不同肥力条件下烟草根际微生物的初步研究

对不同肥力条件下烟草根际细菌、真菌、放线菌进行分离,研究了其数量变化,对根际土壤中7类细菌生理群进行了数量和多样性分析.结果表明,根际细菌和放线菌数量以高肥土壤中最多,中肥土壤次之,低肥土壤最少;根际真菌数量以低肥土壤中数量最多,高肥土壤次之,中肥土壤最少;好气性固氮菌、氨化细菌、纤维素分解菌、硝化细菌和硫化细菌的数量以高肥土壤最大,中肥土壤次之,低肥土壤最少;反硝化细菌和反硫化细菌数量呈现低肥大于中肥大于高肥的变化趋势.不同肥力条件下,烟草根际细菌、真菌、放线菌及8类细菌生理群的Shannon-Wiener指数和均匀度均以低肥土壤的最大.

Tobacco rhizosphere microorganism in different fertility of soil

The rhizosphere bacteria,fungi and actinomyces from tobacco soils with different fertility were isolated on selective culture medium.The changes of their population size were studied.The population densities and biodiversity of seven bacterial types of bacteria were intensively studied.The results showed that the population density of rhizosphere bacteria and actinomyces in the rich tobacco soils was higher than that in medium and poor tobacco soils,the greatest population density of fungi was found in the poor tobacco soils,the population density of aerobic nitrogen-fixing bacteria,ammoniation bacteria,cellulose-decomposing bacteria,nitrifiers,and sulfurizing bacteria in rich tobacco soils was significantly higher than that in medium and poor tobacco soils.But the population density of Denitrifiers and Anti- Sulfurizing bacteria in poor tobacco soils was higher than that in the medium and rich tobacco soils.Of the different fertility level,the shannon-Wiener diversity index (D) and evenness index (J) of rhizosphere bacteria,fungi,actinomyces and eight types of bacterial groups of soil were the highest in poor tobacco soils.