辣椒疫病生防菌株鉴定及控病机理研究

为筛选出对辣椒疫病菌具有较强抑制活性的生防菌株，达到控制辣椒疫病的目的，从辣椒种植区土壤中分离大量微生物，采用平板对峙法筛选对辣椒疫病菌具有较强抑制作用的生防菌株XD6，通过常规方法和16SrDNA确定其分类地位，并测定相关酶活性变化。试验分离得到的XD6菌株，平板对峙试验防治效果高达80%~100%，初步鉴定为多粘芽孢杆菌(Paenibacillus polymyxa)。酶活测定显示，生防菌株XD6的β-1,3-葡聚糖酶和纤维素酶活性都存在显著变化，且接种XD6菌株的辣椒植株PAL活性、PPO活性、POD活性均明显升高。菌株XD6对辣椒疫病具有较高防效，其生防因子可作用于辣椒疫病菌细胞壁，并诱导辣椒自身防御酶系的增强，具有良好的研究前景。

Study on Identification and Control Mechanism of Biocontrol Phytophthora capsici

The biocontrol strains were screened which had strong inhibitory activity against Phytophthora capsici,in order to control pepper plague.A large number of microorganisms were isolated from soil of pepper growing areas,and a bacterium named XD6 which having strong antagonistic effect on Phytophthora capsici by plate confrontation was obtained.Through methods of traditional and 16S rDNA,the status of category was identified,and then the change the activity of the related-enzymes was measured.The control effect of the strain was 80%-100% in plate confrontation experiment,and was primarily identified as Paenibacillus polymyxa.The result of the activity of the enzymes showed that it had significant change in β-1,3-glucanase and cellulose,and the activity of PAL,PPO and POD was significantly increased before XD6 was inoculated in pepper.The XD6 strain had high efficiency to Phytophthora capsici.The biocontrol factors of XD6 could impose on cell wall of Phytophthora capsici,and XD6 strain could increase the defense enzymes of the pepper. The strain had a great potential in research prospect.