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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 Evaluation of cowpea [Vigna unguiculata (L.) Walp.] genotypes for yield and resistance to pulse beetle [Callosobruchus spp.](Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2017) Thouseem, N; KAU; Beena, ThomasThe present study entitled “Evaluation of cowpea [Vigna unguiculata (L.) Walp.] genotypes for yield and resistance to pulse beetle [Callosobruchus spp.]” was carried out at farmer’s field, Kayamkulam during 2015-2017, with an objective to evaluate cowpea genotypes for yield and resistance to pulse beetle. The study was conducted in two experiments. In experiment-I, yield and resistance to pulse beetle was evaluated in a Randomised Block Design (RBD) with three replications using 30 genotypes collected from different places. Experiment-II was to study the seed morphological and biochemical factors associated with resistance to pulse beetle in five relatively resistant genotypes and five relatively susceptible ones which were identified through experiment-I. The field experiment revealed that the genotype T1 (Ambalappuzha local) showed the highest mean values for days to 50 per cent flowering, length of main stem, pod weight, pod length, number of seeds pod-1, 100 seed weight and crop duration. The maximum yield plant-1 (32.91g) was obtained for the genotype T29 (Sreya) followed byT14 (Alathur local) and T7 (Dhavengarae local), whereas the minimum yield plant-1 (11.07g) was for the genotype T13 (Hridya). Thirteen genotypes were found to be infested under field condition and only very low seed damage via carry over population was noticed. The characters studied were found to be significant for all the genotypes evaluated. The pod weight exhibited the highest GCV (47.73%) and PCV (52.12%). Heritability was high for all the characters except number of primary branches plant-1, number of pods plant-1 and seed yield plant-1 which possessed moderate heritability. GA (% mean) was high for all the characters except crop duration. The association analysis revealed highly significant positive correlation for 100 seed weight, days to 50 per cent flowering, crop duration, number of seeds pod-1, pod girth, and pod length with seed yield both at genotypic and phenotypic levels. The path analysis revealed that 100 seed weight, number of pods plant-1 and number of seeds pod-1 had the maximum positive direct effect on seed yield plant-1. In no choice confinement test under experiment-I, there were significant differences among the genotypes in terms of oviposition, percentage seed damage and percentage seed weight loss. T2 (Kayamkulam local-1) had the least egg load while more eggs were laid on seeds of T29 (Sreya) and T1 (Ambalappuzha local). The highest percentage seed damage and the highest percentage weight loss were recorded for T13 (Hridya) and T27 (Bijapur local) respectively. The lowest percentage seed damage and percentage seed weight loss were observed for the genotype T7 (Dhavengarae local). In the study of seed morphological and biochemical factors associated with resistance under experiment-II, it was found that seed coat texture, seed coat colour and protein content of seeds were found to have no influence on resistance to pulse beetle. However, total phenol content of seed was having significant negative correlation with percentage seed weight loss. An index score was worked out to find out genotypes with good yield and relative resistance to pulse beetle. It was observed that the genotype T7 (Dhavengarae local) had the highest index score followed by T14 (Alathur local). The present study revealed that the genotype T7 (Dhavengarae local) was found to be a good yielder with relative resistance to pulse beetle followed by the genotype T14 (Alathur local). Hence these genotypes can be recommended for future breeding programmes.ThesisItem Open Access Genetic divergence in kiriyat (andrographis paniculata nees)(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2017) Prathibha, S S; KAU; Arya, KThe study entitled “Genetic divergence in kiriyat (Andrographis paniculata Nees)." was under taken at the College of Agriculture, Vellayani during 2015-17 with the objective to assess the genetic variability present in the natural ecotypes of kiriyat from different regions and identifying the superior ecotypes in terms of herbage yield and quality. Thirty accessions of kiriyat were collected from different parts of India and were evaluated for genetic variability with respect to herbage yield (fresh weight) and quality in terms of total extractives (%). Accession A10 from Aruvipuram showed highest mean values for seedling height (15 DAT), number of primary branches, herbage yield (137.25 g), yield plant-1 (dry herbage yield plant-1) (37.79 g) and total extractives (13.6 %) followed by the A14 (Kottakkal) and A7( Kottakkunnu). The accessions A14 (Kottakkal) and A15 (Nilambur) showed highest mean values for number of secondary branches and number of leaves seedlings-1 (15 DAT) respectively. Mean value for days to 50 percent flowering was least for accession A10. The lowest yield was exhibited by A3 (Coimbatore) accession. Average duration of the plants exhibited ranged between 182.67 and 213 days. The earliest accession was A10 (Aruvipuram) with an average duration of 182.67 days. Seedling height, number of leaves seedling-1, number of secondary branches, leaf length and width, stem girth, leaf/stem ratio, plant height, herbage yield, yield plant-1 and total extractives exhibited high coefficient of variations. Heritability was high for all the characters except number of leaves seedling-1 (15 DAT), herbage yield and yield plant-1 which possessed moderate heritability. GA (% mean) was high for all the characters except plant duration. The association analysis revealed a significant correlation among almost all characters and also with yield. Path coefficient analysis revealed that plant height, herbage yield, number of primary and secondary branches had high positive direct effect on yield. The genetic divergence was studied using Mahanalobis D2 statistics and accessions were grouped into seven clusters. Cluster VII accommodated maximum number of accessions (13) followed by cluster VI (5), cluster V (4), cluster IV (3), clusters III and II (2) and cluster I (1). Highest inter cluster distance was between clusters VI and VII while intra cluster distance was highest for cluster IV. The study revealed that variability existed among the different ecotypes of kiriyat and the ecotype collected from Aruvipuram (A10) was found to be superior in terms of herbage yield and quality followed by ecotypes from Kottakkal (A14) and Kottakkunnu (AThesisItem 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 Characterization of kuttiattoor mango (Mangifera indica L.) Cultivar of Kannur district, Kerala(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2017) Reshma Reghu; KAU; Elsy, C RThe present investigation on ‘Characterization of Kuttiattoor mango (Mangifera indica L.) cultivar of Kannur district, Kerala’ was undertaken to characterize Kuttiattoor mango cultivar grown in Kuttiattoor Panchayath and the nearby Grama Panchayaths viz., Kolachhery, Mayyil, Koodali, Munderi and Malappattam and to characterize the similar mango cultivar of the area. The preliminary survey revealed that Kunjimangalam mango cultivar found in Kunjimangalam Grama Panchayath was a similar cultivar to the Kuttiattoor cultivar. Therefore, Kunjimangalam mango cultivar was also characterized. In the present study it was noticed that flowering commenced in the second week of November in majority of the Panchayaths but a slight delay was noticed in Kuttiattoor and Kunjimangalam Panchayat. The peak flowering was observed in third and fourth week of December in most of the Panchayaths while in Kunjimangalam Panchayath it was in the second week of January. The time of fruit maturity was during the fourth week of March and first week of April in trees from most of the Panchayaths but in Kunjimangalam Panchayath, a slight delay was noticed. Kuttiattoor cultivar was noted to have an attractive semi-circular crown shape. Generally, all the trees were tall and found to have spreading type of tree growth habit. Tree height ranged from 13.50 m to 16.10 m with an overall mean of 14.82 m. Trunk circumference ranged from 129.00 cm to 164.20 cm with an overall mean of 144.22 cm. The crown diameter ranged from 10.90 m to 15.90 with an overall mean of 13.12 m. The tree characters did not vary significantly in trees across the Panchayaths. Kuttiattoor cultivar showed medium intensity of anthocyanin colouration in young leaves. The colour of young leaves were light green with brownish tinge. Mature leaves were dark green in colour without leaf blade twisting. Leaf base was obtuse and leaf tip was acuminate. The petiole attitude in relation to shoot was perpendicular. The leaf characters except petiole length did not show significant variation in tree from Panchayath to Panchayath including Kunjimangalam. Leaf blade length ranged from 21.83 cm to 22.46 and leaf blade width ranged from 6.08 cm to 6.33 cm with an overall mean of 6.16 cm. The ratio ranged from 3.54 to 3.59. The spacing of secondary veins in leaf blade ranged from 1.31 cm to 1.49 cm with an overall mean of 1.42 cm. The petiole length ranged from 3.39 cm to 4.02. Petiole length varied slightly in leaves across the Panchayaths. The anthocyanin colouration of the inflorescence was absent or weak uniformily in all the Panchayaths. The inflorescence length ranged from 20.33 cm to 23.95 cm with an overall mean of 22.13 cm. The inflorescence diameter ranged from 17.80 cm to 20.54 cm with an overall mean of 19.54 cm. The inflorescence length and diameter varied slightly across the Panchayaths. Broad elliptic shape in cross section, green colour of skin, medium colour contrast between lenticels and skin, absence of roughness of surface, medium depth of stalk cavity, rounded outward shape of dorsal shoulder, rounded upward type of ventral shoulder, absence of neck, absence of bulging on ventral shoulder, absence of sinus and absence of bulging of proximal stylar scar where the typical qualitative mature fruit characters. The qualitative characters did not vary across the Panchayaths including Kunjimangalam. The fruit length ranged from 8.78 cm to 9.18 cm and the fruit width ranged from 8.11 cm to 8.30 cm. The ratio obtained by dividing the fruit length by fruit width ranged from 1.07 to 1.10 with an overall mean of 1.08. The size of lenticels ranged from 134.78 μm to 137.28 μm with an overall mean of 136.20 μm. Diameter of stalk attachment recorded an overall mean of 4.46 mm. Density of lenticels and diameter of stalk attachment of fruits varied slightly across the Panchayaths. The other fruit quantitative characters did not vary significantly across the Panchayaths. Yellow-orange colour of skin, medium orange colour of flesh, absence of skin speckling were the characters shown by ripe fruits. The characters viz. adherence of skin to flesh, firmness of flesh, juiciness, texture of flesh, amount of fibre attached to stone and amount of fibre attached to skin were recorded as ‘medium’ in fruits from all Panchayaths including Kunjimangalam. The thickness of skin ranged from 1.02 mm to 1.09 mm with an overall mean of 1.06 mm. The relief of stone surface was ridged and the seed shape was reniform. The cultivar was highly polyembryonic. 89.66 per cent of the nuts exhibited polyembryony whereas 10.34 per cent exhibited monoembryony. Biochemical characterization revealed that TSS ranged from 12.62 0Brix to 15.40 0Brix with an overall mean of 14.45 0Brix. TSS was very similar to that obtained for Muvandan in earlier studies. Titratable acidity ranged from 0.14 per cent to 0.21 per cent with an overall mean of 0.18 per cent and carotenoids ranged from 4.48 mg/100g to 7.66 mg/100g with an overall mean of 6.47 mg/100g. Ascorbic acid ranged from 37.65 mg/to 50.98 mg/100g and the crude fibre ranged from 2.56 per cent to 5.05 per cent. TSS and crude fibre showed slight variation in mangoes across the Panchayaths. The cluster analysis grouped 55 trees into two clusters. It was observed that trees from same Panchayath were distributed to both the clusters. Majority of trees from Kunjimangalam were distributed in Cluster I, which had most of the trees of Kuttiattoor, indicating that, the trees identified from Kunjimangalam had close similarity to the trees from Kuttiattoor and nearby Panchayaths.ThesisItem Open Access Characterization of okra [Abelmoschus esculentus L. Moench] genotypes in North Kerala(Department of Plant Breeding and Genetics, College of Agriculture, Padannakkad, 2017) Aswathi, G Prasad; KAU; Namboodiri Raji, VasudevanThe study entitled “Characterization of okra [Abelmoschus esculentus L. Moench] genotypes in North Kerala” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Padannakkad during 2015-2017. The main objective of the study was exploration and collection of okra genotypes in North Kerala and evaluation of collected accessions for morphological characterization, genetic variability and diversity in qualitative and quantitative traits. On the basis of eco-geographic survey conducted in North Kerala, 44 accessions of Abelmoschus esculentus were collected from Kannur, Malappuram and Kasaragod district and the passport data of these accessions were prepared. During the exploration in areas of okra collection, a wide variability was noticed with respect to its morphological traits. Thirty eight accessions out of fourty five were evaluated for various qualitative and quantitative traits in augmented design using two checks viz Salkeerthi a variety released from Kerala Agricultural University and Arka Anamika from Indian Institute of Horticultural Research (ICAR-IIHR), Bangalore. They were subjected to morphological characterization for fourteen qualitative traits based on IPGRI descriptors and genetic variability analysis for nineteen quantitative traits. The morphological characterization showed distinct morphotypes in the okra accessions as depicted by variation in branching habit, stem colour, leaf shape, leaf colour, flower colour, fruit shape, fruit pubescence and fruit position. The analysis of variance indicated significant differences among the accessions for all the quantitative characters except number of locules per fruit and fruit length. However among the checks there was no significant difference for characters such as days to 50 per cent flowering, internode length, number of units in epicalyx, size of sepal, size of petal and fruit diameter. When checks were compared with accessions, characters like number of fruiting nodes, size of sepals and size of petals did not show any significant difference. Two accessions viz, AE-16 followed by AE-20 recorded higher green fruit yield than two checks with AE-16 recording maximum. The accession AE-20 was also superior for characters such as number of marketable fruits per plant, primary branches per plant and required lesser number of days to attain marketable maturity. The accession AE-5 had shown superiority for important fruit characters such as fruit weight and fruit diameter. All these accessions showed no incidence of fruit and shoot borer except AE-5. Among the components of variability, high heritability coupled with high genetic advance as per cent of mean was observed for plant height, primary branches per plant, internode length, fruit weight, fruit diameter, days to marketable maturity and green fruit yield indicating effectiveness of selection based on phenotypic performance of these traits. Yield being a complex character, the association analysis of component characters of yield revealed high positive genotypic correlation for characters such as primary branches, fruit weight and number of marketable fruits. Significant negative genotypic correlation was exhibited by first flowering node with green fruit yield. Path coefficient analysis revealed that internode length, number of fruiting nodes, fruit diameter and number of marketable fruits per plant are the main determinants of green fruit yield in okra as indicated by their high positive direct effects and the characters first flowering node and days to 50 per cent flowering are major determinants of earliness as indicated by their high negative direct effect on green fruit yield. So improvement in yield will be efficient if selection is done based on all these characters. Genetic diversity analysis based on Standardized Euclidean Square Distance for nineteen quantitative characters grouped thirty eight accessions into seven clusters. The clustering showed that there is no parallelism between the geographical distribution and clustering pattern. On the basis of qualitative characters cluster analysis with UPGMA (Unweighted Pair Group Method with Arithmetic mean) method grouped the 38 okra accessions into three main clusters as distinguished by branching pattern, leaf and stem colour. There was a total of twenty cross combinations of genotypes belonging to clusters with high inter cluster distance and superior mean performance based on the overall ranking in the clusters for the four attributes viz. fruit weight, marketable fruits per plant, days to marketable maturity and green fruit yield. AE- 5, AE-10, AE-16, AE-18, AE-20 and AE-30 were identified as promising. The present investigation projected the importance of AE-16 and AE-20 as one of the parents for higher heterosis in F1 and potential transgrents in the subsequent generation. Both these accessions have considerably high green fruit yield per plant greater than the checks Salkeerthi and Arka Anamika. Similarly the accessions like AE-10, AE-18, AE-30 belonging to cluster I, V and IV were identified as superior in yield and AE-5 belonging to cluster VI as promising with highest fruit weight. If these genotypes are involved in crosses with Salkeerthi, the popular variety of KAU with excellent fruit characters will give potentially high yielding segregates with good market value.ThesisItem Open Access Genetic stock development for phytophthora pod rot disease resistance in cocoa (Theobroma cacao L.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2017) Veeresh, S Akki; KAU; Minimol, J SCocoa production is ruthlessly affected by pod rot disease caused by many Phytophthora species. Among these, the pod rot caused by Phytophthora palmivora is of prime importance. Since, the disease infection period is rainy season, the application of fungicides has not evidenced as a successful control measure. Hence, the effective and eco-friendly way to tackle this disease is by developing resistant varieties. The success of any breeding programme depends upon the availability of well characterised genetic resources. In this context, the current study was formulated for characterisation of exotic germplasm and identifying genetic stock of cocoa for Phytophthora pod rot resistance. Morphological characterization of 30 genotypes were carried out by recording ten qualitative and 23 quantitative characters governing leaf, flower, pod and bean. High variability was observed for most of the characters except petal colour and number of ridges and furrows. The germplasm when characterized based on biochemical parameters such as fat, polyphenols and mineral content (Na, K and Ca) also expressed wide variability. It is essential to quantify the diversity available among genotypes in order to design an effective breeding programme. Hence, cluster analysis was carried out by D2 statistics and principal component analysis. Among all the qualitative clusters, cluster III was the biggest with eight members. Cluster analysis of quantitative characters showed that most of the genotypes were placed separately in distinct cluster due to wide variability available in the germplasm. Cluster analysis of biochemical characters also exhibited wide variability which is evident from the fact that it formed 15 clusters even at 25 per cent similarity. Correlation studies and path analysis were employed to know the nature and relationships among the yield attributing characters. Here, it was found that wet bean weight (g) showed positive correlation with pod weight (g), furrow thickness (cm), pod length (cm), pod breadth (cm), weight of the bean (g) and number of beans per pod. Results of path analysis revealed that total wet bean weight (g) was directly influenced by pod thickness (cm), number of beans per pod, single dry bean weight (g) and wet bean weight (g). Since, quantitative and qualitative descriptors serve as an effective tool to discriminate among the genotypes, a evaluation data was constructed for all the genotypes considering distinct characters governing them. The non-pricking and pricking methods of pod inoculation with pure culture of pathogen were employed to know the disease resistance reaction exhibited by different genotypes. In the non-pricking method, five genotypes (ICS 41, SIAL 339, PNG 250, PNG 336 and IMC 20) with zero per cent infection and 14 genotypes (CRU 12, MO 109, GDL 7, GU 261/P, NA 149, PA 156, LX 43, POUND 4/B, JA 10/12, DOM 14, ICS 75, DOM 25, POUND 18 and POUND 16/A) with infection less than 15 per cent were grouped under highly resistant category. However, these genotypes did not show same disease resistance reaction in pricking method which indicated that the resistance was influenced by certain morphological characters apart from the internal resistance and the significance of those morphological characters were lost when pods were pricked. Binomial logistic regression revealed that different phenes like ridge thickness, polyphenol content and calcium content were positively contributing to disease resistance. Whereas, phenes like pod rugosity, pod basal constriction and pod length were negatively correlated with disease resistance. If these phenes are considered for selection, ample increase in the level of resistance will be noticed in the resultant population. Genetic stock was developed considering disease resistance and yield. As opined by many scientists “Disease resistance is a double-edged sword”. The phytotoxin developed in plants against pathogen is not only toxic to the pathogen but also to the plants resulting in yield reduction. Here also same trend was noticed and majority of the genotypes which expressed high resistance were low yielders. The accessions manifested high resistance can be used for further breeding programme.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 Development and validation of novel EST-SSR markers in black pepper(Department of Plant Breeding and Genetics, College of Agriculture, Padannakkad, 2017) Sherin Jose; KAU; Sujatha, RThe study entitled ―Development and validation of novel EST-SSR markers in black pepper (Piper nigrum L.)‖ was carried out at College of Agriculture, Padannakkad, Kasaragod, Kerala during 2015-2017. The main objectives of the study were to develop EST-SSR markers in black pepper, validation of the developed EST-SSR markers in different genotypes of black pepper and to study the genetic relationship among different species of Piper. Different genotypes (53 numbers) including nineteen varieties and sixteen cultivars of black pepper and eighteen different species of Piper were included in the study. The plant materials were collected from Hi-Tech black pepper nursery in College of Agriculture, Padannakad; Indian Institute of Spices Research (ICAR- IISR), Kozhikode; the Experimental farm of IISR, Peruvannamuzhi and Pepper Research Station, Panniyur. Simple sequence repeats (SSR) were mined from the expressed sequence tags (EST) obtained in a previous study about the genes expressed during berry development stage of black pepper. The microsatellite identification tool, MISA was used for detecting SSRs from 1048 unigenes having a total size of 518179 bp and the results were confirmed using another microsatellite identification tool, GMATo. Seventy SSRs were detected from 68 unigene sequences which accounts for 6.49 per cent of total sequences. There were 62 mononucleotides (88.6 per cent), two dinucleotides (2.8 per cent) and six trinucleotides (8.6 per cent) identified from the sequences. Ten microsatellites including six trinucleotides, two dinucleotides and two compound SSRs were selected and primers were designed based on the corresponding unigene sequences to amplify these regions in the genomic DNA. Nine primers (which consist of forward and reverse primer) were designed, viz., PNS1, PNS2, PNS3, PNS4a, PNS4b, PNS5, PNS6, PNS7 and PNS8. Primers were designed for eight repeat motifs including six trinucleotide repeats, one dinucleotide repeat and one compound repeat. The developed primers were screened using genomic DNA isolated from black pepper variety Panniyur-1. Annealing temperature of the primers was standardized through gradient PCR. Based on the specificity of the amplification, five primers (PNS1, PNS3, PNS4a, PNS6 and PNS8) were selected for further validation. Genomic DNA was isolated from the 53 genotypes of Piper spp. and amplified with the selected primers for validation. In total, 34 alleles were obtained for the five loci amplified by the five primer sets. The average number of alleles per locus was 6.8. Polymorphism Information Content (PIC) value of different primers was calculated based on the number of polymorphic bands obtained using each primer set. All the five primers were successful in amplifying the corresponding locus in P. nigrum genotypes as well as in other Piper spp. Among the 34 alleles, seven were found only in P. nigrum, 16 were specific to other Piper spp. and 11 were shared by both groups. PIC value was in the range of 0.16 to 0.83. The maximum PIC value was given by PNS6 with 10 alleles bringing out the difference between all the species and minimum was shown by PNS8. For cluster analysis using the software DARwin version 6, scoring was carried out based on the presence (1) or absence (0) of the alleles in each genotype using each primer. Dissimilarity between the genotypes was found out using dice matrix. Dissimilarity values were in the range of 0.08 to 0.87. The genotypes were grouped into different clusters based on the similarity between genotypes. Different Piper species were present in two clusters, Cluster II with seven species and Cluster III with eleven species. In Cluster III-B, one species, Piper sp. (North East Fragrance) was present along with six black pepper cultivars indicating that this may be a closely related species of P. nigrum. Some of the parental type and corresponding varieties derived from them (Aimpiriyan and Panchami, Balankotta and Panniyur-2) were present in single cluster which indicates the genetic similarity between these genotypes. Allelic size of 400 bp obtained using EST-SSR marker, PNS 1 was unique to Piper sp. (North East). The marker PNS 3 also showed a unique allele in Piper sp. (North East) with two alleles having a size of 230 bp and 210 bp. Allele with a size of 180 bp was given by Piper sp. (Anand) using PNS 3 EST-SSR marker. Allelic size of 400 bp, 320 bp and 300 bp was unique to Piper chaba, Piper ornatum and Piper betle using PNS 6 marker. The markers developed will be linked with a gene, as they are derived from the expressed region of the genome. In the present study also the limited number markers could bring out preliminary information about the existing genetic diversity between certain groups which was reported earlier using other molecular markers such as ISSR and RAPD. However this cannot be generalized, as further information is needed based on more number of SSR markers.
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