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Author: Amit Kumar × End date: 2024 × Start date: 2020 × Type: Thesis ×
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    ThesisItemOpen Access
    Assessment of genetic variability in exotic germplasm of rice (Oryza sativa L.)
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-12) Amit Kumar; Indra Deo
    The present investigation entitled Assessment of Genetic Variability in Exotic Germplasm of Rice (Oryza sativa L.) was undertaken to: (i) evaluate the rice germplasm lines for yield and yield components, (ii) estimate correlation coefficients between different characters, (iii) study direct and indirect effects of yield components on grain yield by path coefficient analysis, and (iv) examine genetic divergence existing in the germplasm collections of the present study. In the present investigation, 299 genotypes of rice germplasm collections, including three checks, showing wide spectrum of variation for various characters, were evaluated in under timely sown and irrigated conditions during Kharif, 2019. The experiment was conducted in augmented design having two blocks at the Norman E. Borlaug Crop Research Centre, Pantnagar. The characters studied were days to 50% flowering, yield/plot, yield kg/h, Plant height (cm), number of tiller/plant, number of filled grain, number of unfilled grain, spikelet fertility (%), 1000 grains weight (g), seed length (mm), seed breadth (mm), L/B ratio. The mean, range, and least significant differences, correlations, path-coefficients and genetic divergence were all calculated using the data from these thirteen characters. The genotype, EC19-100 (8209.32 kg) produced highest grain yield per plant followed by EC19-50 (7403.76 kg), EC19-107 (5948.19 kg), EC19-102 (4987.07 kg) and EC19-19 (5014.85 kg). These five genotypes showed good mean performance for these genotypes. These genotypes could be utilised as parents in a rice hybridization effort aiming at creating high-yielding cultivars. Grain yield per hectare exhibited highly significant and positive correlations with yield per plot and 1000 grain weight and seed length. Path analysis identified Grain yield per plot, followed by spikelet fertility and number of filled grains employed very high order positive direct effects on grain yield per hectare while seed breadth, number of effective tillers per plant, days to 50% flowering and panicle length showed as most important indirect yield components. The Non-hierarchical Euclidean cluster analysis grouped 299 genotypes in to eight clusters. The highest inter-cluster distance was observed between cluster III and VII (6.125) indicating very high degree of genetic diversity between these two clusters. The lowest inter-cluster distance was observed between cluster VI and VIII (1.556), followed by cluster III and VI (1.898) and cluster I and II (1.938). The highest inter-cluster distance was recorded between cluster III and VII (6.125) indicating very high degree of genetic diversity between these two clusters. Thus, crossing of single genotype of cluster III, namely, EC19-19, EC19-65, EC19-107, EC19-108 and EC19-187 with EC19-171, EC19-259, and EC19-283 of cluster VIII is recommended obtaining transgressive segregants for developing high yielding lines of rice. Similarly, crossing of EC19-287 and EC19-271 belonging to cluster VIII with promising genotypes of clusters having very high inter cluster distances from it, namely, EC19-43, EC19-50, EC19-55, EC19-74, EC19-100, EC19-153, EC19-158 and EC19-199 of cluster II is also recommended for isolating desirable segregants.
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    ThesisItemOpen Access
    Comparative study on the melting rate of PCM for circular and semi-circular LHTES system
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-02) Amit Kumar; Verma, Prashant
    Latent heat thermal energy storage (LHTES) technique using different types of phase change materials (PCM) has become popular in the last few decades. It helps to reduce the problems related to discrepancy between supply and demand of energy. In the present study, the melting characteristics of a lauric acid in a semi-circular and circular latent heat storage unit has been studied. The low melting rate of PCM in the lower half of a circular heat storage unit can be enhanced by confining the PCM in the upper region by configuring the outer shell of semi-circular cross-section. The recent literature shows that no work has been carried out on the effect of the melting performance of PCM in a semi-circular LHTES unit. So, it has been decided to investigate the melting performance of PCM experimentally and numerically for semi-circular LHTES system. The investigation of the melting performance of PCM in a semi-circular heat storage unit has been done through by developing a numerical 2D model which has been analysed through ANSYS FLUENT. The results obtained from numerical simulation are validated through experimental results. The enhancement in the melting rate at three different inner tube position values (e = 0.20, 0.23 and 0.25) for inner tube from the bottom surface of outer semi-circular shell is investigated and it is found that the enhancement is maximum when the inner tube is nearest to the bottom surface of the outer shell i.e., for e = 0.20. The melting performance of PCM is also studied for different values of inlet temperature of heat transfer fluid for tube position e = 0.20 and it is observed that the increase in Stefan number, enhances the melting rate of PCM in semi-circular LHTES system. The semi-circular heat storage unit is also compared with circular heat storage unit by considering the equal quantity of PCM in both the cases. The semi-circular LHTES system shows enhancement in melting performance of PCM as compared to circular LHTES system. The semi-circular LHTES system melts the PCM completely in almost half time as compared to circular LHTES system. It is found that the thermal energy stored in PCM for semi-circular LHTES system is 416.4 KJ which is 12.04 % more as compared to TES of PCM for circular LHTES for the same time duration of 4800 sec and the thermal energy storage efficiency of semi-circular LHTES unit is 11 % more as compared to the circular LHTES unit.