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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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  • ThesisItemOpen Access
    Heterosis breeding in sesame (Sesamum indicum L.).
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2011) Gayathri, G; KAU; Dijee, Bastian
    The 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.
  • ThesisItemOpen Access
    Gene pyramiding for bacterial blight resistance in rice variety Uma (Mo 16)
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2016) Tintumol, Joseph; KAU; Rose Mary, Francies
    Exploiting host-plant resistance through pyramiding of resistance genes have been recommended as the best approach to impart durable resistance to rice varieties in order to combat the bacterial blight (BB) disease caused by Xanthomonas oryzae pv.oryzae (Xoo). In lieu of this, F1s were produced by hybridizing the susceptible elite rice variety Uma with resistant donor parent Improved Samba Mahsuri (ISM) harbouring three R-genes xa5, xa13 and Xa21. BC1F1 individuals were generated by backcrossing the F1s using variety Uma as the recurrent parent. The present study aimed to identify the R-genes introgressed individuals in the BC1F1 population as well as to produce BC2F1s and BC1F2s of the identified R-genes introgressed BC1F1s. Foreground selection of the BC1F1 individuals was done using the R gene linked molecular markers. Restriction digestion of the PCR product of STS marker RG 556, linked to R gene xa5, with Dra1 restriction enzyme, resulted in production of alleles of size 128 bp, 514 bp, 587 bp, 624 bp, 650 bp and 836 bp in all the BC1F1 individuals as well as the parents indicating the presence of R gene xa5 in all the individuals studied. Amplification of DNA of the individuals with the functional marker xa5 SR further confirmed the presence of R gene xa5 in both the parents as well as in all the BC1F1s. Restriction digestion of the PCR product of STS marker RG 136, linked to R gene xa13, with Hinf1, produced alleles similar to that of the donor parent ISM in three BC1F1s namely, plant no. 8.3.2, plant no. 8.3.3 and plant no. 8.3.9, indicating the presence of R gene xa13 in these plants. The presence of gene xa13 in the identified BC1F1s was further affirmed by using the functional marker xa13 promoter. The analysis had resulted in the production of 560bp allele associated with the resistant allele of gene xa13 in homozygous state from donor parent ISM in the three BC1F1s mentioned above. Out of the 95 BC1F1 individuals scored with the STS marker pTA 248 linked to R gene Xa21, only BC1F1s plant no. 8.3.2, plant no. 8.3.3 and plant no. 8.3.9 were found to possess Xa 21. Results thus obtained revealed thatBC1F1plant no. 8.3.2, plant no. 8.3.3 and plant no. 8.3.9 were R gene pyramids (xa 5+xa 13+ Xa 21). Background profiling of the three R-genes introgressed BC1F1s using 22 rice microsatellite markers, revealed presence of the donor parent allele in the homozygous state. PCR analysis with the marker RM 307, however, revealed the presence of alleles from both the parents, ISM and Uma in the BC1F1 plant no. 8.3.2. This indicated that the plant was heterozygous at the marker locus and can be expected to segregate for the alleles at this locus in subsequent generations. Considering the segregation of the 22 markers the per cent recurrent parent genome recovery in the R-genes introgressed BC1F1s was estimated to be higher in BC1F1 plant no.8.3.2 but lower than the expected estimate of 75 per cent. This was also confirmed by graphical genotyping. The dendrogram thus generated out of the marker data, grouped the R-genes introgressed BC1F1s with ISM indicating that the three R-genes introgressed BC1F1s exhibited greater similarity with donor parent parent ISM at the genome level. Evaluation of BC1F1 individuals for morphological traits revealed presence of wide variability. The three R-genes introgressed BC1F1s were late in flowering compared to the recurrent parent Uma. Two of these genotypes i.e.,plant no. 8.3.2 (234 days) and plant no. 8.3.3 (228 days) flowered later than the donor parent. However, the three R-genes introgressed BC1F1s resembled the recurrent parent Uma with respect to grain and kernel characteristics. Backcrossing the three R-genes introgressed BC1F1s i.e., plant no. 8.3.2, plant no. 8.3.3 and plant no. 8.3.9 to the recurrent parent Uma resulted in 28 BC2F1s. Simultaneously, selfing of these individuals produced 850 BC1F2 seeds. Foreground and background profiling of these generations can ensure precise identification of genotypes that resembles the recurrent parent Uma possessing the resistance genes of interest with maximum recovery of recurrent parent genome.
  • ThesisItemOpen Access
    Evaluation of superior cultures for yield and yellow vein Mosaic resistance in okra
    (Department of Plant Breeding and Genetics College of Agriculture, Vellayani, 2016) Nikitha, J; KAU; Arya, K
    The present study entitled “Evaluation of superior cultures for yield and yellow vein mosaic resistance in okra (Abelmoschus esculentus (L.) Moench)” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2014-2016, with the objective to identify high yielding and yellow vein mosaic resistant cultures of okra from those evolved through inter-varietal hybridization programme. Fifteen superior cultures of okra obtained from the previous project in the Department viz., VLYA 1, VLYA 2, VLYA 3, VLYA 4, VLYA 5, VLYA 6, VLYA 7, VLYA 8, VLYA 9, VLYA 10, VLYA 11, VLYA 12, VLYA 13, VLYA 14 and VLYA 15 along with two check varieties Varsha Uphar and Kiran were evaluated in a Randomized Block Design (RBD) with three replications during summer season of 2015. The analysis of variance was calculated for the traits under study viz., days to 50 per cent flowering, number of fruits plant-1, fruit weight (g), fruit length (cm), fruit girth (g), yield plant-1 (g), plant height (cm) and duration (days) and these were found to be highly significant for all the genotypes evaluated. The maximum yield was recorded by the genotype VLYA 2 which was on par with genotypes VLYA 5, VLYA 10, VLYA 11, VLYA 13 and VLYA 15 and the minimum yield was observed by the check variety Kiran. The yield plant-1 exhibited moderate GCV (18.42%) and PCV (19.05%), high heritability (94.00%) coupled with high genetic advance (36.69%). The yield plant-1 was found to be significantly and positively correlated with number of fruits plant-1, fruit length, fruit girth, fruit weight and plant height both at genotypic and phenotypic levels. Days to 50 per cent flowering and yellow vein mosaic disease incidence was found to be negatively correlated with yield plant-1. Very high positive and significant inter-correlation was noticed between height of plant and number of fruits plant-1. The path analysis showed that number of fruits plant-1 and fruit weight showed the maximum positive direct effect towards yield. The number of fruits plant-1 had high indirect effect through fruit length. The scoring for yellow vein mosaic disease and the vulnerability index revealed that the genotypes VLYA 5, VLYA 11 and VLYA 13 were resistant to the disease during all stages of crop growth. Number of white flies was found to be highest in VLYA 10 and lowest in VLYA 2. The incidence of fruit and shoot borer was also scored and five genotypes viz., VLYA 2, VLYA 4, VLYA 11, VLYA 13 and VLYA 14 were found to be immune and VLYA 3, VLYA 5, VLYA 15 and Varsha Uphar were found to be resistant. The glass house experiment of vector transmission and graft transmission was conducted for the confirmation of disease resistance and the vulnerability index was calculated to check the severity of the disease. The genotypes VLYA 5, VLYA 11 and VLYA 13 received a score ‘0’ which indicated that these genotypes were highly resistant. Hence the genotypes which obtained a vulnerability index of ‘0’ during both field evaluation and glass house experiment were confirmed to be resistant to yellow vein mosaic disease. Hence the present study revealed that the cultures VLYA 5, VLYA 11 and VLYA 13 were having high yield and yellow vein mosaic disease resistance. So these genotypes can be used for further trials before releasing for field cultivation.
  • ThesisItemOpen Access
    Combination breeding for high protein cowpea (Vigna unguiculata L. Walp)
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2015) Sarath, P S; KAU; Jiji, Joseph
    Cowpea (Vigna unguiculata L. Walp) is one of the most important legume crops grown in India. It is a versatile pulse crop owing to its nutritional value, weed smothering nature, drought tolerant characters, soil restoring properties and multi-purpose uses. Protein deficiency has been reported to be one of the main nutritional problems in the developing world. About one billion people are reported to be suffering from protein deficiency and malnutrition worldwide. Studies have revealed that protein content in cowpea grain ranges between 18 to 40 per cent depending on the genotypes. Identifying high yielding varieties of cowpea with high protein content will not only contribute to food security and alleviate poverty but could also contribute to the alleviation of protein deficiencies. Review on the earlier research pointed to poor emphasis on the genetic improvement of cowpea for improved protein content. Hence, the present study was envisaged to combine the high protein trait with high yielding genotypes. The study was grouped under three experiments, i) Evaluation of cowpea genotypes, ii) Hybridisation of the selected genotypes in line x tester design, iii) Evaluation of F1 hybrids. The experiments were conducted at College of Horticulture, Kerala Agricultural University, Vellanikkara during 2014-2015. All the crop management practices were followed as per KAU (2011). Evaluation of cowpea genotypes revealed that there was wide variability for all the traits studied except branches per plant among bushy and semi trailing types of cowpea. In trailing type, variability was observed for plant height, number of pods per plant, pod weight grain yield per plant and seed protein content. Among the twenty two genotypes evaluated, ten genotypes that exhibited a protein content of above 25 per cent were selected for hybridization programme. The selected genotypes (Vellayani Jyothika, Bhagyalakshmi, Anaswara, Kanakamony, Lola, Vyjayanthi, AV-5, PKB-3, PKB-4 and Sharika) were hybridized in line x tester (6 x 4) design. High magnitude of phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), heritability and genetic advance was observed for plant height, grain yield per plant and length of pods were observed in parents and hybrids suggesting scope for genetic improvement of these traits through selection. Seeds per pod and protein content exhibited low PCV and GCV but high heritability and low genetic gain, indicating that these traits were governed by non-additive gene action and therefore breeding method other than simple selection is required. Combining ability analysis revealed that higher magnitude of specific combining ability (SCA) variances than the general combining ability (GCA) variances for the traits like pods per plant, length of pod, test weight, grain yield per plant and seed protein content indicating preponderance of non-additive gene action in the inheritance of these traits. Higher estimates of GCA variances over SCA variances for plant height, days to flowering, days to first harvest, days to last harvest, pod-weight and seeds per pod implies the preponderance of additive gene action in controlling these traits. The hybrids were ranked based on mean value, sca effects and estimates of heterosis for the traits like days to flowering, pods per plant, seeds per pod, test weight, grain yield per plant and protein content. Four hybrids with the lowest scores were selected. Hybrids H2 (Vellayani Jyothika x PKB-3), H10 (Anaswara x PKB-3), H11(Anaswara x PKB-4) and H12 (Anaswara xSharika) were found to be the most promising. The transgressive segregants with high yield and protein content can be identified on further evaluation of the segregating population from the above hybrids
  • ThesisItemOpen Access
    In vitro mutagenesis and evaluation of somatic embryo derived plantlets in cassava (Manihot esculenta Crantz.)
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2016) Riya, Antony; KAU; Jiji, Joseph
    The present study ‘In vitro mutagenesis and evaluation of somatic embryo derived plantlets in cassava (Manihot esculenta Crantz.)’ was conducted in the Department of Plant Breeding and Genetics, College of Horticulture during 2014-15. They study attempted to assess the variability existing among the in vitro derived plantlets of cassava genotypes Sree Jaya and CC1 as well as to generate further variability through in vitro mutagenesis. With the aim to induce variability, in vitro mutagenesis of callus derived from cassava genotypes Sree Jaya and CC1 was attempted earlier in the department. This had resulted in 10 somatic embryo derived plantlets in primary hardening stage and 58 plantlets yet to be transferred for hardening. The above plantlets formed the basic material for field evaluation undertaken in the present study. Sree Jaya and CC1 genotypes were planted as control. Out of the 58 plantlets transferred from the in vitro cultures to hardening, only 34 plantlets survived i.e., the survival was found to be 58.62 per cent. All the ten plants that were already in the primary hardening stage survived. Observations were recorded during field evaluation of the in vitro mutagen treated plants at three, six and nine months after planting as per the descriptor of cassava (Fukuda et al., 2015). The plants varied with respect to qualitative characters like colour of apical leaves, leaf retention, shape of leaf lobe, petiole colour, leaf orientation, colour of stem exterior, extend of root peduncle, shape of tuber, root colour, colour of root pulp and colour of root cortex. Variability was also observed for quantitative characters like length and width of leaf lobe, length to width ratio of leaf lobe, petiole length, distance between leaf scars, height of plant, tuber weight per plant, tuber girth, stem girth, extend of root peduncle, starch content and dry matter content. Among the mutagen treated plants of Sree Jaya none of in vitro mutagen treated plants were found to be superior with respect to tuber yield while in CC1 genotype, six plants yielded better than the control. Sensory evaluation of the tubers produced by in vitro mutagen treated plants as well as control plants was done by twelve panelists to assess consumer perception. The tubers from plant 32 (Sree Jaya; 1.2 % EMS), followed by plant 31 (Sree Jaya; 1.2 % EMS) and plant 42 (CC1; 0.9 % EMS) were most preferred for various sensory attributes evaluated. In vitro mutation being a potential method to induce variability, mutation of callus derived from genotypes was as attempted to create more variants. The callus cultures of Sree Jaya and CC1 genotypes were established as per the protocol standardised by Magaia, (2015). Friable embryogenic calli production was higher in the media MS + 8 mg L-1 2,4-D + 1 mg L-1 NAA + 0.5 mg L-1 BAP using leaf explants. Calli were subjected to physical (γ irradiation at 30- 60 Gy at an interval of 10Gy) and chemical (EMS 0.1 - 0.9 % at an interval of 0.1%) mutagens as advocated by Magaia, (2015). However, regeneration of mutagen treated friable calli was not obtained in both genotypes. Quantum of variability expressed in the in vitro mutated plants of cassava with respect quantitative traits shows the efficiency of in vitro mutagenesis in creating variability in cassava. In vitro mutagenesis is a potential tool in the hands of plant breeder to create variability especially in vegetative propagated crops. The evaluation of in vitro mutagen treated plants in the field showed wide variation with respect to most morphological as well as biometrical traits. All the plants evaluated can hence, be advanced to next generation of evaluation (M1V1) with replication to identify the mutants. From the results obtained on induction of in vitro mutation to create more variants in cassava, it is concluded that the friable callus in both the genotypes need to be cultured in alternate regeneration medium for successful regeneration of somatic embryos.
  • ThesisItemOpen Access
    Invitro propagation in ashoka : saraca asoca (Roxb.) de wilde.
    (Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2011) Brindha Devi, I; KAU; Sreenivasan, E
    Asoka (Saraca asoca) is an important medicinal and ornamental tropical tree currently facing the threat of extinction due to overexploitation of trees occurring in forests and other natural habitats. Unscientific and destructive extraction of bark from trees has lead to acute shortage of raw bark by ayurvedic industries. Hence, 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. It is considered as the sacred tree of buddhists and Hindus. Literally the term ‘asoca’ means ‘sorrow-less’ and the tree is believed to remove the grief and unhappiness. The tree has immense medicinal properties. Its bark is considered as the primary medicinal part. 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. It is mainly propagated by seeds. Due to heterozygous and cross pollinated nature of the species, it never gives a true to type progeny. Therefore the present study was undertaken to standardize the technique of in vitro propagation of Saraca asoca. Standardization of suitable explants, surface sterilization procedures and culture establishment protocol, Induction of multiple shoots and Elongation of root, hardening and planting out are the major objectives of the study. Nodal segment, Internodal segment and shoot tip were the three explants tried. Various surface sterilization procedures were tried using Chloramphenicol, ethyl alcohol, 0.1% mercuric chloride and combination of ethyl alcohol and mercuric chloride in various concentration and duration, using nodal segments as explant. Surface sterilization using 70% ethyl alcohol for 3 minutes followed by 0.1% mercuric chloride for minutes proved to be the best, which gave the maximum survival percentage of 80.   The next part of the study was standardisation of suitable explants for culture establishment. Among the three explants, Nodal segments gave maximum response of 60 per cent in ½ MS medium with BAP 0.5mg/l. This was followed by shoot tips in the same medium, which gave 10 per cent response. Internodal segments did not respond in any of the media used. Standardisation of basal media for culture establishment was done using nodal segments as the explants. Three media supplemented with BA 0.5 mg.l-1 were tried viz. MS, Half strenght MS, Woody plant media. Among the three, ½ MS media was identified as the best basal medium followed by MS medium. No response was seen in WPM medium. Culture establishment as well as Shoot bud initiation was attempted in ½ MS and MS media with various growth regulator combinations. Maximum response of 60 per cent was obtained in ½ MS medium containing BAP 0.5 mg/l followed by 30 percent in the same medium containing BAP 1.5 mg/l. There were no response with 2,4-D. The response obtained was callusing in all cases. Induction of multiple shooting was tried in ½ MS medium supplemented with BAP, and Kn alone as well as combinations of BAP, IAA at various concentration. Here highest response of 30 per cent of single shoots was recorded in ½ MS media containing BAP 0.5 mg/l. Response was in the form of single shoot. The single shoots with a mean length of about 1.5mm after one week of growth was obtained. With BAP 2.0 mg/l, single shoots were produced in about 5% of cultures within 54 days. Effect of Kn in various concentration ranging from 0.5 to 2.0 mg/l was found to be low in shoot induction. The maximum length of shoot of about 1.6 cm was recorded in combination of BAP 0.5 mg/l and IAA0.5 mg/l. Various combinations of IAA and IBA at different concentrations were tried for rooting of in vitro shoots. However there was no response in any of the combinations tried.
  • ThesisItemOpen 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 V
    Asoka (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.
  • ThesisItemOpen 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, P
    The 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.
  • ThesisItemOpen 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 M
    Pepper 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.