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ThesisItem Open Access Characterisation of drought tolerance in rice (Oryza sativa L.) genotypes(College of Horticulture, Vellanikkara, 2015) Jeevan, S; KAU; Rose, Mary FranciesMoisture stress during the crop ontogeny has been one of the main constraints for sustainable rice productivity, especially in uplands. Crop losses vary depending upon the intensity and duration of drought and growth stages. The solution to overcome this lies in either making water available for crop growth or breeding drought resistant cultivars. Increased irrigation inputs are not a viable option because the water resources are unavailable or limited. Improvements in crop drought tolerance are, therefore, sought through plant breeding. Consequently, a need to elucidate the response of genotypes, in cultivation in the uplands of Kerala, with the timing of drought was felt. A study was thus envisaged to characterize rice genotypes suitable for upland cultivation and elucidate their response to moisture stress. Twenty one rice genotypes consisting of nine high yielding varieties and twelve traditional rice varieties were evaluated in an upland field trial (Experiment I: Morphological characterization of rice genotypes for yield and yield attributes) as well under controlled moisture regimes (Experiment II: Characterization of rice genotypes for drought tolerance). Experiment II comprised of two sub experiments i) Rapid evaluation test for drought tolerance [Experiment II (A)] and ii) Characterisation of rice genotypes for drought tolerance under controlled moisture regimes [Experiment II (B)]. All experiments were conducted at College of Horticulture, Kerala Agricultural University, Vellanikkara during 2014-2015. Results of the upland field experiment revealed existence of wide variability among the twenty one genotypes for yield and yield attributes indicating ample scope for improvement of the traits through selection. Early maturity, higher chlorophyll stability index (CSI), productive tillers, spikelet fertility and plant height being advantageous in uplands, genotype Parambankayama followed by Karanavara was found to be the most promising. Other promising genotypes for upland cultivation included PTB 28, Nerica, PTB 60, Karuthamodan, Kalladiaryan, Parambuvattan, Karuthadukkan, Arimodan and Thottacheera. Most of these genotypes recorded high chlorophyll stability index. On rapid evaluation for drought tolerance [Experiment II (A)] conducted as per the method advocated by Bouslama and Schapauugh (1984), moisture stress (- 6 bars) was found to affect the germination and early seedling growth parameters. Considering that higher speed of germination, shoot and root length, seedling vigour index and biomass under moisture stress are indicative of the capacity of genotypes to combat moisture stress, genotype Parambuvattan followed by Arimodan was found to be the most promising. Karuthamodan, Karanavara, Parambankayama, Kalladiaryan, Thottacheera, PTB 60, Nerica and Karuthadukkan were the other promising genotypes. Speed of germination and seedling vigour index were found to be high in these genotypes Based on the outcome of upland field experiment and the laboratory screening study, ten promising drought tolerant genotypes were selected to delineate their response towards moisture stress [Experiment II (B)] imposed at seedling stage (15 day after sowing), vegetative stage (35 day after sowing) and reproductive stage (50 day after sowing). In all the population subjected to moisture stress, reduction in relative water content, chlorophyll content, number of productive tillers per plant, panicle length and weight, spikelets and grain per panicle, flag leaf area, 1000 grain weight, plant height, dry weight of shoot and root, root volume, grain and straw yield per plant and harvest index, was observed. A delay in flowering was observed on exposure to moisture stress. The magnitude of change in different traits varied with timing of moisture stress. PTB 60 and Karanavara recorded the highest grain yield per plant, irrespective of growth stage at which moisture stress was imposed. These genotypes maintained a high number of productive tillers, grains per panicle, 1000 grain weight, dry weight of shoot and root, root length and root volume, straw yield and harvest index under stress. Invariably, on exposure to moisture stress at different growth stages, Parambankayama, Nerica and Karathadukkan were found next best to PTB 60 and Karanavara .ThesisItem Open Access Generation mean analysis in brinjal (solanum melongena L.) for yield and yield attributes(College of Agriculture, Vellayani, 2015) Soumya, B Nair; KAU; Wilson, DThe project entitled “Generation mean analysis in brinjal (Solanum melongena L.) for yield and yield attributes” was carried out at College of Agriculture, Vellayani during 2013-15 to study the gene action and inheritance pattern of yield and yield attributes using generation mean analysis. In generation mean analysis six generations viz., P1, P2, F1, F2, B1 and B2 of three crosses (Wardha local x Surya, Wardha local x NBR-38 and Swetha x Haritha) were evaluated in a field experiment for thirteen yield components. Results showed that in cross 1 additive gene effects (additive, additive x additive) were important for fruit girth, fruit volume, number of fruits per cluster, yield per plant and non additive gene actions (dominance, additive x dominance and dominance x dominance) were recorded for fruit length, days to first flower, days to first harvest, calyx length, fruit volume, number of fruits per plant, number of primary branches and plant height. In cross 2 additive gene effects were predominant for fruit weight, yield per plant and fruit and shoot borer incidence while only non additive gene actions were important for all other traits. In cross 3 additive gene action was reported for fruit and shoot borer incidence and days to first harvest and all other characters were under the control of non additive gene action. Duplicate type of epistasis was observed for most of the crosses. The study of F2 population was undertaken in compact family block design with eight families and five progenies within family to assess the variability between families and among progenies within each family. Eight F1 hybrids selected were selfed to raise eight F2 families. Based on the mean values of eight families and their progenies, variability among the families and progenies within families were studied. The analysis of variance conducted for eight F2 families showed significant differences among the progenies for different characters. Family 2 (Wardha local x Surya) took the minimum number of days to first flowering and first harvest. Maximum fruit length and number of fruits per cluster were recorded in Family 7 (Wardha local x Selection Pooja). Maximum number of fruits per plant was recorded in Family 4 (Wardha local x Swetha) and maximum plant height, fruit volume, fruit weight and yield per plant were recorded in Family 6 (Surya x Haritha). The magnitude of variation shown among the progenies of eight families revealed the heterogenous nature of F2 families. All families except family 6 showed significant variation among progenies for days to first flowering and fruit length. Variations among progenies for girth of fruit was expressed by all families except family 8. None of the families exhibited significant variation among the progenies for number of fruits per cluster. All the families possess significant variations among progenies for number of primary branches, days to first harvest, plant height, number of fruits per plant, fruit weight and yield. Families 2 and 8 revealed significant variation among the progenies for volume of fruit. All families except family 4 and 6 showed significant difference among progenies for calyx length. Family 4 and 5 showed significant difference among progenies for percentage of plants infested with shoot and fruit borer. Based on the results wide variability among the families and progenies within families revealed the heterogenous nature of F2 families. The study revealed that among the families studied family 6 recorded maximum fruit weight and yield per plant. Superior F2 progeny can be used in further improvement programmes. The predominance of additive gene effects as well as non-additive gene effects were recorded for fruit weight, fruits per plant and yield per plant. The study suggested that characters governed by predominance of additive component could be improved through selection.ThesisItem Open Access Genetic analysis of phenological variations for yield and quality in turmeric (Curcuma longa L.)(College of Agriculture, Vellayani, 2015) Anju, Vijayan; KAU; Mareen, AbrahamThe present investigation entitled “Genetic analysis of phenological variations for yield and quality in turmeric (Curcuma longa L.)” was taken up during the period from May, 2014 to January, 2015. The objective of the study was to understand the phenological variation in yield and quality attributes in turmeric. The intention of the study was to verify if earlier harvest yields better quality which is the widely held view among the farmers. Twelve genotypes of turmeric were evaluated under split plot design. Genotypes studied were Prabha, Prathibha, Kedaram, Alleppey Supreme, Suvarna, Sudarsana, Kanthi, Varna, Sona, Shobha, Suguna and Wayanad local. Data recorded at 160, 200 and 240 days after planting (DAP) suggest that the plant height, number of tillers, number of leaves, leaf length and leaf breadth differs significantly during the three dates of harvest. Plant height was the maximum at 240 DAP (97.08 cm). The maximum number of tillers was observed at 240 DAP (2.74), it was on par with 200 DAP (2.73). Leaf length recorded the maximum at 240 DAP (49.95 cm) and leaf breadth recorded maximum at 200 DAP (12.62 cm). Fresh rhizome yield per plant, dry rhizome yield per plant, fresh rhizome yield per plot, dry rhizome yield per plot and the quality parameters like oleoresin, starch, volatile oil and curcumin content differ significantly during the three dates of harvest and they were found to be the maximum at 240 DAP. There was no serious pest or disease incidence during the crop period. High values of phenotypic coefficient of variation and genotypic coefficient of variation were observed for fresh yield per plant (31.02 and 30.93), volatile oil (25.23 and 24.89), curcumin (23.55 and 23.26), oleoresin (20.66 and 20.53), number of leaves (20.40 and 20.10) and number of tillers (20.40 and 19.09). Heritability was high for all characters studied except leaf breadth. GA was the highest for fresh yield per plant (63.53%). The positive phenotypic and genotypic correlation with fresh rhizome yield per plant was observed for plant height (0.766 and 0.773), oleoresin (0.708 and 0.716), starch (0.554 and 0.559), number of tillers (0.475 and 0.494), leaf breadth (0.340 and 0.487) and number of leaves (0.406 and 0.404). Path analysis revealed that plant height exhibited the highest positive direct effect on fresh yield per plant (0.7180) followed by number of tillers (0.3034). The highest selection index value was obtained by Sudarsana followed by Kedaram. In addition to this, the meteorological parameters like rainfall, maximum temperature, minimum temperature, relative humidity and evaporation were also recorded during the crop period. Out of the three dates of harvest, third harvest (240 DAP) was found superior in terms of yield and quality. Sudarsana was the best genotype regarding fresh rhizome yield whereas Kedaram was best regarding dry rhizome yield. Maximum curcumin content was recorded by Kanthi and Varna. The characters plant height, number of tillers, fresh rhizome yield, number of leaves, oleoresin, volatile oil and curcumin can be used in selection of genotypes for developing superior varieties