioides)and Hb1(C.theobromicola)were isolated and tested for pathogenicity by spore suspension,and the most virulent strains were se-lected for further experiments.The biological characteristics of the pathogenic bacteria were studied by the plate culture method.Screening of antagonistic bacteria was done by the plate confrontation method.Xbd1 strain could infect healthy coffee leaves,and its virulence was the strongest among the four strains.The most suitable medium for the vegetative growth was PDA.The optimal nitrogen source was tryptone.The most suitable carbon source was glucose.The opti-mum temperature was 28℃.The optimal pH was 7.The difference of vegetative growth was not significant under dif-ferent light conditions.Bacillus subtilis MC4-2,B.tequilensis D5-8,B.velezensis MC2-1 and B.flexus ZLSY3 and B.amyloliticus GJ7 showed good antagonistic effect in indoor screening.B.subtilis MC4-2 had the best antagonistic effect,with an inhibitory rate of 57.8%.The study would lay the foundation for the control of anthrax and the development of biocontrol agents.