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Birsa Agricultural University, Ranchi

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2022 - 20232
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Author: Priyanka Kumari × Start date: 2020 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    GENETIC STUDIES ON SPIKELET STERILITY AND BREEDING TECHNIQUES OF RICE (Oryza sativa L.)
    (Birsa Agricultural University, Ranchi, 2022) Priyanka Kumari; Krishna Prasad
    The present investigation was conducted at the experimental plot of Birsa Agricultural University, Kanke under the rainfed conditions of Jharkhand, India during kharif 2020 and 2021 in the F6 and F7 generation seeds of the cross Pusa-1176 x BPT-5204 respectively. The F6 generation plants were particularly examined for the trait spikelet sterility and plants to be grown in F7 generation were selected based on sterility percentage. Then, selected plants were sown as panicle to progeny rows at two different dates as set I and set II with the interval of 15 days in order to study the influence of environment on the traits under study. The traits undertaken in the research work for which the observations were recorded are basically classified into qualitative and quantitative traits. The qualitative traits include presence of awns, awn colour, leaf sheath colour, stigma colour, leaf margin colour, apiculus colour and pollen viability test whereas the quantitative traits comprised of days to flowering, number of tillers per plant, plant height, panicle length, number of panicles per plant, number of filled spikelet, number of unfilled spikelet, grain length, grain width, 100 seed weight and seed yield per plant. The chi-square test revealed that genetic ratios obtained for the segregating families were monogenic, digenic and trigenic as well for the qualitative traits concluding that it is governed by single gene, two and three genes respectively depending on the segregation pattern. It exhibited that the respective segregation ratio of each family showed dissimilar segregation pattern for both set I and set II in the family no. 42, 44, 62, 83 and 84 for the trait presence of awns, family no. 42, 44, 62, 72, 211, 288 and 309 for awn colour, family no. 230, 95, 211 and 92 for leaf sheath colour, family no. 42, 309, 72, 211, 83, 275 for stigma colour, family no. 230, 95, 71, 42, 92, 83 for leaf margin colour, and family no. 42, 71, 230, 72, 82 for apiculus colour that displayed the influence of changes in temperature and photoperiod. But the respective segregation ratio was found similar in the family no. 84 and 230 for the presence of awns, family no. 83, 84, 230 and 275 for awn colour, family no. 309, 44, 42, 72, 83, 275, 84, 82 for leaf sheath colour, family no. 44, 82, 95 for stigma colour, family no. 321, 309, 44, 62, 72, 211, 275, 84, 82 for leaf margin colour and family no. 321, 309, 62, 83, 211, 275, 92, 84, 95 for apiculus colour concluding that the behaviour and expression of the concerned genes were found persistent in both the sets sown and remained unaffected by the environmental fluctuations. In set I, presence of linkage was detected between presence of awns and awn colour in the family no. 455, awn colour and apiculus colour in the family no. 42-3, awn colour and leaf sheath colour in the family no. 455, apiculus colour and leaf margin colour in the family no. 95-7, 95-14 and 455, apiculus colour and stigma colour in the family no. 42-3, 95-7, 95-14, 230 and 455, apiculus colour and leaf sheath colour in the family no. 95-14, leaf margin colour and stigma colour in the family no. 42-3, 95-7 and 95-14, leaf margin colour and leaf sheath colour in the family no. 42-3, 95-14 and 230 and between stigma colour and leaf sheath colour in the family no. 95-14. Whereas in set II, family no. 83-6 exhibited the presence of linkage between all possible combination of the traits such as awn color, leaf sheath colour, stigma colour, leaf margin colour and apiculus colour except presence of awns. The cytological study of pollen grains via iodine-potassium iodide (I2KI) staining method revealed that pollen sterility was found to be governed by two genes since it exhibited digenic segregation ratio. The SSR marker based analysis exhibited segregation distortion among the genotypes in which amplicons of multiple alleles were found to be distributed in different segregants. The reported genes linked with the polymorphic markers were pms4, tms5, rpms1, tms4 and tms8. However, to determine the linked genes in the present research, sample size should be increased for precise and accurate assessment. The results of skewness and kurtosis that mild selection would be sufficient for improvement in the characters number of panicles, number of unfilled spikelet, 100 seed weight and seed yield per plant in set I and for days to flowering, number of tillers, number of panicles and spikelet fertility in set II whereas stringent selection might be deployed for trait improvement in panicle length and grain length in set I and only for grain length in set II. The characters number of tillers, plant height, panicle length, number of panicles, number of filled spikelet, number of unfilled spikelet, spikelet fertility, grain width, L/B ratio and 100 seed weight showed highly significant positive correlation with seed yield per plant in both the sets. But path analysis revealed that number of panicles and number of filled spikelet exhibited the highest positive direct effect on seed yield per plant in both the sets among all other characters under study and could be used as selection criteria for effective improvement of grain yield. Moreover, few EGMS segregants have been identified from set I such as plant no. 368, 1931, 2071, 2743 based on the cytological study of pollen grains and spikelet fertility. It showed highly sterile pollen grains but possessed high grain setting indicating high spikelet fertility, so it might be considered as EGMS segregant and thus could have great contribution in two-line hybrid breeding of rice. Furthermore, around 503 out of 2765 segregants from set I and 259 out of 1468 segregants from set II showed higher grain yield in terms of seed yield per pant and have been recognized as agronomically suitable segregant but further selection among these agronomically suitable segregant based on L/B ratio would be useful in identifying the segregant as consumer preferable. Hence, 50 segregants from set I with plant no. 184, 199, 248, 249, 251, 259, 368, 732, 776, 785, 801, 912, 1003, 1013, 1024, 1034, 1125, 1509, 1549, 1611, 1651, 1668, 1714, 1715, 1722, 1749, 1759, 1771, 1791, 1912, 1945, 1999, 2005, 2121, 2124, 2126, 2130, 2131, 2133, 2134, 2135, 2189, 2278, 2540, 2543, 2552, 2557, 2632, 2670, 2687 and 20 segregants from set II with plant no. 47, 58, 76, 117, 422, 621, 679, 784, 981, 1010, 1036, 1082, 1083, 1245, 1249, 1258, 1259, 1345, 1361, 1445 were found to be better performing genotypes . This would be advantageous and beneficial to the farmers in enhancing the farm produces as well as their income. However, it is concluded from the result of embryo culture that embryo could be cultured efficiently at the earliest after 14 days of pollination which might be useful in overcoming the barriers of wide hybridization and shortening of breeding cycle consequently leading to rapid generation advancement.
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    ThesisItemOpen Access
    CHARACTERIZATION OF MAIZE (Zea mays L.) GENOTYPES USING MORPHOPHYSIOLOGICAL TRAITS AND MOLECULAR MARKER
    (Birsa Agricultural University, Ranchi, 2023) Priyanka Kumari; Manigopa Chakraborty
    Maize (Zea mays L.) belongs to family, Poaceae, having worldwide growing versatility ranges from 58° N to 40° S; from below sea level to altitudes higher than 3000 m and in areas with 250 mm to more than 5000 mm of rainfall per year. Germplasm distribution across the world’s geographical area represents the wide spectrum of exploitable genetic variability for specific purpose like higher productivity or quality or combination thereof under drought stress. Drought stress being the integral part of any agro-ecosystem affecting the growth and development of crop plants. Drought is one of the major constraints in deciding maize productivity all over the world. In India, out of total maize area about 4.0 million hectares are prone to drought. Drought effects the growth and development of plants in variety of ways. For development of drought tolerant maize cultivars, the knowledge of critical sensitive stages and consequences of moisture stress, variability of germplasm, screening techniques and breeding strategies to be adopted are having very crucial importance for getting the effective result. Classical and/or molecular breeding approaches can be adopted for incorporation of available drought stress tolerant genes in appropriate genetic background. The present experiment was conducted to identify the inbreds and hybrids suitable for irrigated (30kpa) and moisture stress (50kpa) for that significant traits to be used for selection under theses environments. To determine best selection method, mean performance values, correlation coefficient, components of variance and heritability, diversity, Stress tolerance indices were analysed. Keeping above facts in mind 4 testers (drought tolerant) and 8 lines were used for development of thirty two single cross hybrids to study the genetics of yield and yield attributes under normal moisture (30kpa) and under, moisture stress condition (50kpa). Twelve parents (8 lines and 4 testers) were mated in LX T mating design, thirty two hybrids were developed and compared with checks (CM600 (inbreds), Suwan Composite, BAUMH-5 (hybrids), 1532 X Suwan (hybrids)). All the forty eight genotypes were evaluated at Research Farm, Birsa Agricultural University, Kanke, Ranchi, Jharkhand, during kharif 2020 seasons. Extensive phenotyping for morphophysiological characters along with stress indices were done for all the trials. The experimental materials were found to be significantly different from each other for all the characters under normal moisture (30kpa) and under, moisture stress condition (50kpa) and this is evident from the analysis of variance for RBD. This showed the inherent genetic difference among the genotypes under study. Correlation studies delineated that crop yield under moisture stress indicated highly significant positive genotypic and phenotypic correlation with plant height, ear height, number of plants with grain yield and number of kernels per row. This suggested that these characters can be considered for selection of plants tolerant to moisture stress. This reflected preponderance of nonadditive gene action in controlling these traits which further suggested reliable crop improvement through selection of such traits. Different genotypes responded differentially under different environments for the expression of different quantitative traits. The genotype which performs well in one environment may not perform same on the other environments. Grain yields were higher under the optimum environment compared to stress environments. Four tester parents BAUIM-1, BAUIM-2, BAUIM-5, IC622968 were found to be significantly superior stress condition for maximum number of traits including grain yield (GY/P) and yield attributing traits. These tester parents may be used for development of improved lines and hybrids for the respective environments where they were found to be significant. All the thity two Hybrids viz., IC624174 XBAUIM-2, IC624159 X BAUIM-2, IC624148 X BAUIM-2, IC624160 X BAUIM-2, IC624180 X BAUIM-2,IC624161X BAUIM-2, IC624157 XBAUIM-2, IC624151 X BAUIM-2, IC624174 XIC622968, IC624159 XIC622968, IC624148 XIC622968, IC624160XIC622968, IC624180X IC622968, IC624161 XIC622968, IC624157 X IC622968, IC624151 XIC622968, IC624174 XBAUIM-5, IC624159 XBAUIM-5, IC624148 XBAUIM-5, IC624160X BAUIM-5, IC624180 X BAUIM-5, IC624161X BAUIM-5, IC624157X BAUIM-5, IC624151 XBAUIM-5, IC624174 XBAUIM-1, IC624159 X BAUIM-1, IC624148 X BAUIM-1, IC624160 X BAUIM-1, IC624180 XBAUIM-1, IC624161 XBAUIM-1, IC624157 X BAUIM-1, IC624151 X BAUIM-1 under stress condition were found to be significantly superior for maximum number of traits than the best check including grain yield (GY/P ) observed through the standard heterosis. These superior hybrids may be used for cultivation or development of superior segregants depending upon their gene action and effect. The analysis of variances for L x T analysis under normal moisture condition (30kpa) and moisture stress (50kpa) revealed significant difference in environments for all the forty six morphophysiological traits confirming diverse nature of environments selected, which influenced the expression of the traits studied among each other in relation to the performance of the genotypes. All The traits showed non-additive genetic variance with over dominance effect of genes under all the environmental situations indicating the over expression of heterozygous loci for these characters. The predominance of non-additive gene action on implies that breeding gains can be made via inbreeding followed by crossbreeding. The type of genetic effects for grain yield is highly variable, depending on the type of parents and environments under consideration. Molecular analysis indicated that the genotypes IC622968 and IC624176 were the most diverse ones. These diverse parents can be used for development of superior hybrids and segregants tolerant to stress condition. These superior hybrids may be used for cultivation or development of superior segregants depending upon their gene action and effect. The hybrids were good performer (heterotic) across the different moisture regimes under variable moisture regimes. These hybrids may be recommended for cultivation under wide range of environment. For leaf characters angle between blade and stem under irrigated condition and non-irrigated condition maximum frequency of (55.55%) and (72.22%) as found for “small” state of expression while minimum frequency (4.44) found for “medium” state of expression under moisture stress condition. AMOVA (Analysis of molecular variance) revealed mean sum of squares due to genotypes showed highly significant differences for all the traits under study at 5% and 1% level of significance. In molecular Dendrogram picture using Jaccard’s similarity coefficient ranged from 0.52 to 0.95. Further this 2 main clusters were classified into 6 subcluster. Further, Cluster A showed four subcluster and Cluster B showed two subcluster.