甜瓜枯萎病拮抗内生细菌筛选研究

Selection of Endophytic Bacteria for Suppression of Melon Wilt Caused by Fusarium oxysporum

从长势健壮的黄瓜、南瓜和甜瓜苗的根部及茎部分离获得294株内生细菌,与枯萎尖孢镰孢菌进行对峙培养,获得具有抑菌活性细菌18株,占总菌株数的6.1%。再利用生长速率法、孢子萌发法对其进行体外生物活性检测,结果表明,H-2、H-4、H-6、N-7、T-16、T-18等6个菌株的发酵滤液对枯萎镰孢菌的拮抗作用较强,但H-1与H-4对种子萌芽有强烈的抑制作用。H-5、H-6和N8等菌株对甜瓜幼苗具有促生作用,对甜瓜枯萎病的防效分别为75.6%、60.1%和66.7%。H-5菌株对甜瓜枯萎病可能具有潜在的生防功能。

Two hundreds and nlnety-four strains of endophytic bacteria were isolated from roots and sterns of healthy cucumber, pumpkin and melon seedlings. By duel test of in vitro screening, about 6. 1% of the total strains screened, 18 antagonistic strains against Fusarium oxysporum f. sp. melonis （Leach） Syn were gotten. Among the 18 strains, 6 strains （H-2, H-4, H-6, N-7, T-16, and T-18） had been proved that their fermented solution inhibited significantly Fusarium oxysporum by using in vitro dilution plate technique test and spore germination test, 2 strains （H-1 and H-4） inhibited melon seed germination. The growth-promoting effects on melon seedling, and control effects against melon wilt of the 18 strains were studied. The results showed that control efficacies of 3 strains, H-5, H-6 and N-8, were 75. 6%, 60. 1% and 66. 7% respectively, meanwhile, their growth promoting effect were found also. H-5 was able to be a biocontrol agent to control the melon wilt Fusarium oxysporum.