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ThesisItem Open Access APPLICATION METHODS OF VA MYCORRHIZAL INOCULUM FOR CROPS IMPORTANT IN AGRICULTURE, HORTICULTURE AND FORESTRY(University of Agricultural Sciences, Dharwad, 1999) G, MAMATHA; BAGYARAJ, D JABSTRACT NOT AVAILABLEThesisItem Open Access STUDIES ON Azospirillum ISOLATES OF ORNAMENTAL PLANTS AND THEIR EFFECT ON Gaillardia pulchella var picta Fouger(University of Agricultural Sciences, Dharwad, 1999) GADAGI, RAVI; KULKARNI, J HInvestigations were carried out on the isolation, identification, genetic diversity, screening of Azospirillum and their inoculation effect on the growth and flowering of Gaillardia. Attempts were made to improve the nitrogen-fixing efficiency of Azospirillum through mutagenesis. From the present investigation, it can be concluded that Azospirillum is common inhabitant of roots of ornamental plants. From the 88 isolations made, 55 percent of isolate were Azospirillum lipoferum while Azospirillum brasilense represented 41.57 percent. The nitrogen fixation by Azospirillum isolates in the semi-solid medium ranged from 1.40 (OAD-36 and OAD-72) to 20.54 (OAD-2) mg gi of malate. Further, ability- to fix dinitrogen was also confirmed by acetylene reduction assay. Although all the Azospirillum isolates could produce variable quantity of IAA and GA, Strain OAD-57 produced the highest plant growth-promoting substances. Genetic diversity of Azospirillum isolates was analyzed through intrinsic antibiotic resistance, protein and plasmid profile. The isolates showed wide diversity with respect to intrinsic antibiotic resistance. However, using the protein finger printing the two definite groups of Azospirillum could discerned. All the isolates contained only one plasmid (22 kb). Seven efficient isolates were selected for further field study, based on preliminary screening of all the isolates under pot culture. From the field experiment, it can be concluded that OAD-2 can play an important role in the N-nutrition of Gaillardia pulchella. Further 25 AziR and EDAR mutants were obtained through NTG mutagenesis. TShese mutants had higher nitrogenase activity and in vitro N fixed g-1 malate. The AziR OAD-904 and EDAR OAD-209 performed better than their respective wild type, in pot cultures in augmenting plant growth and N-uptake of Gaillardia pulchella.ThesisItem Open Access CHARACTERIZATION OF ETHYLENE DIAMINE RESISTANT MUTANTS OF Azospirillum Spp. DERIVED FROM WHEAT(University of Agricultural Sciences, Dharwad, 1999) S, SHUBHA; SAVALAGI, V PExperiments were conducted to isolate native Azospirillum strains from the rhizoplane and endorhizosphere of 27 wheat genotypes and 32 Azospirillum isolates were obtained. Among these six were Azospirillum lipoferum, 13 were Azospirillum brasilense and 13 isolates could not be grouped into either of the two categories. The isolate WAS-15 was found to fix in vitro high amount of nitrogen (24.80 mgN/g of malate) and could reduce acetylene (584r| moles/mg of protein/h). All the Azospirillum isolates were checked for the different salt tolerance levels, metal resistance and resistance to ethylenediamine. Based on above observations, the Azospirillum isolate WAS-15 with maximum resistance to ethylenediamine (0.02%) and higher acetylene reduction activity was subjected to mutation by gamma irradiation and NTG. All the mutants were characterized for colony morphology on different media and biochemical characterization, to observe any change has occurred as compared to its wild type. The observation revealed that mutant GWAS-15-3 could fix higher amount of nitrogen (50.17 mg of N/g malate) along with higher nitrogenase activity (1200 r\ moles/mg protein/ h). This was followed by GWAS-15-6 which could also fix higher level of nitrogen (48.91 mg of N/g malate) along with higher nitrogenase activity (1098 r| moles/mg protein/h). Paranodules in wheat were obtained at 0.6ppm concentration of 2,4-D and plasmid profile of the wild type were observed. Both mutants GWAS-15-3 and GWAS-15-6 possessed higher ammonia excretion than their wild type. Nitrogenase activity was not repressed in both the mutants even in presence of 0.1 mM NH4CI.ThesisItem Open Access PHOSPHORUS NUTRITION AND GROWTH OF Leucaena leucocephala AS INFLUENCED BY INTERACTION BETWEEN Glomus aggregatum, Bacillus polymyxa AND ROCK PHOSPHATE IN AN ALFISOL(University of Agricultural Sciences GKVK, Bangalore, 1993) Singh, Arvinder; Manjunath, AABSTRACT NOT AVAILABLEThesisItem Open Access EFFECT OF LONG TERM INTEGRATED NUTRIENT MANAGEMENT OF SORGHUM [Sorghum bicolor (L.) Moench] BASED CROPPING SYSTEMS ON DYNAMICS OF SOIL MICROFLORA AND SOIL ENZYMES(University of Agricultural Science, Dharwad, 1999) Govekar, Yeshwanth R; Emmimath, V S"The dynamics of soil microflora and soil enzymes were studied in a long term integrated nutrient management experiment in a fixed site during the year 1998-1999. A field experiment was initiated by AICRP on Sorghum at rmain research station - Dharwad (1991 -92) which included two cropping systems as a main plots and five combination of organic and inorganic sources as a sub - plots. Cropping systems had significant influence on soil microflora (Bacteria, fungi, actinomycetes, nitrogen fixing bacteria and P-solubilizing bacteria) and soil enzymes (urease and dehydrogenase). Groundnut-sorghum cropping system recorded maximum microbial population and enzyme activities as compared to the sorghum - safflower cropping system. Cropping systems had no significant influence on chemical properties of the soil. However, groundnut-sorghum cropping system recorded higher level of organic carbon, available nitrogen and available phosphorus as compared to the sorghum - safflower cropping system. Organic carbon, available nitrogen, available phosphorus, soil microflora and enzyme activities of the soil were significantly increased, with the combined application of organic and inorganic fertilizers as compared to RDF and control (without any application). There was positive correlation between soil microflora, soil enzymes and nutrient availability. Application of crop residues + 50% RDF recorded the highest sorghum and groundnut yield during kharifvjhen compared with other treatments. Whereas during rabi application of FYM + 50% RDF registered the higher safflower yield. However, 50% RDF + crop residues recorded the highest sorghum yield during rabi season."ThesisItem Open Access EFFECT OF PENDIMETHALIN AND ENDOSULPHAN ON BIOLOGY AND NITROGEN FIXATION OF TWO Azolla spp.(University of Agricultural Science, Dharwad, 1996) Kalpana, R; Shivappa Shetty, KABSTRACT NOT AVAILABLEThesisItem Open Access EFFECT OF POLLUTED WATER IRRIGATION ON SOIL NITRIFICATION(University of Agricultural Science, Dharwad, 1997) Kalpana; Vishwanth, N RABSTRACT NOT AVAILABLEThesisItem Open Access INFLUENCE OF VAM INOCULATION AT DIFFERENT LEVELS OF PHOSPHORUS ON GROWTH OF MICROPROPAGATED PLANTS(University of Agricultural Science, Dharwad, 1997) Shashikala, B N; Bagyaraj, D JABSTRACT NOT AVAILABLEThesisItem Open Access INFLUENCE OF PROTOZOA ON THE GROWTH AND ACTIVITIES OF BENEFICIAL SOIL MICRO-ORGANISMS IN RICE SOILS(University of Agricultural Science, Dharwad, 1997) Nagaveni, N M; Hegde, S VABSTRACT NOT AVAILABLE