链格孢菌Alternaria augustiouoidea突变菌株毒素的除草活性研究

通过对链格孢菌Alternaria augustiouoidea菌株AAEC05紫外线诱变得到的8个诱变菌株进行除草剂活性测定，筛选出的AAEC05—3、AAEC05—5、AAEC05—8和AAEC05-2等4个诱变菌株具有较强的除草剂活性，其中AAEC05—3和AAEC05—5菌株效果最好。研究表明，pH值对菌株产毒能力影响很大，以pH5．0最佳。用石油醚、三氯乙烷、乙酸乙酯萃取培养滤液制备粗毒素。生物测定结果表明，以乙酸乙酯萃取所得粗毒素对稗草种子萌发及生长抑制作用最强。

The Herbicide Activity of Mutant Isolates from Aiternaria augustiouoidea

The herbicide activity of eight mutant isolates, obtained by ultraviolet ray mutation strain Alternaria augustiouoidea AAEC05 was evaluated in the study. 4 mutant isolates, i.e. AAEC05-3, AAEC05-5, AAEC05-8 and AAEC05-2, showed stronger herbicidal activity, among them, AAEC05-3 and AAEC05-5 were the two best for inhibiting the germination and seedling growth of Echinochloa crus-galli L. The results also showed that different pH of Czapek media had significant influences on herbicidal activity and pH 5.0 was the best among the pH values tested. The crude toxin could be extracted using petroleum ether, trichloroethane and ethyl acetate, and the ethyl acetate extracts had a strongest inhibitory activity on the germination and seedling growth of Echinochloa crus-galli L.