香蕉不同生育期根际土壤细菌群落变化研究

The Variation of Bacterial Community in the Banana Rhizosphere Soil at Different Growth Stages

土壤微生物是土壤质量和健康的敏感性指标。研究认为,根际微生物区系失调是作物土传病害发生的一个重要原因。通过对香蕉不同生长期根际土壤中细菌多样性和数量的研究,对香蕉枯萎病发生的机理及生物防治具有重要意义。实验采用Real-time PCR和T-RFLP技术,对巴西蕉不同生长期根际细菌数量和多样性进行了研究。结果表明:随着香蕉生长期的增加,根际土壤细菌数量从3月的1.1×1010copies/g土壤逐渐增加到7月的2.7×1010copies/g土壤,随后逐渐减少。然而,根际细菌多样性从3月到7月呈逐渐减少趋势,到7月达到最低,为1.99。另外,不同月份中优势菌的种类和在总细菌中所占的比例也不同。在实验期内,随着香蕉生育期的延长,某些细菌种类大量繁殖,土壤根际细菌群落结构失衡,土壤微生物环境有恶化趋势。

Soil microorganism is a sensitivity index of soil quality and health. Some studies have indicated that the decline of microbial communities in the rhizosphere is an important reason for soil-borne diseases. The research on bacterial diversity in the rhizosphere of banana can be helpful to understand the mechanism of fusarium and know how to control it by biological methods. In this study, the techniques of Real-time PCR and terminal restriction fragment length polymorphlsm were used to analyze the abundance of soil bacteria and bacterial diversity in the rhizosphere of banana. During the growing stages from March to July, the abundance of bacteria changed from 1.1×10^10 copies.g-1 soil in March to 2.7×10^10 copies/g soil in July, and then gradually decreased. In contrast, the indices of bacterial diversity decreased from 2.52 in March to 1.99 in July. However, it increased gradually from July to September. In addition, significant changes of the bacterial community abundance and diversity of dominant bacteria were observed in the rhizosphere of banana. The species and proportion of dominant bacteria were significantly changed in different growing stages of banana. The results indicated that the abundance of soil bacteria and bacterial diversity in the rhizosphere were changed during the growing stage of banana.