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2017 - 20183
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Subject: Crop Physiology × End date: 2018 × Start date: 2017 × Thesis Type: Ph.D ×
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Now showing 1 - 3 of 3
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    ThesisItemOpen Access
    "Effect of Temperature Regimes on Chickpea (Cicer arietinum L.) Productivity"
    (University of Agricultural Sciences, Dharwad, 2018-06) Kiran, B.O.; Chimmad, V.P.
    Chickpea (Cicer arietinum L.), in its reproductive stage, is sensitive to day/night temperatures with consequent substantial loss of potential yields at high temperatures. Two field experiments were conducted with 44 and four genotypes under three temperature regimes (D1: 41st, D2: 44th and D3: 48th SMW) during rabi, 2015-16 and 2016-17 at Main Agricultural Research Station (MARS), Dharwad. Among four genotypes, JG-11 recorded least pollen sterility (17.15 %) followed by JG 14 (17.49 %), while crop sown in 41st SMW recorded least pollen sterility (19.42 %) when compared to crop sown in 44th and 48th SMW. Genotype, Annigeri-1 recorded maximum pollen germination (62.90 %) and pollen tube length (171.36 µm). Crop sown in 44th SMW significantly higher seed yield (24.19 q ha-1) followed by 41st SMW (22.17 q ha-1). However, genotype JG 11 recorded maximum seed yield (23.12 q ha-1) followed by JG 14 and Annigeri-1 (21.75 and 21.22 q ha-1 respectively). The overall reproductive phase efficiency was stable in JG 11 across environments. Among 44 genotypes, the total chlorophyll, membrane stability index, SPAD values recorded at 65 DAS was higher in crop sown in 44th SMW compared to 48th SMW. The seed yield was significantly higher for crop sown in 41st SMW (13.29 g plant-1) followed by 44th SMW (11.95 g plant-1). Among the genotypes, JAKI 9218 recorded higher seed yield (19.25 g plant-1) followed by GCP-107 and PA 0102334 (18.59 and 17.32 g plant-1, respectively). Genotypes, ICC-4958, GCP-107, BGD-9812, ICC-5383 and BGD-132 recorded higher stability for grain yield across environments. However, genotypes GCP-107 (23.54 g plant-1), PA-0102334 (19.66 g plant-1) and BGD-1044 (18.37 g plant-1) recorded higher yield and yield components under normal sown conditions (44th SMW), while H-206, ICCL-82108, ICC-88201, RSG-44, Local Collection, ICC-5383, AKG-70 and ICC-1745 were found suitable for late sown condition (48th SMW) for grain yield. Mean performance but confined to specific environments. Genotype ICCV-2 and JG-130 was found early with average regression coefficient and least deviation recommended for late sown conditions. Further, genotypes, The maximum pollen germination and least pollen sterility was recorded under 44th SMW (40.86%) and 41st SMW (17.10 %). Genotype, ICC-790197 recorded least pollen sterility (12.56%), while maximum pollen germination was recorded in genotype JAKI 9218 (69.95%) followed by Annigeri -1 (63.83%). Genotypes, ICCV-2, JG-130, JG-11, GCP-107, MI-35 and BGD-9920 were highly stable for seed yield under 44th SMW. The environment index was higher under 41st and 44th SMW for genotypic adaptability. Further, the degree of association for seed yield and components decreased with delayed sowing. Under 44th SMW, seed yield recorded positive association with pod number, pod weight, total flower production, total dry matter, test weight and harvest index. The experiment concluded that, reproductive efficiency for heat stress tolerance was higher in genotypes ICC-4958, GCP-107, BGD-9812, ICC-5383 and BGD-132 and further helpful in breeding program.
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    ThesisItemOpen Access
    Development and Identification of Drought Tolerant Maize (Zea mays L.) Hybrids
    (University of Agricultural Sciences, Dharwad, 2018-01) Patil, Akshata S.; Mummigatti, U.V.
    The investigation was carried out to elucidate the genetic mechanisms underlying the drought tolerance in maize by withholding water before fifteen days of anthesis and silking interval at the Main Agricultural Research Station, University Agricultural science’s Dharwad. From the 100 inbred lines evaluated (rabi / summer 2014-15) ten drought tolerant inbred lines (DMIL 230, DMIL 438, DMIL 447, DMIL 516, DMIL 553, DMIL 607, DMIL 692, DMIL 715, CML 425 and NC 468) were selected based on genetic diversity (D2) and morphological traits for developing 45 single cross hybrids through half diallel mating design (kharif, 2015). These 45 hybrids and their parents were further evaluated during rabi / summer, 2016. Identified five top yielders (DMIL 438  DMIL 447, DMIL 512  DMIL 692, DMIL 425  DMIL 230, DMIL 448  DMIL 607 and DMIL 438  NC 468), five drought susceptible yielders their parents and two checks (CP-818 and GH-0727) were evaluated during rabi / summer, 2016-17 for drought tolerance. Simultaneously, evaluated for various root and shoot morphological traits under water stress condition in polythene bag upto 60 DAS. Five hybrids viz., DMIL 516  DMIL 230 (6,338 kg/ha), DMIL 553  DMIL 447 (3,687 kg/ha), CML 425  DMIL 516 (3,905 kg/ha), DMIL 607  DMIL 516 (3,416 kg/ha) and NC 468  DMIL 692 (3,641 kg/ha) were superior drought tolerant hybrids based on relative water content, chlorophyll content, anthesis to silking interval, root traits and yield components under water stress condition. DMIL 715, CML 425, DMIL 447 and DMIL 516 have the best general combining ability for drought tolerance. These hybrids and the general combiners can be considered for moisture stress situations and for developing hybrids for drought tolerance, respectively.
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    ThesisItemOpen Access
    Drought Tolerance Studies in hirsutum Cotton Genotypes
    (University of Agricultural Science, Dharwad, 2017-10) Megha B.R.; Mummigatti, U.V.
    Experiment with 20 cotton (Gossypium hirsutum) genotypes planned for screening for water stress tolerance. Initially, laboratory screening for seed germination and seedling growth under different osmotic stress (using Polyethylene glycol-6000 solution) and seedling growth under different soil moisture levels (grown in polybags) were conducted during 2014-15 at ARS, Dharwad. The osmotic screening was done using PEG-6000 with different osmotic potentials viz., 0 MPa (control), -1.47 MPa (10 %) and -3.49 Mpa (20 %) and polybag growth study was conducted in rain out shelter with different field capacities moisture levels viz., 100, 50 and 25 per cent. Observations on germination percentage, root length, shoot length, root to shoot ratio, leaf proline and chlorophyll content were measured. From these studies, ten genotypes viz., BS-37, BS-39, ARBH-1352, GBHV-182, PH-1060, SCS-1062, TCH-1777, GSHV-169 and AKH-09-5 were identified as drought tolerant. These ten identified genotypes along with two checks (RAH-100 and LRA-5166) were subjected for field performance for two seasons. The selected 12 cotton genotypes were further evaluated in field condition during kharif 2015-16 and 2016-17 under rainfed and need based irrigated (flowering and boll development) conditions. Observations on morpho-physiological, phenological, biochemical, yield and yield components were recorded. The pooled data of two years was analyzed under split plot design. Significantly higher seed cotton yield was recorded under rainfed condition as compared to irrigated condition. Mainly relative water content (-10.55), cell membrane stability (15.61 %), specific leaf weight (-4.52 %), excised leaf water loss (16.48 %), stomatal frequency (16.72 %), trichome density (-29.91 %), chlorophyll (7.41 %), proline (-75.00) and phenol (-9.61) content which indicates the tolerance of these genotypes to water stress condition . Based on the criteria of least per cent reduction in maximum number of parameters, five cotton genotypes GSHV-169, BS-37, BS-39, AKH-09-5, ARBH-1352 were identified as more tolerant to water stress.