Thumbnail Image

Thesis

Browse

2008 - 200912010 - 20131
 Reset filters

Settings

Author: Basamma ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    ThesisItemOpen Access
    Molecular phylogenetic analysis of xanthomonas axonopodis pv. punicae isolates and bio-prospecting of selected botanicals and bio-agents against bacterial blight of pomegranate
    (UASD) Basamma; V. I. Benagi
    Pomegranate, Punica granatum L., regarded as the “Fruit of Paradise” is subjected to various disease problems. Among diseases, bacterial blight caused by Xanthomonas axonopodis pv. punicae (Hingorani and Singh, 1959) Vauterin et al. is one of the important diseases, which caused a great havoc in recent years. The present investigation was undertaken to assess the diversity among different isolates collected from different agroclimatic regions and to manage this disease effectively. Water soaked lesions on leaves were produced after six days of inoculation. All the eighteen isolates of Xap showed hypersensitive symptoms in Nicotiana tabacum leaves. Colony characters of eighteen Xap isolates varied from circular and entire colony shape; slightly to highly mucoid character. Among the varied temperature and pH levels tested, 28±10C and pH of 6.0 to 7.0 were found optimum. All eighteen isolates of Xap produced fuscan pigment on LB agar after nine days of incubation. Among the bactericides, K-Cycline was found effective against all isolates of Xap, which was significantly superior to rest of the bactericides. The multiplex polymerase chain reaction was performed using template containing DNA from Xap targeting 16S rRNA and gyrB gene by 16S rRNA and gyrB specific primers. High intensity of amplification of the gene specific products of 1537 bp and 491 bp corresponding to 16S rRNA and gyrB were obtained at annealing temperature of 57.5º C for 1 minute as compared to other temperatures. Aqueous soapnut extract, Pseudomonas fluorescens strain [326(4)] and Pink Pigmented Facultative Methylotroph (PPFM) strain 10L, CuSO4, ZnSO4, COC, Streptocycline showed inhibition zone. Average fruit yield of two locations recorded significantly higher fruit yield per tree in T9 (COC 0.3% + streptocycline 0.05%) and T5 (P. fluorescens strain 326 (4) 1.0% + soapnut 5.0%) which were on par with each other. The maximum C:B ratio was observed in COC + streptocycline (0.3+0.05%).
  • Thumbnail Image
    ThesisItemOpen Access
    Integrated management of sclerotium wilt of potato caused by Sclerotium rolfisii Sacc.
    (UAS, Dharwad, 2008) Basamma; K.S.Naik
    Potato (Solanum tuberosum L.) is one of the important vegetable crops of Karnataka. Sclerotium wilt of potato caused by Sclerotium rolfsii Sacc. is one of the most important soil borne diseases which is attaining the major status in potato in Karnataka. Potato plants were raised in an inoculated pots and after 6th week a pure culture of Sclerotium rolfsii was obtained from wilted plants and pathogenicity was proved successfully. Maximum dry mycelial weight was recorded on 10th day of inoculation. Among nonsynthetic media tested against Sclerotium rolfsii, potato dextrose agar, oat meal extract agar and Sabouroud’s agar supported maximum radial growth. Among synthetic media tested, Richards’s agar supported maximum growth. The temperature of 30°C, pH of 5.0 and 12 h light and 12 h darkness were found to be the best for fungal growth. Sucrose and potassium nitrate were found to be the best carbon and nitrogen sources respectively for the growth of the pathogen. Due to infection by S. rolfsii total phenol content was increased but reducing, non-reducing and total sugars were decreased. All the cultivars screened against S. rolfsii showed highly susceptible reaction. Soil solarization increased the soil temperature maximum by 9.9°C over nonsolarized. Reduction in soil microbial population i.e. fungi, bacteria, actinomycetes and S. rolfsii was noticed in solarized plot. Among non-systemic fungicides, thiram, emisan and mancozeb recorded cent per cent inhibition at 0.1, 0.2 and 0.3 per cent concentrations. Among systemic fungicides difenconazole, hexaconazole and carboxin at 0.05, 0.1 and 0.2 per cent concentrations recorded cent per cent inhibition of S.rolfsii. Among bioagents tested maximum inhibition of the pathogen was recorded in Trichoderma harzianum. Soil solarization in combination with carboxin + Trichoderma harzianum tuber treatment along with soil application of FYM and neem cake reduced the wilt incidence and increased yield of potato.
  • Thumbnail Image
    ThesisItemOpen Access
    Molecular phylogenetic analysis of xanthomonas axonopodis pv. punicae isolates and bio-prospecting of selected botanicals and bio-agents against bacterial blight of pomegranate
    (UAS Dharwad, 2013) Basamma; V. I. Benagi
    Pomegranate, Punica granatum L., regarded as the “Fruit of Paradise” is subjected to various disease problems. Among diseases, bacterial blight caused by Xanthomonas axonopodis pv. punicae (Hingorani and Singh, 1959) Vauterin et al. is one of the important diseases, which caused a great havoc in recent years. The present investigation was undertaken to assess the diversity among different isolates collected from different agroclimatic regions and to manage this disease effectively. Water soaked lesions on leaves were produced after six days of inoculation. All the eighteen isolates of Xap showed hypersensitive symptoms in Nicotiana tabacum leaves. Colony characters of eighteen Xap isolates varied from circular and entire colony shape; slightly to highly mucoid character. Among the varied temperature and pH levels tested, 28±10C and pH of 6.0 to 7.0 were found optimum. All eighteen isolates of Xap produced fuscan pigment on LB agar after nine days of incubation. Among the bactericides, K-Cycline was found effective against all isolates of Xap, which was significantly superior to rest of the bactericides. The multiplex polymerase chain reaction was performed using template containing DNA from Xap targeting 16S rRNA and gyrB gene by 16S rRNA and gyrB specific primers. High intensity of amplification of the gene specific products of 1537 bp and 491 bp corresponding to 16S rRNA and gyrB were obtained at annealing temperature of 57.5º C for 1 minute as compared to other temperatures. Aqueous soapnut extract, Pseudomonas fluorescens strain [326(4)] and Pink Pigmented Facultative Methylotroph (PPFM) strain 10L, CuSO4, ZnSO4, COC, Streptocycline showed inhibition zone. Average fruit yield of two locations recorded significantly higher fruit yield per tree in T9 (COC 0.3% + streptocycline 0.05%) and T5 (P. fluorescens strain 326 (4) 1.0% + soapnut 5.0%) which were on par with each other. The maximum C:B ratio was observed in COC + streptocycline (0.3+0.05%).