Department of Molecular Biology and Biotechnology, Rajasthan College of Agriculture, Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
Department of Soil Science and Agricultural Chemistry, Rajasthan College of Agriculture, Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
Arch Microbiol. 2020 Sep;202(7):1809-1816. doi: 10.1007/s00203-020-01904-0. Epub 2020 May 20.
Pigeon pea (Cajanus cajan (L.) Millspaugh) is among the top ten legumes grown globally not only having high tolerance to environmental stresses along, but also has the high biomass and productivity with optimal nutritional profiles. In the present study, 55 isolates of rhizobia were identified from 22 nodule samples of pigeon pea collected from semi-arid regions of India on the basis of morphological, biochemical, plant growth promoting activities and their ability to tolerate the stress conditions viz. pH, salt, temperature and drought stress. Amongst all the 55 isolates, 37 isolates showed effective nodulation under in vitro conditions in pigeon pea. Further, five isolates having multiple PGP activities and high in vitro symbiotic efficiency were subjected to 16S rRNA sequencing and confirmed their identities as Rhizobium, Mesorhizobium, Sinorhizobium sp. Further these 37 isolates were characterized at molecular level using ARDRA and revealed significant molecular diversity. Based on UPGMA clustering analysis, these isolates showed significant molecular diversity. The high degree of molecular diversity is due to mixed cropping of legumes in the region. The assessment of genetic diversity and molecular characterization of novel strains is a very important tool for the replacement of ineffective rhizobial strains with the efficient strains for the improvement in the nodulation and pigeon pea quality. The pigeon pea isolates with multiple PGPR activities could be further used for commercial production.
兵豆（Cajanus cajan (L.) Millspaugh）是全球十大种植豆类之一，不仅对环境胁迫具有高度耐受性，而且具有较高的生物量和生产力，以及最佳的营养特性。在本研究中，根据形态学、生物化学、植物促生活性以及耐受 pH 值、盐度、温度和干旱胁迫等应激条件的能力，从印度半干旱地区采集的 22 个兵豆根瘤样本中鉴定出 55 株根瘤菌。在所有 55 株分离株中，37 株在兵豆的体外条件下表现出有效的结瘤作用。此外，有 5 株分离株具有多种植物促生活性和高体外共生效率，通过 16S rRNA 测序进行鉴定，它们被确认为根瘤菌、中慢生根瘤菌和中华根瘤菌。进一步，用 ARDRA 对这 37 株分离株进行了分子水平的特征分析，揭示了它们具有显著的分子多样性。基于 UPGMA 聚类分析，这些分离株显示出显著的分子多样性。这种高度的分子多样性是由于该地区豆类的混合种植造成的。对新型菌株的遗传多样性和分子特征评估是用有效菌株替代无效根瘤菌菌株以提高结瘤和兵豆品质的重要工具。具有多种 PGPR 活性的兵豆分离株可以进一步用于商业生产。
