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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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Subject: Agricultural Entomology × Author: Harish, E R × Author: KAU × End date: 2018 × Start date: 2018 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Characterization of Bemisia tabaci (Gennadius) (hemiptera: aleyrodidae), for genetic variability, endosymbionts and vector-virus interactions in cassava
    (Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2018) Harish, E R; KAU; Mani Chellappan
    Cassava is one of the important tuber crops cultivated all over the World. Cassava Mosaic Disease (CMD) is the most important limiting factor in its production. Silverleaf whitefly, Bemisia tabaci (Gennadius) is the vector responsible for the transmission of Cassava mosaic virus in cassava, which causes CMD. Genetic variation among the members of B. tabaci, makes them very difficult to manage. Endosymbionts present in the whitefly system could be a factor responsible for making them a successful sucking pest. There are various kinds of interactions existing between whitefly and the CMV. Studying these interactions precisely will help to understand the behavioural and physiological variations in whiteflies. In this background the present study, “Characterization of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), for genetic variability, endosymbionts and vector-virus interactions in cassava” was proposed and carried out at the Department of Agricultural Entomology, College of Horticulture, Vellanikkara, during Mrch 2014 to April 2016, with the objectives to analyse the genetic variability in cassava whitefly, characterization of its endosymbionts and elucidation of cassava whitefly - cassava mosaic virus interactions. Various life stages of B. tabaci were collected from different cassava growing agro ecological zones of Kerala and reared in laboratory as well as in polyhouse at optimum conditions. Genetic variability study was conducted with 10 selected ISSR primers which had shown polymorphism in their banding pattern; with amplicon size ranged between 200bp to 2900bp. Phylogenetic analysis using NTsys software revealed the presence of two major clusters with Sultan Bathery population as out group. Similarity matrix had shown up to 49 per cent variation between the samples. Polymerase chain reaction using mitochondrial cytochrome oxidase1 primers, C1-J2195 and L2-N-3014 had given amplicon of 850bp. Nucleotide sequences had shown variation up to 16.5 per cent and dendrogram generated out of the sequences using MEGA-6 (Neighbor Joining Method) gave two clusters and one out group. Sequence similarity check using reference sequences from NCBI data base indicated the presence of two biotypes, AsiaI and AsiaII5 in cassava plants of Kerala. Morphometric studies were conducted to assess the variations in different pupal and adult characters of thirteen whitefly populations. Significant variations were found in pupal length and pupal width of the biotypes. Pupal length varied between 0.746 mm to 0.668 mm and pupal width varied between 0.539 mm to 0.468 mm in female pupa. Out of 14 characters of pupa studied, variations in length and width were found to be significant. Among seven characters of adults studied, variations in wing, antennal length, body length and width were significant. AsiaI biotype was found to have lesser body length, but more width compared to AsiaII5. AsiaII5 was found to be an important biotype of B. tabaci infesting cassava in 12 out of the 13 locations surveyed. Endosymbiont characterization from whitefly using Next Generation Sequencing (NGS) - Illumina platform revealed the variations in microbiota. At phylum level, Proteobacteria was found at 87.57 per cent in whitefly populations collected from plains. The populations from high ranges contained Firmicutes at 82.67 per cent. Arsenophonus, an ‘indirect helper’ for virus spread by protecting viral coat protein from degradation in insect system with their GroEL chaperones were found at 24. 69 per cent in B. tabaci populations collected from plains. Behavioural and life cycle variation study of B. tabaci using six cassava genotypes had shown that virus infection in B. tabaci altered the dispersal and settling. Speed of movement observed to be maximum at 16.25 cm/s in non- virulent female whiteflies on the genotype CMR-9. Life cycle of virulent and non-virulent whiteflies was found to vary between 19.57 days to 30.77 days. A thorough understanding of genetic variations, endosymbiont diversity and behavioural response to virus could help the researchers in planning proper management strategies for B. tabaci. In future, information generated of such kinds could also help the researchers and policy makers to foresee and manage any possible outbreak of the pest and avoid any havoc caused by them.