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ThesisItem Restricted Heterosis and Combining Ability Studies for Yield and Baby Corn Traits in Maize (Zea mays L.)(University of Agricultural Science, Dharwad, 2016-07) Bhat, Lasya; Deshpande, S.K.Baby corn is the ear of maize plant harvested at immature (unfertilized) stage. Despite high demand and market potential, very little information is available on breeding strategies followed for improvement in baby corn. Hence, this investigation was undertaken to evaluate field corn 50 inbreds and 55 hybrids (generated from eleven lines identified for baby corn traits and five testers using line x tester design) for baby corn and grain yield traits and also to study heterosis and combining ability. PDM-24-3 and PDM-53 were superior inbreds for the baby corn traits. PDM-112-2 and PDM-56-2 were superior for grain yield and related traits. HKI-163 x BLSB-5, PDM-112-2 x BLSB-5 and CM-150-Y-1 x BLSB-5 were the superior crosses for baby corn traits. CM-136-1 x NK 6240 M-2 followed by CM-150-Y-1 x PDM-260-2 and PDM-6571 x PDM-167-1 were the superior combinations for grain yield. The combination, HKI-163 x BLSB-5 was good for both baby corn and grain yield. Based on pooled combining ability, lines HKI-163 and PDM-112-2 and tester BLSB-5 were the excellent combiners for baby corn traits and PDM-112-2 x BLSB-5 was the best combination. For grain yield and related traits, the lines CM-136-1 and CM-150-Y-1 and tester CM-135-1 were excellent combiners. Among the hybrids CM-136-1 x NK 6240 M-2 was the best specific combination for grain yield. The superior combinations based on pooled sca value for baby corn traits, viz., HKI-163 x BLSB-5, PDM-112-2 x BLSB-5 involved the parents representing different heterotic groups based on SCA_PY (Specific Combining Ability combined line Pedigree and hybrid Yield) and HSGCA (Heterotic group’s Specific and General Combining Ability) methods.ThesisItem Open Access Genetic Diversity Studies for Durable Leaf Rust Resistance in Wheat(University of Agricultural Science, Dharwad, 2016-07) Shalini D.N.; Kamatar, M.Y.Leaf rust is the major disease which causes much yield losses to wheat crop worldwide. Genetic resistance is the most economical and effective method for the control of the disease. Hence, the present investigation was undertaken during rabi 2015-16 in Dharwad under both natural and epiphytotic conditions using 500 genotypes to know the extent of disease development. The 500 genotypes were screened for presence of slow rusting genes in laboratory. Of the 500 genotypes, 9.8 per cent had Lr34 gene, 20.6 per cent had Lr46, 22 per cent had Lr68 and 3.8 per cent had Lr67. The 500 genotypes were evaluated under field condition indicate the presence of 57 slow rusting genotypes. Three gene combination of Lr34, Lr46 and Lr68 was observed in UP 262 whereas HYB 65 carried other combination of Lr46, Lr68 and Lr67. Combination of Lr34+Lr46+Lr68 produced higher yield than Lr46+Lr68+Lr67 which can be utilized in durable resistance breeding. Tetraploid wheat and hexaploid wheat genotypes were grouped separately into eight and thirteen clusters respectively using K-means cluster analysis. Cluster V of tetraploid genotypes recorded highest cluster mean values for thousand grain weight (43.93 g) and grain yield (81.30 g) whereas in hexaploid genotypes cluster VI recorded highest cluster mean values for thousand grain weight (39.2 g) and cluster III recorded highest grain yield (87.02 g) which suggested that genotypes from these clusters can be used to get superior segregants for these traits. Number of seeds per spike and grain yield recorded high heritability estimates in hexaploid genotypes whereas in tetraploid genotypes days to flowering, spike length, thousand grain weight and grain yield recorded high heritability coupled with high GAM in both natural and epiphytotic conditions indicating presence of additive gene action which helps in deciding the scope of improvement through selection for the development of superior varieties.ThesisItem Open Access Studies on Genetics of Qtls for Yield, Yield Component and Fibre Quality Traits in Cotton(University of Agricultural Science, Dharwad, 2016-08) Nagaraju CH; Khadi, B.M.To understand the types of gene action controlling sixteen yield, yield component and fibre quality traits in cotton, QTL mapping was performed to dissect the main-effect QTLs (M-QTLs) responsible for the trait performance in 150 recombinant inbred lines (RILs) of interspecific hybrid DCH-32 and two testcross (TC) F1 populations derived from these RILs. Totally, 450 genotypes along with six checks were evaluated at two locations (Dharwad and Devihosur) during kharif 2015 in augmented design. The analyses of variance and the PCV and GCV indicated the presence of wide genotypic and phenotypic variation for all the traits studied. Correlation between seed cotton yield and fibre length and strength were negative. The TC hybrids viz., DRBH-83 x Sahana (3,490 kg/ha) followed by DRBH-56 x Sahana (3,318 kg/ha) and DRBH-32 x Sahana (3,317 kg/ha) recorded significantly higher seed cotton yield compared to check, DHH-11 (2,407 kg/ha). DRBH-63 x Surabhi, recorded significantly higher seed cotton yield (3198 kg/ha) with significantly higher fibre length (29 mm) and strength (27.20 g/tex). The genetic linkage map constructed in RIL populations using Cotton SNP 63K array Bead Chip was utilized for QTL analysis in RILs and TC hybrids. Totally, 95 M-QTLs were identified and classified into two predominant groups, additive QTLs (74) detected primarily in RILs and dominant QTLs [21; 5 (23.80%) from TCF1s of Sahana and 16 (76.19%) from TCF1s of Surabhi] identified exclusively in TC populations. Over-dominant QTL (qSCY-22-1) flanked by i57905Gb and i01031Gh markers (11.96 and 13.33% phenotypic variation) were found common between TCF1 of Surabhi and Surabhi Hmp. In between i38941Gh and i11395Gh markers, three traits viz., lint index (qLI-25-1), ginning outturn (qGOT-25-1) and seed cotton yield (qSCY-25-1) were co-localized on chromosome 25. Genetic effects of these identified QTLs with linked markers have significant implications in genetic improvement of cotton through marker assisted selection.ThesisItem Open Access Genetic Analysis of the Traits Related to Mechanical Harvesting in Chickpea (Cicer arietinum)(University of Agricultural Science, Dharwad, 2016-08) Shridevi B.M.; V. Rudra NaikThe objective of the present study was to assess the genetic variability, inter character association, diversity, gene action and to identify potential cross combinations for the traits related to mechanical harvesting and yield attributes in chickpea. Present investigation revealed considerable variability and heritability for majority of traits. Correlation studies indicated highly significant negative relationship between productivity traits and traits related to mechanical harvesting. D2 analysis revealed that number of seeds per plant, days to maturity and seed yield per plant contributed maximum to the divergence. In total, 58 genotypes were screened and twelve genetically diverse genotypes were selected for developing cross combinations in LxT design. For the traits related to mechanical harvesting, line ICCX 40183 and tester ICCX 40111 were the best general combiners. Genotypes like RVSSG 9, BGD 1068 and Phule G 0215-2 were found to be very good sources of favorable genes for yield related traits. Crosses like AT 2-3 x RVSSG 10 and Phule G 0215-2 x ICCX 40111 were found superior for most of the mechanical harvesting traits. For productivity traits, crosses like GJG 0907 x BGD 1070, GJG 0907 x BG 256 and RVSSG 9 x ICCX 40111 showed significant sca effects. Among 36 crosses, seventeen were evaluated for generation mean analysis. The magnitude of non-additive gene action was predominant in nature with duplicate epistasis for most of the traits studied suggesting development of multiple crosses and raising of large segregating populations followed by intermating of desired segregants could help in enhance the frequency of additive genes. Based on the combining ability studies and performance of F2 crosses, segregants of crosses viz., AT 2-3 x ICCX 40111, RVSSG 9 x RVSSG 10 and RVSSG 9 x BG 256 were found to be potential for combining mechanical harvesting and productivity traits.ThesisItem Open Access Germplasm Screening and Genetic Analyses for Drought Tolerance Improvement in Maize (Zea mays L.)(University of Agricultural Science, Dharwad, 2016-08) Musvosvi, Cousin; Wali, M.C.Drought is one of the major abiotic challenges to maize production in India and in the world. This study focused on identification and development of drought tolerant germplasm and understanding the genetics of drought tolerance in maize. Hundred inbred lines were screened for drought tolerance and the following were selected: DMR-M-81, M4, FA6, DMR-M-83, GPM36, DMR-M-88, DMR-M-84, M39, M53, FA3, GPM43, and M53. Lines DMR-M-88, FA6, GPM36, M39, and M53 were stable across environments. The twelve drought tolerant lines were involved in half diallel analysis. Pooled (across traits) general combining ability effect (gca) of lines and pooled specific combining ability effect (sca) of crosses were estimated. Good general combiners under drought were: DMR-M-88, M39, FA3, and GPM43. Five among best crosses under drought, namely [FA3 / M39], [GPM43 / DMR-M-88], [DMR-M-84 / DMR-M-83], [FA3 / DMR-M-81], and [DMR-M-83 / FA6], had positive sca effects both under drought and well-watered conditions. Two crosses, [FA3 / M39] and [GPM36 / M4] were high yielding and stable across diverse environments. Genetic distances (GD) among the twelve lines were estimated using microsatellite (SSR) marker data. The correlation coefficient between GD and mid-parent heterosis in respect of grain yield under drought was significant and negative, but low and unreliable for predictive purposes. The correlation coefficients between GD and per se performance and sca were not significant. Lines GPM36, DMR-M-88 and FA6 were good general combiners in a study involving the twelve tolerant lines and two adapted hybrid testers. The testers, BIO-9681 and ARBMH-1 differed in terms of mean testcross grain yields, implying differences in gene frequencies at loci governing grain yield. Regarding interrelationship among traits under drought, grain yield (t ha-1) (GY) was highly and positively correlated with ears per plant, ear length, ear diameter, number of kernels per ear row, number of kernels per ear, and grain yield per plant. Conversely, GY was highly and negatively correlated with drought susceptibility index. In generation mean analysis under drought, additive gene effects were important for inheritance of anthesis-silking interval. For grain yield and its component traits, non-additive gene effects were more important.ThesisItem Open Access Stability Analysis in Advanced Breeding Lines and Bruchid Resistance Studies in Cowpea [Vigna unguiculata (L.) Walp.](University of Agricultural Science, Dharwad, 2016-08) Vishwanathreddy K.H.; Deshpande, S.K.An experiment was carried out involving twenty seven promising advanced breeding lines which were in F6 generation and three promising germplasm lines of cowpea along with four checks viz., DCS-47-1, DC-15, C-152 and DC-16 at three diverse locations to assess the stability of genotypes. According to Eberhart and Russel stability model (1966) the stable genotypes identified for seed yield (kg ha-1) were F6 progenies of crosses namely, C-152 × IC 198701, C-152× IC 201079, C-152 × IC 202710, GC-3 × IC 202872 and V-118 × IC 249141. The promising genotypes identified for yield per se were F6 lines of crosses viz., DC-15 × DCS-47-1, C-152 × CP-206, DC-15 × Subhra, C-152 × IC 97767 and DC-15 × JOB-129. In cowpea, bruchid (Callosobruchus maculatus F.) is the most serious storage pest due to the fact that cowpea is the primary host in India. It causes 90 to 100 per cent loss in seed quality upon progressive storage. The resistance of cowpea to bruchid infestation has been a major concern to plant breeders as some elite cowpea varieties become susceptible to the bruchids. Keeping this point in view, screening of 250 F3 segregants of cross between DC-615 × Dharwad local was carried out against bruchids (Callosobruchus maculatus F.). Bruchid infestation (%) measured through different damage parameters revealed that segregants viz., F3-2, F3-95, F3-221, F3-223, F3-199, F3-4, F3- 24, F3-92, F3-232 and F3-241 were found superior for bruchid resistance because they exhibited least bruchid infestation, minimum per cent seed damage, minimum actual and apparent weight loss, minimum number of bruchids emerged. The parameters related to germination and vigour of seeds were influenced to the lowest degree from the damage by bruchids.ThesisItem Open Access Stability Analysis for Nitrogen Use Efficiency in Bread Wheat (Triticum aestivum L.)(University of Agricultural Science, Dharwad, 2016-08) Malipatil, Ramanagouda; Kamatar, M.Y.Thirty bread wheat (Triticum aestivum L.) genotypes were evaluated to determine the stable performance for grain yield in relation with nitrogen use efficiency at four levels of nitrogen (0, 50, 100 and 150 kg/) application across the three environments viz., Dharwad, Nippani and Ugar during rabi, 2015-16. Stability model Additive Main Multiplicative Interaction (AMMI) showed significant differences among the genotypes, environment and genotype x environment interaction. Genotype x environment interaction further partitioned into principal component analysis 1 which was significant. Mean grain yield across the different levels of nitrogen indicated that grain yield increased from 2,485 kg/ha to 3,704 kg/ha with increase in nitrogen application from 50 kg/ha to 100 kg/ha but decreased at 150 kg/ha nitrogen. The mean nitrogen use efficiency increased from zero nitrogen level (14.94) to 50 kg/ha nitrogen (15.27) application then decreased with the increased application of nitrogen from 50 kg/ha to 150 kg/ha. The AMMI biplot analysis indicated that following genotypes were superior for grain yield with nitrogen use efficiency and were stable across the three environments at different levels of nitrogen application: Zero level: DBW 14, Third SATYN 9402, and Second WYCYT 34 50 kg/ha: WH 1022, Third SATYN 9402, Fifth CISA HTEM 10211 and Second WYCYT 34 100 kg/ha: Fifth CISA HTEM 10211 and Fifth CISA HTEM 10212 150 kg/ha: Fifth CSISA HTEM 10228, Fifth CISAHTEM 10211, HD 2189 and HD 2967. Ugar environment was better for expression of grain yield and nitrogen use efficiency. These identified stable genotypes can be used as donor parents for transferring high yield with high nitrogen use efficiency to the locally well adapted varieties.ThesisItem Open Access Genetic Diversity and Variability Studies for Drought Tolerance in Bread Wheat (Triticum aestivum L.)(University of Agricultural Science, Dharwad, 2016-08) Deepak D.A.; Biradar, Suma S.The uncertainty of sufficient moisture availability necessitates the development of wheat varieties for drought situation. The main objective of this investigation was to dissect out the drought tolerance mechanisms in different genetic backgrounds by conducting separate experiments using hundred genotypes in drought and irrigated condition by following alpha lattice design during rabi 2015-16. The traits like leaf waxiness, ground cover, tillers per meter and grain yield exhibited high GCV and PCV. High heritability coupled with high genetic advance as per cent mean were observed for traits like plant height, leaf waxiness, spike length, tillers per meter, grains per spike and grain yield. The indices viz., Stress Susceptibility Index (SSI) and Stress Tolerance Index (STI) were adopted to identify drought tolerant genotypes. Ten genotypes based on SSI and five genotypes by STI, were identified as drought tolerant. It is interesting to note here that drought tolerant genotypes identified in the present investigation exhibited comparable root parameters with standard checks along with other physiological parameters. Among which, early vigour, early completion of life cycle, higher flag leaf chlorophyll content, high membrane stability, root length and root volume contributed to drought tolerance under different genetic backgrounds. The traits viz., spike length, thousand grain weight, spikelets per spike, relative water content and tillers per meter were found to be least sensitive for moisture stress and exhibited high genetic diversity. It is deduced from both the indices that the genotype UAS 323 recorded higher yield under moisture stress which was manifested by higher spike length, thousand grain weight, grains per spike and biomass. Markers xbarc319, xgwm626, xgwm540, xgwm557, xwmc323 and xwmc634 showed polymorphism and can be further validated. Thus, identified trait specific drought tolerant genotypes can be used to identify QTLs with the help of molecular markers.ThesisItem Open Access Development and Evaluation of Turcicum Leaf Blight Resistant Hybrids Using Newly Developed Inbred Lines of Maize (Zea mays L.)(University of Agricultural Science, Dharwad, 2016-07) Kiran K.K.; G. ShanthakumarAn investigation was carried out to screen 36 maize inbred lines against turcicum leaf blight under artificial epiphytotic condition during kharif 2014 at the Main Agricultural Research Station, UAS, Dharwad. Ten inbred lines showed resistant reaction, of which inbred lines viz., DMIT 105, DMIT 113 and DMIT 118 exhibited lowest terminal per cent disease index and area under disease progress curve which can be considered as slow blighters. Nine inbred lines viz., DMIT 105, DMIT 106, DMIT 111, DMIT 113, DMIT 118, DMIT 121, DMIT 123, DMIT 124 and DMIT 125 based on resistance against turcicum leaf blight, per se performance were selected and crossed to develop 36 single crosses following half diallel mating design. The combining ability analysis revealed presence of higher magnitude of SCA variance than GCA variance indicating predominance of non-additive gene action for most of the traits except kernel rows per cob. The parents DMIT 123 and DMIT 125 were found best for most of yield and its contributing traits as they showed significant gca effects. The crosses, DMIT 105 × DMIT 121, DMIT 118 × DMIT 124, DMIT 121 × DMIT 125 and DMIT 123 × DMIT 125 were found best specific combinations for grain yield with highest sca effects and were found resistant to turcicum leaf blight. The generation mean analysis in the cross DMIT 126 × DMIT 136 indicated duplicate gene action for plant height, kernel rows per cob, kernels per cob, cob weight per plant, hundred grain weight, shelling percentage and grain yield per plant. Single marker analysis in F2 population of the cross DMIT 126 × DMIT 136 revealed Phi 330507 and Umc 1221 markers were closely linked to turcicum leaf blight resistant gene and accounted for 13.77 and 22.72 % of the total variance with LOD of 8.01 and 13.94, respectively.
