元阳梯田水稻品种‘月亮谷’根系内生及根际细菌的群落结构

Study on Root Endophytic and Rhizosphere Bacteria of Rice Landrace of Yuelianggu from Yuanyang Terrace

为了解元阳梯田传统水稻品种‘月亮谷’的根系内生及根际土壤的细菌群落结构,本研究以现代品种‘楚粳27’为对照,分别在云南省元阳县和建水县开展种植试验。结果显示:通过菌落分离,共得到202个菌株,结合形态特征、生理生化特性及16s rDNA对其进行初步鉴定研究,可分离到11个种和8个属;聚类分析结果表明:元阳县种植的水稻根系内生细菌的相似水平比建水县的低0.202,但其丰富度更高,差异更大;从0.890的相似水平划分,建水县种植的水稻根际土壤细菌聚为一类,较单一,表明元阳县水稻生长的微生物多样性较丰富。比较两个水稻品种在两个地点的根系内生细菌和根际土壤细菌的相对分离频率发现:假单胞菌属(Pseudomonas sp.)为优势属和共有属,恶臭假单胞菌(P.putida)是两个品种在两个地点种植的共有种,两个地点种植的‘月亮谷’,其根系和根际土壤中均能分离到荧光假单胞菌(Pseudomonas fluorescens)。研究初步表明‘月亮谷’在两个不同生态环境种植其根系内生细菌和根际土壤细菌的差异,从土壤微生态的角度阐述了‘月亮谷’能够在哈尼梯田持续种植的原因。

In order to explicate the community structure difference of rice root endophytic and rhizosphere bacteria in Yuanyang Terrace, ＇ Yuelianggu＇ and ＇ Chujing 27＇ were cultivated in 2 counties of Yuanyang and Jianshui. A total of 202 bacterial strains isolated were identified by morphological characteristics, phys- iological and biochemical analysis combined with 16s rDNA identification. The results showed that 19 cate- gories were differentiated, including 11 species and 8 genera. Clustering analysis showed that root endo- phytic bacteria of rice in Yuanyang were higher diverse of 0. 202 than that of Jianshui, and rhizosphere bac- teria in Jianshui were less diverse than that in Yuanyang. It was suggested that micro-ecological environ-ment of rice growth in Yuangyang was more varied when compared with Jianshui County. Pseudomonas was common and dominant bacteria on the level of genus, and Pseudomonas putida was common strain isolated from the root of 2 varieties in 2 counties, and Pseuclomonas fluorescens could be always isolated from ＇ Yueli- anggu＇ wherever it was planted in Yuanyang difference of root endophytic and rhizosphere or Jianshui County. This study preliminarily clarified that the bacteria of ＇Yuelianggu＇ in two different ecosystem and it may be one of the reasons that ＇ Yuelianggu＇ could be continuous cultivated in Yuanyang Terrace.