列当生防菌层出镰刀菌Br-1发酵条件的优化及田间防治效果

列当是根寄生杂草,很难防除。菌株Br-1是从感病列当中分离出的对列当有较高防治效果的层出镰刀菌。为了提高菌株Br-1的产孢量,本研究通过单因素试验和正交设计试验对其培养基和发酵条件进行了优化。结果表明,菌株Br-1适宜的发酵培养基为葡萄糖1%,NH4NO_3 0.2%,KH_2PO_4 0.3%,Mg SO4·7H_2O0.1%;优化后的培养条件为:最初pH 5.0,培养温度24℃,装液量20%,振荡速度190 r/min,发酵时间6 d。较优化前的初始培养基和培养条件产孢量提高了257.5倍。在田间防治试验中菌株Br-1对弯管列当的防治效果最高可达67.2%。

Optimization of Fermentation Medium Components and Conditions of Fusarium proliferatum Br-1 and Its Field Control Efficacy

Biological control agent Br-1 was isolated from diseased broomrape and identified as Fusarium proliferatum.In order to increase the sporulation of strain Br-1,the medium components and fermentation conditions were optimized by single factor and orthogonal design.The results indicated that optimized medium components of strain Br-1 were glucose 1％,NH4NO3 0.2％,KH2PO4 0.3％,MgSO4·7H2O 0.1％.Optimum fermentation conditions of strain Br-1 were pH 5.0,medium capacity 50 mL/250 mL,temperature 24 ℃,rotating speed 190 r/min,fermentation time 6 d,with sporulation of Br-1 increased by 257.5 times in comparison with that under unoptimized conditions.Field trails showed that control efficacy of Br-1 on Orobanche cernua Loefling was up to 67.2％.