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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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20111
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Subject: Plant Pathology × Author: Hajara, P H × End date: 2011 × Start date: 2011 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Phenotypic and pathogenic variability of sclerotium rolfsii sacc. infecting fruit crops and ornamentals
    (College of Horticulture, Vellanikkara, 2011) Hajara, P H; KAU; Beena, S
    The present study on “Phenotypic and pathogenic variability of Sclerotium rolfsii Sacc. infecting fruit crops and ornamentals” was undertaken in the Department of Plant Pathology, College of Horticulture, Vellanikkara during 2009-2011 with an aim to isolate the pathogen associated with the disease and to study the symptomatology of the disease, variability in phenotypic and pathogenic characters of isolates, compatibility of the different isolates, host range of the pathogen and estimation of IAA and total phenol content in mycelia, culture filtrate and sclerotia. Isolation of pathogen associated with the diseased specimens of selected ornamental plants viz., marigold and chrysanthemum and fruit crops viz., mango and banana yielded a total of 11 isolates of S. rolfsii from different locations. Among them, two isolates from marigold (MG-1, MG-2), four from chrysanthemum (CH-1, CH-2, CH-3, CH-4), three from mango (MN-1, MN-2, MN-3) and two from banana (BA-1 and BA-2) were obtained. The pathogenicity of the isolates was proved by artificial inoculation on their respective host. Symptomatology of disease revealed slight variation in the symptoms produced by the pathogen in different host plants. In marigold and chrysanthemum infection was observed on leaves and collar region. Flowers of marigold were also infected by the pathogen. Mango seedlings and grafts were infected by the pathogen on the collar region. In banana var. Kadali, infection was observed on pseudostem at the base of leaf petiole and pseudostem broken at the point of infection. Dark brown water soaked lesions were present on infected areas of all the plants. Later it was covered with thick white mycelial growth and brown sclerotia. Detailed study on the phenotypic characters of the isolates revealed variations in the cultural and morphological characters. All the isolates produced white coloured colony on all the selected media. Variation in the texture and type of mycelium, sclerotial initiation and maturation, number, position, weight of 100 sclerotia and production of exudates was recorded. Among the different media tested, Potato Dextrose Agar was found to be the best medium for the growth of pathogen. In all the isolates, hyphae are hyaline, branched, septate and the hyphal cell size 52.6-196.32 μm×4.25-8.93 μm. Sclerotia were dark brown, smooth and spherical, 0.5-2.00 mm diameter in size. The maximum size of sclerotia was recorded in MN-2 and minimum in BA-2. Cluster analysis of cultural and morphological characters revealed a degree of variability among the isolates. The lowest dissimilarity index was noticed between isolates CH-1 and BA-2. The isolates viz., MG-1, MG-2, CH-1, CH-2, CH-3, CH-4, MN-1 and MN-2 were found more similar and were grouped under the sub cluster A1 of cluster A. The isolates from banana stands separate and showed more dissimilarity with all other isolates. Mycelial compatibility between the different isolates of S. rolfsii was tested by dual culture method. Out of 55 combinations, eight Mycelial Compatibility Groups (MCG‟s) were identified. In the compatible reactions, intermingling of the mycelia and sclerotial formation was noticed at the site of interaction between isolates. Complete overgrowth of the mycelium of two isolates was not observed in compatible reactions. The isolates produced sclerotia with exudates in a line at site of interaction between the isolates. Sclerotial formation on the surface of both the cultures was also noticed. In the incompatible reactions, formation of inhibition zone of size 0.2 - 2.6 mm and development of sclerotia on either side of inhibition zone were observed. From the study, it was clear that the virulent isolate from marigold (MG-2) showed mycelial compatibility with virulent isolates from chrysanthemum (CH-2), mango (MN-2) and banana (BA-2). Cross inoculation studies revealed that all the isolates were pathogenic to other hosts but variation in the pathogenic character of these isolates was observed. Variation in the symptom expression was not noticed on the inoculated plants by different isolates obtained from the same host. All the isolates produced infection on the leaves of other hosts, but failed to produce collar infection on mango seedlings. The isolates BA-1 and BA-2 did not initiate infection on collar region of chrysanthemum. It was concluded that different isolates of S.rolfsii obtained from the selected fruit crops and ornamental plants showed variability in their pathogenic character. Host range of S. rolfsii was studied by cross inoculating different isolates of S. rolfsii on selected vegetables viz., tomato, amorphophallus and spices viz., black pepper, ginger. All the plants tested were found susceptible to the pathogen. Symptom appeared as small, water soaked brown discolouration on the inoculated leaves and collar region. Later it enlarged in size and covered with white mycelial growth of the pathogen in all the hosts except in the collar region of amorphophallus inoculated with MG-2 and MN-2. It was also observed that the initial infection was first noticed on leaves and collar region where pinprick have been given before inoculation. Variation among the isolates was observed in the production of sclerotia and was noticed that sclerotial development was completely absent in ginger and tomato on both the leaves and collar region. On the leaves of black pepper, white mycelial growth and sclerotial formation were noticed on the lower side of the leaves. The isolate BA-2 produced concentric zonations on the inoculated leaves of pepper. Estimation of IAA and total phenol in mycelia, culture filtrate and sclerotia of various isolates revealed that all the isolates produced highest IAA and total phenol in the sclerotia. Among the isolates, MG-1 and MG-2 recorded the highest IAA and total phenol in mycelia, culture filtrate and scloerotia of various isolates of the pathogen respectively.