The variety of endophytic and epiphytic diazotrophs is particular to the niche (i.e., leaf, stem, and root) of various genotypes and the organ's nutrition availability.
The cultivation of non-leguminous crops like rice can be facilitated and sustained by immunizing against the local, polyvalent diazotrophs. Therefore, three Indian cultivated [Oryza sativa L. var. Sabita (semi deep/deep water)/Swarna (rain fed shallow lowland)/Swarna-Sub1 (submergence tolerant)] and a wild rice genotype that respond differently to nitrogenous fertilizers have had N2-fixing plant growth promoting bacteria (PGPB) isolated from various parts of the plants. Based on acetylene reduction assay on nitrogenase activity, biochemical tests, BIOLOG, and 16S rRNA gene sequencing, 35 isolates from four rice genotypes were grouped. The bacteria generated between 9.36 to 155.83 mole C2H4 mg dry bacteria per hour, and among these, nifH-sequence analysis was used to supplement the nitrogenase activity of 11 powerful isolates. Based on 16S rDNA sequencing, phylogenetic analysis separated them into five groups (shared 95–100% sequence homology with type strains) that belonged to five classes: alpha (Amylobacter, Az rhizobium, Az spirillum, Rhizobium, Bradyrhizobium, Sinorhizobium, Novosphingobium spp.), beta (Burkholderia sp.), gamma (Micro bacterium sp.). In addition, all bacterial strains produced siderophore (from 0.16 to 0.57 mol/l) and indole (0.44 to 7.4 g/l), ammonia (0.18 to 6 mmol/l), and nitrite (0.01-3.4 mol/l) as inherent PGP characteristics. Select isolates improved plant growth metrics including shoot and root elongation, which were connected with in vitro PGP, in rice (cv. Swarna) seedlings.
Learn more about endophytic brainly.com/question/18178273
#SPJ4
