Division of Basic Sciences and Humanities, FoH, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar, Kashmir, J&K, 190025, India.
Division of Environmental Sciences, FoH, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar, Kashmir, J&K, 190025, India.
Sci Rep. 2022 Apr 25;12(1):6742. doi: 10.1038/s41598-022-11030-0.
The less phytopathogen susceptibility in Himalayan Brassica rapa L. has made it an exceptional crop eluding synthetic pesticide inputs, thereby guarantying economically well-founded and ecologically sustainable agriculture. The relevance of niche microflora of this crop has not been deliberated in this context, as endosymbiosiome is more stable than their rhizosphere counterparts on account of their restricted acquaintance with altering environment; therefore, the present investigation was carried out to study the endophytic microfloral dynamics across the B. rapa germplasm in context to their ability to produce chitinase and to characterize the screened microflora for functional and biochemical comportments in relevance to plant growth stimulation. A total of 200 colonies of bacterial endophytes were isolated from the roots of B. rapa across the J&K UT, comprising 66 locations. After morphological, ARDRA, and sequence analysis, eighty-one isolates were selected for the study, among the isolated microflora Pseudomonas sp. Bacillus sp. dominated. Likewise, class γ-proteobacteria dominated, followed by Firmicutes. The diversity studies have exposed changing fallouts on all the critical diversity indices, and while screening the isolated microflora for chitinase production, twenty-two strains pertaining to different genera produced chitinase. After carbon source supplementation to the chitinase production media, the average chitinase activity was significantly highest in glycerol supplementation. These 22 strains were further studied, and upon screening them for their fungistatic behavior against six fungal species, wide diversity was observed in this context. The antibiotic sensitivity pattern of the isolated strains against chloramphenicol, rifampicin, amikacin, erythromycin, and polymyxin-B showed that the strains were primarily sensitive to chloramphenicol and erythromycin. Among all the strains, only eleven produced indole acetic acid, ten were able to solubilize tricalcium phosphate and eight produced siderophores. The hydrocyanic acid and ammonia production was observed in seven strains each. Thus, the present investigation revealed that these strains could be used as potential plant growth promoters in sustainable agriculture systems besides putative biocontrol agents.
喜马拉雅油菜（Brassica rapa L.）的病原体易感性较低，使其成为一种逃避合成农药投入的特殊作物，从而保证了经济合理和生态可持续的农业。在这种情况下，尚未审议该作物的生态位微生物区系的相关性，因为内共生体比其根际对应物更稳定，因为它们与不断变化的环境的接触受到限制；因此，进行了本研究以研究整个油菜种质资源中内生微生物区系的动态变化，以及它们产生几丁质酶的能力，并对筛选出的微生物区系进行功能和生化特性分析，以促进植物生长。从 J&K UT 的油菜根部共分离出 200 株细菌内生菌，包括 66 个地点。经过形态学、ARDRA 和序列分析，从分离的微生物区系中选择了 81 个分离株进行研究，其中假单胞菌和芽孢杆菌占优势。同样，γ-变形菌纲占主导地位，其次是厚壁菌门。多样性研究暴露了所有关键多样性指数的变化结果，在筛选分离的微生物区系产生几丁质酶的过程中，属于不同属的 22 株菌产生了几丁质酶。在向几丁质酶生产培养基中添加碳源后，甘油添加的平均几丁质酶活性最高。进一步研究了这 22 株菌，在筛选它们对六种真菌种的抑菌行为时，在这种情况下观察到了广泛的多样性。分离株对氯霉素、利福平、阿米卡星、红霉素和多粘菌素 B 的抗生素敏感性模式表明，这些菌株主要对氯霉素和红霉素敏感。在所有菌株中，只有 11 株产生吲哚乙酸，10 株能够溶解磷酸三钙，8 株产生铁载体。在 7 株菌中观察到氢氰酸和氨的产生。因此，本研究表明，这些菌株除了可能的生物防治剂外，还可以用作可持续农业系统中的潜在植物生长促进剂。
