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采用PCR-DGGE技术,对‘寒富’苹果园生长季内土壤氨氧化细菌群落结构、多样性及其与土壤理化因子的相关性进行探讨。结果表明,不同时期土壤硝化强度、氨氧化细菌数量、种群组成及多样性表现出明显差异。其中,11月份土壤硝化强度最高,9月份最低,而氨氧化细菌数量则表现为11月份最低,7月最高。多样性特征分析表明,土壤氨氧化细菌多样性和均匀度指数均表现为11月份最高,9月份最低;而丰富度指数则表现为5月份与7月份最高,11月份最低;优势度指数则为9月份最高,5月份最低。系统发育分析结果表明,苹果园土壤氨氧化细菌均隶属于β-变形菌纲(β-Proteobacteria),多为不可培养菌株,其中亚硝化螺旋菌属(Nitrosospira)为土壤优势菌属。氨氧化细菌与土壤理化性质相关性分析发现,土壤速效磷、速效钾含量与硝化强度、氨氧化细菌多样性指数、均匀度和优势度指数呈显著相关,而与土壤氨氧化细菌数量无明显相关性。说明环境因子时间分布的不均匀性是不同时期土壤氨氧化细菌群落结构组成差异的重要原因。
Using PCR-DGGE, the correlation between soil ammonia-oxidizing bacteria community structure and soil physico-chemical factors in ’Hanfu’ apple orchard during the growing season was discussed. The results showed that there were significant differences in soil nitrification intensity, ammonia oxidizing bacteria population, population composition and diversity in different periods. Among them, the highest soil nitrification in November, the lowest in September, while the number of ammonia oxidizing bacteria showed the lowest in November, the highest in July. The analysis of diversity characteristics showed that the diversity index and evenness index of soil ammonia oxidizing bacteria showed the highest in November and the lowest in September, while the richness index showed the highest in May and July and the lowest in November, and the dominance index was Highest in September and lowest in May. Phylogenetic analysis showed that the ammoxidation bacteria in apple orchard belonged to β-Proteobacteria, mostly uncultured strains, of which Nitrosospira was the dominant soil genus. Correlation analysis between ammonia-oxidizing bacteria and soil physical and chemical properties found that soil available phosphorus, available potassium content and nitrification intensity, ammonia oxidizing bacteria diversity index, evenness and dominance index were significantly correlated with the number of soil ammonia oxidation bacteria was not significantly correlated Sex. It is indicated that the inhomogeneity of temporal distribution of environmental factors is an important reason for the differences in composition of ammonia oxidizing bacteria community in different periods.