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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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20211
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Subject: Plant Biotechnology × Author: Ashwini, M N × Start date: 2021 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Molecular mechanism of virulence in the bacterium, Photorhabdus luminescens (Thomas and Poinar) against Tetranychus truncatus Ehara (Prostigmata: Tetranychidae)
    (Department of Plant Biotechnology, College of Agriculture, Vellanikkara, 2021) Ashwini, M N; KAU; Haseena, Bhaskar
    Spider mites (Tetranychidae) are a major group of sucking pests of many agricultural and horticultural crops worldwide. Tetranychus truncatus Ehara is the predominant mite species infesting economically important crops of Kerala. Novel acaricides are being extensively used for managing mite infestation, which has led to development of significant level of resistance in mite populations to these acaricides. This, along with other adverse effects of synthetic acaricides to the environment, calls for alternative strategies in mite pest management. The entomopathogenic bacteria Photorhabdus luminescens (Thomas and Poinar), a natural symbiont of the entomopathogenic nematode, Heterorhabditis spp. has potential virulent properties and the ability to infect a wide range of insect pests and a few mite pests. An array of toxins produced by the bacteria are responsible for this appreciable insecticidal activity. Most of the orally active toxins are encoded by tca and tcd loci of TC genes. These toxins might also be responsible for the acaricidal activity of the bacterium. In this context, the present study was undertaken to identify the virulent strain of P. luminescens against T. truncatus and to elucidate the molecular mechanism of virulence against T. truncatus. Eleven bacterial isolates associated with the entomopathogenic nematodes, Heterorhabditis spp. were isolated in the study. Cultural characterization of the bacterial isolates showed that the bacterial colonies were circular to irregular, entire, opaque, smooth colonies on NBTA medium. All the isolates were found to be Gram negative and rod shaped. For molecular characterization, the 16S rRNA gene of the isolates was amplified, sequenced and subjected to BLASTn for homology search. One species of EPN symbiotic bacteria, P. luminescens and eight nonsymbiotic/ associated bacteria namely, two isolates of Pseudomonas aeruginosa, five isolates of Ochrobactrum and one isolate of Stenotrophomonas maltophila were identified. Phylogenetic tree was constructed based on the gene sequences of 16S rRNA to validate the bacterial identification.Laboratory bioassays were carried out to evaluate the efficacy of the both cell suspension and cell free supernatant (CFS) of five bacterial isolates (1 isolate of P. luminescens, 2 isolates of P. aeruginosa, and 2 isolates of Ochrobactrum sp.) separately against the eggs and adults of T. truncatus. Though the isolates did not show any significant ovicidal action, they recorded significant adulticidal action against the mite. The P. luminescens isolate was superior over other isolates recording 64.67 and 60.67 per cent mortality for CFS and cell suspension, respectively at 96 h of treatment The virulent P. luminescens isolate was subjected to characterization of the toxin complex (TcdA gene). The full length gene (7.5 kb) was split into eight regions and the primers were designed to amplify each regions separately. Among the eight regions, only six got amplified and were sequenced. Toxin gene sequence of the isolated P. luminescens bacteria involved in the virulence against T. truncatus was partially sequenced and the variations in the sequence were analyzed. The study identified a potential isolate of P. luminescens with significant adulticidal action against T. truncatus and the major gene TcdA encoding the toxin complexes which possess appreciable insecticidal activity was sequenced and characterized. The P. luminescens isolate obtained in the study can be evaluated for efficacy against major insect pests in the region in order to identify the potential in pest management.