枯草芽孢杆菌DNKAS对分枝列当的防效、安全性及作用机理

分枝列当是全寄生性恶性杂草，为探讨生防菌对分枝列当寄生和生长的影响，以枯草芽孢杆菌 DNKAS为材料，通过盆栽、大田和酶活试验，研究DNKAS对分枝列当的防治效果、寄生体系植株生长量、常见作物果蔬生长安全性评价及对寄生体系防御酶系的影响。结果表明：在温室及田间验证下，枯草芽孢杆菌DNKAS对分枝列当防治效果分别为49.7%与43.1%；同时，在大田试验中，枯草芽孢杆菌DNKAS使产量和单果质量分别提高45.91%和45.89%，病虫果数减少48.5%。对5种常规作物生长安全性检测结果表明，该菌剂未对植物生长产生畸变，且具备一定促生作用；通过检测寄生体系的防御酶活性，施用枯草芽孢杆菌DNKAS使加工番茄根部苯丙氨酸解氨酶、多酚氧化酶、超氧化物歧化酶和抗坏血酸过氧化物酶活性分别增加 7.72%、111.41%、24.24%、14.06%，分枝列当酶活分别提高44.32%、137.59%，53.53%、15.67%。可见，枯草芽孢杆菌在分枝列当防除中作用是有效的，在分枝列当寄生期可提高寄生体系防御酶系统活性，阻碍分枝列当的寄生规模和数量，减轻其对寄主植物的危害；同时，菌剂的施用对常见果蔬等生长指标未见不良作用。

Control Effect,Safety and Mechanism of Bacillus subtilis DNKAS on Orobanche aegyptiaca

Orobanche aegyptiaca is malignant parasitic weeds. Bacillus subtilis DNKAS was used as material to study the effects of biocontrol bacteria on the parasitism and growth of Orobanche aegyptiaca. The pot experiment,field experiment and enzyme activity test were conducted to study the control effect of DNKAS on Orobanche aegyptiaca,the growth of parasitic system,the evaluation of fruit and vegetable growth safety in common crops,and to study the effect of DNKAS on defense enzymes of parasitic system. The results showed that in greenhouse and under field conditions,the control effect of Bacillus subtilis DNKAS on Orobanche aegyptiaca was 49.7% and 43.1%,respectively; meanwhile,in the field experiment,Bacillus subtilis DNKAS increased yield and fruit weight by 45.91% and 45.89%,respectively,and the number of fruit decreased by 48.5%. The growth safety of five kinds of conventional crops was determined,the bacteria did not distort the growth of plants,and had a certain effect on growth-promoting; by measuring the activity of defense enzymes in the parasitic system,the application of the Bacillus subtilis DNKAS increased the activities of phenylalanine ammonialyase,polyphenol oxidase,superoxide dismutase and ascorbate peroxidase of tomato root by 7.72%,111.41%,24.24% and 14.06%,respectively,the enzyme activity of Orobanche aegyptiaca increased by 44.32%,137.59%,53.53% and 15.67%,respectively. This study showed that Bacillus subtilis was effective at the control of Orobanche aegyptiaca. The the parasitic period of the Orobanche aegyptiaca could increased the activity of the defense enzyme system of the parasitic system,hinder the parasitic size and number of Orobanche aegyptiaca,reduce the damage to the host plants,at the same time,adverse effect on the growth indexes of common fruits and vegetables was not found.