摘要
从盐碱地水稻根际土分离鉴定促生菌并研究其促生效果,为盐碱地水稻高效种植提供菌种资源。利用稀释平板法、培养基检测法、分子鉴定等技术分离鉴定根际促生菌,通过盆栽实验探究促生菌对盐胁迫下水稻生长的影响。经筛选获得3株根际促生菌,分别鉴定为Pseudoclavibacter sp.、Providencia sp.和Planococcus sp.。盐胁迫下接种促生菌均能促进水稻生长、改善光合作用、提升植株脯氨酸含量和抗氧化酶活性、降低丙二醛含量。其中,Planococcus sp.表现出最高的促生潜力。研究通过综合性实验将微生物与现代农业发展需求有机结合,培养了学生利用微生物解决农业发展面临问题的能力,提升了学生在微生物应用领域的创新思维和实践能力。
[Objective]Utilization of plant growth-promoting rhizobacteria(PGPR)to enhance crop salt tolerance is an eco-friendly strategy employed to improve productivity in saline–alkali agriculture.This study aimed to isolate and identify the PGPR in saline–alkali soils post-rice cultivation and evaluate their growth-promoting effects,thereby providing microbial resources for enhancing cultivation efficiency in saline–alkali soils.[Method]Bacteria were collected and isolated using the dilution plate and streak plate methods.The growth-promoting traits of the isolates,such as nitrogen fixation,phosphorus solubilization,siderophore production,and indole acetic acid production,were analyzed using assay media.The target PGPR isolates were identified through culture and microscopic observations,as well as molecular identification methods.The growth-promotion effects of PGPR isolates on rice plants under salt stress were detected by pot experiments.[Results]Post-screening,three PGPR isolates were obtained and identified as Pseudoclavibacter sp.,Providencia sp.,and Planococcus sp.,respectively.Among them,Pseudoclavibacter sp.could produce siderophores and indole acetic acid;Providencia sp.could fix nitrogen and produce indole acetic acid;and Planococcus sp.had the capacity of phosphorus solubilization,siderophore production,and indole acetic acid production.The results showed that under salt stress,compared with non-inoculated plants,root length,height,root dry weight,and aboveground dry matter weight of the inoculated rice plants increased significantly.In those inoculated with Pseudoclavibacter sp.,these were enhanced by 46.09%,23.64%,111.10%,and 90.00%,respectively;with Providencia sp.by 37.59%,10.86%,66.67%,and 37.00%,respectively;and with Planococcus sp.by 51.06%,17.57%,133.33%and 85.00%,respectively.Under salt stress,compared to the non-inoculated ones,the chlorophyll contents of the rice plants inoculated with Pseudoclavibacter sp.,Providencia sp.,and Planococcus sp.enhanced markedly by 25.73%,23.98%and 32.75%,respectively.Similarly,the leaf proline contents of inoculated rice plants were elevated remarkably by 159.37%,128.67%,and 302.10%;the root contents by 281.18%,84.57%and 667.44%,respectively.A similar trend was detected in the antioxidant enzyme activities in the inoculated rice plants compared to the controls.In leaves,the superoxide dismutase activity increased by 37.44%,4.12%,and 62.40%;peroxidase activity by 44.37%,4.10%,and 67.16%;and catalase activity by 183.42%,59.15%,and 245.66%,respectively.In roots,the superoxide dismutase activity was enhanced by 141.10%,10.44%,and 138.14%;peroxidase activity by 73.26%,17.06%,and 58.76%;and catalase activity by 74.24%,63.54%,and 199.15%,respectively.However,the leaf malondialdehyde content of the inoculated rice plants was significantly lowered by 18.20%,15.94%,and 24.04%,respectively;the root contents by 39.03%,30.26%,and 41.64%,respectively,than the non-inoculated plants.[Conclusions]In total,three PGPR isolates,Pseudoclavibacter sp.,Providencia sp.,and Planococcus sp.,were screened and isolated through culture.All of them promoted rice growth,improved photosynthesis,enhanced the proline contents and antioxidant enzyme activities,but reduced the malondialdehyde contents of rice plants under salt stress.Among them,Planococcus sp.was more effective than the other two,demonstrating a certain application value in enhancing salt tolerance in rice.This study cultivated and improved a hands-on ability in students while using experimental techniques in microbiology through a progressive and comprehensive application of the“isolation–identification–verification effect”method.It also enhanced the capacity of students for innovative and practical thinking in the field of agricultural microbiology by combining the utilization of microbial resources with the needs of modern agricultural development.
作者
张洋
钱佳慧
蒋继辉
李青
苗旺
王进军
胡建
ZHANG Yang;QIAN Jiahui;JIANG Jihui;LI Qing;MIAO Wang;WANG Jinjun;HU Jian(College of Environmental Science and Engineering,Yangzhou University,Yangzhou 225127,China;Key Laboratory of Saline-Alkali Soil Improvement and Utilization(Coastal Saline-Alkali Lands),Ministry of Agriculture and Rural Affairs,Yangzhou University,Yangzhou 225127,China)
出处
《实验技术与管理》
北大核心
2025年第9期128-134,共7页
Experimental Technology and Management
基金
国家自然科学基金项目(42307443)。
关键词
盐胁迫
水稻
根际促生菌
筛选
促生效果
salt stress
rice,growth promoting rhizobacteria
screening
promoting effect
