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20174
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Subject: Plant Pathology × End date: 2018 × Start date: 2017 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Variability In Pyricularia grisea (Cooke) Sacc. and Integrated Management of Foliar Diseases of Pearl Millet
    (University of Agricultural Science, Dharwad, 2017-09) Roopadevi; Patil, P.V.
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    ThesisItemOpen Access
    Studies on Spot Blotch of Tetraploid Wheat Caused by Bipolaris sorokiniana (Sacc.) Shoem.
    (University of Agricultural Science, Dharwad, 2017-01) Pradeep P.E.; Kalappanavar, I.K.
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    ThesisItemOpen Access
    Studies on Etiology and Management of Wilt Complex of Betelvine (Piper betle L.)
    (University of Agricultural Science, Dharwad, 2017-09) Divya Bharathi A.R.; Benagi, V.I.
    Laboratory experiments were conducted at Department of Plant pathology, College of Agriculture, Dharwad and field experiments were carriedout under naturally infected farmer’s field at Kakol and Ranebennur of Haveri district to study the etiology and integrated management of wilt complex of betelvine (Piper betle L.). Roving survey conducted in Bagalkot, Belagavi, Davanagere and Haveri district depicted maximum wilt incidence in Davanagere district (17.2 %) during 2015-16 and in Haveri district (19.2 %) during 2016-17. The maximum disease incidence recorded in Kariyele and drumstick + Erythrina as supporting plants. Fusarium spp., Rhizoctonia bataticola, Sclerotium rolfsii and Meloidogyne spp. were major pathogens. Under variability studies, potato dextrose agar medium supported best growth of all fungal pathogens. Ten isolates of S. rolfsii, R. bataticola and 30 isolates of Fusarium spp. varied for morphological and cultural characters, the isolates of Fusarium spp. were further grouped based on their pathogenic and molecular variability. SGM-1, Swarna Kapoori, Andaman RPM and Mysore local were moderately resistant out of 20 genotypes. Under in vitro studies, non-systemic fungicide captan was effective. Systemic fungicides, hexaconazole, propiconazole and tebuconazole were effective. Carboxin 37.50 % + thiram 37.50 % and captan 70 % + hexaconazole 5 % WP were also effective. Garlic, black tulsi and turmeric extract (1:1:1) and Trichoderma harzianum (IOF isolate) was effective against all the three fungal pathogens. Adoptive module comprising of soil application of organic amendments (T. harzianum enriched Farm yard manure @ 1 kg/vine + Neem cake @ 250 g/vine), fungicides (carboxin 37.50 % + thiram 37.50 % WP @ 2.5 g/l and captan 70 % + hexaconazole 5 % WP @ 2 g/l) and nematicide (carbofuran 3G @ 100 g/vine) recorded lower disease incidence (14.57 %), highest yield (44.83 lakh leaves/ha) with the B: C ratio of 6.93:1.
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    ThesisItemOpen Access
    Studies on Coat Protein Mediated Resistance Against Chilli Veinal Mottle Virus Associated with Murda Complex Disease in Chilli (Capsicum annuum L.)
    (University of Agricultural Science, Dharwad, 2017-06) Abdul Kareem M.; Byadgi, A.S.
    Molecular identification, characterization, development of recombinant gene construct and transformation work was carried out in Departments of Plant Pathology and Biotechnology, University of Agricultural Sciences, Dharwad. Chilli plants showing typical symptoms of murda complex were collected and total RNA was isolated from diseased and healthy samples of chilli. Subsequently cDNA was synthesized from the RNA using oligo dT primer and reverse transcriptase enzyme. The cDNA was used as a template for amplification of ChiVMV, GBNV, TMV and CMV using gene specific primers. Similarly, total DNA from virus infected and healthy samples of chilli plants was isolated and used as template for amplification of ToLCV using gene specific primers. None of chilli murda complex disease samples were amplified for ToLCV, GBNV, TMV and CMV except ChiVMV with amplicon of ~531 bp was amplified. Thus, the investigation focused on molecular identification, convincingly revealed ChiVMV association with the chilli murda complex. The ChiVMV coat protein gene (~531 bp) was cloned into pTZ57R/T cloning vector. Gene sequence and BLAST analyses clearly revealed that ChiVMV coat protein gene had 95 per cent homology with the reported nucleotide sequences. Recombinant gene construct was developed by sub-cloning the ChiVMV-CP gene into plant transformation pHS100 vector. Recombinant gene construct was mobilized into Agrobacterium tumefaciens LBA4404 strain. Agrobacterium mediated flower dip method of transformation was adopted to develop transgenic chilli plants expressing ChiVMV-CP gene. Among 55 T1 plants, 18 putative transformants showed positive results for PCR and GUS analysis. Post challenge inoculation studies identified twelve T1 transgenic plants viz., 1-1, 1-2, 2-2, 2-5, 3-3, 3-4, 4-2, 6-4, 7-2, 7-5, 8-1 and 10-5 with complete resistance to ChiVMV and six T1 transgenic plants viz., 3-1, 5-4, 6-2, 7-1, 7-3 and 11-3 T1 showed delayed symptoms. Resistant T1 transgenic plants can be used to mitigate ChiVMV with further validation.