Selection of antagonistic strains against the rice sheath blight and adapted to rice straw retention | 适应水稻秸秆还田的抗稻纹枯病拮抗菌株的筛选

Chinese. [目的] 筛选适应水稻秸秆还田的抗水稻纹枯病的拮抗菌株。[方法]从土壤中分离出4株芽胞杆菌和9株木霉, 测定其对水稻秸秆的降解能力, 对具有较好降解能力的菌株测定其对水稻纹枯病菌的抑制效果和对水稻秸秆的适应性。[结果] 芽胞杆菌B4菌株和木霉T3、T5、T6和T9菌株对水稻秸秆有较好的降解效果, 其中木霉T5和T9的降解效果最好; 芽胞杆菌B4菌株对水稻纹枯病菌的抑制率达40.48%, 而且抑菌带能持久地保持, 木霉T3、T5、T6和T9菌株对水稻纹枯病菌的抑制率较高, 抑制率分别为46.48%、45.63%、50.99%和53.38%, 这5种拮抗菌的代谢物都能抑制菌丝的生长和完全阻止菌核的形成, 而且这5株菌株对水稻秸秆都有一定的适应能力。[结论] 木霉T5和T9具有较好的秸秆降解和抑制稻纹枯病菌的双重效果。

English. [Objective] To select antagonistic strains against rice sheath blight and adapted to rice straw retention.[Method] Straw degradability of 4 bacterial strains of Bacillus and 9 Trichoderma strains isolated from soils were studied. Antagonistic ability of Bacillus B4 and Trichoderma T3,T5,T6 and T9,which showed better straw degradability, against rice sheath blight and adaptability to rice straws were tested.[Result]Bacillus B4 and Trichoderma T3,T5,T6 and T9 had much better degradative efficacy than other strains, of which Trichoderma T5 and T9 showed the best degradability. The results showed that the inhibition rate of Bacillus B4 was 40.48% against rice sheath blight on dual culture, and inhibition zones could maintain stable. Trichoderma T3, T5, T6 and T9 had higher inhibition rates, which were 46.48%,45.63%,50.99% and 53.38%,respectively.The metabolites from the 5 strains could inhibit the growth of rice sheath blight and completely prevent the formation of sclerotium, and the 5 strains had stronger adaptability to rice straws.[Conclusion] Trichoderma T5 and T9 had not only better straw degradability, but also stronger inhibition to rice sheath blight.