Ramesh ChandraYadav, Pushpa2019-02-052019-02-052018-07http://krishikosh.egranth.ac.in/handle/1/5810093628The study was undertaken for isolation and characterization of the Mesorhizobium isolates from diverse soils, their characterization and evaluation for enhancing nodulation, plant growth, yield, nutrient uptake in chickpea (Cicer arietinum L.) and soil properties. Out of total 59 isolates, 22 were confirmed to be Mesorhizobium based on cultural and plant infection test. Among these, 8 solubilized phosphate, 9 indicated production of IAA, 8 production of GA, 6 HCN and 5 siderophores and 5 ACC deaminase activity in in vitro conditions. Functional diversity of 10 selected isolates through utilization of different carbohydrates and molecular diversity through phylogenetic relationship based on 16S rDNA through RFLP revealed their diversity at varying level of Jaccard’s similarity coefficient. The symbiotic efficiency of the 10 multi-trait mesorhizobial isolates was compared in chickpea under field experiment during Rabi 2016-17. The experimental soil was sandy loam of pH 6.90 and EC 0.24 dS m-1 having 0.67% organic C and 180.2, 20.1 and 261.4 kg ha-1 available N, P and K, respectively. Treatments consisting seed inoculation with 10 mesorhizobial isolates with uninoculated and RDF (20 kg N ha-1 + 40 kg P2O5 ha-1) controls were laid out randomized block design in 3 replications. The test crop variety was PG-186. Inoculation of Mesorhizobium isolates improved the nodule number ranging from 27.0 to 66.2% at 40 DAS, 22.1 to 46.3% at 60 DAS and 30.3 to 73.7% at 80 DAS, nodule dry weight from 10.4 to 28.8% at 40 DAS, 12.8 to 26.4% at 60 DAS and 18.7 to 36.5% at 80 DAS and plant dry weight from 27.1 to 40.7% at 40 DAS, 59.7 to 92.9% at 60 DAS and 20.5 to 61.1% at 80 DAS over the uninoculated control. Inoculation with different isolates also enhanced leghaemoglobin content in nodule and chlorophyll content in leaves. All isolates, except CR-11 and CR-21, produced significantly more grain yield of 17.4 to 34.4% and numerically higher straw yield of 21.4 to 38.5% over the uninoculated control. Inoculated isolates also increased the nitrogen content in nodule and N and P uptake by plants at different intervals in comparison to the uninoculated control. The Mesorhizobium isolates increased the grain and straw N uptake from 22.0 to 69.7% and 19.4 to 72.4% and P uptake from 20.2 to 46.5% and 39.3 to 69.5% over uninoculated control, respectively. Organic C and available N, P in soil at harvesting was 14.8 to 25.0%, 40.6 to 57.0% and 14.5 to 25.2% significantly more following inoculation with different isolates. Different isolates also significantly increased the microbial biomass C, by16.4 to 47.1% and microbial biomass N, by 27.1 to 112.4% over the control. They also enhanced the dehydrogenase and acid and alkaline phosphatase activities in soil suggesting their favourable impact on soil health. Isolates CR-53, CR-3 and CR-40 were found superior to others in improving the nodulation, productivityand nutrient uptake in chickpea and soil health in Mollisol.enThesis