中文摘要：

利用平板分离法从多种昆虫肠道中分离出14株昆虫肠道菌，活性筛选表明从大黑金龟子肠道分离出的JC-03菌株粗提物对反枝苋具有较好的除草活性，进一步研究表明其活性物质主要集中在中等极性的乙酸乙酯提取物中。安全性实验表明JC-03菌株粗提物对常见作物（油菜、大豆、西红柿、辣椒）的安全性较高。通过形态学特征观察和5.8S rDNA测序分析，初步确定该菌株为赤霉菌（Gibberella intermedia）。JC-03菌株作为微生物源除草剂值得进一步研究。

英文摘要：

14 strains were isolated from intestines of many kinds of insects by means of flat plate isolation method. Among them the crude extract of strain JC-03 isolated from intestine of big black scarab （Holotrichia diomphalia Bates） showed potent herbicidal activity against redroot （Amaranthus retroflexus）. Further research showed that its main active substances were concentrated in moderate polar part of the ethyl acetate extract. Safety experiments indicated that the crude extract of JC-03 was highly secure to the common crops （rape, soybean, tomato and pepper）. JC-03 was initially identified as Gibberella intermedia by the morphological features and 5.8S rDNA sequence analyses. The strain JC-03 was worth further study as a kind herbicide of microbial sources.