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University of Agricultural Sciences, Dharwad

The University of Agricultural Sciences, Dharwad was established on October 1, 1986. The University has 5 Colleges, 27 Research Stations, 6 Agriculture Extension Education Centers, 6 Krishi Vigyan Kendras and ATIC. The University has its jurisdiction over 7 districts namely Bagalkot, Belgaum, Bijapur, Dharwad, Gadag, Haveri, and Uttar Kannada in northern Karnataka. Greater diversity exists in soil types, climate, topography cropping and farming situations. The jurisdiction includes dry-farming to heavy rainfall and irrigated area. Important crops of the region include sorghum, cotton, rice, pulses, chilli, sugarcane, groundnut, sunflower, wheat, safflower etc. The region is also known for many horticultural crops. Considerable progress has been registered in the field of education, research and extension from this University.

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2009 - 200912010 - 20111
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Subject: Plant Biotechnology × Author: Archana Kumari ×
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    ThesisItemOpen Access
    Molecular Characterization of Mineral Phosphate Solubilization In Serratia marcescens AND Methylobacterium sp.
    (UAS, Dharwad, 2011) Archana Kumari; P.U. Krishnaraj
    The major goal of the present investigation was to study the mechanism of mineral phosphate solubilization in Serratia marcescens and Methylobacterium sp. All the 157 isolates of S. marcesens and 73 isolates of pink pigmented facultative methylotrophs were screened for their mineral phosphate solubilization phenotype on solid media viz., Modified Sperber’s and TCP agar media. Eight most potent isolates along with one reference strain Serratia marcescens ER2 were further screened for pH drop and Pi release in NBRIP-BPB and TCP broth. Both pH drops and Pi release were highly correlated upto 15 days. AUDS-151 and PPFM87 were the most potent ‘P’ solubilizing isolates. Gluconic acid was detected in the culture supernatants of these isolates through thin layer chromatographic technique. Effect of buffering and phosphate stress on MPS phenotype of these isolates were observed by external supply of tris buffer and K2HPO4 to the MSM agar medium. It indicates the metabolic control of mineral phosphate solubilization by external factors which either resist the change in pH or alters the gene expression. Tn5 mutants were generated from the most potent P solubilizing isolate AUDS-151 by biological (Tn5) mutagenesis. Mutants failed to show MPS activity even after 5 DAI. Strainal identity of AUDS-151 and PPFM-87 was confirmed as S. marcescens and Methylobacterium mesophilicum respectively through 16S rDNA sequencing. All the pqq operon gene (s) were amplified from AUDS-151 and PPFM-87 and the most conserved pqqE gene was cloned into E. coli DH5a from both the isolates. Both the clones pAMK101 and pASK101 were sequenced and showed 97 per cent homology with the Methylobacterium sp. (CPOOOO367) and 94 per cent homology with Serratia marcescens (DQ868536), respectively.
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    ThesisItemOpen Access
    Enahancement of trichoderma endochitinase secretion in tobacco cell culture using α-amylase signal peptide
    (UAS, Dharwad, 2009) Archana Kumari; Sumangala Bhat
    The present investigation was carried out to compare Trichoderma endochitinase signal peptide (SP) with -amylase signal peptide (plant) for better secretion into intercellular spaces in plants. -amylase signal peptide was synthesized and fused with endochitinase gene (ech42) cloned from Trichoderma virens previously (pSUM1C). The chimeric gene was named as PSP -amyech42 and recombinant vector was named as pMASG. A plant transformation vector (pMASGK) was constructed carrying PSP -amyech42 and transferred to Agrobacterium tumefaciens strain LBA4404. Tobacco leaf discs (cv. White Burley) were co-cultivated with separately with Agrobacterium tumefaciens strain LBA4404 carrying pMASGK and Agrobacterium tumefaciens strain LBA4404 carrying pSUM1C to compare the two signal peptides for efficient secretion of endochitinase. Putative transformants were selected on MS medium with kanamycin (200 mg/l). Only 29 out of 50 survived plants were positive for PSP -amyech42 and 5 out of 8 survived plants were positive for ech42. For confirmation of secretion of endochitinase, well established callus was initiated from 5 transformants with PSP -amyech42, 2 transformants with ech42 having its own SP and non transformed plant in three weeks. Cell suspension cultures were established from initiated callus in one week. Chitinase activity was checked from media and cell extracts of suspension cultures. Plants carrying PSP -amyech42 showed higher endochitinase activity (9-12 times) than plants carrying ech42SP (7-8 times) in both media and cell extracts. For further confirmation of secretion of endochitinase, bioassay against pathogen was done. Media extracts (200 μg of total protein) of PSP -amyech42 suspension on PDA plate showed 73% and 53% growth inhibition of Sclerotium rolfsii and Rhizoctonia solani respectively whereas media extracts (200 μg of total protein) of ech42SP suspension showed 14% and 24% growth inhibition of Sclerotium rolfsii and Rhizoctonia solani respectively. The chimeric gene can be further used in important crop plants to have better resistance to fungal pathogens.