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ThesisItem Open Access Combination breeding for high protein cowpea (Vigna unguiculata L. Walp)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2015) Sarath, P S; KAU; Jiji, JosephCowpea (Vigna unguiculata L. Walp) is one of the most important legume crops grown in India. It is a versatile pulse crop owing to its nutritional value, weed smothering nature, drought tolerant characters, soil restoring properties and multi-purpose uses. Protein deficiency has been reported to be one of the main nutritional problems in the developing world. About one billion people are reported to be suffering from protein deficiency and malnutrition worldwide. Studies have revealed that protein content in cowpea grain ranges between 18 to 40 per cent depending on the genotypes. Identifying high yielding varieties of cowpea with high protein content will not only contribute to food security and alleviate poverty but could also contribute to the alleviation of protein deficiencies. Review on the earlier research pointed to poor emphasis on the genetic improvement of cowpea for improved protein content. Hence, the present study was envisaged to combine the high protein trait with high yielding genotypes. The study was grouped under three experiments, i) Evaluation of cowpea genotypes, ii) Hybridisation of the selected genotypes in line x tester design, iii) Evaluation of F1 hybrids. The experiments were conducted at College of Horticulture, Kerala Agricultural University, Vellanikkara during 2014-2015. All the crop management practices were followed as per KAU (2011). Evaluation of cowpea genotypes revealed that there was wide variability for all the traits studied except branches per plant among bushy and semi trailing types of cowpea. In trailing type, variability was observed for plant height, number of pods per plant, pod weight grain yield per plant and seed protein content. Among the twenty two genotypes evaluated, ten genotypes that exhibited a protein content of above 25 per cent were selected for hybridization programme. The selected genotypes (Vellayani Jyothika, Bhagyalakshmi, Anaswara, Kanakamony, Lola, Vyjayanthi, AV-5, PKB-3, PKB-4 and Sharika) were hybridized in line x tester (6 x 4) design. High magnitude of phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), heritability and genetic advance was observed for plant height, grain yield per plant and length of pods were observed in parents and hybrids suggesting scope for genetic improvement of these traits through selection. Seeds per pod and protein content exhibited low PCV and GCV but high heritability and low genetic gain, indicating that these traits were governed by non-additive gene action and therefore breeding method other than simple selection is required. Combining ability analysis revealed that higher magnitude of specific combining ability (SCA) variances than the general combining ability (GCA) variances for the traits like pods per plant, length of pod, test weight, grain yield per plant and seed protein content indicating preponderance of non-additive gene action in the inheritance of these traits. Higher estimates of GCA variances over SCA variances for plant height, days to flowering, days to first harvest, days to last harvest, pod-weight and seeds per pod implies the preponderance of additive gene action in controlling these traits. The hybrids were ranked based on mean value, sca effects and estimates of heterosis for the traits like days to flowering, pods per plant, seeds per pod, test weight, grain yield per plant and protein content. Four hybrids with the lowest scores were selected. Hybrids H2 (Vellayani Jyothika x PKB-3), H10 (Anaswara x PKB-3), H11(Anaswara x PKB-4) and H12 (Anaswara xSharika) were found to be the most promising. The transgressive segregants with high yield and protein content can be identified on further evaluation of the segregating population from the above hybridsThesisItem Open Access Morphogenesis and reproductive biology of water lily (Nymphaea spp.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2015) Tincy, Tom; KAU; Presanna, Kumari K TGenus Nymphaea forms a complicated group of aquatic perennials having immense ornamental and medicinal value. Two phenological groups based on flowering viz., diurnals and nocturnals are recognized in this genus. Information on the reproductive biology and developmental features specific to the phenological groups are lacking in this genus. The present study entitled “Morphogenesis and reproductive biology of water lily (Nymphaea spp.)” was taken up in this background in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, during 2013-2015 for elucidating and comparing the reproductive biology and developmental pattern of leaves, flowers and fruits in day as well as night blooming types of Nymphaea. A survey was conducted in the water lily growing tracts of Thrissur district and 12 accessions were collected. Five among these accessions were selected based on blooming time and seed set for further detailed evaluation. Growth and development pattern of leaves and flowers were observed to be uniform in all the accessions. However, the accessions differed in the number of days taken by the leaf and flower bud to reach the water surface and maturity. The rate of elongation of the petiole was significantly and positively correlated with sunshine hours and maximum temperature. There was no significant correlation between pedicel elongation and weather parameters. The leaves in all the accessions evaluated were simple orbicular with subpeltate lamina which was deeply cleft near to the petiole base. However, there was variability in the colour, margin and tip of the lamina. The night bloomers could be easily distinguished by the sinuately dentate margin and thick prominent veins on the abaxial surface of the lamina. Flowers were pedicellate and complete with all the floral whorls in a spiral fashion on the floral axis. Significant variability in both qualitative and quantitative characters were observed among the accessions for floral characters. The night bloomers differed from the day bloomers in having larger flowers with stamens devoid of appendages. Besides, the sepals were observed to have five to six prominent nerves on both sides. The flower opened in the morning and closed in the evening in day blooming types. In night bloomers the flower opening was in the evening hours and closing in the morning hours. The time of opening and closing further varied with the accessions. The process of opening and closing continued for four days and on the fifth day the flower submerged in water. The anther dehiscence started on the second day of flower opening and it proceeded from the outermost whorl to the inner most whorl of the stamens. The dehiscence was hence completed in two days in day bloomers. However, in night bloomers the stamens of all the whorls dehisced simultaneously on the first day of flower opening. The presence of honey dew like secretion in the stigmatic cup indicated the initiation of stigma receptivity in all the accessions irrespective of blooming time. The receptivity started 14 to15 hours before flower opening and was retained for 34 hours even after flower opening in day bloomers. In night bloomers the onset of receptivity was six to nine hours prior to flower opening and remained receptive only for 16 to 18 hours after flower opening. Stingless bee (Trigona irridipennis), honey bee, house flies, weevils and flower beetles were the major insects visiting the flowers. Cross pollination was the rule in all the accessions due to the protogynous nature of the flower. Fruit set was noticed only in two of the day blooming types evaluated. Fruit was a many seeded dehiscent capsule which developed under water. All the floral whorls were persistent in the mature fruit. It took 20 to 25 days for the fruit to mature. Seeds were arillate with an embryo, two fleshy cotyledons and a mucilaginous covering. Despite being a dicot, the germination was initiated by the emergence of coleoptile. Acid scarification as well as leaching treatment enhanced the speed of germination of the seeds. Bulbils served as the propagules in the non seed forming accessions.ThesisItem Open Access Genotype X environment interaction in blackgram (Vigna mungo L. Hepper)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2015) Gambhire, Vilas Bhagwat; KAU; JijiBlackgram (Vigna mungo (L.) Hepper) is an important short duration pulse crop occupying unique position in Indian agriculture. Its seeds are highly nutritious and used in the preparation of many popular dishes. Pulses are part of the daily diet of vegetarians world over. They are rich in protein (20-30 %) and are an excellent source of dietary fiber, low molecular weight carbohydrates, essential aminoacids, poly unsaturated fatty acids and range of micronutrients. In recent years there has been an increase in consumption of pulses in several developed countries where they are increasingly considered as health food. In Kerala, cultivation of pulses especially black gram as third crop i.e., in summer fallows in paddy growing areas was a common practice by the farmers. However, this trend has come down in the near past due to non availability of labourers for harvesting and low yield of traditional varieties. Raising blackgram in coconut gardens seems as a viable option to increase area of cultivation. In Kerala, high yielding varieties suited to both open and shaded conditions are not available. The study on “Genotype x environment interaction in black gram” was an attempt to identify suitable cultures for cultivation under open condition as a sole crop in rice fallow lands and as an intercrop in coconut garden. Materials used for the study consisted of ten black gram cultures developed by pedigree breeding from four crosses in the stabilized generation at the Department of Plant Breeding and Genetics. The check varieties were TAU-1, T-9, Sumanjana and Syama. The crop was raised under open and shade condition during kharif , rabi and summer seasons of 2013-2014. The plants were raised in plots of five meter square with two replications. All the observations were recorded at harvest except days to flowering. The data was analyzed for stability by Eberhart and Russell’s model as pooled over open condition, pooled over shade condition and pooled over all the six environments. According to Eberhart and Russell’s model of stability a good genotypes is the one having high mean value, non significant bi and S2di value. Stability analysis by Eberhart 13 and Russell’s model pooled over open condition showed that there was no variation between genotypes under three seasons for days to flowering, length of pod and number of seeds per pod. Also none of the genotypes showed stability for protein content. Genotypes were ranked based on stability, yield and major yield contributing characters. The genotypes with least score were T6, T5 and T9. These can be recommended for cultivation under open condition. Stability analysis by Eberhart and Russell’s model pooled over shade condition showed that that there was no variation between genotypes under three seasons for number of seeds per pod. None of the genotype was stable for protein content. Ranking of genotypes showed that genotypes T3, T5, T6 and T10 can be recommended for cultivation as an inter crop in coconut garden. Estimation of stability by Eberhart and Russell’s model pooled over six environments showed that there was variation between genotypes under the environments for all the traits studied. Genotypes were ranked based on stability, yield and major yield contributing characters. The genotypes with least score were T6, T5 and T3. These can be recommended for cultivation under both the conditions. Based on G x E analysis done by AMMI model also genotypes T5, T6 and T 3 were identified as suitable for planting under the six environments. The identified genotypes suitable for each condition that is genotypes T3, T5, T6,T9 and T10 has be evaluated in large plots to confirm the results and the quality of these genotypes has to be assessed for developing as variety suitable for open condition and intercropping.ThesisItem Open Access Analysis of bean characters in cocoa (Theobroma cacao L.) hybrids bred for bold beans(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2015) Rubeena, M; KAU; Presannakumari, K TCocoa is a tropical tree crop cultivated for its beans which form the main source of chocolate. Many of the cocoa varieties cultivated by the farmers, even though high yielders, are having small beans. However, the standard for cocoa bean in the international market is one gram or above. The size of bean is significantly influenced by various environmental conditions especially temperature, prevailing during the pod formation stage. Hence, the cocoa beans produced in summer months may fail to keep the international standards. To overcome this, it is necessary to evolve varieties with large beans of more than 2g so that even if reduction occurs during summer months the beans will have enough size to meet the international standards. The present study which forms part of an ongoing project at Cocoa Research Centre (CRC), KAU, Vellanikkara was hence, taken up during 2012-14 to evaluate the inheritance of various bean characters and to assess the threshold bean size as well as the heterotic effect for various bean characters. Forty hybrid progenies derived from four crosses involving five parents, which are in full bearing stage and maintained at CRC, Vellanikkara formed the material for the study. These hybrids were subjected to morphological and biochemical evaluation along with their parents. The morphological evaluation based on eight qualitative and 14 quantitative characters was done using the descriptor developed by Bekele and Butler (2000). Fat and polyphenol contents were estimated following standard procedures for biochemical characterization. Variability was observed among the hybrid progenies for all the qualitative characters evaluated. Variations expressed by the hybrid progenies in terms of pod and bean quantitative characters were also significant, indicating the heterogeneity among them. Analysis of bean characters revealed that the hybrids 13.7, 16.8, 14.6 and 12.5 expressed higher values with respect to wet weight of unpeeled bean (460g), length of peeled bean (17.78mm), breadth of peeled bean (10.81mm) and peeling ratio 82.4% respectively. The highest wet weight of peeled bean (1.78g) was recorded by hybrids 12.5 and 12.6. The dry weight of peeled bean (1.31g) and thickness of peeled bean (4.98mm) were the highest in hybrid 12.6. The fat content ranged from 33.3% in hybrid 7.8 to 58.5% in hybrid 10.6 and polyphenol content ranged from 0.15% in hybrid 16.8 to 0.56 % in hybrid 5.7. Among the pod and bean characters evaluated wet weight of peeled bean exhibited high GCV (510%), high heritability and high genetic gain (1163%). The bean characters varied significantly over seasons in hybrids as well as parents. Relatively higher bean weights were observed in September- November period harvests in contrast to the lower bean weights during June to August period. Assessment of performance of hybrids based on year round observation on bean characters revealed that the major factors contributing significantly to boldness of bean were weight, breadth and thickness of beans. Based on these parameters a descriptor was developed confirming the international standards, for deciding the threshold bean size. The descriptor scales were prescribed based on the best subset values in the post hoc tests. Hybrids 12.6, 13.7 and 14.6 satisfied the developed scales Significant positive heterotic effect (average heterosis as well as heterobeltiosis) for various bean characters was expressed by hybrids 13.7 and 12.6. Among the hybrid progenies evaluated hybrid 13.7 was found to be a desirable one with low pod index value (PI value), high pod breadth, pod weight and wet weight of unpeeled bean coupled with significant positive heterotic effect for various bean character followed by hybrids 12.6, 16.5 and 14.6.ThesisItem Open Access Genotype x Environment interaction in blackgram (Vigna mungo L. Hepper)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2015) Gambhire, Vilas Bhagwat; KAU; Jiji, JosephBlackgram (Vigna mungo (L.) Hepper) is an important short duration pulse crop occupying unique position in Indian agriculture. Its seeds are highly nutritious and used in the preparation of many popular dishes. Pulses are part of the daily diet of vegetarians world over. They are rich in protein (20-30 %) and are an excellent source of dietary fiber, low molecular weight carbohydrates, essential aminoacids, poly unsaturated fatty acids and range of micronutrients. In recent years there has been an increase in consumption of pulses in several developed countries where they are increasingly considered as health food. In Kerala, cultivation of pulses especially black gram as third crop i.e., in summer fallows in paddy growing areas was a common practice by the farmers. However, this trend has come down in the near past due to non availability of labourers for harvesting and low yield of traditional varieties. Raising blackgram in coconut gardens seems as a viable option to increase area of cultivation. In Kerala, high yielding varieties suited to both open and shaded conditions are not available. The study on “Genotype x environment interaction in black gram” was an attempt to identify suitable cultures for cultivation under open condition as a sole crop in rice fallow lands and as an intercrop in coconut garden. Materials used for the study consisted of ten black gram cultures developed by pedigree breeding from four crosses in the stabilized generation at the Department of Plant Breeding and Genetics. The check varieties were TAU-1, T-9, Sumanjana and Syama. The crop was raised under open and shade condition during kharif, rabi and summer seasons of 2013-2014. The plants were raised in plots of five meter square with two replications. All the observations were recorded at harvest except days to flowering. The data was analyzed for stability by Eberhart and Russell’s model as pooled over open condition, pooled over shade condition and pooled over all the six environments. According to Eberhart and Russell’s model of stability a good genotypes is the one having high mean value, non significant bi and S2di value. Stability analysis by Eberhart and Russell’s model pooled over open condition showed that there was no variation between genotypes under three seasons for days to flowering, length of pod and number of seeds per pod. Also none of the genotypes showed stability for protein content. Genotypes were ranked based on stability, yield and major yield contributing characters. The genotypes with least score were T6, T5 and T9. These can be recommended for cultivation under open condition. Stability analysis by Eberhart and Russell’s model pooled over shade condition showed that that there was no variation between genotypes under three seasons for number of seeds per pod. None of the genotype was stable for protein content. Ranking of genotypes showed that genotypes T3, T5, T6 and T10 can be recommended for cultivation as an inter crop in coconut garden. Estimation of stability by Eberhart and Russell’s model pooled over six environments showed that there was variation between genotypes under the environments for all the traits studied. Genotypes were ranked based on stability, yield and major yield contributing characters. The genotypes with least score were T6, T5 and T3. These can be recommended for cultivation under both the conditions. Based on G x E analysis done by AMMI model also genotypes T5, T6 and T 3 were identified as suitable for planting under the six environments. The identified genotypes suitable for each condition that is genotypes T3, T5, T6,T9 and T10 has be evaluated in large plots to confirm the results and the quality of these genotypes has to be assessed for developing as variety suitable for open condition and intercropping.ThesisItem Open Access Combining ability for tolerance to iron toxicity in rice (Oryza sativa L.)(Department of plant breeding and genetics, College of horticulture, Vellanikkara, 2015) Tess Joseph; KAU; Rose Mary, FranciesThree lines tolerant to iron toxicity [L1: Mo 19 (Krishnanjana), L2: PTB 53 (Mangala Mahsuri) and L3: PTB 57 (Swetha)] were crossed to six high yielding testers [Tl: PTB 43 (Swarnaprabha), T2: PTB 49 (Kairali), T3: PTB 39 (Jyothy), T4: PTB 45 (Matta Triveni), T5 : IR 64 and T6: Triguna] in a line x tester mating design resulting in eighteen hybrid combinations. Observations taken on yield and yield attributes were statistically analysed to deduce the nature and extent of variability and association among yield and yield attributes, estimate the genetic parameters, assess the combining ability effects and quantify the magnitude of heterosis in hybrid. Wide variability was found to exist among parents and hybrids for yield and most yield attributes studied indicating ample scope for improvement through selection. Variability among genotypes was low with respect to total number of roots, manganese content in old leaf, total tillers/plant and productive tillers/plant. High heritability coupled with high genetic advance as per cent of mean were observed for grain yield, visual scoring for iron toxicity, iron adsorbed on root surface, iron content in root, iron content in third leaf from tip, youngest fully open mature leaf, oldest leaf, days to fifty per cent flowering, plant height, culm length, panicle length, spikelets/panicle, grains/panicle and shoot weight indicating that substantial improvement in the expression of these attributes over base population can be expected through selection. Results emphasized that an improvement in days to fifty per cent flowering at tillering and flowering, panicle length, seed set per cent and root weight at maturity are reliable predictor variables for increased yield and tolerance to iron toxicity. Negative selection for traits viz., dry weight of roots, manganese content in third leaf and youngest fully open mature leaf at tillering and flowering, may also lead to simultaneous improvement of grain yield and tolerance to iron toxicity. Higher estimates of GCA variance over SCA variance indicative of preponderance of additive gene action was evident in case of plant height, culm length, panicle length, seed set per cent, shoot weight and root weight at maturity. Pre-ponderance of non-additive gene action indicated by higher SCA variances than GCA variances was registered for traits spikelets/panicle, grains/panicle, thousand grain weight, root length, visual scoring for iron toxicity symptoms and grain yield. Evaluation of parents for yield alone based on both mean performance and gca effects revealed L2 (PTB 53) and L1, (Mo 19) to be promising, while, parents L2 (PTB 53), L3 (PTB 57), T1(PTB 43), T2 (PTB 49), T3 (PTB 39) and T4 (PTB 45) were found promising for tolerance to iron toxicity. Scoring of the gca effects and mean estimates for all the yield and yield attributes revealed that, line L2 (PTB 53) followed by line L3 (PTB 57) were the most promising parents. Hybrid H13 (PTB 57/PTB 43) was found to exhibit 'Resistance' reaction to iron toxicity indicating high tolerance to iron toxicity whereas hybrids HIO (PTB 53/PTB 45) and H17 (PTB 57/IR 64) with high mean grain yield were found to be moderately susceptible to iron toxicity. Based on the scoring of estimates of heterosis, sca and mean performance for yield and yield attributes, hybrids, H7 (PTB 53/PTB 43), HIO (PTB 53/PTB 45) and Hl6 (PTB 57/PTB 45) ranked the best. Hence, attempts to identify promising segregants with high yield and tolerance to iron toxicity from these cross-combinations may prove fruitful. Performance of the genotypes (30th day after sowing) in the laboratory screening revealed that, a drastic reduction in shoot length, total number of roots, vigour index (SL/RL) and biomass was found to occur at 600 ppm, while, root length, number of fresh roots, iron adsorbed on root surface and visual scoring for iron toxicity tolerance (susceptibility to iron toxicity) was found to increase with increase in iron level. Parental line L3 (PTB 57) was the least affected perceptibly by the change in iron level followed by Line L1, (Mo 19), tester T6 (Triguna) and check C2 (PTB 30). Considering the performance of the genotypes for all the attributes at varying levels of iron, it was revealed that check variety C2 (PTB 30) was least affected by higher levels of iron. Among parents, tester T 6 (Triguna) and T3 (PTB 39) and line L1, (Mo 19) were also found to be less affected by varying levels of iron. Ample variability among genotypes for yield, tolerance to iron toxicity and other yield attributes as evident in the study indicate ample scope for isolation of superior genotypes through concerted breeding programmes.ThesisItem Open Access Evaluation of genotypes for yield and resistance to leaf curl in bird chilli (Capsicum frutescens L.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2015) Bandla, Srinivas; KAU; Beena, ThomasThe project entitled “Evaluation of genotypes for yield and resistance to leaf curl in bird chilli (Capsicum frutescens L.)" was under taken with an objective to identify high yielding genotypes of bird chilli with resistance to leaf curl. The data for the investigation were collected from two field experiments. In experiment I, 78 accessions of bird chilli collected from different parts of Kerala were evaluated in the field for yield and resistance to leaf curl. The accession A4 (Vandithadam-I ) showed highest mean values with respect to number of primary branches, number of secondary branches, fruit length, plant height and lowest number of white flies per plant and categorised as tolerant to leaf curl. The accession A50 (Kumarapuram-I) showed highest mean values for number of fruits per plant, average fruit length, average fruit width and fruit yield per plant and it had zero vulnerability index i.e. resistance to leaf curl. The number of thrips per leaf and number of mites per leaf were lowest for accessions A28 (Kottakkal-IV) and A38 (Palakkad-I) respectively. The genetic divergence among 78 genotypes, in experiment I was studied and the genotypes were grouped into nine clusters. Cluster II accommodated maximum number of genotypes (24) followed by cluster IV with 13 genotypes, cluster I with 11 genotypes, cluster V with 9 genotypes, cluster IX with 8 genotypes, cluster VI with 7 genotypes, cluster VII with 3 genotypes, cluster VIII with 2 genotypes and cluster III with 1 genotype. Cluster VIII and cluster IX were found to be superior to the other clusters with respect to the desirable characters. It was observed that there was no close correspondence between geographical distribution and genetic divergence. In experiment II, 10 accessions of bird chilli (Capsicum frutescens L.) selected from experiment I, were studied. These genotypes showed significant difference for all the biometric characters. They all showed high heritability coupled with high genetic advance except for number of days to first flowering and average fruit length for which the genetic advance was low and moderate respectively. The maximum values for phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) were recorded for incidence of leaf curl disease and fruit yield per plant and the minimum values were for number of days to first flowering. High positive correlation was recorded for fruit yield per plant with individual fruit weight, number of fruits per plant, plant height, number of secondary branches, average fruit width, number of primary branches, average fruit length and number of days to first flowering. Path coefficient analysis revealed that individual fruit weight and number of fruits per plant had high positive direct effect on fruit yield per plant. Hence, through selection for these characters yield can be improved. The genotype T5 (Kumarapuram-I) was ranked first with respect to yield and resistance to leaf curl and this can be developed as a superior bird chilli variety.ThesisItem Open Access Evaluation of a collection of Indica rice genotypes under organic management adopting farmer participatory evaluation strategy(College of Agriculture, Padannakkad, 2015) Manjunatha, G A; KAU; Vanaja, TThe experiment entitled ‘Evaluation of a Collection of Indica Rice Genotypes under Organic Management Adopting Farmer Participatory Evaluation Strategy’ was conducted in the Department of Plant Breeding and Genetics, College of Agriculture, Padannakkad, Kerala Agricultural University during 2013 - 2015. Field trials were laid out during rabi season in the field of a progressive organic rice farming group (Arayidam padasekharam) in Mayyil Panchayath of Kannur district, Kerala. The main objectives of the study were identification of rice genotypes suited for organic farming and the key organic varietal traits. The materials comprised of 65 genotypes of rice conserved in the Department of Plant Breeding and Genetics, College of Agriculture, Padannakkad, which include 14 traditional genotypes of Kerala, a collection of 41 improved varieties developed for conventional rice farming, out of which 32 are of KAU, and 10 rice varieties/ cultures developed by Kerala Agricultural University adopting strategies of Organic Plant Breeding (OPB). Out of 65 rice genotypes evaluated under organic management, ‘Anaswara’, the variety developed by KAU for conventional farming and Culture MK-157, the genotype developed based on strategies of Organic Plant Breeding (OPB) (it was released in the name ‘Jaiva’ in 2015 by KAU as the first organic rice variety) ranked first for grain yield and also showed tolerance to the major pests and diseases on visual observation. But in quality analysis, the variety ‘Jaiva’ ranked best for all the four quality parameters evaluated namely, volume expansion, kernel elongation ratio, alkali spreading value and sensory evaluation, whereas ‘Anaswara’ variety ranked only for kernel elongation ratio. Hence considering yield, quality and biotic stress tolerance together, ‘Jaiva’ variety can be ranked first. Out of seven genotypes namely, ‘Aishwarya’, ‘Dhanu’, ‘Aruna’, ‘HariyanaBasmathi’, ‘Kanakom’, ‘Sagara’ and Culture MK-115, which ranked as second set with on par performance with respect to grain yield, the genotypes ‘Dhanu’, ‘Aishwarya’ and the flood tolerant pre-release organic Culture MK-115 showed top performance for various yield component traits, few cooking qualities, and pest and disease tolerance. Hence these three genotypes can also be considered for organic farming after ‘Jaiva’ and ‘Anaswara’. Out of 99 varieties of KAU developed for conventional farming in ordinary wetland using chemical fertilizers, 32 varieties were evaluated under organic management in this study. Out of these, ‘Anaswara’ variety followed by ‘Dhanu’ and ‘Aishwarya’ can be considered for organic farming for the time being as per the suggestion of IFOAM that, till enough organic varieties are developed adopting Organic Plant Breeding(OPB) strategies, those varieties developed for conventional farming using chemical fertilizers but performs well under organic management can be considered. The remaining 67 varieties of KAU developed for conventional farming has to be tested under organic management which may be the future line of work. Out of eighteen growth and yield parameters studied under organic management, four parameters namely, number of tillers plant-1 at harvest, number of productive tillers plant-1, number of grains panicle-1 and straw yield plant-1 showed both positive significant correlation and direct effect with grain yield plant-1. Hence these four characters can be considered as organic varietal yield component traits. Based on variation, correlation and path analysis studies, the genotypes which can be selected as parents for various organic varietal yield component traits for future breeding programmes of organic variety development are given below. Parents for the straw yield plant-1 are ‘Kanakom’, ‘Dhanu’, ‘Anaswara’, ‘Jaiva’, Culture MK-115, ‘Makam’, ‘Remanika’, and ‘Vytilla-4’. Parents for the number of productive tillers plant-1 are ‘Badhra’, ‘Dhanu’, ‘Anaswara’ and ‘Makam’. Parents for the number of tillers plant-1at harvest are ‘Dhanu’, ‘Badhra’, ‘Anaswara’, ‘Makam’, ‘Jaiva’, and ‘Remanika’ and parent for number of grains panicle-1 is ‘Mahsuri’. Genotypes which can be selected as parents for important cooking quality characters which are considered as organic varietal traits are ‘CO-47’, ‘Jaiva’ and ‘Valankunhivithu’ for volume expansion and ‘Pusabasmathi’, ‘Jaiva’, ‘FL-478’, ‘Ezhome-1’, ‘Mahsuri’, ‘Gouri’, ‘Swarnaprabha’, ‘Dhanu’, ‘IR-28’, ‘Aasha’ and ‘Aishwarya’ for sensory evaluation like taste, texture, colour, aroma etc. On the basis of visual observation of pests and diseases, the genotypes that can be selected as parents for tolerance to major pests, namely, stem borer, leaf roller and rice bug are Culture MK-115, ‘Anaswara’, ‘Dhanu’ and ‘Mahsuri’. The parents that can be selected for tolerance to major diseases namely, blast and sheath blight are ‘Jaiva’, ‘Kasthuri’, ‘Pusabasmathi’, ‘Anaswara’, ‘Ayirankana’ and ‘CO-47’.Validation through scientific screening is necessary.ThesisItem Open Access Assessment and induction of variability through in vitro mutagenesis incassava (Manihot esculenta, Crantz)(College of Horticulture, Vellanikkara, 2015) Hilario Ernesto Magaia; KAU; Jiji JosephThe study entitled “Assessment and induction of variability through in vitro mutagenesis in cassava (Manihot esculenta, Crantz.)” was carried out between 2012 and 2014 in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara. The objective of the study was to assess the genetic variability in the short duration cassava germplasm and induction of variability through in vitro mutagenesis in selected genotypes. Field evaluation, standardization of protocols for in vitro regeneration, in vitro mutagenesis and assessment of variability of in vitro mutated plants were done. Wide genetic variability existed among the collected short duration cassava genotypes. The colour of petiole and root cortex was found to be the most variable qualitative trait for above ground and tuber portions respectively. High magnitude of phenotypic and genotypic coefficient of variation along with high heritability and high genetic gain was observed for branch number, branch height, tuber fresh weight, and Cassava Mosaic Disease. All traits except tuber neck, branch number, scar number and internode length were positively correlated with fresh tuber yield. High direct contribution towards tuber yield was exerted by shoot biomass, tuber dry matter content and harvest index indicating that these are reliable predictor variables for increased yield. Among the biochemical traits, high heritability and high genetic gain was observed for HCN content, amylose content and starch content. Biochemical analysis indicated the occurrence of high starch genotypes (Sree Jaya, CC10 and CC7) suitable for industrial starch production. Vellayani Hraswa with lower starch content was more suited for food or feed purposes, than industrial purposes. The genotype CC10 with easiness in peeling, good taste after cooking and less cooking time scored maximum in organoleptic evaluation. Sree Jaya was sweet on chewing, had highest starch content, lowest HCN content and less fibre content. 213 Diversity analysis indicated that the cassava genotypes grouped into five clusters. No parallelism was found to occur between geographic distribution and genetic diversity. Selection index constructed for the identification of the best genotypes indicated that CC1 and Sree Jaya were the most promising genotypes. CC1, a farmers’ variety from Malappuram district was found to be the best genotype with respect to yield and resistance to CMD, but with a comparatively high HCN content. In vitro mutagenesis in cassava was done using the genotypes CC1 and Sree Jaya. Sterilization of cassava nodal and leaf explants was accomplished by washing with 5 per cent Teepol solution for two minutes, followed by washing for one minute with 75 per cent ethanol and washing for one minute with 0.05 per cent solution of mercuric chloride. Friable embryogenic callus (FEC) for both CC1 and Sree Jaya genotypes was obtained from immature leaf explants cultured in MS media with 3.0 per cent sucrose (MS3), either with 6.0 to 8.0 mg l-1 of 2,4- D , or with 1.0 mg l-1 BAP + 0.2 to 0.5 mg l-1 NAA. Somatic embryos for both genotypes were obtained from FEC cultured in media MS3 with 8.0 to 10.0 mg l-1 picloram and germinated into the plantlets on MS3 media with 4.0 mg l-1 BA or 0.25 mg l-1 TDZ. In vitro regeneration and multiplication from nodal explants were obtained in MS3 media containing either 0.25 mg l-1 TDZ or 2.0 mg l-1 BAP. Rooting of the in vitro plantlets was obtained in MS3 + 0.25 mg l-1 TDZ or 1/2MS1. The LD 50 value varied with the cultures used for in vitro mutagenesis. The LD 50 value for gamma radiation was 40 Gy, 30 Gy and 50 Gy for FEC, somatic embryoids and plantlets, respectively. LD 50 value for EMS was 1.20 per cent for FEC and somatic embryoids and 0.90 per cent for plantlets. Variation in response to mutagenesis was also observed between the two genotypes subjected to in vitro mutagenesis. There was significant difference in the growth characteristics of the mutagen treated in vitro cultures in both genotypes. Reduction of the number of shoots and leaves were more in CC1 compared to Sree Jaya. 214 A combination of SoilriteTM with pure sand at 1:1 proportion was the best substrate for acclimatization of the plantlets outside the tissue culture lab. Fan and pad green house was the best structure for in vitro acclimatization of plantlets resulting in 47 per cent of success rate. Variability with respect to quantitative traits like height, number of shoots and number of leaves was observed in vitro plantlets in the hardening stage. The qualitative traits like colour of the petiole, stipule, emerging leaf and of the stem and the shape of central lobe of leaves varied between the mutated plants.
