Abstract: 【Objective】 To study the relationship between quantities and functional diversity of soil microorganism and walnut rot disease and provide a theoretical basis for the further prevention and control of walnut rot disease by microbiological control techniques.【Method】Soils of 12 years walnut trees at health, mild disease, moderate degree and severe disease status were taken as the research object to determine microbial diversity in root soil using culturable microorganism count and biolog ecological plate and to analyze the correlation microbial diversity with the degree of disease.【Result】The results showed that there were significant differences in the number of three culturable microbes in the rhizosphere soil of walnut with different degrees of rot disease. Compared with the healthy soil, the numbers soil bacteria in different levels of soil increased first and then decreased, the soil of mild and moderate onset soil increased by 15.67% and 12.28% respectively, and the soil of severe onset decreased slightly by 33.46%.. The number of soil actinomycetes in moderate and severe soil decreased by 47.33%, 32.98% and 19.27% respectively, and the number of fungi decreased by 49.32, 22.68% and 42.68%, respectively. The utilization of Biolog carbon sources showed that soil microbial diversity of walnut rot was significantly different with different degrees of disease. From the AWCD value of 144 h, it could be seen that the microbial activity in the soil of mild disease was the highest. The healthy soil decreased by 12.03%,the soil of moderate and severe disease decreased by 14.56% and 18.42% compared with the soil of mild disease respectively. The Shannon richness index (H) of mild disease soil was higher than that of healthy, moderate and severe soil. The study on the utilization of different carbon sources showed that the soil microbes of healthy and mild disease had strong utilization to carbohydrate and amino acid. However, the use of carbohydrates, amino acids and phenolic acid carbon sources in the soil where the disease was more serious was decreasing. The principal component analysis showed that there were certain differences in soil microbial communities under different levels of rot disease. Among the 31 carbon sources, carbohydrates and amino acids determined the differences of the principal components.【Conclusion】The microbial activities in the soils of moderate degree and severe disease were lower than those in the soil of the lower degree disease and the healthy soil. Therefore, according to the different carbon sources used by soil microbes, designing reasonable trace element fertilizer will hopefully reduce the occurrence of walnut rot disease.

Key words: walnut; different levels of rot disease; culturable microbial quantities; biolog ecological plate; microbial diversity

摘要： 【目的】 研究土壤微生物数量和功能多样性与核桃腐烂病之间的关系,为核桃腐烂病微生物调控技术研究奠定良好的理论基础。【方法】以健康、轻度、中度和重度4类不同病害程度的12年生核桃树为试材,采用可培养微生物计数和Biolog生态板测定其根区土壤微生物数量和功能多样性的异同,分析其与病害程度之间的相关性。【结果】不同腐烂病发病程度核桃根际土壤三大可培养微生物类群数量差异显著。与健康土壤相比,不同发病程度土壤细菌数量呈先上升后下降趋势, 轻度、中度发病土壤分别提高了15.67%和12.28%,重度发病土壤则下降了33.46%。轻度、中度和重度发病土壤放线菌数量分别下降了47.33%、32.98%和19.27%,真菌数量分别下降了49.32%、22.68%和42.68%。Biolog碳源利用表明,核桃腐烂病不同发病程度土壤微生物多样性也存在显著差异。从144 h的AWCD值可以看出,腐烂病发病较轻的核桃根区土壤中,微生物活性最高,健康土壤降低了12.03%,中、重度发病土壤分别降低了14.56%和18.42%。轻度发病土壤的Shannon丰富度指数(H)高于健康和中、重度发病土壤。健康和轻度发病的土壤微生物对糖类和氨基酸类碳源有较强的利用能力,而腐烂病发病较重的土壤中利用糖类、氨基酸类和酚酸类碳源的微生物在减少。主成分分析表明,发病程度不同的核桃根区土壤微生物群落有一定的差异。31种碳源中,糖类和氨基酸类碳源决定着主成分的分异。【结论】腐烂病发病程度较重的土壤中微生物活性低于健康和腐烂病发病程度较轻的土壤。根据土壤微生物利用的不同碳源,设计出合理的微量元素肥料,将有望减轻核桃腐烂病病害的发生。

关键词: 核桃, 腐烂病发病程度, 可培养微生物数量, Biolog技术, 微生物多样性