果园杂草对枯草芽胞杆菌控制石榴枯萎病的增效作用

测定枯草芽胞杆菌(Bacillus subtilis)在石榴园6种优势杂草胜红蓟(Ageratum conyzoides)、三叶鬼针草(Bidens pilosa)、大籽蒿(Artemisia sieversiana)、鸭跖草(Commelina communi)、牛筋草(Eleusine indica)、牛膝菊(Galinsoga parviflora)根部及根际土壤中的定殖动态,及杂草与枯草芽胞杆菌协同控制石榴枯萎病(Ceratocystis imbriata)的效果,为生防细菌的应用提供新的方法.结果显示,枯草芽胞杆菌在胜红蓟、三叶鬼针草、大籽蒿和鸭跖草的根部定殖能力都相对较强.在大籽蒿的根部定殖能力最强.而枯草芽胞杆菌只有在大籽蒿根际土中的可检测浓度持续到接种后的30 d.各种杂草结合枯草芽胞杆菌防治石榴枯萎病的结果表明,大籽蒿和胜红蓟表现卓越的增效作用.表明石榴园部分优势杂草可能通过促进枯草芽胞杆菌在其根系及根际中的定殖从而增强控制石榴枯萎病的作用.

The synergistic effect of weeds in orchards on pomegranate wilt control by Bacillus subtilis

The present study was carried out to evaluate the role of six orchard weeds in stimulating the effect of pomegranate wilt control by B.subtilis,and to find new methods for biological control.The dynamics of B.subtilis population in the roots and rhizosphere soil of six weeds,including Ageratum conyzoides,Bidens pilosa,Artemisia sieversiana,Commelina communis,Eleusine indica and Galinsoga parviflora,and the effect of B.subtilis on the control of pomegranate wilt were examined.It showed that the colonization potential of B.subtilis in roots of A.conyzoides,B.pilosa,A.sieversiana and C.communis were stronger than that in other weed roots.The colonization potential of B.subtilis in A.sieversiana roots was the strongest among all weeds.B.subtilis could be detected 30 days later after its inoculation in the rhizosphere of A.sieversiana.The control efficiency of pomegranate wilt disease was obviously different in different combinations of B.subtilis and weeds.The combination of A.conyzoides and A.sieversiana with B.subtilis showed excellent synergistic effects on wilt control,whose disease index was constantly lower than those in other treatments.The effect of B.subtilis on the control of pomegranate wilt disease could be stimulated by dominant pomegranate orchard weeds.