防治多种链霉菌引起的马铃薯疮痂病生防芽孢杆菌的筛选

Screening of Bio-control Bacillus Against Potato Common Scab Caused by Various Streptomyces

马铃薯疮痂病(Potato common scab)是世界范围内普遍发生的土传病害,由致病链霉菌(Streptomyces spp.)引起。为筛选得到可较好抑制马铃薯疮痂病菌的芽孢杆菌(Bacillus spp.),通过室内平板抑菌试验进行抑菌活性测定,利用邻接法建立基于gyrB序列的系统发育树进行种类分子鉴定。试验检测了13株芽孢杆菌对S.scabies HP4抑制作用,5株芽孢杆菌菌株BEV2、BAM7、GF3、BPU6和BMO8对S.scabies HP4抑菌圈直径均大于9.0 mm。系统发育树鉴定BEV2和GF3为贝莱斯芽孢杆菌(Bacillus velezensis),BAM7为解淀粉芽孢杆菌(B.amyloliquefaciens),BPU6为短小芽孢杆菌(B.pumilus),BMO8为莫海威芽孢杆菌(B.mojavensis)。检测4种芽孢杆菌及其组合对3种致病链霉菌及其组合抑菌活性,其中BEV2+BAM7对致病链霉菌的抑菌圈直径至少达到(29.5±2.7)mm,当多种致病链霉菌同时出现时仍表现出较好抑菌效果,表明BEV2+BAM7对多种马铃薯疮痂病菌有稳定防治效果。该试验筛选出能拮抗不同致病链霉菌的多种芽孢杆菌,可扩大对马铃薯疮痂病菌的抑菌谱、提高病害防治效果的稳定性,为马铃薯疮痂病生物防治及生物菌剂的开发奠定基础。

Potato common scab is a common soil-borne disease worldwide,which is caused by Streptomyces spp.In order to screen Bacillus ssp.that may have a good inhibitory effect on scab pathogen,plate antibacterial tests in laboratory were conducted for determination of antibacterial activity,and the phylogenetic tree was constructed for molecular identification of Bacillus species based on gyrB sequence by neighbor joining(NJ)method.The inhibition effect of 13 strains of Bacillus on S.scabies HP4 was detected,and it was found that the inhibition zone diameter of the five strains of BEV2,BAM7,GF3,BPU6 and BMO8 on S.scabies HP4 was greater than 9.0 mm.BEV2 and GF3 were identified as B.velezensis,BAM7 as B.amyloliquefaciens,BPU6 as B.pumilus,and BMO8 as B.mojavensis based on the phylogenetic tree.The antibacterial activity of four strains of Bacillus and their combinations against three pathogenic bacteria were determined.Among them,BEV2+BAM7 had an inhibitory circle diameter of at least(29.5±2.7)mm against pathogenic Streptomyces.When multiple pathogenic Streptomyces appeared simultaneously,it still showed good inhibitory effect,indicating that BEV2+BAM7 have a stable control effect on various potato common scab pathogens.In this experiment,various strains of Bacillus that antagonize different pathogenic Streptomyces are screened,which could expand the antibacterial spectrum against potato common scab and improve the stability of disease prevention and control effects.This may lays the foundation for the biological control of potato common scab and the development of biological agents.