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Assam Agricultural University, Jorhat

Assam Agricultural University is the first institution of its kind in the whole of North-Eastern Region of India. The main goal of this institution is to produce globally competitive human resources in farm sectorand to carry out research in both conventional and frontier areas for production optimization as well as to disseminate the generated technologies as public good for benefitting the food growers/produces and traders involved in the sector while emphasizing on sustainability, equity and overall food security at household level. Genesis of AAU - The embryo of the agricultural research in the state of Assam was formed as early as 1897 with the establishment of the Upper Shillong Experimental Farm (now in Meghalaya) just after about a decade of creation of the agricultural department in 1882. However, the seeds of agricultural research in today’s Assam were sown in the dawn of the twentieth century with the establishment of two Rice Experimental Stations, one at Karimganj in Barak valley in 1913 and the other at Titabor in Brahmaputra valley in 1923. Subsequent to these research stations, a number of research stations were established to conduct research on important crops, more specifically, jute, pulses, oilseeds etc. The Assam Agricultural University was established on April 1, 1969 under The Assam Agricultural University Act, 1968’ with the mandate of imparting farm education, conduct research in agriculture and allied sciences and to effectively disseminate technologies so generated. Before establishment of the University, there were altogether 17 research schemes/projects in the state under the Department of Agriculture. By July 1973, all the research projects and 10 experimental farms were transferred by the Government of Assam to the AAU which already inherited the College of Agriculture and its farm at Barbheta, Jorhat and College of Veterinary Sciences at Khanapara, Guwahati. Subsequently, College of Community Science at Jorhat (1969), College of Fisheries at Raha (1988), Biswanath College of Agriculture at Biswanath Chariali (1988) and Lakhimpur College of Veterinary Science at Joyhing, North Lakhimpur (1988) were established. Presently, the University has three more colleges under its jurisdiction, viz., Sarat Chandra Singha College of Agriculture, Chapar, College of Horticulture, Nalbari & College of Sericulture, Titabar. Similarly, few more regional research stations at Shillongani, Diphu, Gossaigaon, Lakhimpur; and commodity research stations at Kahikuchi, Buralikson, Tinsukia, Kharua, Burnihat and Mandira were added to generate location and crop specific agricultural production packages.

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20211
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Subject: Plant Pathology × Author: Mohana, Pradeep R K × End date: 2021 × Start date: 2021 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    CULTURAL, MORPHOLOGICAL AND MOLECULAR VARIABILITY AMONG ISOLATES OF Rhizoctonia solani CAUSING WEB BLIGHT OF GREEN GRAM (Vigna radiata (L.) WILCZEK)
    (AAU, Jorhat, 2021) Mohana, Pradeep R K; Sharma, Supriya
    Web blight of green gram is one of the major constraints which incur huge losses and hold back the production of green gram in Assam. A comprehensive study was made during 2020-21 on the variability of Rhizoctonia solani isolates based on morpho- cultural characteristics and molecular variation. Web blight infected plants were collected from different geographical locations was designated as SH-1, SH-2, AAU-1, TT-1, and MJ- 1 and identified based on a typical character with right angle branching near the distal septum of the young vegetative hyphae. A high virulence pattern for all the isolates was recorded based on pre-emergence seedling rot and complete leaf blighting appearance within 48 hours of inoculation in susceptible cultivar (SGC-16). All the five isolates showed variation in morpho-cultural characteristics such as colony growth diameter, colony texture, concentric rings on radial growth, colony color, growth pattern, hyphal width, distribution pattern of sclerotia, sclerotial initiation, maturation, color, aggregation, exudate droplets on sclerotial surface, position of sclerotia and sclerotia on lid, sclerotial diameter, number and weight in different growth media Potato Dextrose Agar (PDA), Rose Bengal Agar (RBA), Richard’s Agar (RA), Czapeck’s Dox Agar (CDA) and Sabouraud Dextrose Agar (SDA) where most of the isolates were categorized into three and four groups based on hyphal width and sclerotial initiation respectively. The size, number, and weight of sclerotia were highly variable across different isolates concerning media. They are arranged in the central, central- peripheral, sub-central, sub-central peripheral, peripheral and scattered manner on the petri- dish with respect to media. Among different media, Sabouraud Dextrose Agar medium (85.85%) is the best growth media to study morpho-cultural variability with quantitative variables like sclerotial maturation and initiation which directly correlated with virulence of our R. solani isolates based on principal component analysis. There is no evidence of molecular variability among our isolates from different geographical locations of Assam.