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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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20152
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Subject: Nematology × End date: 2015 × Start date: 2015 ×
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    ThesisItemOpen Access
    BIOLOGY AND MOLECULAR CHARACTERIZATION OF ROOT-KNOT NEMATODES OF ASSAM
    (AAU, Jorhat, 2015-08) Kshetrimayum, Sumita; Das, Debanand
    Investigations were carried out to find the molecular characterization of root-knot nematode of Assam, morphological and morphometric variations among the populations of root-knot nematode (s) of Assam and effect of temperature on the biology (embryogenesis, penetration and multiplication) of root-knot nematode, Meloidogyne incognita. PCR analysis using specific primer, MiF-MiR for M. incognita showed that all the populations of root-knot nematode collected from nine districts (Jorhat, Golaghat, Sibsagar, Lakhimpur, Dhubri, Nagaon, Dibrugarh, Kokrajhar and Kamrup) of Assam produced a PCR product of 399bp for all the root-knot nematode isolates. A representative of four different isolates from four districts viz., Jorhat, Lakhimpur, Nagaon and Kamrup were partially sequenced. Sequenced similarity of Mi isolates from four districts showed 89 per cent to 99 per cent homology. Results of molecular characterization using RAPD primers revealed that populations of root-knot nematode of nine districts of Assam formed three clusters with a bifurcation at 0.47 similarities. The first cluster had five isolates viz., Jorhat, Sibsagar, Kokrajhar, Kamrup and Dhubri. The second cluster comprised of three isolates viz., Golaghat, Lakhimpur and Dibrugarh, while Nagaon was found to be totally different from other isolates. Study on the morphological variations among the populations of Meloidogyne incognita from nine districts of Assam exhibited variations only in the tail shape, while other morphological characters showed similarities among the populations. Tail shape of second stage juveniles of M. incognita collected from Golaghat, Kokrajhar, Nagaon and Sibsagar district was similar in shape. Likewise, tail shape of second stage juvenile of Dibrugarh, Jorhat and Lakhimpur population showed similarity but, Dhubri and Kamrup population showed variation from other populations. No variation on perineal pattern was observed in size and shape of perineal pattern of M. incognita collected from nine districts of Assam. Studies on morphometric variations (body length, stylet length, lip height, lip width, MB, a, b, b´, c and c´) among the populations of M. incognita from nine districts of Assam showed no distinct variations in the major characters, except in MB value. MB value of Kamrup population was higher (61.79) than other populations. Present investigation on effect of temperature on the biology (embryogenesis, penetration and multiplication) of root-knot nematode, Meloidogyne incognita revealed that M. incognita completed embryogenesis within 4.468 days at 28°C, which was found to be the favorable temperature for embryogenesis than 31°C (5.168 days) and ambient temperature (7.645 days). Penetration was not affected by temperature but, migration and post-penetration inside the root tissue were influenced by temperature. At 27±1°C, M. incognita second stage juvenile took 5 days to reach stele region followed by 31±1°C and 23±1°C (7 days) while, at 21±1°C, it took 10 days. Multiplication of M. incognita was greatly affected by temperature. Maximum number of galls per root system (119.6), number of egg masses per root system (275.2), number of eggs per egg mass (343.6), final nematode population (1335.2) and reproduction factor of nematodes (2.67) was observed at 27±1°C followed by 31±1°C, 23±1°C and 21±1°C.
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    ThesisItemOpen Access
    DIVERSITY OF ENTOMOPATHOGENIC NEMATODES (EPN) IN ASSAM
    (AAU, Jorhat, 2015) Borgohain, Nivedita; Gogoi, B. B.
    An investigation was carried out to see the diversity and distribution of Entomopathogenic nematodes in Assam. EPNs were recovered at a frequency of 14.75 per cent from 45 samples out of the 305 number samples. The highest frequency of 30.00 per cent was recorded in Karbi-Anglong district and lowest of 10.00 per cent was from Dhubri district. Identification of EPNs isolates were made on the basis of morphological and morphometric studies on the developmental stages of the nematodes. Four species of EPN viz., Steinernema abbasi, Steinernema karii and Heterorhabditis bacteriophora and Heterorhabditis sonorensis were identified. Heterorhabditis sonorensis is for the first time reported from India. Among the identified species Steinernema abbasi is more prevalent, like Heterorhabditis sonorensis are more abundant in our ecosystem. Highest record of EPNs was in forest eco-system (20%) followed by perennial fruit crops (18.18), grass land (15.4%), ornamental crops (9.43%) and vegetables (6.00%). Steinernema spp. isolated from acidic to alkaline soil whereas Heterorhabditis spp. from acidic to alkaline soil with low to high organic matter content. On the basis of soil types, highest EPNs were recorded from sandy loam soil