三江平原大豆根系和水稻根系土壤细菌的分离与鉴定

摘要

Soil around soy bean roots and rice roots contains different types of microbes, among which the quantity of bacteria is the largestest, actinomyce is the second, and fungi is the smallest. The total number of soil microoganism around roots is much larger than that outside roots. Microbes from soil around soy bean roots and rice roots in Sanjiang Plain are isolated and initially identified according to the individual and colony character and physiology and biochemistry reaction. The result shows that there are six dominant genus in the soil around soybean roots： Bacillus, Xanthomonas, Aeromonas, Methylomonadaceae, Pseudomonas, and Rhizobium; the soil around rice roots contains five dominant genus： Micrococcu, Flavobacterium, Rhizobium, Neisseria and Staphylococcus. Meanwhile, effection of part of soil physical and chemical characters on soil microoganism around soybean and rice roots is discussed, relation between bacteria number around roots and soil moisture, organic matter content and pH is clarified, which provide guidence for fertilization of soybean and rice field and increase of food production in the future.%大豆根系和水稻根系土壤的微生物类群中，细菌数量最多，放线菌数量次之，真菌数量最少，且根系土壤微生物总数明显高于根外土壤微生物总数．对三江平原大豆根系和水稻根系土壤中的细菌进行分离，根据细菌个体特征、菌落形态特征及其生理生化特性进行初步鉴定．结果表明，大豆根系土壤中主要分布着芽孢杆菌属、黄单胞菌属、气单胞菌属、甲基单胞菌属、假单胞菌属、根瘤菌属6个菌属；水稻根系土壤中分布着微球菌属、黄杆菌属、根瘤菌属、奈瑟氏球菌属、葡萄球菌属5个菌属．同时，探讨了土壤部分理化性质对大豆和水稻根系细菌数量的影响，明确了根系细菌数量与土壤含水量、有机质含量、pH等有一定的相关性，对今后大豆和水稻田间施肥，提高粮食产量具有一定的指导意义．