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Subject: Genetics and Plant Breeding × End date: 2018 × Start date: 2017 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    SNP Based Linkage Mapping and Qtl Analysis for Fibre Quality and Yield Traits in Gossypium barbadense l. Cotton
    (University of Agricultural Science, Dharwad, 2017-06) Mohan Kumar N.V.; Katageri I.S.
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    ThesisItemOpen Access
    Studies on Genetic Basis and Molecular Mechanisms of Spot Blotch [Bipolaris sorokiniana (Sacc.) shoemaker] Disease Resistance in Tetraploid Wheat Species
    (University of Agricultural Science, Dharwad, 2017-04) Chethana C.K.; V. Rudra Naik
    The present investigation was carried out during rabi, 2014-15 at the Agricultural Research Station (ARS), Arabhavi, UAS, Dharwad. The six generation (P1, P2, F1, F2, B1 and B2) mean analysis was used to study the gene action for spot blotch disease resistance in four durum and two dicoccum crosses. High GCV, PCV, heritability and GAM were observed for seed yield, disease severity and AUDPC. The disease severity (%) and AUDPC were negatively associated with seed yield and its components. The duplicate gene action and additive × dominance genetic effects were played an important role in genetic control of spot blotch resistance. The higher percentage of transgressive segregants for disease resistance was observed in F2 population of durum cross Bijaga Yellow × NIDW-295 (15.56 %) and in dicoccum cross DDK-1025 × DDK-50044 (11.00 %). The highly susceptible Bijaga Yellow and resistant NIDW-295 genotypes were analyzed for host pathogen interaction studies at histopathological and molecular level. The infection pattern of Bipolaris sorokiniana at different time points after inoculations was studied. The histopathological studies revealed that six host resistant components viz., number of trichomes on leaves, number of spore per lesion, spore germination, lesion size and lesion frequency were differed in resistant and susceptible genotypes. The expression stability of five housekeeping genes were analyzed by Bestkeeper, gNORM, NormFinder and comprehensive ranking methods suggested that CDC 48 was found most stable and used as reference gene for quantitative RT-PCR. The relative expression profiling of defense related genes during spot blotch infection were analyzed and showed significant up regulation of pathogenesis related (PR) genes, salicylic acid, jasmonic acid, ethylene biosynthesis and transcription factor genes at early stages of infection in NIDW-295 (Resistant) compared to Bijaga Yellow (Susceptible) implying their role in the defense response against spot blotch infection in tetraploid wheat.
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    ThesisItemOpen Access
    Genetics of Resistance to Anthracnose in Chilli (Capsicum annuum L.)
    (University of Agricultural Science, Dharwad, 2017-12) Rajaput, Sanjeevsingh; Kamatar, M.Y.
    The present study was undertaken in chilli crop at Department of Genetics and Plant Breeding, UAS, Dharwad during 2013-15 to study the inheritance pattern for anthracnose disease resistance in the two crosses derived from Byadgi Kaddi and two resistant lines GPM 288-1 and GPM 302-1. Further variability, character association and genetics of yield and component traits were studied. Efforts were also made to demonstrate breeding possibilities of using interspecific hybridization between Capsicum chinense and Capsicum annuum. Segregation pattern in the F2 exhibited ratio of 1:3, indicating that anthracnose disease resistance is governed by single recessive gene, which was further confirmed by segregation ratio of 1:1 in B1 backcross population. The F3 families showing resistance needs to be advanced to further generations to develop inbreed lines with anthracnose disease resistance. High heritability coupled with high genetic advance over means was observed for plant height, number of primary branches, number of secondary branches, number of fruits and dry fruit yield per plant in both the populations. In Byadgi Kaddi  GPM 288-1 and Byadgi Kaddi  GPM 302-1 populations, association of number of fruits per plant and fruit pericarp weight with dry fruit yield per plant was highly positive and significant. Higher estimates for colour, oleoresin and capsaicin content in all F3 lines were noticed. The F1 seeds of cross of C. chinense × C. annuum were incompatible as their hybrid expressed hybrid weakness such as VLS (virus-like syndrome). The presence of significant dominance  dominance type of gene interaction for most of the traits studied indicated that these traits can be utilized in the exploitation of heterosis.
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    ThesisItemOpen Access
    Genetic Studies on Abiotic and Biotic Stress Resistance in Maize (Zea mays L.)
    (University of Agricultural Science, Dharwad, 2017-10) Mani B.R.; Deshpande, S.K.
    Maize inbreds with drought and turcicum leaf blight (TLB) resistance were used in this study conducted at the Department of Genetics and Plant Breeding, College of Agriculture, Dharwad. Thirty one superior inbreds and two testers were crossed in line × tester design to derive 62 test hybrids. Parents, test hybrids and checks (Bio9631, Bio9681, Super 900M) were evaluated for drought tolerance and yield under stress and non-stress conditions during summer 2016 and 2017. Inbreds PDM6529, HKI163 and PDM6576 under stress and HKI163, PDM6518, PDM6529 under non-stress condition were found to be best general combiners while, the crosses PDM4211 × LM13, PDM6547-1 × LM13 and PDM6547-2 × LM13 under stress and PDM6516 × LM17, PDM6547-1 × LM13 and MLB28-1 × LM13 under non-stress condition were best specific combiners for traits related to drought tolerance and yield. Mean yield of the cross PDM4211 × LM13 under stress and non-stress conditions (81.46 q ha-1) was 12.79 per cent superior over best commercial check Bio9631 (72.22 q ha-1). Six generation mean analysis using susceptible (BM125) × resistant (BM135) parents indicated non-additive gene action for TLB resistance. Heterosis breeding approach is suitable to develop resistant hybrids. Of the 146 SSR markers used in the study, three markers viz., bnlg1045, bnlg1940 and mmc0411 were identified to be associated with TLB resistance apart from validating the linkage of marker phi109642 with TLB resistance. The best three general combiners viz., PDM6529, HKI163 and PDM6576 for drought tolerance and yield can serve as donor parents in breeding for drought tolerance these lines can be crossed in diallele fashion to derive superior hybrids. The test hybrid PDM4211 × LM13 with yield superiority has potential for commercial cultivation. New markers bnlg1045, bnlg1940 and mmc0411 linked to TLB resistance can be utilized in marker assisted selection for TLB resistance.
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    ThesisItemOpen Access
    Genetic Divergence Studies and Molecular Characterization of Fertility Restorer Genes in Mini Core Collection of Sorghum [Sorghum bicolor (L.) Moench]
    (University of Agricultural Science, Dharwad, 2017-08) Prasad, Bhima Hari Vara; Biradar, B.D.
    The present study using minicore collection of sorghum (Sorghum bicolor (L.) Moench) has (i) identified maintainers and restorers on Milo and Maldandi source of male sterility, (ii) characterized restorer genes using Rf linked markers, (iii) assessed genetic diversity and (iv) heterotic combinations using diallel crosses. It was conducted during rabi seasons of 2014 to 2017 at Main Agriculture Research Station, University of Agricultural Sciences, Dharwad. Of the 228 genotypes, 43 (25.59 %) were classified as strong restorers (R-lines) with greater than 90 per cent seedset and 22 genotypes (13.10 %) as maintainers (B-lines) with zero seedset on Milo cytoplasm. On Maldandi cytoplasm 19 genotypes (13.87 %) were strong restorers and 37 genotypes (27.01 %) were maintainers. Xtxp250 marker (SSR marker) linked to Rf1 gene at a distance of 1200 bp clearly distinguished B-lines and R-lines on Milo cytoplasm based on the presence or absence of gene. This marker can be utilized in selection of plants with Rf1 gene in segregating populations at the seedling stage itself. D2 analysis grouped 228 genotypes into 22 clusters. Cluster I comprised of maximum genotypes (115) followed by cluster II (45). Inter-cluster distance was maximum between the clusters III and XXI (33.50). Panicle weight contributed more towards divergence (25.64 %). High significant standard heterosis for yield over M 35-1 was exhibited by the crosses BJV-44 × IS 31651 (54.54) and BJV-44 × IS 26025 (38.46). The significant heterosis was observed in B × R crosses rather than B × B and R × R crosses which indicate greater diversity between B and R lines. The genotype IS 31651 was found to be good general combiner for earliness and yield.