与油菜菌核病菌在土壤中存活有关的木霉及其生物防治潜在能力(英文)

将油菜菌核病菌 (S .sclerotiorum)之菌核作为诱饵埋入油菜土壤中 ,二个月后从菌核表面和内部分离到 5 2株木霉 ,其中黄绿木霉 (T .aureoviride) 2 5株 ,占总数 48 1% ;钩状木霉 (T .hamatum) 17株 ,32 7% ;哈茨木霉 (T .harzianum ) 7株 ,13 3% ;康氏木霉 (T .koningii) 2株 ,4 0 % ,以及拟康氏木霉 (T .pseudokoningii) 1株 ,2 %。将木霉菌株与核盘菌在PDA平板上的玻璃纸条上对峙培养 ,发现木霉菌丝平行于核盘菌菌丝生长 ,并伸出短枝样菌丝或勾状菌丝紧紧附着在核盘菌丝上 ,最终导致核盘菌菌丝断裂和消解。如果两菌直接在PDA平板上双相生长 ,2 4h后两菌落接触 ,在多数情形下 ,在核盘菌一侧会产生褐色、黄褐色宽窄不等的拮抗带 ,拮抗带中的核盘菌菌丝肿胀、断裂和原生质解体。 2周后有 42个木霉菌落覆盖过核盘菌菌落 ,占供试木霉菌株的 84%。而且核盘菌菌落中形成的菌核数量比对照明显减少 ,有些木霉菌株能完全抑制菌核产生。木霉的非挥发性代谢产物对核盘菌菌丝的生长、菌核的数量和大小有明显影响。而挥发性代谢产物仅仅对菌核大小有一定抑制作用。将拮抗作用强的木霉菌株培养物导入土壤后 ,埋入土壤中的菌核多数将发生腐烂 ,即使未腐烂的菌核其产子囊盘萌发能力也大大降低

Trichoderma Species Associated with Survival of Sclerotia of Sclerotinia Sclerotiorum of Rape in Soil and Their Potential in Biocontrol

Fifty two Trichoderma isolates, which are associated with survival of sclerotia of Sclerotinia sclerotiorum, are obtained from the different areas of province Sichuan. They are 25 T.aureoviride (48 1% of the total), 17 T.hamatum (32 7%), 7 T.harzianum (13 3%), 2 T.koningii (4 0%) and 1 T.pseudokoningii (2 0%). The dual culture of Trichoderma spp. and S.sclerotiorum on a cellophane strip indicate that Trichoderma hypha parallel and touch to those of S.sclerotiorum, sometimes coiling around the later, two days after the dual culture is made. The hypha adjacent to Trichoderma is to be broken and their cytoplasms are collapsed. The results of dual culture made directly on PDA plates, however, indicate when the colonies contact each other, those of S.sclerotiorum stop extending. In most cases, an yellowish brown antagonistic zone is produced in the side of colony of S.sclerotiorum. In this zone, sclerotinia hypha becomes brown, swollen and broken. Furthermore, 84% of Trichoderma isolates can overran the colonies of S.sclerotiorum and make sclerotia formed by S.sclerotiorum decrease. 5 tested isolates of Trichoderma spp. can suppress the production of sclerotia completely. The non volatile substances of Trichoderma have the obvious inhibitions to the hyphal growth, number and size of sclerotia of S.sclerotiorum. But the volatiles have only an inhibition to the size of sclerotia. When the cultures of Trichoderma isolates which possess the stronger antagonistic ability to S.sclerotiorum are introduced into the soil, the sclerotia burried in this soil is to decay six months later, the carpogenic germination of sclerotia that has not decayed reduces sharply.