Browsing by Author "BAYYAPU REDDY, K"
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ThesisItem Open Access GENETIC ANALYSIS OF FIBRE QUALITY TRAITS IN INTRASPECIFIC HYBRIDS OF COTTON (Gossypium hirsutum L.)(Acharya N.G. Ranga Agricultural University, Guntur, 2015) BAYYAPU REDDY, K; Dr. V. CHENGA REDDYThe present study on “Genetic analysis of fibre quality traits in intra-specific hybrids of cotton (Gossypium hirsutum L.)” was conducted to elicit the information on the genetic diversity among the genotypes, character association, direct and indirect effects of yield components, type of gene action and combining ability effects in intraspecific hybrids of cotton, heterosis of hybrids, stability parameters of hybrids over environments for yield, yield components and quality characters and to identify the donor parents having favourable alleles. Ten parents (G. hirsutum L.) were selected based on their performance in genetic divergence study with 63 genotypes during kharif, 2012-13. Forty five intra-specific cross combinations were made in a half-diallel fashion during off season at RARS Lam Farm, Guntur, Andhra Pradesh. Evaluation of these hybrids along with the parents and standard check was carried out at three locations i.e., RARS Lam, Guntur, ARS, Jangamaheswarapuram and ARS, Darsi during kharif, 2013-14. The three methods of grouping revealed the presence of genetic divergence among the selected 63 cotton genotypes. D2 analysis and Ward’s minimum variance method grouped the 63 cotton genotypes into 8 clusters each. In D2 analysis, lint index followed by micronaire, seed index, days to 50% flowering contributed maximum for the divergence. In Principal component analysis seven principal components (PCs), contributed 84.004 per cent of cumulative variance. The first principal component contributed maximum towards variability (23.799). Ten divergent genotypes NDLH 1938, L 788, L 770, NA 1325, L604, SURABHI, RAH 1004, HYPS 152, MCU 5 and G COT 16 were selected for crossing based on their per se performance for different characters along with inter-cluster distance in Mahalanobis’ D2, principal component and cluster analysis. The analysis of variance revealed significant differences among the genotypes for all the characters under study. Wider genetic variability was observed for lint index, seed cotton yield plant-1 and lint yield plant-1. High heritability coupled with high genetic advance as per cent of mean was observed for number of bolls plant-1, seed index, lint index, ginning out-turn, micronaire, seed cotton yield plant-1 and lint yield plant-1. The character association analysis revealed that number of monopodia plant-1, number of bolls plant-1, boll weight, chlorophyll content, 2.5% span length, bundle strength and lint yield plant-1 has significant positive association with seed cotton yield plant-1 at both phenotypic and genotypic levels. The path coefficient analysis indicated that the number of bolls plant-1, boll weight, seed index, 2.5% span length and lint yield plant1 showed direct positive effects and significant positive correlation with seed cotton yield plant-1 indicating their importance in direct selection. The pooled analysis of variance of 56 genotypes (45 hybrids, 10 parents and 1 check) showed significant differences due to locations, parents, hybrids and various interactions indicating the existence of sufficient variation in the material under study. The ratio of gca to sca indicated the presence of non-additive gene action in all the characters except for days to 50% flowering and 2.5% span length. The gca effects from pooled analysis revealed that none of the parent recorded significant gca effects for all the characters. Among the parents, NDLH 1938 showed significant positive gca effects for most of the yield and quality characters. The crosses, NDLH 1938 × L 604, NDLH 1938 × RAH 1004 and NDLH 1938 × L 770, recorded high per se performance, significant positive sca effects and high standard heterosis over the standard check, Bunny, for seed cotton yield plant-1. Genotype × environment interaction studies with Eberhart and Russell model revealed that no hybrid had stable performance for all the characters in all the locations. The hybrids, NDLH 1938× NA 1325, NA 1325 × MCU 5, SURABHI × MCU 5, RAH 1004 × G COT 16 and MCU 5 × G COT 16 had stability for seed cotton yield plant-1 over locations. The hybrid, NDLH 1938 x L 604 predicted to perform well in the favourable environments and the hybrid, NDLH 1938 x L 770, predicted to show good performance in poor environments. Identification of unique favourable alleles in the donor parents analysis revealed that for improving NDLH 1938 × RAH 1004 hybrid for 2.5 % span length the donor parent SURABHI and for lint index L 788 and NA 1325 were showed significant positive μG' estimates. Whereas, for boll weight three parents, L 788, L 770 and L 604, showed the significant positive μG' estimates in combined analysis. Only one parent i.e., G COT 16, showed the significant positive μG' estimates in combined analysis for boll weight for improving NDLH 1938 × L 770 hybrid. The hybrids NDLH 1938 × L 604, NDLH 1938 × RAH 1004 and NDLH 1938 × L 770 recorded high per se performance, significant positive sca effects and high standard heterosis for seed cotton yield plant-1 along with yield contributing characters like number of bolls plant-1, boll weight, lint yield plant-1 and quality traits like 2.5 % span length, micronaire, bundle strength, uniformity ratio and elongation %. These hybrids may be tested over large number of environments for further confirmation before they are being exploited commercially.ThesisItem Open Access INFLUENCE OF ACCELERATED AGING AND GA3 PRIMING ON SEED QUALITY OF SORGHUM(2021-09-03) YASASHWINI, S.; BAYYAPU REDDY, KThe present investigation was carried out in the Department of Seed Science and Technology, Advanced Post Graduate Centre, Lam, during 2019-20 to assess the influence of accelerated aging on physiological and biochemical parameters of sorghum seed also to study the effect of priming with gibberellic acid on quality of accelerated aged seed of sorghum, variety NTJ-5 and to predict the storage potential of sorghum seed using accelerated aging test. Initially seed of sorghum variety, NTJ-5 was subjected to accelerated aging for 24, 48, 72 and 96 h. The physiological and biochemical parameters of accelerated aged seeds were tested along with control (unaged seed). The accelerated aging caused highly significant decline in all the seed quality parameters viz., germination, seedling length, seedling vigour index, field emergence, total soluble sugars and peroxidase (POX) activity. Moisture content, electrical conductivity (EC) of seed leachates, proline content, hydrogen peroxide (H2O2) and malondialdehyde (MDA) content showed a highly significant increase with increase in the duration of accelerated aging. Maximum per cent decline in germination (39.55%), seedling length (24.79%) seedling vigour index (54.63%), field emergence (37.18%), total soluble sugars (30.06%) and peroxidase (POX) activity (45.02%) over the control was observed with 96 h of accelerated aging. Correlation studies showed a highly significant positive correlation among all the physiological parameters except moisture content and EC of seed leachates which showed highly significant negative association with the remaining characters. Total soluble sugars and POX activity exhibited a significant positive association and proline, H2O2 and MDA content had a significant negative correlation with all the physiological parameters under study except EC of seed leachates. The accelerated aged seed was subjected to hormonal priming with GA3 50 ppm for various durations (3, 6, 9 and 12 h) along with control to standardize the best duration of priming. The seed quality traits were studied by performing standard xvi germination test by between paper method. Among different durations, highest germination (%), seedling length (cm) and seedling vigor index were recorded with 9 hours duration and beyond that the seed quality declined gradually upto 12 hours. Based on standardization results the aged and unaged seed of sorghum was subjected to seed priming with GA3 50 ppm for 9 hours and shade dried to reach safe moisture content. The invigorated aged seed along with untreated aged and unaged seed was used for assessing physiological and biochemical characters. Results revealed that accelerated aging caused a highly significant reduction in all the physiological parameters except EC of seed leachates and showed a highly significant increment in all the biochemical parameters under study except total soluble sugars and POX activity. Hormonal priming with GA3 50 ppm showed a highly significant improvement in seed quality and biochemical parameters. The interaction effect between accelerated aging and hormonal priming with GA3 showed a significant impact on all the physiological and biochemical parameters except germination and field emergence. Correlation studies showed a highly significant positive correlation among all the physiological parameters except EC of seed leachates which exhibited significant negative association with the remaining characters. Total soluble sugars showed a positive association and POX activity had a significant positive correlation with all the physiological parameters except EC of seed leachates. Proline content exhibited a significant negative association whereas H2O2 and MDA contents showed a highly significant negative association with all the physiological parameters under study except EC of seed leachates. The seed samples with different levels of germination and seedling vigour thus obtained by accelerated aging along with the control were kept for storage in cloth bag under ambient conditions. The physiological parameters were tested at monthly interval, while biochemical characters were assessed at bimonthly intervals. The physiological parameters, total soluble sugars and POX activity decreased significantly and the EC of seed leachates, proline, H2O2 and MDA content showed a highly significant increase due to accelerated aging and period of storage. The results indicated that the germination recorded at 24 h of accelerated aging was almost equivalent to normal (unaged) seed stored for 4 months. From the results it can be found that accelerated aged exhibited lesser storability compared to unaged seed. Correlation studies of biochemical characters with germination, seedling quality parameters and EC of seed leachates of accelerated aged seed of sorghum during storage revealed that total soluble sugars and POX activity showed a positive correlation and proline, H2O2 and MDA content exhibited a negative correlation with all the physiological parameters under study except EC of seed leachates. The present study proved that hormonal priming with GA3 50 ppm significantly improved the quality of accelerated aged seed of sorghum. Accelerated aging test can be used to predict the storability of sorghum seed.ThesisItem Open Access INFLUENCE OF SEED INVIGORATION ON SEED QUALITY AND YIELD IN CHICKPEA (Cicer arietinum L.)(Acharya N.G. Ranga Agricultural University, 2018) SUMA VARSHINI, PATURI; BAYYAPU REDDY, KThe present investigation was carried out in the Department of Seed Science and Technology, Advanced Post Graduate Centre, Lam, Guntur (laboratory studies) and Agricultural Research Station (ARS), Jangamaheswarapuram, Guntur (field studies) during 2017-18 to study the influence of seed invigoration treatments on field performance and seed quality of aged seed of chickpea variety NBeG-3. Initially standardization was done to know the best duration of soaking for the hydration treatments in aged (Rabi, 2015-16 harvested) seed of chickpea variety NBeG-3. Hydration was done for various durations ranging from 2 to 24 hours with an equal increment of 2 hours and the seed quality traits were studied by testing in between paper method and sand method of germination. Among the hydration durations, highest germination (%), root length (cm), shoot length (cm), seedling length (cm), root / shoot ratio and seedling vigor index were recorded with 8 hours of hydration and beyond that the seed quality declined gradually upto 24 hours. Standardization was also done to know the best concentration of PEG and duration of osmo-conditioning in aged seed of chickpea. The aged seed was subjected to osmo-conditioning with different concentrations of PEG 6000 (0, -0.5, -1.0, -1.5 and -2.0 MPa) for various durations (3, 6, 9, 12 and 24 hours) and the seed quality traits were studied by testing in between paper method and sand method of germination. Among the various concentrations and durations, osmo-conditioning with -0.5 MPa PEG for 6 hours recorded highest germination (%), root length (cm), shoot length (cm), seedling length (cm), root / shoot ratio and seedling vigor index. The aged seed of chickpea was subjected to invigoration treatments viz., hydration, hydration followed by seed treatment with thiram, 50 ppm GA3, 2 % KH2PO4, 2 % CaCl2 and 2 % KNO3 for 8 hours and osmo-conditioning with -0.5 MPa PEG for 6 hours and shade dried to reach 9 % moisture content. The invigorated aged seed along with untreated aged (Rabi, 2015-16 harvested) seed and fresh (Rabi, 2016-17 harvested) seed was used for assessing seed quality and field performance. Among the invigoration treatments, seed treated with CaCl2 and osmo-conditioning with PEG showed significantly higher germination and other seed quality traits over untreated aged seed. The germination and seedling vigor index in CaCl2 treated seed were significantly higher than that in fresh seed also. In the field studies also, seed treated with CaCl2 showed highest improvement in most of the field parameters viz., field emergence, plant height at 60 DAS and maturity, number of branches per plant, number of pods per plant, seed yield per plant and seed yield per plot which were superior to that of untreated aged seed as well as fresh seed. Minimum number of days taken to reach 50 % flowering was recorded in seed treatment with GA3 followed by CaCl2. Seed invigorated with KNO3 and hydration also showed improved field performance in all the above mentioned parameters and was on par with the fresh seed. The seed yield recorded per plot was statistically superior in all the invigoration treatments over the untreated aged seed. The seed quality studies from the harvested crop indicated that there was no significant difference among the different invigoration treatments for seed germination but significant variation was observed for root length, shoot length, seedling length and seedling vigor index, which were highest in the seed harvested from invigoration treatment with CaCl2. The root / shoot ratio was highest in the harvested seed of KNO3 treatment. Correlation studies showed highly significant positive association of number of pods per plant, number of branches per plant, field emergence and plant height at maturity with seed yield. The increase in any of these traits led to increase in the seed yield. Path coefficient analysis revealed that plant population m-2, number of pods per plant, shelling percentage, seed yield per plant, field emergence, plant height at maturity and days to 50 % flowering had positive direct effects and number of branches per plant and 100 seed weight exhibited negative direct effect on seed yield. The present study proved that seed invigoration with 2 % CaCl2, 2 % KNO3 and hydration treatment may be suggested for improvement of seed quality and field performance in aged seed of chickpea.ThesisItem Open Access INFLUENCE OF SEED TREATMENT ON FIELD PERFORMANCE AND STORABILITY OF ACCELERATED AGED SEED OF SORGHUM(Acharya N G Ranga Agricultural University, Guntur, 2019) SATISH, MURARI; BAYYAPU REDDY, KThe present investigation was carried out in the Department of Seed Science and Technology, Advanced Post Graduate Centre, Lam, Guntur and Agricultural Research Station (ARS), Jangamaheswarapuram, Guntur during 2017-18 to study the impact of accelerated ageing on seed quality and storability and influence of seed treatment on initial seed quality, field performance of accelerated aged seed of sorghum variety NTJ -4. Initially freshly harvested (Rabi, 2017-18) seed of sorghum was subjected to accelerated ageing for 24, 36, 48 and 60 h. The standard germination and seed quality parameters of accelerated aged seeds were tested along with control (unaged seed). The accelerated ageing exhibited significant decrease in all seed quality parameters viz., germination, seedling length, seedling vigour index and field emergence. The electrical conductivity of seed leachates increased with the duration of accelerated ageing. Maximum per cent decline in germination (8%), seedling length (27.17%) seedling vigour index (33.03%) and field emergence (12%) over the control was noticed with 60 h accelerated ageing. The seed samples with different levels of germination and seedling vigour thus generated by different durations of accelerated ageing along with the control were kept for storage in cloth bags under ambient conditions. The germination and seed quality parameters were tested at monthly interval. The germination and seed quality parameters gradually decreased, while the electrical conductivity of seed leachates increased due to accelerated ageing and period of storage. The result indicated that 24 h, 36 h, 48 h and 60 h were used to predict the seed quality parameters of normal (unaged) seed of sorghum variety NTJ-4 stored for 1 to 3 months, 3-5 months, 4-8 months and 68 months of respectively xiii The accelerated aged seed was subjected to seed invigoration with 50 ppm GA3, 2% KH2PO4, 2% CaCl2 and 2% KNO3 for 10 h duration. The initial seed quality and field performance of the invigorated accelerated aged seed along with untreated accelerated aged was assessed. Results revealed that the duration of accelerated ageing caused a significant reduction in all the seed quality parameters except electrical conductivity of seed leachates, crop growth, yield and its contributing characters. But electrical conductivity of seed leachates and duration of flowering and maturity increased with increasing duration of accelerated ageing. Seed priming with different chemicals showed significant improvement in seed quality, crop growth, field performance and yield. The interaction effect between accelerated ageing and seed treatment had non-significant influence on all the seed quality and field parameters except germination and field emergence. Among the treatments seed priming with different chemicals, 2% KH2PO4 and 2% CaCl2 showed highest improvement in germination, seedling length, seedling vigour index and field emergence and decline in electrical conductivity of seed leachates. In field studies also the accelerated aged seed treated with 2% KH2PO4 and 2% CaCl2 recorded significantly highest plant height at 60 DAS and at maturity, earhead weight, earhead length, earhead width, number of seeds per head, single plant yield and 1000 seed weight along with lesser duration of 50% flowering and maturity. The seed quality studies from the harvested crop indicated that duration of accelerated ageing and seed treatment with different chemicals showed significant but marginal difference in germination, seedling length and seedling vigour index. However, the interaction between duration of accelerated ageing and seed treatment was non-significant. The present study proved that accelerated ageing test can be used to predict the storability of sorghum seed. Significant enhancement in seed quality is possible through seed priming of aged seed of sorghum with either 2% KH2PO4 or 2 % CaCl2.