小麦蚕豆间作对蚕豆根际微生物群落功能多样性的影响及其与蚕豆枯萎病发生的关系

通过田间小区试验，研究了小麦与蚕豆间作对蚕豆枯萎病发生和根际微生物代谢功能多样性的影响。结果表明，小麦与蚕豆间作使蚕豆枯萎病的发病率和病情指数分别比单作显著降低20%和30.4%。与单作处理相比，间作显著增加了蚕豆和小麦根际微生物对31种碳源的平均利用率（AWCD），其中间作蚕豆的AWCD值最高，比单作增加82.7%，单作蚕豆最低。间作蚕豆和间作小麦根际微生物的Shannon多样性指数与丰富度指数均显著高于单作，间作使蚕豆和小麦的丰富度指数分别增加29.2%和30.3%。根际微生物对六类碳源的利用强度百分比以糖类、羧酸类和氨基酸最高，分别为41.96%，19.80%和18.13%。主成分分析表明，小麦与蚕豆间作改变了根际微生物的群落组成；相关分析表明，糖类、羧酸类和氨基酸类碳源是区分单间作处理差异的主要碳源，其中氨基酸类碳源是最敏感的碳源。小麦与蚕豆间作增加了根际微生物活性，提高了Shannon多样性指数和丰富度指数，改变了微生物群落功能多样性，是抑制蚕豆枯萎病的有效措施。该研究为阐明根际微生物功能多样性变化在间作体系病害控制中的作用与机制奠定了理论基础。

Relationship between rhizosphere microbial community functional diversity and faba bean fusarium wilt occurrence in wheat and faba bean intercropping system

Field experiment was conducted to examine the effects of wheat and faba bean intercropping on rhizosphere microbial community functional diversity and occurrence of faba bean fusarium wilt. Results showed that fusarium wilt incidence and disease index of faba bean were significantly decreased by 8.72% and 25.81% in wheat and faba bean intercropping system. Comparing with monocropping,intercropping significantly increased the average well color development(AWCD) of wheat and faba bean, and the AWCD value of intercropped faba bean was the highest and the monocropped faba bean was the lowest, AWCD value of intercropped faba bean was increased by 82.7% when compared with monocropping. Functional diversity index of Shannon index (H) and substrate richness (S) in Biolog ECO microplates were significantly higher in intercropping than in monocropping system. Substrate richness of intercropped wheat and faba bean were increased by 29.2% and 30.3% respectively. The carbon sources with higher utilization intensity percentage by rhizosphere microbes were carbohydrates, amino acids and carboxylic acids, c.e. 41.96%, 19.80% and 18.13% respectively. Principal component analyses and correlation analyses demonstrated that the significant difference between monocropping and intercropping mainly depended on amino acids-dominated carbon sources and secondarily on carbohydrates and carboxylic acids. Intercropping had improved AWCD value, Shannon-wiener diversity index and richness of wheat and faba bean, changed soil microbe community functional diversity. Therefore, intercropping could be an effective measure to control faba bean fusarium wilt occurrence. It established the theory foundation for explanations diseases control in intercropping system.