提高水稻耐盐能力的根际核心菌株筛选及应用  

Isolation and Application of Rhizosphere Core Strains to Improve Salt Tolerance of Rice

作　　者：马爱媛 任轶 汪姣 严河 石晨雨 沈其荣 张瑞福 荀卫兵 MA Aiyuan;REN Yi;WANG Jiao;YAN He;SHI Chenyu;SHEN Qirong;ZHANG Ruifu;XUN Weibing(College of Resources and Environmental Sciences/Jiangsu Key Laboratory of Solid Organic Waste Utilization,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学资源与环境科学学院/江苏省固体有机废弃物资源化高技术研究重点实验室,南京210095

出　　处：《土壤学报》2024年第5期1410-1420,共11页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(42107328);中央高校基本业务费(KYQN2022014);江苏省沿海开发集团有限公司2022年科技揭榜挂帅研发项目(No.2022YHTDJB01)资助。

摘　　要：根际微生物能通过多种途径增强作物对盐胁迫的适应性。为获得能显著提高水稻耐盐性的根际促生菌并探究其应用效果,选择耐盐品种湖南籼和盐敏感品种南粳46两个水稻品种,分别比较了耐盐水稻和盐敏感水稻在自然盐土和灭菌盐土中的生理指标,然后基于16S rRNA基因扩增子测序,通过根系细菌群落差异分析和共现网络分析,鉴定了在耐盐水稻根际富集且与耐盐性相关的关键类群。随后,采用根际微生物宏培养方法从耐盐水稻根际筛选出关键细菌类群的可培养菌株。最后通过盆栽试验评估了菌株增强盐敏感水稻耐盐能力的作用效果。结果表明,自然盐土中耐盐水稻株高和根长均显著高于灭菌土壤中的植株,而脯氨酸含量则显著低于灭菌土壤中的植株,表明耐盐水稻品种根际的微生物群落在增强水稻耐盐能力中具有重要作用。扩增子测序分析发现耐盐水稻品种和盐敏感水稻品种根际微生物群落差异显著,差异分析明确黄杆菌科(Flavobacteriaceae)和假单胞菌科(Pseudomonadaceae)为耐盐水稻根际富集的关键细菌类群。通过设置盐胁迫下盐敏感水稻发芽试验和苗期水培试验,筛选出普氏假单胞菌P34和大安金黄杆菌C18两株功能菌。最后通过盆栽试验证明C18和P34作为直接接种剂或种子包衣剂均能在盐胁迫下显著促进盐敏感水稻生长。综上,C18和P34具有良好的增强水稻耐盐能力的潜力,可作为开发盐碱地专用的种子包衣及微生物肥料的候选菌剂。【Objective】Rhizosphere beneficial microorganisms can enhance plant salt stress tolerance through multiple pathways,including re-establishing ion and osmotic homeostasis,preventing damage to plant cells,and resuming plant growth in saline soil.This study aimed to obtain plant growth-promoting rhizobacteria that can improve salt tolerance of rice and to explore its application effects.【Method】Two rice cultivars were used in this study,of which one is salt-tolerant cultivar Hunanxian and the other is salt-sensitive cultivar Nanjing 46.The physiological characteristics of rice seedlings were compared after planting in sterile and non-sterile saline soils.Then,the key rhizobacterial groups associated with salt tolerance,which were enriched in the rhizosphere of salt-tolerant rice cultivars,were identified by compositional differences and co-occurrence network analyses based on the 16S rRNA gene amplicon sequencing.Subsequently,the culturable strains of the key rhizobacterial groups were isolated through the high-throughput cultivation and identification method of rhizobacteria.Finally,pot experiments were conducted to evaluate the beneficial effects of the strains on enhancing the salt tolerance of salt-sensitive rice cultivar.【Result】The height of shoot and root length of salt-tolerant rice were significantly higher while the content of proline was significantly lower when cultivated in non-sterile soil than in sterile soil under salt stress.This indicates that the rhizosphere microbial community of salt-tolerant rice cultivars may play a crucial role in enhancing the salt tolerance of the host plant.Amplicon sequencing results demonstrated that the composition of the rhizosphere microbial communities of salt-tolerant and salt-sensitive rice cultivars was significantly different.The bacterial families of Flavobacteriaceae and Pseudomonadaceae were the key rhizobacterial groups that were both enriched in the rhizosphere of the salt-tolerant rice.Several bacterial strains affiliated with Flavobacteriaceae a

关 键 词：盐土 水稻耐盐胁迫 根际 可培养菌株 种子包衣 

分 类 号：S154.3[农业科学—土壤学]