【摘要】 在大豆生产中充分发挥共生固氮作用，在减少氮肥的施用、增加土壤微生物的活性、保证耕地及农业生态系统健康、促进绿色农业的可持续性发展等方面具有重要意义。本研究以高产、优质、多抗、广适的大豆品种中豆63为捕获宿主，对湖北省洪湖市高产示范田中的中豆63根瘤菌进行分离与鉴定。采用平板划线分离、BTB反应试验等方法筛选出符合根瘤菌表观特征的菌株，并将获得的菌株进行16S rDNA序列扩增，构建系统发育树，鉴定从中豆63的单个根瘤中分离得到的2个大豆根瘤菌菌株，分别命名为Y63-1与Y63-2。通过抗生素抗性分析表明，Y63-1具有羧苄青霉素（Carbenicillin）、头孢霉素（Cefotaximesodium）、氨苄青霉素（Ampicillin）和利福平（Rifampin）4种抗性，Y63-2具有硫酸卡那霉素（Kanamycin）、羧苄青霉素（Carbenicillin）、氨苄青霉素（Ampicillin）和利福平（Rifampin）4种抗性。最后以慢生型根瘤菌113-2及快生型根瘤菌HH103作为对照，将获得的两个根瘤菌Y63-1与Y63-2按一定的比例通过盆栽回接中豆63，在接种后42天及51天分别对不同接种比例下中豆63植株地上部分鲜重、结瘤数及根瘤干重进行统计学分析，结果表明Y63-1∶Y63-2=2∶1接种中豆63时结瘤效应最佳。混合接种后根瘤中Y63-1与Y63-2的比例初步鉴定结果显示，Y63-1为主效根瘤菌。本研究丰富了我国的根瘤菌资源，研究结果为大豆根瘤菌混合接种技术在大豆生产中的推广应用提供了理论依据，也为生产中通过接种高效根瘤菌提升中豆63及其它品种产量潜力奠定了理论基础。更多还原

【Abstract】 Giving full play to symbiotic nitrogen fixation in soybean production is important in reducing nitrogen fertilizer application, increasing the activity of soil microorganisms, ensuring the health of arable land and agroecosystems, and promoting the sustainable development of green agriculture. In this study, the high-yielding, highquality, multi-resistant and widely adapted soybean variety Zhongdou 63 was used as the capture host, and soybean rhizobium Y63 was isolated and identified from a high-yielding demonstration field in Honghu City, Hubei Province. The strains with the apparent characteristics of rhizobia were screened by using plate scribing and BTB reaction test, and the 16S rDNA sequences were amplified and a phylogenetic tree was constructed to identify two soybean rhizobia strains, both named Y63-1 and Y63-2, as rhizobia from a single nodule of Zhongdou 63. The antibiotic resistance analysis showed that Y63-1 was resistant to Carbenicillin(Car), Cefotaximesodium(Cef), Ampicillin(Amp) and Rifampin(Rif), and Y63-2 was resistant to kanamycin(kan), Carbenicillin(Car) and Ampicillin(Amp),Rifampin(Rif). Finally, the two rhizobia Y63-1 and Y63-2 were inoculated in pots at certain ratios with the slowgrowing rhizobium 113-2 and the fast-growing rhizobium HH103 as controls, and the fresh weight of above-ground parts, the number of nodules and the dry weight of nodules of Zhongdou 63 were statistically analyzed at 42 and 51days after inoculation. The results showed that Y63-1∶Y63-2=2∶1 had the best nodulation effect when inoculated with Zhongdou 63. The preliminary identification of the proportion of Y63-1 and Y63-2 in the nodules after mixed inoculation showed that Y63-1 was the dominant rhizobium, consistent with the nodulation phenotype. This study enriches the rhizobial resources in China, and the results provide a theoretical basis for the application of mixed rhizobial inoculation techniques in soybean production, as well as a theoretical basis for incising the yield potential of Zhongdou 63 and other varieties through inoculation with highly efficient rhizobia in production.更多还原