阿尔山不同时期落叶松根际土壤固氮菌的多样性研究  

Community Structure and Diversity of Culturable Nitrogen Fixing Bacteria from Larix gmelinii Rhizosphere Soil at Different Stages in Arxan

作　　者：郭振华 陈立红[1] GUO Zhenhua;CHEN Lihong(Agricultural College, Inner Mongolia Agricultural University, Hohhot 010019,China)

机构地区：[1]内蒙古农业大学农学院,呼和浩特010019

出　　处：《西北植物学报》2019年第4期729-739,共11页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(31260173)

摘　　要：利用传统的细菌分离培养,结合16S rDNA序列分析等方法,对阿尔山地区不同时期落叶松根际可培养固氮菌群落的多样性进行分析,以揭示落叶松根际固氮菌的多样性及群落结构的季节变化规律,为森林生态系统的可持续发展提供理论依据。结果显示:(1)从阿尔山落叶松根际土壤中共计分离纯化细菌菌株112株,分属于14属41种,包括假单胞菌属、伯克氏菌属、根瘤菌属、叶杆菌属、节杆菌属、类芽孢杆菌属、沙雷菌属、欧文菌属、短小杆菌属、芽孢杆菌属、肠杆菌属、不动杆菌属、柄杆菌属、红球菌属;其中优势菌群为假单胞菌属,次优势菌群为叶杆菌属、伯克氏菌属和节杆菌属。(2)季节变化对落叶松固氮菌群的变化有显著影响,表现为4月份和10月份最优势类群为γ-变形菌纲(γ-proteobacteria)中的假单胞菌属,6月份和8月份的最优势类群相同,但组成有所差别,其中6月份优势菌群包括假单胞菌属、短小杆菌属、红球菌属、节杆菌属,8月份的优势菌群为假单胞菌属、不动杆菌属、肠杆菌属、短小杆菌属、红球菌属和节杆菌属。(3)不同时期的物种均匀度指数(McIntosh index)差异显著,8月份最大,4月份最小,变化范围在0.83～1.164之间;物种丰富度指数(Shannon-Wiener index) 6月份和8月份显著高于4月份和10月份;优势度指数(Simpson index) 4月份和10月份显著高于6月份和8月份。研究表明,阿尔山地区落叶松根际微生物的多样性较高,群落相对复杂,分离的14个菌属多为根际促生菌,且不同时期固氮菌的群落组成受季节的影响明显。We analyzed the diversity of nitrogen-fixable bacterium communities in the rhizosphere of larch in different periods in Arxan region by traditional bacterial isolation and culture combined with 16S rDNA sequence analysis, so as to reveal the diversity of nitrogen-fixable bacteria in the rhizosphere of larch and the seasonal variation rules of the community structure, and to provide theoretical basis for the sustainable development of forest ecosystem. The results show the following:(1) From Arxan Larix gmelinii rhizosphere soil, a total of 112 bacterium strains, isolation and purification of points belonging to 14 genera of 41 species. They include Pseudomonas, Burkholderia, Rhizobium, Phyllobacterium, Arthrobacter, Paenibacillus, Serratia, Erwinia, Curtobacterium, Bacillus, Enterobacter, Acinetbacter, Caulobacter,and Rhodococcus. Pseudomonas dominated among the bacterial isolates, followed by Phyllobacterium, Burkholderia and Arthrobacter.(2) Seasonal changes had a significant effect on the change of nitrogen-fixing flora of larch, which showed that the most dominant group in April and October was Pseudomonas from the γ-proteobacteria. The most dominant groups in June and August were the same,but the composition was different. Both of them were gamma proteobacteria and actinomycetes. In June, the dominant bacterium groups included Pseudomonas, Curtobacterium, Rhodococcus and Arthrobacter. In August, the dominant bacterium groups were Pseudomonas, Acinetbacter, Enterobacter, Curtobacte-rium, Rhodococcus and Arthrobacter.(3) Species evenness index(McIntosh index) varies significantly in different periods, with the largest in August and the smallest in April, and the variation range is between 0.83 and 1.164. The Shannon-Wiener index was significantly higher in June and August than in April and October. Dominance index, Simpson index in April and October is significantly higher than in June and August. The results showed that the rhizosphere microbial diversity of larch in Arxan area was relatively high, and the c

关 键 词：阿尔山 落叶松 根际固氮菌 季节变化 群落结构 

分 类 号：Q939.96[生物学—微生物学] Q948.1