中国农业微生物菌种保藏管理中心大豆根瘤菌精准评价

Accurate evaluation of soybean rhizobia preserved in the Agricultural Culture Collection of China

摘要:

大豆(Glycine max)是世界上重要的粮食作物和油料作物。农业供给侧结构性改革需要增加优质食用大豆种植面积，但由于我国耕地资源的固有特性，大豆的国内产量远不能实现自给自足，亟需提高国内大豆种植面积和产量，摆脱对进口的依赖。根瘤菌(rhizobia)是研发最早的微生物肥料，但在我国的接种面积极低。目的 本研究拟从库藏根瘤菌中筛选出大豆促生结瘤菌株，为缓解粮食问题提供种质资源保障。方法 以中国农业微生物菌种保藏管理中心数十年收集的大豆根瘤菌为实验材料，结合16S rRNA基因和recA序列分析，复核菌种保藏信息；通过水培结瘤实验，综合考虑结瘤率、根瘤数量和根瘤质量以及植株株高和干重，评价菌株的结瘤和促生能力。结果 共活化获得213株大豆根瘤菌菌株，其中156株隶属于慢生根瘤菌(Bradyrhizobium)、48株隶属于中华根瘤菌属(Sinorhizobium)、9株隶属于根瘤菌属(Rhizobium)。在这些菌株中，149株能与本研究选用的大豆品种匹配结瘤，43株能够显著促进大豆植株生长。结论 本研究进一步明确了库藏大豆根瘤菌的分类地位，评价了其结瘤促生能力，为大豆根瘤菌菌剂的开发提供了丰富的菌质资源。

关键词:大豆;根瘤菌;结瘤促生;根瘤菌种质资源

Abstract:

Soybean (Glycine max) is an important cereal and oil crop in the world, and the supply-side structural reform in the agricultural sector requires an increase in the planting area of high-quality edible soybean. Due to the inherent characteristics of arable land resources in China, the domestic production of soybean is far from self-sufficiency, and there is an urgent need to increase the planting area and production of soybean domestically, reducing the dependence on imports. Rhizobia are the earliest developed microbial fertilizer, while their application area is limited in China.Objective To select suitable strains from the stored rhizobia to provide germplasm resources for alleviating food issues.Methods We reviewed taxonomic status of rhizobia preserved in the Agricultural Culture Collection of China over decades based on the 16S rRNA and recA gene sequences. The hydroponic nodulation test was carried out to assess the nodulating and soybean growth-promoting effects based on comprehensive consideration of the nodulation rate, nodule number, nodule weight, plant height, and dry weight.Results A total of 213 strains of soybean rhizobia were activated and identified, including 156 strains of Bradyrhizobium, 48 strains of Sinorhizobium, and 9 strains of Rhizobium. Among them, 149 strains were able to nodulate with soybean cultivar selected in this study, and 43 strains significantly contributed to the growth of soybean plants.Conclusion This study further clarifies the taxonomic status of preserved soybean rhizobia and evaluates their nodulating and plant growth-promoting effects, providing abundant microbial resources for the development of soybean rhizobia-based agents.

Key words:Glycine max;rhizobia;nodulating and growth-promoting effects;germplasm resources of rhizobia