Department of Molecular Biology and Biotechnology, Rajasthan College of Agriculture, Maharana Pratap University of Agriculture and Technology, Udaipur, 313001, India.
Department of Genetics and Plant Breeding, Rajasthan College of Agriculture, Maharana Pratap University of Agriculture and Technology, Udaipur, 313001, India.
Curr Microbiol. 2020 Aug;77(8):1550-1557. doi: 10.1007/s00284-020-01963-y. Epub 2020 Apr 4.
Rhizobium are nitrogen-fixing bacteria which possess the nif gene that codes for the nitrogenase enzyme involved in the reduction of atmospheric dinitrogen (N) to ammonia. Thirty rhizobial strains were identified from ten groundnut plant root nodules collected from semi-arid regions of Rajasthan, India. The isolates were initially identified on the basis of morphological, biochemical, and molecular characteristics. These rhizobium strains were further screened for plant growth promoting activities. Twenty-eight strains were able to produce indole acetic acid, nine strains could solubilize phosphate, and twenty-nine strains exhibited positive results for siderophore and ammonia production. All the bacterial strains were able to efficiently nodulate the groundnut under pot conditions and based on multiple PGP activities six strains were selected for field evaluation. Field experiments confirmed the effectiveness of these selected rhizobium strains resulted in significantly higher nodule number, nodule dry weight, grain yield, and yield components of inoculated plants. Inoculation of the rhizobium strain GN223 followed by GN221 resulted in high yield and field efficiency. Isolation of effective microbial strains is the prerequisite to increase the yield which is evident from the field data of the present study. Hence, these strains might serve as proficient inoculants.
根瘤菌是固氮细菌，它们拥有编码固氮酶的 nif 基因，该酶参与将大气中的二氮 (N) 还原为氨。从印度拉贾斯坦邦半干旱地区采集的 10 株花生植物根瘤中鉴定出 30 株根瘤菌。这些分离物最初是根据形态学、生物化学和分子特征进行鉴定的。这些根瘤菌菌株进一步筛选了促进植物生长的活性。28 株能够产生吲哚乙酸，9 株能够溶解磷酸盐，29 株表现出铁载体和氨产生的阳性结果。所有细菌菌株都能够在盆栽条件下有效地结瘤花生，并且基于多种 PGP 活性，选择了 6 株进行田间评价。田间试验证实，这些选定的根瘤菌菌株能够显著提高接种植物的根瘤数量、根瘤干重、籽粒产量和产量构成。接种根瘤菌菌株 GN223 后再接种 GN221 可获得高产和田间效率。从本研究的田间数据可以明显看出，有效微生物菌株的分离是提高产量的前提。因此，这些菌株可能作为有效的接种剂。
