AIagawadi, Dr.A.R.MAHESH KUMAR, K. S.2019-10-312019-10-311998-08-19Th-4922http://krishikosh.egranth.ac.in/handle/1/5810133629Investigations were carriedout on the rhizosphere microflora of bamboo as well as their population and activities under leaf litter of bamboo plantation during different seasons. The enumeration of microflora in the rhizosphere of different species of bamboo grown at different locations indicated that Dendrocalainus harboured maximum number of total bacteria and N2-fixers whereas Bambusa arundinaceae recorded highest number of P-solubilizers and Bambusa recorded highest population of fungi and actinomycetes. Bamboo plants grown in medium black soil showed higher population of different groups of microorganisms than those grown in red soils. Out of 32 representative major bacterial isolates obtained from bamboo rhizosphere, 16 were found to be N^-fixers, six were P-solubilizers and 10 were predominant general bacterial isolates. The N,-fixers mainly belonged to the genera Azotobacter Azospirillum. The P-solubilizers belonged to Pseudomonas, Xanthomonas and Erwinia. Predominant bacterial isolates belonged to Bacillus, Erwinia, Pseudomonas and Xanthomonas. Among N2-fixers, Azospirillum isolates were found to fix higher amount of nitrogen than Azotobacter isolates. In case of P-solubilizers, strains PSER-1 and PSER-2 showed maximum solubilization of tricalcium phosphate with maximum reduction in pH of the broth. All N2-fixers and P-solubilizers were found to produce lAA and GA. Inoculation of bamboo seeds with selected efficient nitrogen fixers or P-solubilizers either individually or in combination showed increased growth of bamboo seedlings. In general single inoculation treatments gave better results than combined inoculations. All the inoculation treatments enhanced the seed germination root and shoot length as well as dry matter accumulation of bamboo seedlings. The microbial load and enzyme activities in soil under leaf litter of bamboo were significantly higher than that of control soil (unplanted soil). Among the bamboo plant densities, the soil under highest plant density showed maximum population of bacteria, fungi, actinomycetes, N2-fixers, P-solubilizers and cellulose degraders, as well as dehydrogenase, urease and phosphatase activities.ennullThesis