小单孢菌属X46马唐致病菌的筛选

目的]研究小单孢菌属X46马唐致病菌的筛选方法及致病作用。方法]采用改良的高氏I号培养基从马唐、稗草根际土壤中分离出1株马唐致病菌X46,对其最优化产毒素条件进行测定并对其安全性进行评估。结果]经鉴定,马唐致病菌X46为小单孢菌属;其最优化培养条件为：在高氏I号培养液中,300ml三角瓶装液量30ml,初始pH值6.0～6.5,采用10%接种量,180r/min28℃发酵120h即可使毒素产生量最大。该菌对玉米、番茄和黄豆具有明显的促生长作用,对小麦有轻微的抑制作用,对黄瓜生长抑制作用明显。结论]X46是一株具有开发为中国北方用生物除草剂的潜力菌株。

Screening of Digitaria sanguinalis Pathogenic Bacteria X46 Belonging to Micromonosporaceae

Objective]The study aimed to research the screening method and the pathogenesis function of Digitaria sanguinalis pathogenic bacteria X46 belonging to Micromonosporaceae.Method]A strain of D.sanguinalis pathogenic bacteria X46 was segregated from the rhizosphere of D.sanguinalis and Echinochloa crusgalli (L.) Beauv.by using the improved Gause No 1 medium.Its optimization condition of producing toxin was determined and its security was estimated.Result]D.sanguinalis pathogenic bacteria was identified as Micromonosporaceae and its the optimization culture conditions were as followings:in the Gause No 1 medium,filling 30 ml culture liquid in 300 ml flasks with its initial pH of 6.0-6.5 and 10% inoculation concn.and fermenting at 180 r/min and 28 ℃ for 120 h,which could produce the maximum amount of toxin.D.sanguinalis pathogenic bacteria X46 showed the obvious action of promoting the growth on the maize,tomato and soybean,the light control action on the wheat and the obvious control action on cucumber.Conclusion]D.sanguinalis pathogenic bacteria X46 is a potential strain that will be developed as the biological herbicide in North China.