木霉菌T115D发酵滤液对马铃薯晚疫病菌的抑制作用

测定了木霉T115D发酵滤液对马铃薯晚疫病菌的抑制作用,结果表明,发酵滤液对晚疫病菌孢子囊萌发,游动孢子释放,游动孢子萌发有抑制作用,发酵滤液对菌丝生长也有一定抑制作用但不明显。发酵滤液原液对晚疫病菌孢子囊萌发的相对抑制率为57.60%。孢子囊释放游动孢子的相对抑制率为75%,对游动孢子萌发的相对抑制率为60.02%。     

生防菌哈茨木霉FJAT-9040固体发酵条件的响应面优化

为优化生防菌哈茨木霉FJAT-9040固体发酵条件,结合初始含水量、初始接种量及培养温度3个单因素,Box-Behnken设计和响应面分析法进行研究。以产孢量为指标,单因素试验确定初始含水量、初始接种量及培养温度分别为50%、5%、28℃。响应面分析结果表明:初始含水量和温度与产孢量有显著相关性(P0.05),通过求解回归方程可得,当初始含水量为53%,初始接种量为7%,培养温度29℃时,产孢量达到4.04×109个·g-1,与实际值3.86×109个·g-1相近。     

Efficacy of plant extracts and biocontrol agents against Pythium aphanidermatum inciting chilli damping-off

The fungitoxic effects of 66 medicinal plants belonging to different families were evaluated in vitro on Pythium aphanidermatum, the causal agent of chilli damping-off. Of these, Zimmu leaf extract (Allium sativum L. × Allium cepa L.) showed the highest inhibition of mycelial growth of P. aphanidermatum (13.7 mm). The antimicrobial compounds were isolated from Zimmu leaf extract and 22 compounds were identified through gas chromatography mass spectroscopy (GC–MS). Biocontrol agents Trichoderma viride and Pseudomonas fluorescens and Zimmu extract were also tested alone and together in vitro and in vivo experiments for control of P. aphanidermatum. The in vitro studies revealed that combination of T. viride + P. fluorescens + Zimmu leaf extract showed the highest mycelial growth inhibition over the control. Both antagonists were compatible with each other and with Zimmu leaf extract. The pot culture studies revealed that seed treatment with combined application of T. viride + P. fluorescens + Zimmu leaf extract was superior in reducing the pre and post-emergence damping-off incidence (8.3 and 17.0%, respectively), and increased the plant growth and yield (shoot length and root length of 13.7 and 6.3 cm, 146 g/plant, respectively) of chilli when compared to control.