枯草芽孢杆菌AR11菌株对南方根结线虫的生物防治

用枯草芽孢杆菌(Bacillus subtilus)AR11菌株处理南方根结线虫(Meloidogyne incognita)的二龄幼虫(J2)和卵，以评价生防菌AR11对南方根结线虫的防治效果。结果表明：在处理12、24、36和48h后，5倍稀释菌液(AR11-5)对J2的活性抑制率分别比对照(清水)高55．7％、59．5％、58．0％和47．5％；用10倍稀释菌液(AR11-10)和5倍稀释上清液(S—AR11-5)处理卵8d后，卵孵化率分别比对照高29．1％和29．7％。用不同浓度的AR11菌液进行温室盆钵实验，结果显示：8周后根系上的根结和卵块数明显减少，其中以10倍稀释菌液处理组减少最为明显，分别比对照少68．2％和75．0％；同时番茄的冠重比对照组高25．6％。上述结果表明：AR11菌株对番茄根部根结和卵块的形成有明显的抑制作用，可抑制二龄幼虫的活性，但对雌虫产卵能力没有影响；低浓度的菌悬液和上清液对卵的孵化有促进作用；此外，该菌株还对番茄的生长有促进作用。

Biocontrol evaluation of Bacillus subtilus strain AR11 against Meloidogyne incognita

Bacillus subtilus strain AR11 was evaluated for its ability to control the root-knot disease caused by Meloidogyne incognita.Bacterial suspension and the supernatant of fermentation were used for treatment of M.incognita eggs and the second stage juveniles(J2)in vitro assay.In 12,24,36,and 48 hours treatment,5 times dilution of AR11 bacterial suspension showed the inhibiting efficiencies to J2 as 55.7%,59.5%,58.0%,and 47.5% respectively.Hatching percents of eggs were 29.1% and 29.7% higher in 8 days treatment with 10 times dilution of AR11 bacterial suspension and 5 times dilution of AR11 bacterid supernatant than in the control.The greenhouse experiments showed that AR11 could not only promote the growth of tomato plant with 25.6% mass weight increase,but also suppress the formation of the galls and egg mass which were 68.2% and 75% less in the treatment of 10 times dilution of AR11 suspension than in the control group.