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ThesisItem Open Access Influence of Dual Inoculation of Azospirillum and P-Solubilizing Fungal Isolates on Growth, Nutrient Uptake and Biomass of Maize (Zea mays L.)(University of Agricultural Sciences, Dharwad, 2017-07) Amrutha G.; Savalgi, V.P.ThesisItem Open Access Influence of P-Solubilizing Fungal Isolates on Growth, Nutrient Uptake and Biomass of Soybean (Glycine max L. Merill.)(University of Agricultural Sciences, Dharwad, 2017-07) Prem Kumar T. M.; Savalgi, V.P.ThesisItem Open Access Effect of Mycorrhization in the Management of Striga in Sugarcane Under Field Conditions(University of Agricultural Science, Dharwad, 2016-09) Manjunatha H.P.; P. Jones NirmalnathThesisItem Open Access Isolation and Screening of Nitrogen Fixing Paenibacillus spp. for Growth Promotional Traits and Their Effect on Growth and Yield of Maize (Zea mays L.)(University of Agricultural Science, Dharwad, 2017-01) Basavesha K.N.; Savalgi, V.P.ThesisItem Open Access Isolation, Characterization and Screening of Gluconacetobacter diazotrophicus From Various Crops and Their Influence on Growth and Yield of Maize (Zea Mays L.)(University of Agricultural Science, Dharwad, 2017-05) Rao, Hema C.; Savalgi, V.P.A total of 113 isolates of Gluconacetobacter diazotrophicus isolated from sugarcane, maize, pineapple and carrot roots through survey from Dharwad, Belagavi, Uttara Kannada, Haveri and Shivamogga districts of Karnataka during 2014, were characterized morphologically, physiologically and biochemically and subjected for in vitro nitrogen fixation which ranged between 14.01 to 147.1 µg mg-1. The highest N2 was fixed by the native isolate NFGS25 (147.1 µg mg-1). Twenty best isolates were screened for further functional characterization viz., P and Zn solubilization, phytohormone production, antagonistic activity and endoglucanase activity. The zone of solubilization of P and Zn (3.1 and 2.5 cm), IAA and GA production (11.54 and 10.1 µg ml-1) and endoglucanase activity (86 µg ml-1) were maximum in NFGS25. The highest per cent inhibition was exhibited by NFGS25 against Rhizoctonia bataticola (83.33%) and Exserohilium maydis (88.86%). Five best isolates (NFGS25, NFGS26, NFGM5, NFGM6 and NFGP7) were selected for screening of growth parameters and N uptake of maize in the pot trial. The results revealed that plant height, stem girth, root length, chlorophyll content, dry weight, per cent N and N uptake were significantly highest in the treatment inoculated with NFGM5 at 75 % RDN followed by NFGS25 at 75% RDN. The population of G. diazotrophicus was maximum in the treatment NFGM5 at 75 % RDN (7 x 104 cfu ml-1). Based on their performance in pot trial, two efficient isolates (NFGM5 and NFGS25) were selected for field trial and confirmed as G. diazotrophicus isolates by molecular characterization. The results of the field experiment conducted during kharif 2016 at MARS, Dharwad, revealed that all the growth and yield parameters (number of cobs, cob weight, grain yield per plant and test weight) were significantly highest in the treatment NFGM5 at 75% RDN followed by NFGS25 at 75% RDN. The maximum grain yield of 183.33 q ha-1 (15% higher than control) was observed in the treatment NFGM5 at 75 % RDN which was better than the reference strain Azospirillum ACD15 with 75% RDN. Thus it is evident that the inoculation of native isolates of G. diazotrophicus (NFGM5 and NFGS25) at 75% RDN promotes better growth, grain yield and saves nitrogenous fertilizer up to 25% of recommended dose in field condition.ThesisItem Open Access Isolation and Screening of Arbuscular Mycorrhizal Fungi for Suppression of Orobanche sp., a Parasitic Weed in Tobacco (Nicotiana tabacum L.)(University of Agricultural Science, Dharwad, 2017-10) Chandrashekharagowda B.; Jones Nirmalnath, P.An investigation was carried out to isolate native arbuscular mycorrhizal fungal (AMF) isolates from the Orobanche suppressive soils of tobacco growing areas of Nippani in Belagavi district, in order to screen them for their ability to suppress obnoxious weed Orobanche as well as to promote plant growth under pot culture studies. These experiments were conducted at the Weed Control Scheme, Main Agriculture Research Station and Department of Agricultural Microbiology, University of Agricultural Sciences, Dharwad from 2014-16. The results of the pot experiment revealed that the native AMF isolates UASDAMFT5 (Glomus fasciculatum), UASDAMFT2 (Glomus radiata), UASDAMFT6 (Glomus deserticola), UASDAMFT3 (Glomus mosseae), AMF consortium (standard) and UASDAMFT consortium (tobacco native) suppressed the Orobanche parameters and plant growth parameters of tobacco over uninoculated plants in the presence of Orobanche. Inoculation of AMF isolates significantly improved the spore count over the uninoculated plants. The maximum spore count was recorded in AMF consortium (standard) (621 spores per 50 g), UASDAMFAMFT consortium (tobacco native) (619 spores per 50 g) and native isolates viz., UASDAMFT5, UASDAMFT2, UASDAMFT6 and UASDAMFT3 (277, 268, 267 and 265 spores per 50 g respectively ) over the uninoculated control (45 spores per 50 g). The present study has indicated that UASDAMFT5, UASDAMFT2, UASDAMFT6 and UASDAMFT3 isolates are quite promising in inhibiting Orobanche seed germination similar to AMF consortium (standard) and UASDAMFT consortium (tobacco native) under pot culture studies. Thus, it can be concluded that UASDAMFT5 and UASDAMFT2 isolates can suppress the Orobanche seed germination efficiently and these can be used as a biotic tool in the Orobanche management.ThesisItem Open Access Studies on Growth of Microalgae and Lipid Production in Dairy Industrial Effluent for Biodiesel Production(University of Agricultural Science, Dharwad, 2017-10) Sahana S.P.; Shirnalli, Geeta G.A study was conducted under laboratory conditions in the Department of Agricultural Microbiology, University of Agricultural Sciences, Dharwad during 2015-17 to evaluate growth of microalgae and lipid production from dairy industrial effluents for bio-diesel production. Untreated (W1) and treated (W2) dairy industrial effluent were collected from Karnataka Milk Federation Unit, Dharwad and were diluted with tap water at the rate of 20 (D1), 40 (D2), 60 (D3), 80 (D4) and 100 (D5) per cent. The initial physico-chemical parameters were analyzed and incubated for three weeks after inoculating with the microalgal strains viz., Chlorella MA-6 (S1), Chlorella MA-14 (S2), Botryococcus MA-5 (S3), Botryococcus sp. (S4) and Scenedesmus sp. (S5). The physico-chemical parameters of these effluent samples were analyzed and the growth of microalgae was measured in terms of biomass. The highest biomass was obtained in treated effluent with dilution D5 (100 %) and strain S1 (3.69 g/l) which was on par with untreated effluent of dilution D2 (40%) and strain S1 which showed 3.18 g/l. These treatments were selected for optimization of growth of microalgae using different nitrogen supplements viz., cow dung (N1), biogas spent slurry (N2), urea (N3) and di - ammonium phosphate (N4) used at the concentrations of 0 (C1), 0.1 (C2), 0.3 (C3), 0.5 (C4) and 0.7 (C5) per cent. The highest amount of biomass, lipid and chlorophyll content was obtained in treatment W2N1C5. The treated effluent without dilution supplemented with cow dung at 0.7 per cent concentration was optimum for the growth of microalgae Chlorella MA-6. The microalgae was harvested after three weeks and the lipid content obtained from the biomass was 23 ml (0.56 ml/g of microalgal biomass) and the biodiesel obtained was 20.83 ml (0.504 ml of biodiesel per gram of microalgae).ThesisItem Open Access Isolation, Characterization and Selection of Efficient Fluorescent Pseudomonads Against Sclerotium rolfsii and Colletotrichum truncatum of Soybean(University of Agricultural Science, Dharwad, 2017-10) Priyanka; Goudar, Geeta D.A study was made to isolate, characterize and select efficient fluorescent pseudomonads against Sclerotium rolfsii and Colletotricum truncatum in soybean, in the Department of Agricultural Microbiology, University of Agricultural Science, Dharwad. Sixty two fluorescent pseudomonads were isolated from 37 rhizosphere soil sample of soybean collected from Belagavi and Dharwad districts of Karnataka, during 2016. These isolates were subjected for their morphological, biochemical, physiological and functional characterization. All the isolates were gram negative rods, exhibiting light green, green, dark green and light orange coloured colonies under UV light. Fifty native fluorescent pseudomonads were tentatively identified as Pseudomonas fluorescens, 10 as P. aeruginosa and 2 isolates as P. aureofaciens strains based on Bergey’s manual of Determinative Bacteriology. With respect to functional characterization, fifty two isolates were positive for P- solubilization. Forty seven isolates were positive for hydrogen cyanide (HCN) production, among which 10 of the isolates were strong HCN producers. All the isolates were positive for siderophore production (6.00 to 36.37 mm). Whereas, indole acetic acid (IAA) and gibberlic acid (GA) production ranged from 39 to 28.03 and 0.5 to 18.52 g/25 ml of broth, respectively. Out of 62 isolates, 51 and 38 were inhibitory to S. rolfsii and C. truncatum respectively in dual plate technique. Seven potential isolates were selected for pot culture evaluation against both the pathogens. Under pot culture experiment, out of seven isolates, DFP48 exhibited highest plant growth promotional activity with least disease incidence of 13.09, 19.89, and 21.96 per cent at 15, 30 and 60 DAS respectively against S. rolfsii top soil challenge inoculated with 5 per cent of S. rolfsii. Similarly DFP54 showed maximum plant growth promotional activity and recorded least anthracnose disease incidence of 11.90 and 13.87 at 30 and 60 DAS respectively, against Colletotricum truncatum foliar spray inoculated with 105 CFU/ml (Colony Forming Unit).ThesisItem Open Access Bacterial Endophytes in Bioremediation of Sewage(University of Agricultural Science, Dharwad, 2017-07) Archana K.; Patil, C.R.A laboratory study was conducted aiming at isolating bacterial endophytes from the plant parts in contact with sewage. 13 plant samples were collected near by constructed wetland and along sewage drains of Hubli-Dharwad municipal corporation, Karnataka state were collected and used for isolation of endophytic bacteria. The surface sterilization procedure was standardized and a total of 109 (50 from root, 43 from leaf and 16 from stem) bacterial endophytes have been isolated. For all the isolates morphological (microscopic study and fluorescence ability) and biochemical (EPS production, Sugar utilization pattern and E.coli inhibition test) characterization were done. The isolates were tested for the traits suited to remediate sewage such as pH, EC, Biological Oxygen Demand, Chemical Oxygen Demand, Total phosphorus and Nitrate nitrogen. Out of which three isolates viz. E67, E84 and E104 were found very efficient as they reduced EC by 53 to 63 per cent, BOD by 66 to 70 per cent, COD by 50 to 55 per cent, nitrate nitrogen by 45 to 47 per cent and total phosphorus by 42 to 55 per cent when inoculated to sewage. These three efficient isolates in consortia were subjected to a pilot scale study both in the presence and absence of host plant (Bracharia mutica) under greenhouse conditions. Floating bed technique was followed with four treatments. Among the four treatments treatment 2 recorded the highest reduction of BOD (79.10 per cent), COD (78.73 per cent), pH (7.78), EC (0.11 dS/m), nitrate nitrogen (70.98 per cent) and total phosphorus (59.81 per cent) was best followed by treatment 4 recording a reduction in BOD (58.67 per cent), COD (76.45 per cent), pH (7.8), EC (0.14 dS/m), nitrate nitrogen (58.60 per cent) and total phosphorus (42.67 per cent) over control. The results revealed that the efficient isolates have ability to remediate sewage.
