土壤因子对海洋多粘类芽胞杆菌L1-9在黄瓜根表土壤定殖的影响

摘要

本试验考察了土壤温度、有机质含量和pH对海洋生防细菌多粘类芽胞杆菌L1-9在黄瓜根表土壤中定殖的影响.采用实时荧光定量PCR方法检测了不同时期黄瓜根表土壤中菌株L1-9的16S rDNA拷贝数.结果表明,土壤有机质含量、土壤温度和pH对菌株L1-9在黄瓜根表的定殖有显著影响(P＜0.01).25℃定殖数量最高,为5.79×108拷贝/g土,是15℃时的3.4倍;添加有机肥20～40 g/kg土壤,可以促进菌株L1-9在黄瓜根际定殖;pH 7时,菌株L1-9在黄瓜根表土壤中的定殖数量最高.本研究为海洋生防菌L1-9防治黄瓜土传病害提供了理论依据.%In this study,the effects of soil organic matter contents,temperature and soil pH value on colonization of marine biocontrol bacterium of L1-9 in root surface soil were investigated.16S rDNA gene fragments of the strain in the root surface soil were quantified using quantitative real-time PCR method.The results showed that soil organic matter content,temperature and pH exhibited significant impacts on colonization of the strain L1-9 in root surface soil (P ＜ 0.01).The propagation of the strain L1-9 in root surface soil was faster under the temperature of 25 ℃,which was 5.79× 108 copies per gram dry soil,and 4.3 times of that under 15 ℃.Addition of organic matter (20-40 g/kg) increased the population density of the strain L1-9.The maximum colonization level of the strain L1-9 in the root surface soil was achieved in pH 7.This study laid a foundation for the development and application of the marine biocontrol bacterium L1-9 against soilborne diseases of cucumber.