瓜果腐霉菌丝中除草活性物质的初步研究

Primary study of herbicidal substance in mycelia of Pythium aphanidermatum

将瓜果腐霉进行液体发酵,其菌丝用等体积乙酸乙酯和甲醇进行依次萃取,甲醇萃取液旋转蒸发去溶剂后进行硅胶柱层析,以乙酸乙酯和石油醚(V/V=3:1和V/V=2:1)的混合液进行梯度洗脱,每50 mL收集为一个馏分,共收集到40个馏分。生物测定结果表明,以乙酸乙酯和石油醚(V/V=2:1)洗脱得到的馏分21 24对供试杂草马唐表现出了较强的活性,其对马唐的生长抑制作用均为4级。合并馏分21 24,以乙酸乙酯和石油醚(V/V=2:1)的混合液为展开剂进行等度洗脱,每50 mL收集为一个馏分,共收集到20个馏分。生物测定结果表明,馏分3对马唐有较强的抑制活性。HPLC分析发现,该馏分主要含有3个组分,其保留时间分别为12.7、14.0和30.5 min。

Pythium aphanidermatum was cultured in PD medium and the mycelia were extracted with ethyl acetate and methanol,and the methanol extracts were separated gradually by silica gel column using ethyl acetate mixture and petroleum ether（V/V=3：1 and V/V=2：1） as the developers.Eluents were collected and each 50 mL were considered as a fraction and bioassayed.The results revealed that fraction 21-24 showed strong activity against Digtaria sanguinealis with the inhibition level of 4.The combined fractions of 21-24 were eluted with the mixture of ethyl acetate and petroleum ether（V/V=2：1） as the developer and 20 fractions were collected.Bioassay results showed that fraction 3 had the stronger inhibitory activity against Digtaria sanguinealis.HPLC analysis suggested that this fraction mainly contained 3 components,the retention time of which was 12.7,14.0 and 30.5 min respectively.