Loading...
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.
Browse
43 results
Search Results
ThesisItem Open 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, FranciesExploiting 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.ThesisItem Open 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, KThe 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.ThesisItem Open Access Combination breeding for high protein cowpea (Vigna unguiculata L. Walp)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2015) Sarath, P S; KAU; Jiji, JosephCowpea (Vigna unguiculata L. Walp) is one of the most important legume crops grown in India. It is a versatile pulse crop owing to its nutritional value, weed smothering nature, drought tolerant characters, soil restoring properties and multi-purpose uses. Protein deficiency has been reported to be one of the main nutritional problems in the developing world. About one billion people are reported to be suffering from protein deficiency and malnutrition worldwide. Studies have revealed that protein content in cowpea grain ranges between 18 to 40 per cent depending on the genotypes. Identifying high yielding varieties of cowpea with high protein content will not only contribute to food security and alleviate poverty but could also contribute to the alleviation of protein deficiencies. Review on the earlier research pointed to poor emphasis on the genetic improvement of cowpea for improved protein content. Hence, the present study was envisaged to combine the high protein trait with high yielding genotypes. The study was grouped under three experiments, i) Evaluation of cowpea genotypes, ii) Hybridisation of the selected genotypes in line x tester design, iii) Evaluation of F1 hybrids. The experiments were conducted at College of Horticulture, Kerala Agricultural University, Vellanikkara during 2014-2015. All the crop management practices were followed as per KAU (2011). Evaluation of cowpea genotypes revealed that there was wide variability for all the traits studied except branches per plant among bushy and semi trailing types of cowpea. In trailing type, variability was observed for plant height, number of pods per plant, pod weight grain yield per plant and seed protein content. Among the twenty two genotypes evaluated, ten genotypes that exhibited a protein content of above 25 per cent were selected for hybridization programme. The selected genotypes (Vellayani Jyothika, Bhagyalakshmi, Anaswara, Kanakamony, Lola, Vyjayanthi, AV-5, PKB-3, PKB-4 and Sharika) were hybridized in line x tester (6 x 4) design. High magnitude of phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), heritability and genetic advance was observed for plant height, grain yield per plant and length of pods were observed in parents and hybrids suggesting scope for genetic improvement of these traits through selection. Seeds per pod and protein content exhibited low PCV and GCV but high heritability and low genetic gain, indicating that these traits were governed by non-additive gene action and therefore breeding method other than simple selection is required. Combining ability analysis revealed that higher magnitude of specific combining ability (SCA) variances than the general combining ability (GCA) variances for the traits like pods per plant, length of pod, test weight, grain yield per plant and seed protein content indicating preponderance of non-additive gene action in the inheritance of these traits. Higher estimates of GCA variances over SCA variances for plant height, days to flowering, days to first harvest, days to last harvest, pod-weight and seeds per pod implies the preponderance of additive gene action in controlling these traits. The hybrids were ranked based on mean value, sca effects and estimates of heterosis for the traits like days to flowering, pods per plant, seeds per pod, test weight, grain yield per plant and protein content. Four hybrids with the lowest scores were selected. Hybrids H2 (Vellayani Jyothika x PKB-3), H10 (Anaswara x PKB-3), H11(Anaswara x PKB-4) and H12 (Anaswara xSharika) were found to be the most promising. The transgressive segregants with high yield and protein content can be identified on further evaluation of the segregating population from the above hybridsThesisItem Open Access 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, JosephThe 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.ThesisItem Open 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, EAsoka (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.ThesisItem Open Access Reproductive biology of water lily (Nymphaea nouchali Burm.f.)(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2012) Fahida, P K; KAU; Presanna KumariWater lilies are a group of fascinating aquatic perennial herb belonging to the genus Nymphaea. Among the different species of Nymphaea, Nymphaea nouchali is one common in south India. This species is commonly known as blue water lily, blue star water lily or star lotus. The plant is historically and functionally significant since it is associated with our culture and tradition. This species which forms an important constituent of aquatic flora possesses immense medicinal and ornamental values. Despite of its immense potentialities, water lily has received very little attention of crop improvement workers. Information on developmental pattern and reproductive biology which is fundamental for crop improvement programmes is lacking in this plant. Hence this investigation entitled ‘Reproductive biology of water lily (Nymphaea nouchali Burm.f.) was under taken up with the objective of elucidating the reproductive biology and developmental pattern of flowers and fruits in Nymphaea nouchali. Two flower colour variants of Nymphaea nouchali- blue and white types maintained in cement tanks were selected for the study. The study was conducted during 2010-2012 in the Department of Plant Breeding and genetics, College of Horticulture, Vellanikkara. The leaves of both the colour variants are simple, orbicular with sub-peltate lamina and deeply cleft near to the petiole base. The petiole of both the type was long, glabrous and brownish in colour with lamina floating on the water surface. The blue type was significantly superior to the white type for mean length of leaf as well as means width of leaf at middle and tip. In both the types it took almost six days for the flower bud to reach the water surface and the flower opening occurred nearly three days after the bud reaching the water surface. Even after the flower opening the pedicel elongation continued in both the types to an extent of 4 cm. Maximum growth rate of the pedicel was observed on the day just prior to the flower opening. The white type produced longer flower bud and thus larger flowers when compared to blue type. However the circumference of the flower bud was more for blue type. The flowers of both the types were faintly fragrant. The flowers opened in morning and closed in the evening hours and again opened on next day. The opening time of the flower varied from 7.30 am to 9.45 am. The closing time varied from 5.15 pm to 6.15 pm. Bright and sunny days favoured early opening of the flower. The blossom life was three days for blue type where as it was four days in white type. The flowers were produced throughout the year on an average of 3 to 4 days interval in both the types. Hence it can be well recommended for water gardens. The flowers were found to be solitary, pedicellate, and complete with various floral whorls in spiral fashion on the floral axis. Significant variability was observed on various floral characters among the two types. Each stamen consisted of a filament, anther and a sterile appendage at the tip. The initiation of dehiscence occurred by the longitudinal splitting of the anthers in both the types. The pollen dehiscence occurred only after complete opening of the flower. The stigma receptivity started 17 hours before flower opening and the receptivity was retained up to 20 hours after flower opening. Honey bees, house flies and weevils were found to be the major insects visiting the flowers. Several dead insects were observed in the stigmatic cup of both the types indicated the insectivorous nature of the flower. The pollen grains were found to be round, yellow in colour and monocolpate with reticulate exine in both the colour variants. No fruit or seed development were observed in both the colour variants. The absence of fruit or seed set can be attributed to very low fertility of the pollen and some incompatibility mechanisms in the flower. The vegetative propagation from leaf was found prominent in both the colour variants under study.ThesisItem Open Access Epidemiology and management of black rot of cauliflower in plains of kerala(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2011) Lakshmi Prasanna, S; KAU; Ravi, SThe present study “Epidemiology and management of black rot of cauliflower in plains of Kerala” was taken up at Department of Plant Pathology, College of Horticulture, Vellanikkara and Agriculture Research Station, Mannuthy during 2009-2011 with an aim to study the epidemic factors influencing the incidence, development and severity of black rot caused by Xanthomonas campestris pv. campestris in plains of Kerala and to conduct field studies on its management. The pathogen was isolated from the leaves and curds of cauliflower showing typical symptoms of the disease, on PSPA medium. The colonies of the isolate were yellow in colour, circular, slimy and smooth convex with entire margin. Studies on morphological, cultural and biochemical characters confirmed the bacteria as Xcc. Various types of viz., chlorotic lesion, V shaped lesions, vein blackening; necrosis and vascular discoloration were produced by the pathogen. The symptoms were initially localized and later became systemic and stunting of plants was noticed due to systemic infection. Progression and severity of the disease was studied by inoculating the plants at five days interval starting from 10 days after transplant (DAT) up to 60 DAT. Cauliflower plants of all age group were found to be susceptible to this disease. But, young plants were succumbing to death due to infection. As the age increased there was gradual decrease in the systemic infection. Plant mortality also decreased with the increase in age at which they got infected. Sixteen cauliflower varieties were screened for black rot disease under field conditions. The incidence, calculated as A- value (AUDPC), varied from 0.53 to 12.81. These varieties were grouped in to four categories based on the scale; 0-resistant, 0-3 moderately resistant, 3-5 moderately susceptible and >5 susceptible. Out of sixteen varieties, none was found to be resistant, eight were found to be moderately resistant, two were moderately susceptible and remaining six were susceptible. An attempt was made to formulate a score card for this disease for easy observation and which has a bearing on the yield. The actual area of infection in the leaf at 10, 25 and 40 days old plants were correlated with yield and a equation y=389.061+3.371(10 DAT)-0.986(25 DAT)-2.391(40 DAT) was obtained. Three system of score card were formulated and their relationships with the yield were re-correlated statistically and three additional equations were arrived. The equation two was comparable with the original equation and that score card can be better adopted as it showed 95 per cent similarity to the original, where scale 1 and 3 showed 77.5 and 90.1 per cent similarity respectively. An attempt was made to determine the role of weather parameters on incidence of this disease. The weather factors such as maximum temperature and sunshine hours were positively correlated prevailing to the observation on 9th day and average of 7, 8 and 9 days. Similarly average of 4, 5, 6; 5, 6, 7 and 6, 7, 8 days were positively correlated with only sunshine hours. A partial multiple regression equation is also derived for predicting the disease incidence. Such correlation studies have to be conducted for at least five years consecutively to arrive at a better prediction model. Initial in vitro evaluations were done to identify the chemicals, botanicals and bioagents to be carried to the field. Field trail showed that garlic extract 10 per cent, tetracycline 250 ppm and Pseudomonas fluorescens were best treatments against Xcc.ThesisItem Open Access Morphological and biochemical characterization of aromatic rice(Oryza Sativa L.) cultivars of Wayanad district of Kerala(Department of Plant Breeding and Genetics, College of Horticulture,Vellanikkara, 2010) Sumalatha, T V; KAU; Elsy, C RThe present study was undertaken in the Department of Plant Breeding and Genetics and in the Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Ve!!anikkara and at RARS, Ambalavayal during 2008-2010 with an aim to characterize the aromatic rice cultivars of Wayanad district, based on morphological, nutritional and biochemical studies. Gandhakasala and Jeerakasala are two popular and traditional non-Basmati aromatic ricecultivars of Wayanaddistrict, Kerala. In Wayanad Gandhakasala is cultivated in an area of 327 ha, while Jeerakasala in 22 ha. Based on grain characters 10 samples of Gandhakasala and two samples of Jeerakasala were selected for characterization. Deepthi (WND.3) was used as check variety. Among morphological studies, qualitative characters like leaf bladepubescence, . panicle exsertion, spikelet awning, awn colour, lemma and palea pubescence and seed . . coat colour showed variation and hence these can be used as morphological markers to distinguish aromatic genotypes among themselves and with Deepthi. Straw coloured short and partial awns were the characteristic feature' of Jeer aka sa I a grains, while awns were absent i!1 Gandhakasala and Deepthi. Aromatic genotypes exhibited well exserted panicles and white seed coat colour whereas Deepthi showed moderately welIexserted . . panicles and red seed coat colour. Mean performance of aromatic genotypes indicated that ligule length, grain length, grain breadth, 1000 grain weight, days to 50 per cent heading, milling recovery and maturity days provided a good base for selection. Jeerakasala genotypes took more days to 50 per cent heading and to maturity than Gandhakasala genotypes and Deepthi . . In general Gandhakasala genotypes had lesser 1000 grain weight with a mean value of 13.78 gm compared to Jeerakasala (19;82 gm) and Deepthi (26.17 gm). High grain breadth and grain length would have added to high 1000 grain weight in Deepthi. In general aromatic genotypes have lesser milling recovery than Deepthi, indicating the need [or specially designed milling machines for maximum milling recovery. The genotype GT2 appeared to have higher total carbohydrate content of 81.87 per cent/while it Was Iow for JT12 (58. 40%). Jeerakasala genotypes exhibited low mean carbohydrate content of 61.06 per cent' compared to Gandhakasala( 69.56%) and Deepthi (71.73%). The three Gandhakasala genotypes GT3, GT9 and GT7 exhibited intermediate proteincontent, indicating their nutritional superiority. The amylose content of aromatic genotypes ranged between 17.87(GT4) and 23.07 (GT2) percent. Five aromatic genotypes GT1, GT2, GT8, GTlO and JT12 had intermediate amylose content. Since intermediate amylose rice is preferred in most of the rice growing regions of the world, these genotypes will have better preference in market. Most of aromatic genotypes under study were moderately aromatic, indicating their suitability for commercial cultivation. Biochemical characterization based on isozyme studies revealed the possibility of utilizing peroxidase polymorphism for identifying the aromatic rice genotypes especially Gandhakasala genotypes from other cultivars. Studies on esterase. polymorphism revealed the presence of EST-2 band only in Deepthi indicating its use as a biochemical marker to distinguish aromatic rice genotypes from Deepthi. Heritability and genetic gain studies indicated that selection of characters like length of sterile glumes, lOOO grain weight, grain length and peroxidase activity may be effective in crop improvement programme. Correlation and path studies revealed that grain yield could be improved by simultaneous selection for high seedling height, grain breadth, milling recovery and straw yield.ThesisItem Open Access Characterisation of genotypes of orchids(Department of Plant Breeding and Genetics,College of Agriculture, Padannakad, 2016) Yusuf Abbas; KAU; Sujatha, ROrchids occur mainly in humid tropics and temperate regions of the world. They are known for their long lasting and bewitchingly beautiful flowers. Out of the nearly 30,000 species of orchids in the world, India contributes around 1200 species. In India, the north eastern region accounts for about 800 species, while the Western Ghats has around 275 species of orchids. Western Ghats is one among the 34 biodiversity hotspots identified in the world. However, due to the continuing loss of habitat, fragmentation, expanding human population and other activities, some of the flora and fauna in this region are included in the highly threatened group, orchids being one among them. Many of the orchids in this region are indiscriminately exploited for the local traditional medicine and for horticulture purpose and thus face the danger of being extinct. Hence the present study was undertaken in order to assess the orchid diversity in selected regions in Central western Ghats and to conserve few genotypes which are threatened. The study on “Characterisation and conservation of promising genotypes of orchids from Central Western Ghats” was carried out at Central Western Ghats and College of Agriculture, Padanakkad, Kasargod, Kerala during 2014-2016. The study was based on the survey carried out in 6 natural habitats of Central Western Ghats namely Aralam Wildlife Sanctuary, Ranipuram Wildlife Sanctuary, Pushpagiri Wildlife Sanctuary, Brahmagiri Wildlife Sanctuary, Talakavery Wildlife Sanctuary and Rajeev Gandhi National Park. The survey revealed that, a total of 9463 accessions of orchids belonging to 70 species classified under 30 genera were present in these habitats. Among these, maximum number of orchid genera was recorded from the Brahmagiri Wildlife Sanctuary (23 genera, 39 species), whereas minimum in the Ranipuram Wildlife Sanctuary (15 genera, 22 species). The diversity analysis was made by using Shannon Index (H') and Simpson Diversity Index (D). The highest diversity was recorded for Bharamagiri Wild Life Sanctuary, with the values of H' - 3.37991 and D - 0.95834, whereas it was lowest for Ranipuram Wildlife Sanctuary with value of H' - 2.540636 and D -0.87597. The preliminary survey indicates higher diversity of orchids in natural forests, which includes rare, endangered species such as Bulbophyllum mysorense, Aerids cripa, A maculosa, Dendrobium crepidatum, Cymbidium bicolor, Rhyncostylis retusa etc. With respect to the species diversity four genera had more number of species compared to other genus, viz., Dendrobium, Bulbphyllum, Hebanaria and Oberonia and maximum number of orchid species were recorded in the genus Dendrobium followed by Bulbophyllum. A total of 46 accessions belonging to14 genera were rescued and established in the orchidarium of which 26 were native to Central Western Ghats; 4 accessions from CoA, Padannakkad in which two accessions were tissue culture plants maintained at Department of Plant Biotechnology (one species each of Dendrobium and Phalenopsis) and 2 accessions from natural habitat of Padanakkad (one species each of Dendrobium and Acampe); 7 accessions from Sikkim (1 Vanda, 1 Coelogyne, and 5 Cymbidium) and 9 accessions were hybrids collected from Bengaluru, comprising of 6 Dendrobiums, 1 Mini Cattleya, 1 Oncidium, and 1 Phalaenopsis. The vegetative and reproductive characters of orchids were recorded based on descriptor available from National Research Centre on Orchids, Sikkim, and were further classified based on their generic characteristics. The vegetative characters reveal variations among the species which could effectively differentiate the accessions from one another. The plant height ranged from 5.9 cm to 126 cm. The maximum plant height and number of leaves were recorded in PDK/ORP-5 (Vanda), the maximum leaf length in PDK/ORP-25 (Cymbidium) and highest number of sprouts in PDK/ORP-25 (Bulbophyllum fischeri). The reproductive characters were recorded at flowering phase for 6 accessions. The flowers were exquisite and showy which exhibit different shapes and colours, the largest flower was recorded in PDK/ORP-16 (Dendrobium hybrid 4) and the longevity of the flower ranged from 8 days (PDK/ORP-45: Acampe) to 26 days (PDK/ORP-20: Dendrobium sp. from Brahmagiri). The molecular characterization was done to study the diversity of the selected 17 accessions belonging to the 14 genera. Out of 30 RAPD primers 10 RAPD primers were selected based on the quality and intensity of amplification. The 10 selected primers produced a total of 399 scorable DNA fragments of high polymorphism that were present among 14 orchids genera, with amplicons in the size range of 300 – 1700 bp. The dendrogram separated the 17 accessions into 6 groups, the range of similarity coefficients was from 0.08 to 0.48 in 14 genera. A total of 20 diagnostic bands were observed, in which OPA 18 produced 6 species specific bands whereas OPA 16 failed to produce any diagnostic band. The intra generic characterization was carried for detecting polymorphism and duplicates, if any, in Vanda and Dendrobium. Nine accessions each of genera Vanda and Dendrobium were separately amplified using 5 selected primers. A total of 192 RAPD bands were produced in Vanda (size range : 150–1450 bp ) whereas 186 RAPD bands in Dendrobium (size range:175–1625 bp) . The range of similarity coefficients for the Vanda was 0.15 to 0.80, and for Dendrobium was 0.15 to 0.70 and the dendrogram separated the accessions into 3 groups each. The Mycorrhizal association study was carried on 14 genera which were subjected to investigations for detecting mycorrhizal association in accessions. The epiphytic species were found to be more associated with mycorrhizae, as their roots are in contact with mosses and debri of organic material. The aerial roots and new roots showed infestation only when they had contact with the substrate. The hyphae and spore of mycorrhizae detected in all samples were of similar type, but they varied in the colonization percentage (60-100%). The study revealed that, ideal period for general growth of the plants under Padanakkad condition is January-February while the sprouting was more during June. Genera like Acampe, Bulbophyllum, Coelogyne, Cymbidium, Dendrobium etc showed faster growth in the orchidarium compared to the rest. Six of the accessions flowered in the orchidarium among which one was a wild collection from Brahmagiri. It is a promising genotype which can be used for breeding purposes as it has the longest flower duration (26 days), bright colour, large petals (45.7mm) & sepals (35.6mm) and it flowered two times within 10 months. Morphological and molecular data revealed that there is no duplication in the collection, even within the same genus.
