苦瓜枯萎病生防细菌ZB36的分离鉴定及其定殖特性研究OA北大核心CSTPCD

[Objective]This study aimed to screen and identify an antagonistic strain with biocontrol and plant growth-promoting effects against bitter gourd Fusarium wilt,and analyze its colonization character-istics in bitter gourd tissues.[Method]The antagonistic strain ZB36 with stable antimicrobial activity against Fusarium oxysporum f.sp.momordicae was isolated and purified from the cultivated land in Zi-bo,Shandong Province,by gradient dilution coating flat plate method.Based on its morphological char-acteristics,physiological and biochemical properties,and 16S rRNA and gyrA conserved gene sequence analysis,the strain ZB36R was identified.Meanwhile,the antibiotic-marked strain ZB36R with stable ge-netic characteristics and antagonistic activity was obtained by using rifampicin induction method,and its colonization characteristic in bitter gourd tissues was analyzed.[Result]Strain identification demonstrated that the antagonistic strain ZB36 was identified as Bacillus velezensis.The results of pot experiments showed that the strain not only had a significant control on bitter gourd Fusarium wilt,with a control effi-cacy of 74.76％,but also had a plant growth promotion effect.After inoculation with ZB36,the fresh weight and plant height of the aerial parts of bitter gourd increased by 28.65％and 22.48％,respective-ly.The colonization experiment results showed that ZB36 could colonize the roots,stems and leaves of bitter gourd,and could still be stably colonized in these tissues of 28 days post inoculation.[Conclusion]Bacillus velezensis ZB36 not only has a significant control and plant growth-promoting effects on bitter gourd Fusarium wilt,but also has a higher colonization capacity.In summary,the strain ZB36 is an ex-cellent resource with biocontrol potential to Fusarium wilt of bitter gourd.