Isolation and Screening of Nitrogen Fixing Paenibacillus spp for Growth Promotional Traits and Their Effect on Growth and Yield of Maize Zea mays L

Abstract

One seventy six isolates of nitrogen fixing Paenibacillus sp. (NFPBS) isolated from newlinecalcareous soils of North Karnataka were characterized morphologically, physiologically and newlinebiochemically. Further, five efficient isolates were taxonomically identified as Paenibacillus zanthoxyli newlineusing 16S rDNA sequencing. The plant growth promotional traits recorded showed ranging from newline77.00 to 436.33 and#956;g/mg of protein, Per cent P-solubilization from 3.01 to 6.33, zinc solubilisation from newline0.94 to 7.41 ppm and phytohormone production viz., IAA (1.15 to 21.43 and#956;g/ml), GA (0.12 to 2.91 newlineand#956;g/25 ml) and cytokinin (19.73 to 47.10 and#956;g/l). Under in vitro condition 22 isolates showed siderophore newlineproduction, 42 isolates showed organic acid production, 11 isolates antagonistic activity against newlineFusarium oxysporum while 17 isolates were found antagonistic against Rhizotonia solani. newlineIt was observed that the growth parameters viz., plant height, nitrogen content and chlorophyll newlinecontent were maximum in treatment inoculated with NFPBS 4, NFPBS 21, NFPBS 30, NFPBS 90 and newlineNFPBS 137 along with the absence of nitrogen in pot culture. The growth parameters, yield newlineparameters and enzyme activities were maximum in the treatments inoculated with isolates NFPBS newline137 with 75 per cent RDN and NFPBS 4 with 75 per cent RDN, Reference strain with 75 per cent newlineRDN and RDF in green house condition. newlineIn field evaluation efficient isolates were recorded maximum inoculation of NFPBS 137 with newline100 per cent RDN at 30, 60 and at harvest dry matter production (24.28, 95.45 and 376.90 g/plant, newlinerespectively), chlorophyll content (44.16, 60.60 and 56.33, at 30, 60 SPAD value, respectively). Yield newlineand yield parameters viz., cob weight (285.77 g), test weight (32.20 g) and yield (64.48 q/ha). The newlinepredominant soil enzymes viz., dehydrogenase, alkaline phosphatase and urease activity which were newlineon par with the treatment inoculated with NFPBS 4 and Reference strain with 100 per cent RDN was newlinecomparable with treatment inoculated Reference strain with 100 per cent RDN. newline