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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Heterosis breeding in sesame (Sesamum indicum L.).(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2011) Gayathri, G; KAU; Dijee, BastianThe study entitled ‘Heterosis breeding in sesame (Sesamum indicum L.)’ was undertaken at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara. The objectives of the study were to collect and evaluate different genotypes of sesame for morphological traits and yield attributes, to identify useful parents producing heterotic crosses and developing hybrids in sesame. The study also intended to develop male sterile lines in sesame through interspecific hybridization with Sesamum malabaricum. Sesamum indicum and Sesamum malabaricum accessions were collected from Kerala and Tamil Nadu and evaluated for their morphological traits. Wide range of variation was noticed for characters like plant height, number of days to flowering and seed yield per plant which contributed maximum to genetic divergence. The genotypes studied were grouped into six clusters. High genotypic coefficient of variation (GCV) was recorded for number of capsules per plant, plant height, seed yield per plant and number of branches per plant. High heritability with high genetic advance as per cent of mean was recorded for number of days to flowering, plant height, number of branches per plant, number of capsules per plant and seed yield per plant. This indicates that the characters are governed by additive gene effects and selection for these traits will be effective. Association analysis revealed that seed yield per plant was correlated to plant height, number of capsules per plant and number of days to flowering. Path coefficient analysis indicated maximum positive direct effect by number of capsules per plant, capsule length, plant height and 1000 seed weight on seed yield per plant. In order to develop hybrids, fourteen parents were selected based on the per se performance of the genotypes. They were crossed in line X tester mating design. Forty eight hybrid combinations obtained were raised in the field along with the parents and evaluated for their heterosis and combining ability effects. Parental genotypes AVTS-06-5, AVTS-06-10, IVTS-06-12, KYM-1, Tilak and TMV-6 were identified as high combiners based on general combining ability (gca) effects. Two combinations viz. AVTS-06-5 X KYM-1 and IVTS-06-12 X TMV-3 had significant values of per se performance, specific combining ability (sca) effects and standard heterosis for seed yield per plant. They can be evaluated for their hybrid vigour over locations and seasons. The crosses AVTS-06-5 X TMV-3, AVTS-06-5 X TMV-6 and TCR 3279A X KYM-1 have been identified as potential cross combinations for isolation of promising segregants as the parents involved in these crosses had high significant gca effects for seed yield per plant but the hybrids recorded non significant sca effects. Interspecific hybridization between S.malabaricum and S.indicum was attempted to develop male sterile lines. Seed set was noticed in three interspecific hybrids which failed to germinate due to embryo abortion. Hence these embryos were rescued and raised in vitro to obtain the hybrids.ThesisItem Open Access Variability in asoka (Saraca asoca(Roxb.) de wilde)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2010) Vidhu Francis, Palathingal; KAU; Radhakrishnan, V VAsoka (Saraca asoca) is a sacred tree among the Buddhists and Hindus. It is called sorrow-less tree as it removes the grief. The tree has immense medicinal properties. Its bark is mainly used for correcting uterine problems. The well-known Ayurvedic preparations of asoka bark are Asokarishtam and Asokaghrutham. Due to over exploitation of this tree for its bark, this has now become almost extinct. The International Union for Conservation of Nature and Natural Resources (IUCN) has listed this species under ‘globally vulnerable’ category. It is also enlisted among the 36 threatened and endangered medicinal plants of India. Due to its acute short supply compared to its demand, various development and research activities are being prioritized to conserve, utilize and improve this species. Therefore the present study was undertaken to assess morphological variations in existing germplasm and to study the reproductive biology of S. asoca. Collection of seeds and evaluation of seed and seedling traits, evaluation of therapeutical components and molecular characterisation of asoka were the other objectives of the study. Variability studies for morphological traits of asoka indicated that height of plant and stem girth have high correlation with bark yield as well as higher direct effect. These traits can be used for identifying better genotypes for higher bark yield. In discriminant function analysis, the selection index involving height of plant along with bark yield constituted for selection criteria among asoka genotypes. Using this selection index, accessions IC566463, IC566489, IC566488, IC566482 were selected as better accessions for higher bark yield. The 43 accessions maintained in germplasm of asoka at AICRP on M&AP were grouped into two major clusters based on morphological traits. These clusters further formed 6 clusters. Accession IC566488 grouped alone in one cluster indicated that this accession was different from all other accessions. In all the other 5 clusters, accessions from Thrissur was included. This indicated that accessions did not follow geographical distributions. Some of the accessions from Thrissur may have relationship with accessions from other districts. Reproductive biology of asoka was studied. It indicated that the reproductive traits like floral biology, anthesis, pollen morphology, its viability have variability among eight trees studied in KAU campus. Among the eight trees studied, ‘KAU8’ have better reproductive traits compared to the rest. Preliminary studies were carried out in pollination system and agents for pollination in asoka. The studies indicated that ants may be one of the pollinating agents. Seed and seedling behaviour of asoka were studied on seeds collected from 80 trees located in different districts of Kerala. Seed breadth, seed volume, height of plant and stem girth were identified as selection traits for better seedlings. Hence at seed stage, bigger sized seeds with higher seed volume will result into better seedlings. Vigorous seedlings is produced from tall seedlings with higher stem girth and in mature plants for higher bark yield, height of plant and stem girth can be selection traits. Thus the selection parameters were worked out in three stages in asoka. Based on seed and seedling selection parameters, OKL4, OKL2 from Odakkali, KKL2 from Kottakkal and TVM2 from Thiruvananthapuram were selected as better mother plants for higher bark yielding accessions. The biochemical constituents (phenol and tannin content) imparting medicinal properties were estimated among the different age groups of asoka. Both phenol and tannin contents were higher in bark compared to flower and leaves. About 50 per cent of therapeutical constituents are available in flowers and hence at non destructive level, flowers of asoka can be substituted for bark. The trees KAU8, KAU7, KAU6 and among the accessions IC566474, IC566467 and among the seedlings VKA6, VKA7, VKA8, KMK3 indicated higher phenol and tannin content compared to rest. Molecular characterisation among the selected asoka accessions representing the different districts of Kerala were studied. RAPD analysis was attempted among ten accessions selected. Dendrogram was constituted based on pooled RAPD data. The ten selected accessions were grouped into two major clusters as done in morphological grouping. In grouping at molecular level, the accession IC566488 kept apart as a single group indicating the same trend at its morphological level.The clustering pattern based on molecular characterisation did not follow geographical distribution of accessions.ThesisItem Open Access Cross compatibility analysis for production of hybrids in anthurium andreanum linden(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2010) MadhuKumar, K; KAU; Mayadevi, PThe present study, ‘Cross compatibility analysis for production of hybrids in Anthurium andreanum Linden’ was undertaken to identify suitable parents with commercial qualities and to determine the cross compatibility among the selected parents in anthurium. The present investigation was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during the period 2006-2009. The analysis of variance revealed significant variation among the 40 genotypes for the eighteen characters studied. This reveals the high genetic potential for the improvement in this crop. Variability studies indicated high phenotypic and genotypic coefficients of variation for the characters for anthocyanin content, pollen fertility, leaf size/leaf area, spathe size and spadix length. The high heritability coupled with high genetic advance values were found for characters plant height, leaf size/leaf area, internodal length, spathe size, total anthocyanin content, spadix length, inclination of candle with spathe, number of flowers per spadix, life of spadix, days to initiation of female phase, days to inter phase, duration of male phase, pollen fertility and pollen size. These characters are therefore controlled by additive gene action and amenable to genetic improvement through selection. Pollen fertility estimated using acetocarmine method indicated that most of the genotypes had low fertility values. Liver Red had the highest pollen fertility of 43.01 per cent followed by Lady Jane (36.14 per cent). Pollen emergence was low in the months from March to June, during which the average maximum and minimum temperatures were relatively high. Pollen emergence was highest during October to December months. A study of six qualitative characters such as colour of young leaf and petiole, spathe colour, spathe texture, candle colour and type of inflorescence axis also showed considerable variation among the genotypes studied. Plant height was found to have highly significant positive phenotypic and genotypic correlation with leaf size/leaf area, internodal length, total Anthocyanin content, spadix length, number of flowers per spadix and life of spadix. Number of flowers per spadix had significant positive genotypic correlation with plant height, leaf size/leaf area, internodal length, spathe size, spadix length, total anthocyanin content, life of spadix, pollen fertility and pollen size. Spadix length had significant positive genotypic correlation with plant height, leaf size/leaf area, internodal length, spathe size, number of flowers per spadix, life of spadix and pollen size. Days to initiation of female phase exhibited significant negative correlation with plant height, leaf size/leaf area, spadix length and pollen fertility. The environmental correlations were absent for almost all pairs of characters except for number of leaves/spadices per plant with spathe size. Path analysis revealed that spadix length, plant height, leaf size and life of spadix had high positive direct effect on number of flowers per spadix. Mahalanobis D2 analysis clustered the 40 genotypes into seven clusters. The maximum number of genotypes (17) were included in Cluster I, followed by cluster II (7), cluster III (5), cluster IV (5) and cluster V (4). Clusters VI and VII had one genotype each. Maximum divergence was shown between the Clusters II and VI, while the minimum divergence between clusters I and II. The intracluster distance was highest for the Cluster II. Among the 13 characters considered, life of spadix contributed maximum towards divergence followed by days to initiation of female phase. Grouping of genotypes into different clusters did not reflect the geographical origin of the varieties. Selection index analysis revealed that genotype Liver Red attained the maximum selection index value followed by PR x LR and PR x DT (1) and the minimum estimates were recorded for Rembolina, W x LJ and Corolix. The grouping of genotypes by selection indices followed almost the same pattern as their clustering pattern in the D2 analysis. Intervarietal hybridization was done to analyse the cross compatibility between 15 genotypes based on the percentage of candles bearing fruits, fruit set and seed germination. A total of 127 crosses were attempted based on the availability of receptive spadices and fresh pollen, out of which 80 were found to be successful. In almost all cross combinations the percentage of candles bearing fruits ranged from 50 to 100 per cent. Among the 15 genotypes, the maximum percentage of candles bearing berries was obtained for PR x OG (90.00 per cent) followed by AW (66.67 per cent) and PR x LR (65.00 per cent). The lowest value 5 per cent was obtained for Esmeralda and 11.11 per cent for Dragon’s Tongue. The number of fruits per candle ranged from 5 in Esmeralda x (PR x OG) to 85 in (PR x OG) x (OG x DT). The crosses LR x DT, (OG x DT) x (PR x OG), LR x FR and (PR x OG) x DT also recorded higher number of fruits per candle. The average number of fruits per candles was highest for Liver Red and lowest for Esmeralda. The percentage of fruit set was below 50 per cent for all the crosses. The lowest and highest percentage of fruit set was observed for Ceasor Violet and ‘Liver Red respectively. The berries obtained from different cross combinations took 4.5 to 7 months to mature. Most of the crosses had a high percentage of single seeded berries compared to double seeded berries except for the cross FR x LR. Among single seeded berries maximum seed size was for AW x (PR x OG). In a berry largest seed among the two seeded berries were observed for the crosses AW x (PR x OG) followed by [(PR x LR) x (PR x DT (2)]. The number of days taken for germination varied from four to nine days. The seeds obtained from most of the crosses showed germination except three crosses i.e., DT x LR, (KR x LR) x LJ and Esmeralda x (PR x OG) did not germinate at all. Percentage of germination was lowest in [PR x DT (2)] x LJ and highest in (PR x LR) x C. Seedlings of 57 out of 73 crosses that germinated survived for more than four months. The seedling survival percentage ranged from 38.46 per cent in LJ x (PR x OG) to 81.25 per cent in (KR x LR) x DT. The highest average survival was recorded by Liver Red and lowest was recorded for the genotype Lady Jane. Compatibility parameters estimated based on the performance of the fifteen genotypes as pollen parents. Highest percentage of candles bearing fruits was shown by PR x OG followed by Fla Red, Dragon’s Tongue and PR x LR. Lowest percentage were recorded for Flirt and KR x LR. Number of fruits per candle was the highest for the genotype PR x DT (2) followed by PR x OG, Dragon’s Tongue and Acropolis white. In Lady Jane, Flirt and KR x LR the number of fruits were relatively lower. Higher percentage fruit set was observed for the genotypes Dragon’s Tongue while it was lowest in Lady Jane. Percentage of seed germination was the highest for Fla Red and lowest for Lady Jane. Scoring of the compatibility reactions based on the percentage of fruiting candles, fruit set and seed germination on a scale ranging from zero to nine. After scoring the different genotypes, the crosses with highest compatibility score was for the crosses (PR x OG) x (OG x DT), (PR x LR) x C, FR x DT, AW x (PR x OG), (OG x DT) x (PR x OG), (PR x LR) x (PR x OG),PR x DT (2) x (PR x OG), (OG x DT) x LR, LJ x LR, (PR x OG) x DT, (PR x OG) x LR, (PR x OG) x (PR x LR) and (PR x LR) x FR. So these were the most compatible crosses. The performance of the variety as female parent was found to be different from its performance as male parent. The female parents PR x OG, PR x LR, Lady Jane, OG x DT and PR x DT (2) got the high varietal scores. Among male parents PR x OG, DT, OG x DT, FR and PR x LR got the high varietal scores. So PR x OG, OG x DT and PR x LR could be judged as the best male as well as female parents. Among the seedlings of the successful crosses maximum number of days for maturity of leaves was taken by the cross LJ x (PR x LR) and the least number of days was taken by C x (PR x OG). Number of leaves ranged from 4.50 in DT x FR to 6.33 in [(PR x OG) x (OG x DT)]. The leaf area was maximum for the cross LR x FR and it was minimum for LJ x (PR x OG). The colour of young leaf showed a range from brown to reddish brown to greenish brown to green. The colour of petiole also varied from brown to reddish brown to greenish brown to green.ThesisItem Open Access Genetic analysis of yield and leaf curl virus resistance in chilli (Capsicum spp.)(Department of Plant Breeding, College of Agriculture, Vellayani, 2010) Anandhi, K; KAU; Abdul Khader, K MPepper fruits (Capsicum spp.) are among the most consumed vegetables as fresh green or red and dried whole or ground forms in the world for its pungency. Leaf curl virus is an important biotic stress transmitted by the vector, Bemisia tabaci. Controlling the vector can be the only way to manage the disease and results in only partial control of disease. The incidence of disease is more in summer season and makes the cultivation uneconomical. There is an immediate need to develop leaf curl resistant varieties especially for summer cultivation. Hence the present investigation was undertaken at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2007-2009 with the objective of estimating the combining ability, heterosis and gene action involved in the inheritance of yield and leaf curl virus resistance. Five resistant C. frutescens accessions Mangalapuram Local, Thavanur Local, Kayamkulam Local, Mavelikkara Local and Nenmara Local were crossed in L x T pattern with three high yielding susceptible varieties Jwalamukhi, Jwalasakhi and Vellayani Athulya and 15 F1s were produced and evaluated along with the parents in randomized block design. Analysis of variance revealed highly significant genotypic difference for all the characters studied. The observations recorded were plant height (cm), number of branches, number of days to first flowering, plant spread (cm), duration of flowering (fruiting span), number of fruits per plant, fruit length (cm), fruit width (cm), pedicel - fruit ratio, fruit colour at intermediate stage, green fruit yield per plant (g), average fruit weight (g), number of seeds per fruit, hundred seed weight (g), duration of crop, vector population and virus disease scoring. Higher estimates of PCV and GCV were recorded for vulnerability index and green fruit yield per plant. High heritability coupled with high genetic advance were exhibited for days to first flowering, duration of flowering, number of fruits per plant, green fruit yield per plant, number of seeds per fruit, duration of crop and vulnerability index. Combining ability analysis showed that the line Mavelikkara Local and Nenmara Local were alone good general combiners for fruit yield along with leaf curl resistance. Four hybrids viz., Mavelikkara Local x Jwalasakhi, Nenmara Local x Vellayani Athulya, Kayamkulam Local x Jwalamukhi and Thavanur Local x Jwalamukhi exhibited significant sca effect for fruit yield. Considering per se performance, standard heterosis and sca effect two hybrids Mavelikkara Local x Jwalasakhi and Nenmara Local x Vellayani Athulya were found to be superior. Generation mean analysis was carried out using six-parameter model. Six generations viz. P1, P2, F1, F2, B1, B2 were built up among the crosses Mavelikkara Local x Jwalasakhi and Nenmara Local x Vellayani Athulya. Presence of additive, dominance and epistatic interaction for all the characters indicated that hybridization or recombination-breeding programme can be followed for future breeding.ThesisItem Open Access Characterisation and systematic evaluation of genetic resources of the genus Vigna(Department of Plant Breeding and Genetics, College of Horticulture,Vellanikkara, 2010) Latha, M; KAU; Presannakumari, K TVigna belonging to the family Leguminoseae is a large genus comprising of seven sub-genera and over 150 species. The two sub-genera Vigna and Ceratotropis contain the most important cultivated species. The taxonomical identification of many of these species is still confusing. The closely related wild species serve as a source of many desirable genes that can be utilised in the interspecific hybridisation programmes. This is possible only when the relationships among the different Vigna species are well understood. In this context, the present study “Characterisation and systematic evaluation of genetic resources of the genus Vigna” was undertaken in the Department of Plant Breeding and Genetics, College of Horticulture at Vellanikkara. Investigations were undertaken to characterise the accessions of Vigna germplasm available at National Bureau of Plant Genetic Resources (NBPGR) Regional Station, Vellanikkara, Thrissur using morphological markers and to confirm the results using biochemical and molecular markers in distinct variants belonging to different taxa as well as to prepare a key for the identification of different Vigna taxa. The 150 accessions available at NBPGR Regional Station, Vellanikkara were subjected to morphological, biochemical and molecular characterisation. For morphological characterisation 48 qualitative and 24 quantitative characters were taken. The biochemical characterisation of the selected distinct variants from each taxa was done by isozymes, peroxidase and poly-phenol oxidase. The molecular characterisation was done with Inter Sequence Repeat Analysis using 10 different primers. The clustering patterns based on all three characterisation were compared and key for identification of different taxa of Vigna was developed. Among the qualitative characters evaluated, type of seed germination, nature of attachment of primary leaves, size of stipule, shape of stipule, presence of ligule, shape of bracteole, nature of pod attachment to peduncle, curvature of pod, shape of seed and shape of hilum were distinct for each taxa. Variability was observed in size and shape of stipules and bracteoles. Based on the qualitative characters the 150 accessions were reclassified into 22 taxa. One accession originally classified as V.radiata var.sublobata was found to be distinct taxa of Vigna and hence regrouped as distinct taxa. All the 24 quantitative characters studied exhibited wide range of variability. The keel pocket was present in all taxa except V.unguiculata, V.marina and V.pilosa. The length of keel pocket also varied from taxa to taxa. Cluster analysis based on qualitative, quantitative, biochemical and molecular characters resulted in 10, 5, 4 and 12 clusters respectively. A statistical methodology was worked out to compare the parallelism among the different clustering patterns. The result showed that there existed a similarity between clusters formed based on quantitative and qualitative characters, with majority of accessions of each taxa in a qualitative cluster falling in the same quantitative cluster. The accessions taken for isozyme and molecular study were distinct. Accessions of same taxa which fell in same clusters based on isozyme and molecular markers fell in different clusters based on quantitative characters and vice-versa, indicating the differences and similarities among these accessions at isozyme and molecular level. Key quantitative characters were also identified for each taxa based on weighted average. Based on morphological, biochemical and molecular characters, a dichotomous key was developed to identify different taxa. The key that is now proposed is different from the existing one which is based on floral and fruit characters alone.ThesisItem Open Access Identification of Potential Donors for superior fruit quality traits and genes for resistance to tomato leaf curl virus (ToLCV) In tomato and allied species(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2017) Nadkarni Siddhesh, Raghvehdra; KAU; Jayalekshmy, V GThe study entitled ‘‘Identification of potential donors for superior fruit quality traits and genes for resistance to tomato leaf curl virus (ToLCV) in tomato and allied species’’ was conducted during the period 2014-2017, in the Department of Plant Breeding and Genetics, Vellayani with an objective of evaluating varieties and allied species of tomato for fruit quality traits and genes for resistance to ToLCV through biochemical analysis and molecular markers and to study compatibility for hybridization and seed set to transfer ToLCV genes to bacterial wilt resistant variety ‘’Anagha’’ from donors of related species. Thirty-four genotypes including allied species of tomato were collected from different sources and studied under four different experiments. First experiment was screening of thirty-four genotypes under natural field condition for tomato leaf curl virus resistance in summer season and scoring for ToLCV by the scale given by Banerjee and Kalloo (1987). Eight genotypes viz., EC 541109 (Solanum pimpinellifolium L.) EC 168283 (Solanum pimpinellifolium L.), IIHR1970 (Solanum peruvianum L.) and LA 2805 (Solanum lycopersicum var. cerasiforme L.), IIHR 2372, IIHR 2200, Vaibhav and Nandi were found to be highly resistant. The scions of these eight highly resistant genotypes were grafted on susceptible root stock with ToLCV symptoms. The scions did not take symptoms after 25 days confirming the resistance of the genotypes. Evaluation of thirty-four genotypes for yield and fruit quality parameters was carried out in field condition during rabi season. The analysis of variance revealed significant difference for all seventeen quantitative and fruit quality attributes. On the basis of mean performance for different yield characters, genotypes viz., Vaibhav, EC 320574, EC 165751, EC 164656 and EC 16786 were superior, whereas genotypes EC 541109, IIHR 2372, Vaibhav and LA 2805 were superior for fruit quality traits. The wild species used in the study had high content of carotene, lycopene and TSS. From coefficient of variation it was evident that the estimates of GCV were higher than the corresponding PCV for all seventeen quantitative attributes indicating the less influence of environment on the expression of these genotypes. The estimates of GCV and PCV were higher for seven characters indicating the existence of high variability in the material studied offering ample scope for selection. Heritability estimates and genetic advance as per cent of mean (GAM) were high for all characters indicating predominance of additive gene action for these characters. Phenotypic and genotypic correlation coefficient analysis with respect to weight of fruits per plant-1 showed positive significant correlation with plant height, number of primary branches plant-1, spread of the plant, number of days to 50% flowering, number of days to first fruit harvest, number of fruits plant-1, weight of fruit and volume of fruit. Path analysis confirmed that direct effect on number of fruits plant-1 expressed highest positive direct effect on weight of fruits plant-1, followed by weight of fruit, spread of the plant, lycopene content, number of primary branches plant-1, number of days to 50% flowering and number of days to first fruit harvest. Molecular markers linked to the three genes Ty2, Ty3 and Ty3a specific to ToLCV resistance were validated with thirty-four genotypes. Genotypes IIHR 2200, Vaibhav and EC168283 (Solanum pimpenellifolium L.) showed the presence of Ty2 gene and genotype IIHR 1970 (Solanum peruvianum L.) showed the presence of Ty3a gene. The identified resistant lines were crossed with ‘‘Anagha’’ the popular bacterial resistant variety with an objective to transfer the resistance. All the seven successful hybrid combinations showed 100% pollen fertility confirming the compatibility of the parents. Evaluation of seven hybrids with parents revealed significant difference for all seventeen quantitative and fruit quality attributes. On the basis of mean performance for different yield and fruit quality traits in hybrids viz., L1 x T1 (Anagha x Vaibhav) showed superiority for characters like weight of fruits plant-1, weight of fruit, volume of fruit, pH of juice and shelf life, L1 x T5 (Anagha x EC 541109) showed superiority for characters like plant height, number of primary branches, lycopene content, TSS %, and carotene content, L1 x T2 (Anagha x Nandi) showed earliness in number of days to 50% flowering and number of days to first fruit harvest, L1 x T4 (Anagha x IIHR 2372) showed superiority for traits like pericarp thickness and vitamin C. Seven hybrids were screened and scored for ToLCV, in natural field conditions. Highly resistant reaction was found in four hybrids viz., L1 x T3 (Anagha x EC 168283), L1 x T5 (Anagha x EC 541109), L1 x T6 (Anagha x IIHR 2200), L1 x T7 (Anagha x LA 2805). This study could identify resistance sources for ToLCV viz., EC 541109, EC 168283, IIHR1970, LA 2805, IIHR 2372, IIHR 2200, Vaibhav and Nandi. The genotypes Vaibhav, EC 320574, EC 165751, EC 164656, EC 16786, EC 541109, IIHR 2372 and LA 2805 which showed superiority in yield and fruit quality traits can be used for breeding for improvement of yield and quality traits. The wild species which are found compatible with cultivated species can be used as donors for quality traits as well as resistance. The hybrid L1 x T1 (Anagha x Vaibhav) with superior yield traits and resistance to ToLCV can be recommended for release after yield trials. Hybrid L1 x T5 (Anagha x EC 541109) an interspecific hybrid with superior fruit quality traits can be recommended for release as cherry tomato after trials. The segregating population of interspecific crosses can be used for further evaluation to locate plant types with good yield, fruit quality along with resistance to ToLCV.ThesisItem Open Access Development of near isogenic lines of rice variety 'uma' for blast resistance genes through molecular marker assisted backcross breeding(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2017) Harikrishnan, P J; KAU; Jayalekshmy, V GBlast disease, caused by Magnaporthe oryzae is one of the most devastating diseases in rice and is a great threat to food security worldwide. During kharif season, the disease is prevalent throughout the rice growing areas in India including the southern states of Kerala, Tamil Nadu, Karnataka and Andhra Pradesh. Approximately 100 major blast resistance genes have been reported in rice and hence exploitation of host plant resistance through gene pyramiding can be employed effectively for the management of blast. Developing Near Isogenic Lines (NILs) ie., lines carrying each of the major resistance genes in the background of susceptible recurrent parent is a major step in the pyramiding work to be carried out for developing multi race resistant varieties. So, the present study entitled “Development of Near Isogenic Lines of rice variety „Uma‟ for blast resistance genes through molecular marker assisted backcross breeding” was undertaken at the College of Agriculture, Vellayani Thiruvananthapuram, to develop Near Isogenic lines (NILs) of rice variety Uma for blast resistance genes (Pi1, Pi2 and Pikh) using identified donors through marker assisted back cross breeding. DNA markers closely linked to the blast resistance genes viz., RM527 (Pi2 gene), RM224 (Pi1 gene) and RM206 (Pikh gene) were used for validating marker polymorphism in the identified traditional donors of blast resistance genes viz. PTB21 (Thekkan) with Pi2, PTB7 (Parambuvattan) with Pi1 and Pikh and susceptible recipient parent Uma (MO16). This validation confirmed the absence of genes in the recipient parent, „Uma‟. These polymorphic gene specific markers were used for foreground selection in F1, BC1F1 and BC2F1 plants. Hybridisation was carried out between recipient parent Uma and the two donor parents viz., PTB21 and PTB7 to transfer genes for resistance. F1 plants with heterozygous loci for blast resistance genes specific markers were identified through foreground selection and backcrossed with „Uma‟ the recurrent parent to obtain the BC1F1 generation. The BC1F1 plants were screened with foreground markers and those plants containing the respective resistance genes were identified. Among the plants screened for a particular cross, 12 were found to contain Pi2 gene, 17 had Pi1 gene and 21 plants contained Pikh gene. χ2 test was done with the genotypic data of BC1F1 plants with single genes viz. Pi1, Pi2 and Pikh. Segregation ratio in BC1F1 population from all the crosses except Uma x PTB7 (Pi1) did not show significant deviation from the expected 1:1 ratio suggesting the presence of segregation distortion in the segregants of the cross Uma x PTB7 (Pi1). For the background selection, three parental lines were genotyped with 30 microsatellite loci and the ones polymorphic for Uma and the donors were identified. Twelve markers were found to produce discrete amplicons for distinguishing Uma and PTB21 while 17 markers could distinguish Uma and PTB7. Five of the polymorphic markers were used for background selection in BC1F1 plants with resistance genes of the three crosses. The BC1F1 plants with highest percentage of recurrent parent genome recovery in the three populations were identified. Highest recovery percentage of 70 could be obtained in backcross population of all the three crosses. Morphological data for seven quantitative and one qualitative character (kernel colour) was recorded for the BC1F1 plants with the resistant genes. Euclidean coefficient of dissimilarity was assessed in comparison with the recurrent parent Uma. The Euclidean distance values ranged from 5.9 (A-21) to 21.3 (A-9) in the cross Uma x PTB21 (Pi2), 4.88 (B-8) to 17.8 (B-23) in Uma x PTB7 (Pi1) and from 4.79 (C-34) to 13 (C-15) in case of Uma x PTB7 (Pikh). All the BC1F1 plants with resistance genes were used to raise the BC2F1 generation. The BC2F1 populations of the three crosses were subjected to foreground selection and plants with resistance genes were identified. Background selection was carried out in BC2F1 plants with resistance genes using 12 polymorphic markers in the cross Uma x PTB 21 (Pi2) and 17 markers in plants identified in the BC2F1 of Uma x PTB7 (Pi1 and Pikh). Percentage of recurrent parent genome recovery ranged from 70.83 to 95.83 for the cross Uma x PTB21 (Pi2), 70.59 to 97.06 for Uma x PTB7 (Pi1) and from 61.76 to 94.12 for Uma x PTB7 (Pikh). Euclidean coefficient of dissimilarity was assessed in comparison with the recurrent parent Uma, based on seven quantitative traits (plant height, number of tillers number of productive tillers, panicle length, grain L/B ratio, thousand grain weight and days to maturity) in the BC2F1 plants with resistance genes. The lowest values of Euclidean distance were recorded in the plants A-16-6 (2.24), B-18-2 (3.35) and C-17-3 (4.33) of the three backcross populations respectively. Based on the Euclidean distance and percentage recovery of the recurrent parent genome, five plants were identified from each of the three crosses as potential Near Isogenic Lines (NILs) for the three blast resistance genes Pi2, Pi1 and Pikh. The genotype A-5-1 with a recurrent parent genome recovery of 95.83% and Euclidean distance of 5.55 with Uma was identified as the most potential NIL of Uma for the gene Pi2. Similarly B-27-1 (Euclidean distance – 4.56, % genome recovery - 97.06) and C-17-3 (Euclidean distance - 4.33, % genome recovery - 94.12) were identified as potential NILs for Pi1 and Pikh genes respectively. Selfed seeds (BC2F2) were collected from the identified potential NILs. The present research could identify NILs of Uma for three blast resistance genes viz., Pi1, Pi2 and Pikh with more than 94% recurrent parent genome recovery with two backcrossing through marker assisted selection. This confirms the utility of marker assisted backcross breeding in recurrent parent genome recovery. The NILs can be used in intermating programmes in future to develop pyramided lines of Uma with all the three blast resistance genes (Pi1, Pi2 and Pikh) to ensure high yielding ability and durable broad spectrum resistance to the blast pathogen.ThesisItem Open Access Genetic diversity and combining ability in cucumber (Cucumis sativus L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2017) Suma, A; KAU; Elsy, C RAssessment of genetic diversity is the key tool in any crop improvement and germplasm management programme. Evaluation of genetic variation will help to provide valuable information about new sources of genes. The studies on combining ability and heterosis can support utilization of promising lines in further crop improvement programmes. Cucumber (Cucumis sativus L. 2n= 2x= 14) is an indigenous vegetable crop of India. Even though rich diversity for cucumber is available in India, studies on genetic diversity of this crop are scanty. Therefore, the present project was proposed to explore genetic diversity in cucumber using morphological and molecular markers and to study combining ability and heterosis in selected genotypes. Morphological characterization of 50 accessions of cucumber revealed presence of significant difference among accessions for majority of vegetative, floral and fruit characters. Mean days to first male and female flower opening was 36 and 43 days respectively. Majority of the accessions possessed elliptical elongated fruits with light green skin colour and white flesh colour. Sixteen accessions exhibited significantly higher fruit length than AAUC-2, the standard check, the maximum being exhibited by IC613472 (20.85 cm). Accessions with oblong ellipsoid fruits possessed higher fruit diameter. Mean fruit weight showed high variability among accessions with a range of 33 g to 343 g. Fourteen accessions exhibited significantly high yield than AAUC-2. Number of fruits per plant, yield per plant, loss of weight during storage and sex ratio showed high values for all the genetic parameters studied. IC613481 was the promising genotype identified in morphological characterization, followed by IC613480. Cluster analysis grouped accessions into seven distinct clusters based on the level of similarity in quantitative characters. Random grouping of accessions into various clusters indicated absence of parallelism between genetic diversity and geographical diversity. Cluster II and III were the largest clusters, with 14 accessions each and Cluster V and VI, the smallest ones with single accession each. Results of Principal component analysis revealed that first three principal components, with Eigen values more than unity accounted for 85.80 per cent of cumulative variance, contributed by fruit weight, fruit length, fruit diameter and days to first harvest. The diversity analysis of the accessions was done using DIVA-GIS by generating grid maps. The results of the study indicated that highly diverse accessions with respect to the selected characters were sourced from Mizoram, Tripura and West Bengal. Molecular characterization revealed high level of genetic distinctness between genotypes. SSR11742 and AF202378 were found to be highly polymorphic markers, with high polymorphism information content and number of polymorphic bands. In-depth evaluation of selected 22 genotypes revealed significant difference for all fruit characters except days to last harvest and harvest duration and further revealed the superiority of IC613480. Evaluation of 15 hybrid combinations developed through half diallel mating design and their parents indicated presence of significant difference among parents and hybrids for various characters studied. Among the parental genotypes, IC613480, exhibited significantly high GCA effects for fruit length, number of fruits per plant and yield per plant whereas IC595508A, for fruit weight and loss of weight during storage, and IC613485 for fruit diameter, thus proving to be promising parents for accumulating genes for these characters. The hybrids, IC613480 x IC595508A and IC613480 x IC613471 showed significant SCA effects for yield per plant and sex ratio. IC613480 x IC613471, IC613480 x IC595508A and IC613471 x IC595508A were exhibiting significantly high relative heterosis, heterobeltiosis and standard heterosis for number of fruits per plant and yield per plant. IC613480 and IC613485 were the most promising genotypes identified from the study whereas IC613480 x IC613471 was the most promising hybrid based on SCA effects, heterosis, per se performance on yield contributing characters and organoleptic qualities. This hybrid showed high fruit length (17.01 cm), yield per plant (2163.45 g), number of fruits per plant (11.43) and sex ratio (0.11). IC613480 x IC613476 and IC613485 x IC595508A were the other promising hybrids.ThesisItem Open Access Genotyping of Rf (restoring fertility) loci of rice varieties of Kerala using molecular markers(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2017) Rajib, Das; KAU; Jayalekshmy, V GHybrid rice technology aims to increase the yield potential of rice beyond the level of high yielding varieties by exploiting the phenomenon of hybrid vigour or heterosis. It is the only technology available now to break the yield plateau attained in rice. Commercial production of hybrid rice can be achieved through three line system of hybrid rice development. Identification of restorers and maintainers for the system is the initial step in hybrid rice breeding. So the present study entitled “Genotyping of Rf (Restoring fertility) loci of rice varieties of Kerala using molecular markers” was undertaken as an initial step for the development of hybrid rice for Kerala with the objectives to locate restorers and maintainers from Kerala rice varieties using molecular markers, validation of the restoration of fertility in cross with WA Cytoplasmic Male Sterile (CMS) lines, study of inheritance pattern of restorer gene and to locate heterotic combiners from the possible restorers and maintainers. In the present study twenty one rice varieties were screened with 13 SSR markers linked to different Rf genes i.e Rf3, Rf4, Rf5, Rf6 and Rf7. Three varieties had only one Rf gene, seven varieties had two Rf gene, four varieties had three Rf gene. Rice varieties Remya, Manupriya and Swarnaprabha had four Rf genes and PTB-9 had all the Rf genes. For identification of maintainers and restorers from among the 21 rice varieties under study, these lines were crossed with 4 CMS lines (IR58025A, UPRI95-17A, CRMS31A and CRMS32A). Pollen and spikelet fertility of the hybrids recorded that Remya, Swarnaprabha, Manupriya, Varsha and Aiswarya were restorers for CMS line IR58025A, Remya, Jayathi, Annapoorna, Neeraja, Aiswarya and Pavizham were restorers for UPRI95-17A. Remya, Jayathi, Swarnaprabha, Kanakom and Neearaja were restorers for CRMS31A and Remya, Jayathi, Swarnaprabha, Annapoorna, Kanakom, Mattatriveni and Pavizham were restorers for CRMS32A. Rice variety Remya alone was found to be the restorer for all four CMS lines. Rice varieties Jyothi, Kanchana and Aruna were identified as maintainers for IR58025A. Only one variety Kanchana identified as maintainer for UPRI95-17A. Bharathy, Jyothi, Kanchana and Aruna were identified as maintainers for CMS line CRMS31A, while Kanchana and Bharathy were identified as maintainers for CRMS32A. Kanchana alone was found to be the maintainer for all four CMS lines. In field validation Remya which had 4 Rf genes (Rf3, Rf4, Rf5 and Rf6) was found to be a restorer for all the lines with WA Cytoplasm studied. All the restorers identified through field validation had either Rf3 or Rf4 gene which were reported as the major genes for fertility restoration. Study of inheritance pattern of restorer gene was analysed in F2 generation of the crosses between CMS lines and the restorers. It was found that in UPRI95-17A x Remya, UPRI95-17A x Jayathi, UPRI95-17A x Annapoorna, UPRI95-17A x Aiswarya and UPRI95-17A x Pavizham the restoration of fertility is governed by 2 dominant gene. Co-segregation of the molecular marker linked to Rf loci and the trait of restoration of fertility in the segregating population was analysed through Bulk Segregant Analysis (BSA) and found co-segregation of marker RM1 with Rf3 gene and marker RM171 with Rf4 gene. This shows that the marker loci and fertility restoration genesRf3 and Rf4 are tightly linked. To assess the genetic parameters of the selected twenty one rice varieties they were grown in completely randomized block design with 2 replications in pots and observations were taken on 12 metric traits. The study revealed high heritability coupled with high genetic advance as per cent of mean for Pollen fertility, number of spikelets/panicle, number of filled grains/panicle, LB ratio, number of grains/panicle and grain yield/plant. Hence these traits are predominantly under the control of additive gene action and hence these characters can be improved by selection. Grain yield per plant recorded a significant positive correlation with total no of tillers, number of productive tillers per plant, panicle length, number spikelets/panicle, number of filled grains/panicle, number of filled grains per panicle. Divergence analysis grouped the rice varieties into eight clusters. Cluster II consisting of Mattatriveni and cluster VI consisting of Jayathi, Swarnaprabha, Kanakom and Aiswarya was the farthest. The hybrid developed from 23 crosses between identified restorers and 4 CMS lines were evaluated for heterosis and identified promising hybrids were UPRI95-17A x Aiswarya, UPRI95-17A x Neeraja, UPRI95-17A x Remya and CRMS31A x Kanakom based on high mean grain yield per plant and high standard heterosis over standard check Uma. In order to assess heterosis in different combination of the identified maintainers and restorers an L x T analysis was done with maintainers as the lines and restorers as the testers. Perusal of findings indicated that line Jyothi is a good general combiner as it recorded a high over all GCA status. The hybrid Aruna x Varsha was the best specific combiner followed by, Jyothi x Pavizham and Kanchana x Mattatriveni. Three crosses viz; Aruna x Varsha, Jyothi x Pavizham and Bharathy x Annapoorna registered high significant heterosis for grain yield per plant over mid parent, better parent and standard check Uma. The present study could identify restorers and maintainers for 4 CMS lines from the Kerala rice varieties and also heterotic combination of restorers and maintainers. By reconstituting the identified maintainer with sterile cytoplasm of the CMS lines heterotic hybrids with grain qualities specific to Kerala can be developed. The superior hybrids obtained from identified restorers and CMS lines can be directly used for commercial release after yield trial.
