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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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20186
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Subject: Plant Pathology × End date: 2018 × Start date: 2018 × Type: Thesis × Thesis Type: M.Sc ×
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Now showing 1 - 6 of 6
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    ThesisItemOpen Access
    EFFICACY OF Trichoderma species FROM HILL BANANA AGRO-ECOSYSTEM AGAINST Fusarium oxysporum f.sp. cubense
    (AAU, Jorhat, 2018) EZUNG, AJANBENI; Bhattacharyya, Ashok
    The use of biological control agents (BCAs) has gained its popularity in agriculture as a way to decrease the application of synthetic pesticides. In the genus Trichoderma, a great number of fungal strains have been studied and utilized as BCAs. Exploration of biocontol agents from hill agro- ecosystem has not been intensified from the North Eastern states of India. Under the backdrop, the present investigation was carried out to explore potential Trichoderma spp. from the state of Nagaland. Eight numbers of Trichoderma spp. isolated from hill banana rhizospheric soils from different sub-divisions of the districts, Wokha, Kohima, and Dimapur had been culturally and morphologically characterized. In vitro antagonistic activity of all the eight isolates were carried out against Fusarium oxysporum f.sp. cubense (FoC), the causal organism of Fusarium wilt of banana. The study revealed that all the 8 isolates significantly inhibited the growth of FoC at different levels in all intervals of incubation (72, 120 and 168 hours). Of the isolates, three viz S37-4, S41G and S39 found to be most effective in inhibiting the mycelial growth of the test pathogen with 77.8 per cent, 75.0 per cent and 75.0 per cent respectively. The strains were identified as Trichoderma asperellum (S37-4) and Trichoderma virens (S41G and S39). Enzymatic assays of the isolates revealed significant increase in chitinase and β-1, 3 glucanase. Trichoderma asperellum (S37-4) was found with the maximum activity of cell wall degrading enzymes (CWDEs) i.e., chitinase (32.4 nkat/sec) and β-1, 3 glucanase (171.85 nkat/sec) in comaparison to other two isolates. An investigation was also carried out to study the production of volatile and non-volatile compounds by the Trichoderma spp. and found significant reduction of mycelial growth of the test pathogen was recorded. Trichoderma asperellum (S37-4) recorded the maximum inhibition of the growth of the test pathogen in both the cases of volatile (59.33%) and non-volatile (74.4%) compounds.
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    ThesisItemOpen Access
    MANAGEMENT OF FRUIT ROT OF Capsicum chinense Jacq.THROUGH BOTANICALS
    (AAU, Jorhat, 2018) Sangnunmawia; Senapoty, Daisy
    Fruit rot of Capsicum chinense Jacq. is one of the most destructive disease causing severe damage to the fruits in the field and considerable losses during storage, transit and marketing. The causal fungus of fruit rot of C. chinense was identified and confirmed as Colletotrichum gloeosporioides (Penz.) Penz & Sacc. in National Fungal Culture Collection of India, Pune. The investigation aimed at managing the disease by using few botanicals in vitro and in vivo. Ten botanicals were selected and extraction was done with cold water, acetone and benzene. The extracts were evaluated at 20 per cent concentration in vitro for their efficacy against the pathogen. In these three different method of extraction, three (3) botanicals viz., Lawsonia inermis (85.01, 88.14 & 86.12%), Allamanda cathartica (74.94, 80.53 & 75.83%) and Acorus calamus (72.25, 77.18 & 66.67%) giving high inhibition of mycelial growth were selected from the ten botanical tested. The cold water extract of these botanicals were further tested against C. gloeosporioides at 5, 10 and 15 per cent concentration. L. inermis at 15 per cent concentration showed significantly highest inhibitory effect (80.76%) on the mycelial growth of the pathogen, over the control. This was followed by 10 per cent concentration of L. inermis (73.60%), 15 per cent concentration of A. cathertica (70.02%) and. A. calamus (68.90%). Least inhibition was recorded with 5 per cent concentration of A. calamus (40.94%). These three botanicals at their most effective concentration (15%) were also evaluated for their effect in managing the disease in pot culture conditions (in vivo) and were compared with Captan (0.2%). Captan gives the lowest PDI (percent disease index) (11.12%) followed by L. inermis (15.56%), A .cathartica (17.41%) and A. calamus (21.85%). The phytotoxic effect of these botanicals at 5, 10 and 15 per cent concentration (if any) were tested on 25 days old seedlings of C. chinense. It was observed that the botanicals did not show any phytotoxic effect at all the concentrations tested. The active chemical components of the effective botanicals were then evaluated. The active chemical components of L.inermis was identified as 2-hydroxy 1,4- napthoquinone (Lawsone), A. cathartica have n-hexadecanoic acid, Hexanoic acid, ethyl ester, Octanoic acid, decanoic acid and A. calamus as 2,4,5-trimethyoxy-1- proprenylbenzene (Asarone). The inhibitory effects of the botanicals on the mycelial growth of C. gloeosporioides and a lower percent disease index of fruit rot in in vivo condition may be because of the presence of these chemicals.
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    ThesisItemOpen Access
    EFFECT OF ARBUSCULAR MYCORRHIZAL FUNGI ON Phytophthora WILT OF PIPPALI (Piper longum)
    (AAU, Jorhat, 2018) Deori, Mridusmita; Dutta, Pranab
    Pippali, Long piper; Family: Piperaceae, is found throughout India especially in the warmer places. It is also found in Malaysia, Singapore, Sri Lanka and Asian regions. Leaf blight caused by Phytophthora spp. has been reported to be one of the major diseases of Pippali causing complete failure of the plant. Arbuscular Mycorrhizal Fungi (AMF) is the mother of plant root endosymbiosis that established symbiotic relationship with plants and plays important role in plant growth, disease protection, and overall soil quality. AMF fungi not only enhanced the growth of medicinal plants but also improved the active principle content. But association of mycorrhizal fungi with medicinal plant like Pippali, Piper longum and their use for management of Phythophthora disease more particularly in North East India is not known. In the present study survey was made in 10 pockets of Pippali growing area of Jorhat district of Assam and found to have root colonization of AMF from 46.50% to 66.50% and soil colonization from 110.55 spores/g to 185.80spores/g of soil. AMF isolated were tentatively characterized as Glomus spp. Mass multiplied spore in Maize (chosen as a symbiotic partner, because of its high mycorrhizal dependency) of AMF were used to study the effect of per cent disease of Phytophthora infection and plant growth parameter of Pippali plants. Significantly lowest PDI (6.41%) of Phytophthora was observed in non sterilized soil with inoculums with Highest growth parameter (shoot and root length, internode no., internode length, leaf area and dry weight of roots and shoots). This was followed by Sterilized soil with inoculums with PDI of 8.74%. Highest PDI (25.66%) with lowest growth parameters was observed in sterilized soil without inoculum followed by non sterilized soil without inoculum with PDI of 21.94%. Five different pathogenic mycoflora viz., Curvularia spp., Alternaria spp., Fusarium spp., Rhizoctonia solani and Sclerotium rolfsii were also found associated with the plant.
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    ThesisItemOpen Access
    BIOENGINEERING MICROBIAL ANTAGONISTS WITH JATROPHA (Jatropha curcas) OIL AND RESULTANT SUPPRESSION OF BACTERIAL WILT (Ralstonia solanacearum) OF TOMATO
    (AAU, Jorhat, 2018) BARUAH, KOLLOL PRATIM; Bora, L. C.
    Tomato (Solanum lycopersicum L.) is one of the most important “protective foods” both because of its special nutritive value and widespread production. Bacterial wilt of tomato caused by Ralstonia solanacearum is one of the major disease causing a loss up to an extent of 100 per cent. The use of bio-control agents against vegetable diseases are reported to be quite effective and inexpensive. The efficiency of bio-control agents could be enhanced to a great extent when integrated with a known amount of phyto-extract. The efficacy of Jatropha oil (Jatropha curcas) was evaluated in the present study for suppression of the bacterial wilt pathogen, R. solanacearum The in-vitro studies revealed that Jatropha oil @ 5000 ppm, 10000 ppm & 50000 ppm could suppress the pathogen up to an extent of 25.3, 64.0 and 66.2 per cent respectively. Bioengineering Jatropha oil with five microbial antagonists, viz., Pseudomonas fluorescens, Bacillus thuringiensis, Beauveria bassiana, Metarhizium anisopliae and Trichoderma viride revealed a positive interaction. Amongst these, T. viride was found most compatible followed by P. fluorescens, B. thuringiensis, B. bassiana and M. anisopliae. The in vivo studies revealed that P. fluorescens along with Jatropha oil could suppress bacterial wilt of tomato significantly (80%) followed by T. viride + Jatropha oil (60%); B. thuringiensis + Jatropha oil (40 %) and B. bassiana + Jatropha oil (40%). Combination of these bio agents and Jatropha oil also showed better yield of R. solanacearum inoculated tomato plants when compared to application of bio agents alone. Highest yield was recorded in the treatment combination of P. fluorescens + Jatropha oil (315.8 g/plant) followed by T. viride + Jatropha oil (230.1 g/plant), B. thuruingiensis + Jatropha oil (228.58 g/plant) and B. bassiana + Jatropha oil. (171.92 g/plant) Similarly, the yield attributing characters of tomato treated with bio agents and Jatropha oil was found better as compared to application of bio agents alone.
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    ThesisItemOpen Access
    TAXONOMIC STUDIES OF FUNGI ASSOCIATED WITH RICE AND RICE BASED TRADITIONAL FOOD PRODUCTS OF ASSAM
    (AAU, Jorhat, 2018) SAIKIA, BANDANA; Ali, S.
    Rice is a major crop of Assam. Different communities in the state produces peculiar fermented and non-fermented products like rice beer, sweets and snacks etc. using rice as a substrate. Production of rice beer involves two steps; starter culture preparation and brewing. The starter culture is made of rice and herbal combinations and believed to act as inoculants for brewing. These products often contain mixed microbial population due to allowance of natural fermentation. The present study was undertaken to study the fungi associated with stored rice, starter culture and rice beer. Seven districts of Assam viz., Jorhat, Sivasagar, Golaghat, Lakhimpur, Dhemaji, Majuli and Karbi Anglong were surveyed and samples of three stored rice, six starter culture and six rice beer samples were collected. Nine filamentous fungi from rice, thirtytwo yeast isolates and two filamentous fungi from rice beer and starter cultures were isolated. Morphological identification reveals the presence of Penicillium chrysogenum, P. purpurogenum, Penicillium sp., Acremonium strictum, Cheatomium globosum, Paecilomyces sp., Gibellula sp., Aspergillus niger and Cladosporium sp. in stored rice samples; whereas A.niger and A. oryzae was found to be associated with starter culture. A polyphasic approach encompassing morphological characterization, molecular characterization and Scanning Electron Microscopy (SEM) was undertaken for yeasts identification. Ten yeasts genera were morphologically identified and grouped accordingly as Saccharomyces cerevisiae (Group I), Saccharomycopsis fibuligera (Group II), Candida spp. (G III), Debaromyces hansenii (Group IV), Pichia chambardii (Group V), Mereozyma sp. (Group VI), Saccharomycodes ludwigii (Group VII), Kluyveromyces sp. (Group VIII), Sterigmatomyces sp. (Group IX) and Torulaspora sp. (Group X),. Molecular characterization of yeast were done by amplification of ITS-PCR region, gel electrophoresis of which showed three dominant banding pattern of 900 bp (Group A), 700 bp (Group B) and 600 bp (Group C). All the isolates of morphological Group I showed 900 bp, Group II showed 700bp whereas Group III, IV, V and VI showed 600bp bands. Sequencing of representative samples from each molecular group showed that samples of Group A, Group B and Group C belongs to S. cerevisiae , S. fibuligera and C.tropicalis respectively thus confirming the morphological and molecular grouping. SEM images also confirmed the three yeast species S. cerevisiae, S. fibuligera and C. tropicalis.
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    ThesisItemOpen Access
    EFFECT OF ARBUSCULAR MYCORRHIZAL FUNGI ON Phytophthora WILT OF PIPPALI (Piper longum)
    (AAU, Jorhat, 2018-07) Deori, Mridusmita; Dutta, Pranab
    Pippali, Long piper; Family: Piperaceae, is found throughout India especially in the warmer places. It is also found in Malaysia, Singapore, Sri Lanka and Asian regions. Leaf blight caused by Phytophthora spp. has been reported to be one of the major diseases of Pippali causing complete failure of the plant. Arbuscular Mycorrhizal Fungi (AMF) is the mother of plant root endosymbiosis that established symbiotic relationship with plants and plays important role in plant growth, disease protection, and overall soil quality. AMF fungi not only enhanced the growth of medicinal plants but also improved the active principle content. But association of mycorrhizal fungi with medicinal plant like Pippali, Piper longum and their use for management of Phythophthora disease more particularly in North East India is not known. In the present study survey was made in 10 pockets of Pippali growing area of Jorhat district of Assam and found to have root colonization of AMF from 46.50% to 66.50% and soil colonization from 110.55 spores/g to 185.80spores/g of soil. AMF isolated were tentatively characterized as Glomus spp. Mass multiplied spore in Maize (chosen as a symbiotic partner, because of its high mycorrhizal dependency) of AMF were used to study the effect of per cent disease of Phytophthora infection and plant growth parameter of Pippali plants. Significantly lowest PDI (6.41%) of Phytophthora was observed in non sterilized soil with inoculums with Highest growth parameter (shoot and root length, internode no., internode length, leaf area and dry weight of roots and shoots). This was followed by Sterilized soil with inoculums with PDI of 8.74%. Highest PDI (25.66%) with lowest growth parameters was observed in sterilized soil without inoculum followed by non sterilized soil without inoculum with PDI of 21.94%. Five different pathogenic mycoflora viz., Curvularia spp., Alternaria spp., Fusarium spp., Rhizoctonia solani and Sclerotium rolfsii were also found associated with the plant.