长期施肥对黑土大豆根瘤菌群体结构和多样性的影响  

Influence of long-term fertilization on the community structure and diversity of soybean rhizobia in black soil

作　　者：关大伟[1,2] 李力[1,2] 姜昕[1,2] 马鸣超[1,2] 曹凤明[1,2] 周宝库[3] 李俊[1,2] 

机构地区：[1]中国农业科学院农业资源与农业区划研究所,北京100081 [2]农业部微生物产品质量安全风险评估实验室,北京100081 [3]黑龙江省农业科学院土壤肥料与环境资源研究所,哈尔滨150006

出　　处：《生物多样性》2015年第1期68-78,共11页Biodiversity Science

基　　金：现代农业产业技术体系建设专项资助项目(CARS-04);黑龙江省自然科学基金项目(ZD200813-02)

摘　　要：为揭示长期施肥对黑土大豆根瘤菌群体结构和多样性的影响,采用BOX-PCR、IGS-PCR-RFLP和16S r DNA基因序列分析法,对分离自黑龙江省7种长期不同施肥处理的254株大豆根瘤菌进行了遗传多样性和系统发育分析,结合土壤理化性质分析了大豆根瘤菌群体结构和多样性与土壤因子间的关系。7种处理分别为不施肥(CK)、有机肥(OM)、单施氮肥(N1)、单施2倍氮肥(N2)、氮肥+有机肥(N1+OM)、氮肥磷肥混施(N1P1)和2倍氮肥磷肥混施(N2P2)。系统发育分析结果表明,所有供试菌株均为慢生根瘤菌属(Bradyrhizobium),其中大部分菌株与日本慢生大豆根瘤菌(Bradyrhizobium japonicum)相似性最高,少部分菌株与辽宁慢生大豆根瘤菌(Bradyrhizobium liaoningense)相似性最高。BOX-PCR聚类分析结果表明,供试菌株在70%相似性水平上分为15个群,在与施肥处理相关性分析中分为3个群体,分别对应于不施化肥处理(CK和OM)、化学氮肥处理(N1、N2、N1+OM)、氮肥磷肥处理(N1P1和N2P2)。典范对应分析结果表明,土壤p H、速效氮和速效磷与根瘤菌群体结构相关性极显著(P=0.002,0.004,0.002)。不同施肥措施下大豆根瘤菌的多样性有明显差异:N2P2处理的丰富度指数和Shannon-Wiener指数显著高于其他处理;OM处理的Simpson指数最高;N1和N2处理的3种多样性指数都显著低于其他处理。通径分析结果表明,p H、速效磷对多样性指数有较高的直接正效应;速效氮通过p H的间接负效应影响多样性指数。本研究表明,长期施用化肥改变了根瘤菌群体结构,单施氮肥减少大豆根瘤菌多样性,而氮肥磷肥混施则有助于提高大豆根瘤菌多样性。The objectives of this study were to explore the effects of long-term fertilization on the community structure and diversity of soybean rhizobia in black soil. BOX-PCR, IGS-PCR-RFLP and 16S rDNA gene sequencing methods were used to analyze the genetic diversity of the 254 soybean rhizobia isolated from 7 treatments at Heilongjiang Long-term Fertilization Experiment Station. The 7 treatments were as follows： no fertilization （CK）, organic manure （OM）, chemical nitrogen （Nl）, double chemical nitrogen （N2）, chemical nitrogen-phosphorus （N1PI）, double chemical nitrogen-phosphorus （N2P2）, chemical nitrogen plus organic manure （NI＋OM）. Soil properties were measured and analyzed to test for relationships with the community and diversity of soybean rhizobia. All of the tested rhizobia belonged to Bradyrhizobium, of which the majority were closely related to B. japonicum and the others closely to B. liaoningense. BOX-PCR fingerprints showed that the tested rhizobia could be divided into 15 groups at 70% similarity level. These groups clus- tered into 3 communities that correspond to no chemical fertilizer treatments （CK, OM）, chemical nitrogen fertilizer treatments （N1, N2, NI＋OM）, and chemical nitrogen-phosphorus treatments （N1P1, N2P2）, respectively. Canonical correspondence analysis showed that pH, available N, and available P of the soil were sig- nificantly correlated with the community of rhizobia （P=0.002, 0.004, 0.002, respectively）. Soybean rhizo- bia diversity indices varied significantly among fertilization treatments. Shannon-Wiener and species rich- ness index were highest in N2P2 and Simpson index was highest in the OM treatment. The species richness, Shannon-Wiener and Simpson index in NI and N2 were significantly lower than those in other treatments. The results of path analysis showed that the pH and available P had the greatest direct positive effects on the 3 in- dices, and that available N indirectly affected the 3 indices through pH. In conclusion, lon

关 键 词：多样性指数 BOX-PCR IGS-PCR-RFLP 典型对应分析 通径分析 

分 类 号：Q939.114[生物学—微生物学]