花生根系腐解物对根腐镰刀菌和固氮菌的化感作用研究

[目的]研究花生根系腐解物对花生根腐镰刀菌36194和固氮菌14046的化感作用。[方法]采用培养箱培养的方法得到了不同连作年限的花生根系腐解物,灭菌后添加到花生根腐镰刀菌和固氮菌的培养基中,测定花生根系腐解物对二者生长的影响。[结果]花生根系腐解物对根腐镰刀菌菌丝的生长均有一定的化感促进作用,对固氮菌的生长有一定的化感抑制作用,且化感作用随添加浓度和连作年限的增加而增强。[结论]连作条件下花生根系残茬在土壤中的累积及其腐解物对土壤微生物的化感作用很可能是导致花生连作障碍的原因之一。

Study on Allelopathy of Decayed Peanut Root on Root Rot Fungl and N-fixing Bacteria

[Objective] The aim was to study allelopathy of decayed peanut root on root rot fungi(Fusarium sp.) 36194 and N-fixing bacteria(Bradyrhizobium vigna) 14046.[Method] Decayed peanut root after different years of continuous cropping was got by the method of cultivation in incubator,then put on the culture medium of root rot fungi and N-fixing bacteria after sterilization,to determine the effect of decayed peanut root on the growth of two.[Result]Decayed peanut root promoted the allelopathic promotion effects on the mycelium growth of root rot fungi(Fusarium sp.),and inhibited the allelopathic inhibition effects on the growth of N-fixing bacteria(Bradyrhizobium vigna).The allelopathy strengthened with the increasing of the added concentration of decayed root and continuous cropping years.[Conclusion] The accumulation of peanut root stubble in soil and the allelopathy effects of their decayed material on soil microbes might be one of the reasons of peanut continuous cropping obstacle.