稗草生防菌BC-1的分离及生物学特性研究

为了能够获得低毒且高效的生物除草剂,本研究以苹果园感病稗草为材料,从中分离得到菌株BC-1,形态学观察和16S rDNA序列比对分析后,确认该菌株为露湿漆斑菌(Myrothecium roridum)。菌株BC-1最适生长培养基为PDA和PSA培养基,最适生长温度为25~28 ℃。最适生长pH值为6~7;光照强度对菌丝生长有一定抑制作用;菌丝生长最佳碳源为麦芽糖,最佳氮源为硝酸铵。室内生防试验表明,该菌株分生孢子悬浮液对稗草生防效果最佳,接菌21 d后稗草发病率为100%,鲜重防效达93.7%;对马唐、狗尾草、播娘蒿和反枝苋的生防效果相对较差,鲜重抑制率仅为33.7%,28.3%,-3.2%,16.8%。作物安全性试验表明,该菌株的分生孢子液对玉米、小麦、水稻等作物安全。综上所述,菌株BC-1有开发成商品化生物除草剂的潜力。

Isolation and biological characteristics of the biological control fungi BC-1 for Echinochloa crusgalli

There has been increasing effort in the research and development of biological herbicides because of their low toxicity.Myrothecium roridum ,strain BC-1 was isolated from diseased Echinochloa crusgalli leaves in order to obtain a low toxicity and effective biological herbicide.The BC-1 strain was identified using its cul-ture characters and 16S rDNA sequence analysis.The optimal mycelium growth media were PDA and PSA me-dium.The optimal culture temperature is 25-28 ℃,and optimal initial pH of culture media was 6-7.Dark-ness was beneficial for mycelium growth.The optimal mycelium growth carbon source is maltose,and the best nitrogen source was NH4 NO3 .Additionally,biocontrol testing showed that the E .crusgalli were all infested with BC-1 21 days after innoculation,and fresh weight inhibition was 93.7%.However,the fresh weight inhi-bition effects of BC-1 on Digitaria sanguinalis ,Setaria viridis ,Descuminia sophia and Amaranthus ret-roflexus were only 33.7%,28.3%,-3.2% and 16.8% respectively.Crop safety analysis showed that the strain BC-1 was safe to Zea mays ,Triticum aestivum and Oryza sativa .This study suggests that strain BC-1 has potential to be developed into an effective microbial herbicide with economic and social benefits.