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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 Pathology × Author: KAU × Author: Sanju Balan × End date: 2021 × Start date: 2020 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Characterisation and management of sugarcane bacilliform virus (SCBV) causing leaf fleck disease in sugarcane
    (Department of Plant Pathology, College of Agriculture, Vellanikkara, 2021) Sanju Balan; KAU; Anita Cherian
    Sugarcane (Saccharum officinarum) is a monocotyledonous perennial cash crop cultivated worldwide both under tropical and sub tropical conditions. It is being cultivated in more than 120 countries in the world. Like any other crops, it is also susceptible to biotic stress. Of which, diseases caused by viruses not only pose serious threat to sugarcane cultivation but also result in deterioration and exclusion of elite varieties of the germplasm. One of the major viral disease which affects global exchange of sugarcane germplasm is leaf fleck disease caused by Sugarcane bacilliform virus (SCBV). The research project entitled ‘Characterization and management of Sugarcane bacilliform virus causing leaf fleck in sugarcane’ was initiated with purposive sampling surveys in selected sugarcane fields in districts of Kerala and Tamil Nadu in order to document the symptoms under natural conditions, to assess the disease incidence, severity and to collect infected samples for further studies. The per cent disease incidence of the leaf fleck disease in Kerala ranged from 12 to 51 per cent whereas severity ranged from 10 to 36.5%. In Tamil Nadu the per cent disease incidence ranged from 28 to 56 per cent while severity ranged from 28 to 50.41%. Major symptoms observed on leaves were mottling, chlorotic flecks, chlorotic patches streaks and stripes with general yellowing of the canopy. In the case of severely affected clones, there was reduction in tillering, internodal length, number of internodes and appearance of deep longitudinal cracks. In highly susceptible clones, stunted growth with bunchy top appearance was noticed. On the basis of phenotypic variability of symptom expression, genotypes were classified into five groups. The development of the symptoms was also studied under artificial condition through insect transmission of the virus using pink mealy bug, Saccharicoccussacchari. Morphological characterisation of the virus done using electron microscopy revealed the presence of bacilliform virus particles of size 30 X 130–150 nm which indicated that the virus belongs to genus BADNA and family Caulimoviridae and the etiology of the disease was confirmed as Sugarcane bacilliform virus. The molecular detection of SCBV was also standardized through polymerase chain reaction (PCR). PCR amplification of RNaseH/RT gene was done using BADNA specific and SCBV129 specific primers. The amplicons were sequenced and in silco analysis of sequences showed sequence homology of 99 to 100 percent identity to SCBV. Widespread occurrence of the disease was observed even in the early generation of varietal development and in newly developed varieties. The transmission of the virus was suspected through true seed (fluff) developed by biparental crossing during sugarcane varietal development programme. Hence, the study was conducted to establish possible transmission of the virus from sugarcane parents to their progenies and the role of maternal and paternal parents in disease transmission through true seeds to the progenies. Samples from eight months old seedlings, three months old seedlings and parental clones were tested positive to the virus in PCR assays. Real time PCR was also standardized to assay these clones. Immunodiagnostic technique was validated using DAC ELISA. The technique of immunocapture PCR was also standardized. Minimal dilution of antisera with which SCBV could be detected was 2:1000 (V/V). Plant extract (antigen) at a dilution of 1:5 was found to be optimal for the detection of SCBV. Molecular detection of SCBV from mealy bug vector was also standardized. Both phenotypic and molecular methods were utilized to identify potential sources of natural resistance against SCBV. Based on the severity of symptom expression and PCR assays these were further classified as highly susceptible (HS), moderately susceptible (MS) moderately resistant (MR) and resistant (R). For generation of RNAi hair pin construct, initially forward (SF) and reverse primer (SR) were used to amplify 700 bp fragment of RT/RNase H gene to be cloned in sense orientation of the vector, pHANNIBAL. The linearized vector and the insert were ligated, and the ligation mixture was used to transform competent cells of Escherichia coli and the transformants were selected. Later antisense forward (AF) and reverse (AR) primer pairswere used to amplify 700 bp fragment of RT/RNase H gene to be cloned in antisense orientation. PCR product ligated into antisense direction of the vector and transformed into competent cells of E. coli. The recombinant pHANNIBAL vector was digested with restriction enzymes. The recombinant pHANNIBAL vector harbouringRNase H /RT gene was released from the vector through Not I site and subcloned into plant expression binary vector. Thus, cassette for RNA silencing was prepared.130 Meristem tip culture was also standardized with antiviral chemical tenofovir. Recovery percentage of meristem varied from 70 to 75 per cent and the viral load was quantified using real time PCR. The outcome of the study would facilitate early detection and elimination of the source of infection and prevent the spread of the disease in the field. Information generated in the study could be utilized while planning biparental crossing and reduce the spread of the virus in varietal development programmes. The hair pin construct developed in this study could be further utilized to generate transgenic disease resistant plants.