不同冬瓜品种对疫病的抗性与根际土壤微生物数量的关系

Correlation between phytophthora disease resistance of different wax gourd varieties and the numbers of microorganisms in rhizosphere soil

为了给不同冬瓜品种的疫病抗性评价及其生物防治机制提供依据,研究了不同抗性冬瓜品种的根际微生物群落数量及功能多样性的差异。以不同冬瓜品种为材料,采用自然病圃法调查不同冬瓜品种田间疫病抗病性,并采用叶碟诱导计数法和平板稀释计数法调查不同品种的根际微生物的多样性。结果表明,冬瓜品种之间的病情指数表现为:绿宝极早熟>小家碧玉>B214>铁柱168>S9>P33=B184=莞研1号小冬瓜;不同冬瓜品种根际土壤中疫霉分离频率、细菌、真菌和放线菌数量有一定差异,不同冬瓜品种的病情指数与可培养细菌数量、放线菌数量、B/F值(细菌数量/真菌数量)及A/F值(放线菌数量/真菌数量)均呈极显著负相关,与疫霉分离频率呈极显著正相关。综上所述,不同冬瓜品种根际土壤中的细菌和放线菌总量与品种抗性呈显著正相关,而根际土壤中的疫霉菌数量和品种抗性呈显著负相关。

In order to provided a basis for the evaluation of phytophthora disease resistance of different wax gourd varieties and the biological control mechanism of phytophthora disease,the differences of the number and functional diversity of rhizosphere microbial communities in the different resistant wax gourd varieties were studied..In this experiment,different wax gourd varieties were used as materials.The natural disease nursery method was used to investigate the resistance of different wax gourd varieties to the phytophthora disease.Leaf disk induced counting method and plate dilution counting method were used to investigate the diversity of rhizosphere microorganisms of different wax gourd varieties.The results showed that the disease indices between the varieties of wax gourd were displayed as follows:Lübao>Xiaojiabiyu>B214>Tiezhu168>S9>P33=B184=Guanyan No.1 small wax gourd.There were significant differences in the isolation frequency of Phytophthora,the number of bacteria and fungi as well as actinomycetes in the rhizosphere soil of different wax gourd varieties.The disease indices of different wax gourd varieties was negatively correlated with the number of culturable bacteria,and actinomycetes,as well as B/F and A/F,but positively correlated with the isolation frequency of Phytophthora.In conclusion,the total amount of bacteria and actinomycetes in the rhizosphere soil are positively correlated with the variety resistance,while the total fungi are negatively correlated with the variety resistance.