复合生防菌群对连作大豆根际土壤可培养微生物区系的影响

采用盆栽试验,研究了复合生防菌群对大豆根际土壤可培养微生物区系的调节作用。结果表明,复合生防菌群可以明显改变大豆根际微生物区系组成。在大豆不同时期,复合生防菌群处理的大豆根际细菌、真菌和放线菌在数量上发生了较大改变。在大豆真叶期和复叶期,复合生防菌群接种处理大豆根际细菌较对照增幅分别达到71.8%和114.3%,而根际真菌较对照减少12.9%和22.3%。在大豆真叶期,复合生防菌群接种处理大豆根际放线菌数量较对照减少9.9%,而在复叶期,根际放线菌数量较对照增加27.4%。此外,施用复合生防菌群可有效降低土传病原菌镰孢菌属（Fusarium）和丝核菌属（Rhizoctonia）的比例,并且提高根瘤菌（Rhizobium）、固氮菌（Azoto-bacter）、木霉属（Trichoderma）、假单胞菌属（Pseudomonas）和芽孢杆菌属（Bacillus）等有益菌的比例。

Effects of combined biocontrol agents on soybean rhizosphere culturable microbial flora from continuous soybean cropping soil

Pot experiments were carried out to investigate the effect of combined bioeontrol agents on rhizosphere microbial flora of soybean （ Glycine max） in continuous cropping soil. Results showed that combined bioeontrol agents could effectively change soil microbial flora in soybean rhizosphere. Among different growth stages of soybean, the quantities of bacteria, fungi and actinomyces had changed evidently under combined bioeontrol agents treatment. In euphylla period and compound leaf period, rhizosphere bacteria increased 71.8% and 114.3% , while fungus decreased 12.9% and 22.3% respectively. Actinomyees decreased 9.9% in euphylla period, but in- creased 27.4% in compound leaf period. The results showed that combined biocontrol agents significantly reduced the proportions of soilborne pathogene of Fusarium and Rhizoctonia in soybean rhizosphere, and enhanced the proportions of beneficial microbes including Rhizobium, Azotobacter, Trichoderma, Pseudomonas and Bacillus.