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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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ThesisItem Open Access EVALUATION OF A FEW BOTANICALS AND BIOAGENTS IN SEED TRANSMISSION OF BROWN SPOT OF RICE CAUSED BY BIPOLARIS ORYZAE(AAU, Jorhat, 2019-07) Mazumder, Priyanku; Medhi, T.Brown spot of rice caused by Bipolaris oryzae Subr. and Jain (syn. Helminthosporium oryzae Breda de Haan) is an important disease of rice which has been reported to occur in all the rice growing countries of the world. In India, it is known to occur in all the rice growing states including Assam causing loss of 5-53.33 percent annually. Considering its widespread significance, an experiment was conducted to study the effect of a few botanicals and bioagents in seed transimission of the disease. The location of B. oryzae in the rice seed and its transmission from seed to seedling were studied. Each part of infected seed including embryo, endosperm, lemma, palea, sterile lemma and rachilla, was found to be infected by B. oryzae. The highest level of infection was found in endosperm (78.50 percent) followed by rachilla (68.50 percent). Lowest infection was found in embryo (32.50 percent).Transmission studies from the infected seed to the seedling using test tube agar, blotter and sand indicated that primary symptom appeared on coleoptile and roots after 7 – 14 days. However, recovery of infection percentage was greater in test tube agar and blotter than sand method. Efficacy of three botanicals viz., Turmeric (Curcuma longa), Neem (Azadirachta indica), Tulsi (Ocimum sanctum) in different concentrations (10%, 20% and 50% each in Turmeric in Neem and 20%, 30% and 50% in Tulsi) and one bioformulation, Biogreen @5%, 10% and 15% concentration was studied to reduce growth of B. oryzae in vitro and its transmission from treated seeds to seedlings. Turmeric @50% concentration was found to be most effective in reducing the colony growth of the pathogen (1.97 cm and 72.87 percent inhibition over control) followed by Turmeric 20% concentration (3.16 cm and 56.47 percent inhibition over control), Tulsi 50% and Biogreen 15% concentration (3.52 cm and 3.84 cm respectively). Turmeric 50% and Turmeric 20 % concentration were also the most effective in reducing the transmission of the pathogen from seed to seedling both in test tube agar method and sand method. These four treatments from the in vitro experiments were further studied for their effect on seed transmission of B. oryzae, Percent Disease Incidence (PDI) and seed quality parameters under pot condition. Percent Disease Incidence was found to be the lowest in the treatment Turmeric @50% during all the three observed stages (8.36, 9.58 and 18.54 percent at Tillering, Panicle Initiation and Grain filling stage respectively). At grain filling stage Turmeric @50% was followed by Tulsi @50% (19.44). However at this stage PDI observed in treatments Tulsi @50%, Turmeric @20% (22.71) and Biogreen @15% (24.59%) were at par with each other. Seed yield per plant was highest in the treatment Turmeric @50% (29.40 g) which was at par with that of Carbendazim @0.2% (28.80 g) and Turmeric 20%(28.52 g). Thousand seed weight was also highest in the treatment Turmeric @50% (22.48 g) followed by control treatment (Carbendazim @0.2%) (21.86 g). Seedling vigour and speed of germination were significantly higher in the treatment Turmeric @50% (1244.37 and 10.79 respectively) but germination percentage of the treatment Turmeric @50% (92.50%) was at par with that of treatment Turmeric @20% (89.00%) and Carbendazim @0.2% (93.50%). Mean germination time was also significantly lower in the treatment Turmeric @50% (4.74 days). Mean daily germination was found to be highest in the treatment Turmeric @50% (3.49) which is statistically at par with the treatment Turmeric @20% (3.46) and Carbendazim @0.2% (3.44). The harvested seeds from different treatments showed varying level of association by B. oryzae. Seeds in Agar plate method showed infection of 25.75 percent and 37.72 percent reduction over absolute contol in the treatment Turmeric @50% which was lowest among botanicals and bioagents. The treatment Carbendazim @0.2% was the best in all the observed parameters. However, seed yield per plant, germination percentage, mean daily germination and mean germination time were at par with those of the treatment Turmeric @50% concentration.ThesisItem Open Access EVALUATION OF SOME RICE GENOTYPES UNDER DELAYED SOWN CONDITION IN SALI WITH LOW LEVEL OF FERTILIZER INPUT(AAU, Jorhat, 2019-07) Pathak, Dalibha; Kalita, U.C.An experiment was conducted during the late sali season (August) of 2018 at Instruction cum Research Farm, Assam Agricultural University, Jorhat following 3 replicated RBD. The objective of the trail was to evaluate the performance of the genotypes under late sowing situation. Significant variation was observed for grain yield and its component characters. The mean sum of squares due to various sources of variation for 18 quantitative characters revealed the presence of significant differences for grain yield and its component characters. The estimates of phenotypic coefficient of variation (PCV) was found high for chaffs per panicle, grains per panicle, spikelet sterility %, spikelets per panicle, grain yield (kg/ha), tillers per hill, biological yield (kg/ha). The estimates of genotypic coefficient of variation (GCV) was found high for chaffs per panicle, grains per panicle, spikelet sterility %, spikelets per panicle, grain yield (kg/ha). Low estimates of GCV and PCV were recorded for the character viz., days to 50% flowering and days to maturity. In this study, a high heritability coupled with high genetic advance were observed for chaffs per panicle and grains per panicle indicating that the selection might be effective for bringing about improvement for these characters under delayed sown situation. Among the genotypes only one genotype viz., Gandhari was the top yielder (4170 kg/ha)because of its significantly lower number of days to both 50% flowering (101days) and days to maturing (131 ), spikelet sterility (23.13 %) than their corresponding values of the check Manoharsali; significantly higher spikelets per panicle (238.19), grains per panicle (183.07) grain yield (17.18 g/hill), straw weight (6575.16 kg/ha), biological yield (10745.10 kg/ha) and harvest index (38.86 %) than their corresponding values of the check Manoharsali and moderate performance for the remaining characters. The high GCV was observed for chaffs per panicle, grains per panicle, spikelets per panicle, spikelet sterility (%) and grain yield (kg/ha) and high PCV was observed for chaffs per panicle followed by grains per panicle, spikelet sterility (%), grain yield (kg/ha), tillers per hill, spikelets per panicle and biological yield (kg/ha).Grains per panicle, days to 50 per cent flowering, plant height (cm) , panicle length (cm), spikelets per panicle, chaffs per panicle, grain yield (kg/ha), grain yield (g/hill), spikelet sterility (%), 100-grain weight, days to maturity, biological yield (kg/ha), straw weight (kg/ha) and harvest index (%) had registered high heritability. A high heritability coupled with high genetic advance was observed for plant height (cm), spikelets per panicle, spikelet sterility (%), chaffs per panicle, grains per panicle, grain yield (kg/ha), grain yield (g/hill), biological yield (kg/ha), straw weight (kg/ha) and harvest index (%). Grain yield (kg/ha) exhibited significant positive correlation with plant height(cm), panicle length(cm), grains per panicle, spikelets per panicle, grain yield (g/hill) and straw weight (kg/ha). The significant negative correlation of grain yield (kg/ha) had observed with days to 50% flowering, spikelet sterility (%) and days to maturity. From the findings of this investigation, one genotype viz., Gandhari emerged as the outstanding genotype which could be directly used for cultivation in delayed sown situation. Some other promising genotypes that had average productivity more than 3500 kg/ha and yet significantly high yielder than the check Manoharsali under delayed sown condition were JR 29 , JR 16 , Basundhara and JR 60. These genotypes had shown their promise for recommendation under delayed sown condition provided the investigation is continued for another 2-3 years under the same conditionandcould be utilized as potential parental material in the hybridization programmes designed to develop suitable rice varieties for delayed sown situation.ThesisItem Open Access STUDY ON EFFECT OF MUTATION ON RANJIT SUB-1 FOR YIELD AND YIELD ATTRIBUTING CHARACTERS(AAU, Jorhat, 2019-07) Shivam, Kasturi; Chetia, Sanjay KumarRice (Oryza sativa) has been grown in Assam from time immemorial and it is the single most important crop in the state and its adjoining areas, because of its enormous variability, adaptability and preference in the state. Sali or winter rice is the dominant crop of the state covering 18.7 lakh hectares and contributing 73% of the total rice production. Out of 18.7 lakh hectares of Sali areas 12.7 lakh hectares come under flood free shallow lowland. Shallow lowland is as good as irrigated areas and high yielding varieties like Ranjit, Bahadur, Mahsuri, Gitesh etc. are grown. Amongst the HYVs, Ranjit was the most popular variety but farmers finding it difficult to go for Rabi crops after the harvesting of Ranjit due to its longer duration. One of the reasons for the low farmer‟s income is lower cropping intensity. Farmers of Assam prefer to grow longer duration rice variety during kharif season for which it is difficult to increase cropping intensity. Therefore, it is essential to develop the shorter duration version of popular rice variety Ranjit. The seed of Ranjit Sub-1 was treated with three doses 170Gy, 210Gy and 240Gy of gamma ray during May, 2017. The M1 generation of each doses along with the checks (Luit, Shraboni and Ranjit Sub-1) grown during Sali, 2017. The experiment was conducted by Augmented Design. The data of Days to 50% flowering, Plant height, EBT, Fertile spikelet etc. was recorded. Sterility percentage increases with increases in irradiation. Highest sterility percentage was recorded in 240Gy Gamma ray. Further from the recorded data of 500 plants of each dose, it was found there is significant effect of mutation in all the three doses for all the characters except in tiller numbers. Three desirable early mutants were selected during Sali, 2017. The M2 progeny was raised during Sali, 2018. The segregation for Days to 50% flowering and Maturity duration was studied and it was found to fit well in 9:3:3:1 ratio. The effect of mutagens on Sub-1 QTL was also studied. We have confirmed the presence of Sub-1 QTL in treated seeds with the help of SSR marker (Sub1BC2). Ranjit Sub-1 and Ranjit were considered as positive and negative check respectively. During gel analysis we have observed both positive and negative type among progenies and hence we concluded that there was effect of Sub-1 QTL.ThesisItem Open Access Genetic Variability For Traits Related To Synchronous Maturity In Greengram(AAU, Jorhat, 2019-07) Talukdar, Nivedita; Sarma, R. N.The present study was conducted with 38 greengram genotypes with the objectives to determine the nature and extent of variation in the phenological traits related to synchronous maturity and to assess the pattern of association of yield and yield related attributes with flowering traits and to characterize them with molecular markers. Morphological data recorded on 17 quantitative traits were analysed for different variability parameters with genetic and DNA fingerprint analysis using 16 SSR primers. Analysis of variance revealed significant variation among genotypes for all the characters except for 100 seed weight. The best genotypes for yield and yield attributing characters identified were KM 2355, AKM 12-24, AKM 12-28, MH 2-15, IPM 312-20 and HUM 1. Pant M-4 was the most determinate at 90% pod maturity from first flower. RMG 1092 was the most determinate for plant height from first flower to first pod and 90% pod maturity. RMG 1087 was determinate for plant height from first pod maturity to 90% pod maturity. The GCV and PCV estimates were high for number of pods per plant followed by degree of indetermination of plant height from first pod maturity to 90% pod maturity and number of branches per plant respectively. High heritability coupled with high genetic advance as % of mean was observed for 13 traits including yield per plant. Based on D2 values, the genotypes were grouped into eight clusters. Maximum inter cluster distance was observed between clusters III and cluster VI followed by cluster V and cluster VIII while lowest distance was noticed between cluster I and cluster VII. Days to 90% pod maturity followed by days to first flowering and days to first pod maturity had highest contribution towards genetic divergence. Yield was positively correlated with plant height at first pod maturity, branches per plant, seeds per pods and 100 seed weight but it was negatively correlated with days to first flowering, days to 50% flowering, days to first pod maturity and days to 90% pod maturity. The highest positive direct effect in path analysis was observed for days to first flowering indicating importance of this trait despite negative correlation with seed yield per plant. SSR markers used in the present study revealed low level of polymorphism among genotypes. Per cent polymorphism ranged from 25.67% to 82.00% with an average of 62.9%. The PIC value ranged from 0.478 (CEDG 282) to 0.983 (cp06427) with an average of 0.636. Resolving power (Rp) value ranged from 2.789 (GMES 4255) to 0.368 (cp06427) with an average value of 1.690. Jaccard’s coefficient of similarity ranged from 0.92 (IPM 2-14 between Pant M-4) to 0.00 between several genotypes with an average value of 0.27. Based on dendrogram generated through UPGMA method, two major clusters (A& B) were identified with B having 7 sub-clusters. The clustering patterns indicated that geographical origin did not play role in cluster composition at molecular level and morphological level.ThesisItem Open Access EVALUATION OF RICE VARIETIES FOR YIELD AND ANCILLARY TRAITS UNDER ORGANIC CULTIVATION(AAU, Jorhat, 2019-07) Dutta, Lonishree; Sharma, Kishore KumarAn experiment was laid under both organic and inorganic conditions with ten rice varieties grown under organic situation for more than ten years. The rice varieties collected from farmer’s field were grown with an objective to observe traits suitable for varietal development under organic situation. The analysis of variance for nine quantitative characters, nine grain characters and eight biochemical characters indicated existence of variation of the characters among the varieties. The pooled analysis indicated high G x E interaction for most of the characters under investigation indicating necessity for selection of the characters separately for both organic and inorganic situations. In pooled analysis of variance, it was also found high G x E interaction for Fe (Iron) and Zn (Zinc), which indicated that for these two important micro-nutrients selection, will be effective under organic situation. The correlation coefficient for quantitative character like grain yield is positively correlated to ear bearing tiller (EBT) and Harvest Index (HI) for both organic and inorganic condition, whereas grain yield is negatively correlated to plant height for both the growing situation. It is also observed that Flag Leaf Area (FLA) is positively correlated to grain yield for inorganic condition only. Grain character like Head Rice Recovery (HRR), an important character with respect to marketability of organic produce in the international market and consumer preference, is found to be negatively correlated to Hulling Percentage (HP). In Path Analysis for both organic and inorganic cultivation, it is observed that the highest direct effect is contributed by EBT. High GCV (Genotypic coefficient of variation) and heritability were observed in most of the characters which indicated preponderance of genes in expression of characters. In most of the characters like plant height, EBT etc., GA (Genetic Advance) and Heritability were found to be high indicating additive gene action and effective action of simple selection procedure in improvement of characters under organic situation. Hence, it is concluded from the experiment that variability exist for characters in the indigenous varieties for organic situation and breeding program has to be taken separately for organic situation through selection.ThesisItem Open Access STUDIES ON INDUCED MUTATAION IN GLADIOLUS (Gladiolus hybrida L.) THROUGH GAMMA RAYS(AAU, Jorhat, 2019-07) PRIYA, SHEPHALI; Phookan Borkakati, ReenaGladiolus (Gladiolus hybrida L.) is one of the important bulbous crop, cultivated in various parts of the country. It is an important bulbous crop which occupies important position among cut flowers in domestic as well as international market so, mutation is important for obtaining variety easily. In the present investigation to find out the genetic variability for morphological and quality traits, their association and mutation frequency, effectiveness, efficiency of gamma rays in four genotypes for 13 characters. A factorial randomized block design was conducted in four genotypes which is treated with six doses of gamma rays. The analysis of variance for factorial randomized block design it was observed that significant variation was there for all characters except no. of leaves per plant among 4 varieties. The character spike length, no. of spike per plant exhibited highest PCV, GCV in M1V1 generation. The character plant height, no. of spike exhibited highest PCV, GCV in M1V2 generation. Heritability with genetic advance was found to be high in vase life, days to sprouting, spike length, rachis length and no. of floret per spike in M1V1 generation. In M1V2 generation, heritability high days to sprouting, spike length, vase life, days to spike initiation, breadth of leaf. The effect of interaction between variety and doses indicated that the better plants was found at 20 Gy and as decreased as the doses were increases ‘Red Majesty’ is the best performed variety for breadth of leaf, no. of floret per spike, length of floret, breadth of floret, vase life, no. of spike per plant followed by Red Candiman, Pasibica Beauty. In the correlation studies no. of spike per plant showed a highly significant and positive correlation with the characters plant height, spike length, rachis length, no. of floret per spike, length of floret and vase life. The study of path analysis revealed that the characters no. of floret per spike, breadth of leaf and days to spike initiation had direct positive effect on no. of spike whereas days to sprouting, rachis length, breadth of floret, plant height and vase life showing negative direct effect. Highest mutation frequency observed in 40Gy, mutagenic effectiveness in 20Gy and efficiency in 50Gy of variety Red majesty.
