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Assam Agricultural University, Jorhat
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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 GENETIC VARIABILITY, CHARACTER ASSOCIATION AND DIVERSITY ANALYSIS FOR YIELD AND QUALITY TRAITS IN RICE CULTIVARS FROM MANIPUR AND ASSAM(AAU, Jorhat, 2021) Devi, Ningombam Sonia; Zaman, ShazmiraRice, being a staple food of India, is crucial to enhance its productivity and quality. There are region-wise variations in ethnic preferences of rice. Hence, the study of these variations for quality traits present in different cultivated groups of rice from the region will help in the value addition of the crop. The present experiment was carried out to evaluate 41 rice cultivars from Manipur and Assam to access the genetic variability, correlation, path analysis and genetic divergence for yield and quality traits. The study was conducted in a Randomized Block Design with three replications. The analysis of variance on 24 yield, yield components and quality traits showed the presence of variability in the experimental material for all the characters. A high range of GCV and PCV were observed for the total number of grains per panicle, the number of filled grains per panicle, grain yield per plant, biological yield and harvest index. High heritability coupled with high genetic advance as per cent of mean was observed for most of the characters under study indicating greater transmissibility of these characters and selection can be done effectively based on these characters. Grain yield exhibited positive and significant association with days to 50 per cent flowering, days to maturity, panicle number per plant, the total number of grains per panicle, number of filled grains per panicle, 100-grain weight, spikelet fertility, biological yield, harvest index, panicle harvest index, grain breadth, kernel length, kernel breadth, kernel length after cooking and kernel breadth after cooking. Hence, these characters can be considered to set the selection criteria for increasing grain yield. Path-coefficient analysis revealed that kernel breadth after cooking exhibited the highest positive direct effect on grain yield. Based on Mahalanobis D2 statistics, the genotypes could be grouped into 12 clusters out of which cluster IV had the maximum number of genotypes followed by cluster V. Among all the characters studied, grain length exhibited maximum contribution towards divergence. Cluster X and XII showed the maximum inter-cluster distance and the maximum intra cluster distance was exhibited by cluster XII. Hybridization among the genotypes of these two clusters is presumed to produce better heterotic combinations.ThesisItem Open Access EXTENT OF GENETIC VARIATION AND CORRELATION STUDIES IN OKRA (Abelmoschus esculentus L. Moench)(AAU, Jorhat, 2021) KAMAN, BISWAJIT; Bora, Gobin ChandraThesisItem Open Access EMS and Gamma ray induced quantitative variation in black gram (Vigna mungo (L). Hepper)(AAU, Jorhat, 2021) Biswas, Ardita; Sarma, AkashiAn investigation was carried out with black gram (urdbean) genotype SBC-40 to determine the effects of gamma rays (250Gy, 300Gy, 350Gy, 400Gy, 450Gy and 500Gy) and ethyl methane sulphonate (0.2%). The data was collected on seed germination and survival percentage, shoot length, root length, fresh weight, dry weight in the first generation i.e. in M1 generationThe LD50 value was recorded at 456Gy and GR50 value was recorded at 362Gy for shoot length and 372Gy for root length. The progressive reduction in germination and survival percentage with increasing doses of gamma radiation was observed in the mutagenic treatments. In M2 and M3 generations, the traits viz., days to 50% flowering, days to pod initiation, days to maturity, plant height, number of branches, number of clusters per plant, number of pods per cluster, pod length, number of seeds per plant, hundred seed weight and seed yield per plant were calculated to estimate the genetic variability, character association, path coefficient, mean performance of the genotypes among the nine treatments of black-gram genotypes for eleven quantitative characters. Analysis of genetic variance revealed moderate to high level of genetic variability among all the genotypes in majority of the characters. High to moderate PCV and GCV were recorded for the traits viz., seed yield per plant, number of clusters per plant, number of pods per plant, plant height and number of branches per plant. The high heritability along with the genetic advance as per cent of mean was recorded in 100 seed weight, clusters per plant, plant height and branches per plant and seeds per pod in M2 generation and in M3, the traits viz., branches per plant, number of clusters per plant, number of pods per plant recorded high heritability along with high genetic advance. In M2 and M3 generations, variation in leaf arrangement like pentafoliate and hexafoliate were observed in different treatments along with variation in leaf colour, leaf shape and structure.Correlation studies showed that seed yield per plant exhibited positive significant association with the traits viz., days to 50% flowering, days to pod initiation, days to maturity, clusters per plant, pod length and 100 seed weight.Path coefficient analysis identified that 100 seed weight, days to pod initiation, clusters per plant and pod length had positive direct effect and indirect effect via days to 50% flowering, seeds per pod, days to maturity and branches per plant. Hence, simultaneous selection of the above traits would be more rewarding to bring improvement in black-gram.ThesisItem Open Access EFFECT OF SEED COATING WITH VEGETABLE OILS ON SEED GERMINATION AND SEEDLING ESTABLISHMENT IN GREEN GRAM (Vigna radiata (L.) Wilczek) UNDER HIGH SOIL MOISTURE CONDITION(AAU, Jorhat, 2022) Jamir, Pursangla; Barua, Purna K.Green gram (Vigna radiata L. Wilczek) is an important pulse crop of India and is grown in almost all the states. India is the major producer of green gram in the world. In Assam, it is sown in two seasons, summer (February and March) and kharif (August-September). Kharif sowing generally coincides with the rainy season causing problem in seed germination and seedling establishment. Seed coating is a seed technological technique for enhancing germination and seedling establishment under a wide range of environmental conditions. The present study was carried out to study the effect of seed coating with linseed, castor and mustard oils on green gram seed quality in laboratory conditions and to evaluate the effect of seed coating with these vegetable oils on seedling establishment and crop performance in saturated soil moisture condition in the field. Each of the oils was applied @ 5 ml, 10 ml and 15 ml/kg seed by thorough mixing to impart seed coating. Mustard oil and castor oil treatments were found to improve the seed germination and vigour in the laboratory. In the field, under saturated soil conditions mustard oil and castor oil treatments enhanced field emergence percentage, seedling dry weight, plant height, pod clusters per plant, pods per plant, seeds per pod and seed yield per plant. Linseed oil @10 ml/kg and 15 ml/kg also showed promising performance for seedling dry weight, pod clusters per plant and seeds per pod. In field soil capacity soil condition, linseed and castor oil treatments significantly increased field emergence, plant height, number of branches per plant, pod clusters, seeds per pod and seed yield per plant.ThesisItem Open Access COMBINING ABILITY FOR YIELD AND YIELD ATTRIBUTES IN INDIAN MUSTARD (Brassica juncea (L.) CZERN. & COSS.)(AAU, Jorhat, 2021) Bhattacharyya, Prastuti; Phukan, RumjhumIndian mustard [Brassica juncea (L.) Czern. & Coss.] holds a notable position among the oilseed crops grown in the world and has emerged to be the second most important oilseed crop in India. However, the crop is not popular among the farmers of Assam as it does not fit well into the cropping system due to the longer duration required for its maturity. Thus, developing a mustard variety with short height, shorter duration without compromising the yield can change it into a valuable crop in Assam. The disease Alternaria blight seems to be a major issue in the area affecting the yield up to a great extent, thereby attracting attention for its consideration during the study of the yield parameters. The research was guided with a target to the analysis of variability among the parents and F1s, character interrelationship, and combining ability in the diallel cross. Ten genotypes were grown in the Rabi 2019-20 containing three Alternaria blight tolerant lines, two high yielding lines (under Assam conditions), four single zero varieties, and one genotype that was a double zero variety belonging to the Brassica napus species. Diallel crosses were made between five selected parents to produce F1 progeny including reciprocals to study the nature of gene action involved in the expression of quantitative traits which were subsequently grown in Rabi 2020-21 along with other genotypes. Some of the other crosses that were presumed to be consequential were also developed and evaluated to develop breeding materials having quality oil content with lower amounts of erucic acid with the least impairment in yield. The analysis of variance (pooled) revealed significant variation among the parents for all the characters under study indicating the presence of exploitable variation among the genotypes included in the experiment. Moderate genotypic coefficient of variation and phenotypic coefficient of variance for most of the characters and high broad-sense heritability was observed for all the traits under study. High genetic advance coupled with high heritability was observed for the characters, foot length, thousand seed weight, seed yield per plant, plant height, number of primary branches, number of secondary branches and biological yield per plant which denotes the probable preponderance of additive gene effects and selection may be effective. Since yield is polygenecally controlled and highly influenced by the environment, selection based on yield alone is not effective. From correlation analysis studies in both the years, it can be concluded that days to maturity and plant height were the major yield attributing traits which showed strong negative genotypic correlation with the character, yield per plant. The path analysis of both the years revealed that the characters, days to 50% flowering, number of secondary branches per plant, number of pods per main shoot and number of seeds per siliqua had direct positive effects on seed yield per plant. From the analysis of variance for combining ability, significant variation among the parents, among the total crosses, among F1s and among the reciprocals was inferred, which indicates the presence of genetic differences among the parental genotypes and their prepotency. Moreover, the significance of the difference between Parent vs F1s was observed for all the characters under study, which suggests the presence of heterosis, while in the case of F1 vs Reciprocal, significant variation was observed for most of the characters. This denotes the preponderance of reciprocal effect. From the evaluation of GCA in parents, the genotypes EC339000 and Pusa Mahek were found to be good combiners with high GCA for early maturity, early days to 50% flowering and low foot length, while, TM-2 for seed yield per plant. The crosses TM-2 x PM21, followed by PHR2 x PM21 depicted positive significant SCA effects for seed yield per plant and also exhibited high positive significant heterosis over better parent for the character. The banding patterns of 10 SSR gene-linked markers were studied, out of which 9 primers showed polymorphism. The PIC value was calculated which ranged from 0.190 to 0.927. Clustering was done based on Jaccard coefficient of similarity and the genotypes DLSC-1 and Pusa Mahek were found to be most similar, whereas, TM-2 and PM-22 exhibited the least similarity. The marker data generated can be utilized in further breeding programmes.ThesisItem Open Access CHARACTERIZATION OF SOYBEAN [Glycine max (L.) Merrill] GENOTYPES BASED ON MORPHOLOGICAL AND MOLECULAR MARKERS(AAU, Jorhat, 2021) SAHARIA, NIHARIKA; Sarma, R NSoybean has attained important status in agriculture and oil economy of the country. It is a distinctive multi-purpose crop with ever increasing popularity due to various health benefits. It is imperative to estimate the nature and extent of variability among soybean genotypes to develop improved varieties suitable for varied agro-ecological situations. Moreover, there is limitation of molecular marker based diversity analysis in a precise way among the genotypes used for varietal breeding programme. The present investigation was carried out with 38 soybean genotypes during Kharif, 2020. In the field experiment, the data on qualitative traits were taken on plot basis, while data on quantitative traits on five plant basis were recorded. For molecular analysis, 24 SSR primers were used to asses fingerprint pattern for estimation of genetic relatedness. A wide range of variation was noticed for all characters. Highest GCV and PCV were recorded for the plant height, the branches per plant, the pods per plant and seed yield along with high heritability and genetic advance as per cent of mean. Per se performance revealed that different genotypes possessed different desirable yield attributes. However, genotype NRC-128, JS 22-11, ASb-9, DS 3105 and NRC-109 were the best genotypes based on per se performances for different yield components. Seed yield per plant showed positive association with the plant height, the branches per plant and the pods per plant. Path coefficient analysis identified that the pods per plants could be used as a direct or indirect selection criterion in identification for higher-yielding genotypes, along with emphasis on selecting for more branches per plants in tall plant. Among the qualitative characters, hilum colour, pubescent density and pubescent type had the maximum distinguishing potential (4 classes) indicating their importance in describing the genotypes. Euclidean distance based on qualitative characters indicated the genotype DLSb-2 and JS 22-14 to be most divergent, while that based on quantitative characters revealed the maximum divergence between the genotype NRC 128 and TS20-5. The Mahalanobis D2 value was observed to be highest between NRC-128 and NRC-109, which were placed in different clusters with maximum inter-cluster distance between them. Out of 24soybean specific SSR primers, 19 were found to be polymorphic. The number of SSR allele per locus ranged from one to three with an average of 1.4 alleles per locus. The PIC value ranged from 0.10 (Satt416) to 0.79 (Sat_172) with an average of 0.37.Jaccard’s coefficient of similarity (SSR marker based) ranged from 0.52 to 0.97 with an average value of 0.72. No concordance was found between the distance matrices of morphological and molecular markers.ThesisItem Open Access Assessment of seed quality and incidence of aflatoxin in maize during storage(AAU, Jorhat, 2022) Baruah, Sulakshana; Sarma Barua, NagendraThe present investigation was undertaken to assess the seed quality attributes and incidence of aflatoxin in maize seeds in different treatment combinations at two different storage periods. Equal amounts of seeds of maize composite variety Vivek Sankul Makka-35 were stored in nine different bag-seed treatment combinations consisting of three bags namely, 150micron polyethylene bag (PEB), high density polyethylene interwoven bag (HDPE) and polylined jute bag (PLJB) and three levels of seed treatments viz., turmeric powder @ 20g/ kg of seeds (TP), carboxin 75% WP @ 2.5g/ kg of seeds (carboxin) and control. The seeds were stored up to six months. At three months of storage, PEB gave the most favourable mean performance for germination index, shoot length, seedling length, field emergence, and percent seed infection and it was at par with HDPE for these characters. PEB gave the best mean performance for moisture content, shoot length, seedling dry weight and field emergence at six months of storage. Seeds treated with carboxin 75% WP showed the most favourable mean performances for moisture content, germination index, root length, seedling length, seed vigour index-I, seed vigour index-II, field emergence and percent seed infection at both three and six months of storage. The bag-seed treatment combination of 150 micron polyethylene bag-carboxin 75% WP (PEB-carboxin) gave the best performance than other bag-seed treatment combinations in both three and six months of storage in respect of moisture content, shoot length, seedling dry weight and percent seed infection. PEB-carboxin was found to be appreciably economic as compared to other bag-seed treatment combinations. It was observed from correlation of characters that, with increase in seed moisture content, there was decrease in shoot length, seedling length, seed vigour index-I and seed vigour index-II and increase in percent seed infection at six months of storage. Simple correlation coefficient between two periods of storage i.e., three months and six months, for each character was either significant or highly significant indicating consistent result or trend in increase or decrease of mean performance for a character from three months‟ to six months‟ period. Total aflatoxin concentration in maize seeds was observed to be of less than 3 ppb in six bag-seed treatment combinations while the amount was more in the three control bags at six months of storage. Treatments, thus, were found suitable for getting reduced incidence of total aflatoxin at the end of entire storage period.ThesisItem Open Access FUNCTIONAL ANALYSIS OF NUTRACEUTICAL PROPERTIES FOR DIFFERENT TYPES OF RICE(AAU, Jorhat, 2021) Gogoi, Smrita; Dutta Deka, SharmilaTraditional rice genotypes are endowed naturally with a wide range of nutraceutical properties and thus constitutes to be a potential functional food for nutritional security. The present investigation was undertaken with the objectives to study the diversity of different rice genotypes for yield and yield attributes with varying nutritional components especially iron and zinc. The differential expression of the genes for anthocyanin biosynthesis in relation to iron and zinc content in rice grain and genome wide association study to identify significant marker trait associations for yield and grain quality in rice germplasm collection was also done in the present study. A group of 204 rice genotypes comprising of traditional rice including ahu, Sali, bao, aromatic and glutinous genotypes along with a few high yielding released varieties and high zinc breeding lines developed in IRRI, Philippines were evaluated during Sali 2019-20 in augmented block design and observations were taken for quantitative and qualitative traits as per DUS guideline including important phytochemicals using standard procedure. Out of these, Disang and Dimrou, were recorded as earliest flowering and maturing genotypes, whereas Gopinath and Horu Jahinga possess more number of productive tiller per plant. Joha (Meghalaya) was recorded for high spikelet fertility, whereas Horu Jahinga, Jengoni, and Kajoli chokuwa were recorded high seed yield per plant. To authenticate the common perception of high nutritional value of traditional pigmented rice genotypes, phytochemical analysis were done for 30 genotypes which were selected based on high Fe, Zn content and aleurone colour. Pigmented rice genotypes; Tulashi bora, Ikhojoy, Aus joria and Jengoni were recorded high phytochemical content along with higher Fe and Zn. Jengoni was also recorded high grain yield per plant along with biological yield per plant. Hence, Jengoni along with Tulashi bora, Ikhojoy and Aus joria are identified as promising genotypes for future nutritional breeding combining with good yield. A high significant correlation was also observed between total phenolics and antioxidant activity with total anthocyanin activity. For expression analysis, 5 genotypes were selected including one check i.e. Bahadur, on the basis of high Fe and Zn content and aleurone colour. Seven gene specific primers were designed to study the expression profile in selected genotypes by double delta CT method. The results indicated that there is no direct relationship between anthocyanin and micronutrient content and thus warrants possibility of involvement of different genes other than the tested ones. Genotyping by 6 sequencing using SNP marker was done for the present set of 204 diverse rice germplasm by outsourcing and marker and trait associations for yield and grain quality in rice germplasm collection for 20 traits was investigated. Out of the 20 traits and 75,309 SNPs analyzed, 30 SNPs showed significant associations with plant height, stem length, spikelet fertility and 1000-grain weight and Zn content. Among the 30 SNPs only 18 SNPs were encoded and co-located with major candidate genes. Moreover, for spikelet fertility and 1000-grain weight, four novel QTLs were detected, which were mapped on chromosome 5 and 7 at 12336034bp and 9597295bp position, respectively for spikelet fertility and on chromosome 7 and 12 at position 13808132bp and 6012015bp for 1000-grain weight. Further characterization and validation of the novel QTLs may lead to the identification of new candidate genes for these traits.ThesisItem Open Access Genetics of Brinjal (Solanum melongena L) for Adaptation in Summer Season(AAU, Jorhat, 2022) Imsong, Bendangla; Sarma, AkashiThe present investigation was carried out using twenty three genotypes of brinjal collected from Horticultural Research Station, Kahikuchi, Department of Horticulture, AAU, Jorhat, Tezpur and Mizoram. The experiment was conducted at Horticulture Research Farm, Assam Agricultural University, Jorhat. In the first growing season, the twenty three genotypes were assessed and based on the performance of genotypes and initial plant data, eight lines and three testers were selected and crossed in line x tester mating design to obtain twenty four cross combinations. The parental lines, their cross combinations and a check variety was sown in the second season.The analyses of variance revealed significant variation at genotypic level among the twenty three genotypes for all the sixteen characters except one i.e, fruit length. Between the replication, it was observed that there was significant variation in respect of leaf blade length. The characters, plant spread, fruit circumference, number of fruits per plant, fruit weight, fruit volume and fruit yield per plant had high estimates of both GCV and PCV. High heritability coupled with high genetic advance was observed for the traits, plant spread, fruit circumference, number of fruits per plant, fruit weight, fruit volume and fruit yield per plant. The fruit yield per plant had a significant positive genotypic and phenotypic correlation with plant height, plant spread, number of primary branches per plant, leaf blade length, fruit pedicel length, fruit circumference, number of fruits per plant and fruit weight. There were characters which manifested to be negatively correlated with yield indicating which were days to first flowering, days to 50% flowering, days to first fruiting and days to 50% fruiting. The highest positive direct effect was of days to first flowering (6.064). The genotypic residual effect was observed to be 0.122. The twenty three genotypes were grouped into 5 clusters with cluster I having the maximum number with twelve genotypes. Cluster IV that the highest intra cluster and the inter cluster D2 value was observed to be maximum between cluster III and cluster IV. The highest contribution per cent was manifested for days to 50% flowering. The qualitative characters studied in total were fourteen. From the analysis of variance for line x tester mating design, it was found that the parents, crosses and parents vs crosses exhibited highly significant difference. The analysis of 58 variance of combining ability showed significant difference for the lines, tester and line x tester interaction. Except for the character, plant height, all the other characters exhibited significant difference for line x tester interaction. The estimates of SCA variance were higher than GCA variance which resulted in ratio of σ2GCA to σ2SCA less than one. The proportional contribution of line x tester interaction to total variance was more than the lines and testers. The proportional contribution of lines to total variance was more than testers and line x tester interaction in respect of fruit length and total phenol. Amongst parents, the line Longai Purple Long was observed to be the highest yielder, desirable lowest content of solasodine and exhibited earliness in days to first flowering, days to 50% flowering, days to first fruiting and days to 50% fruiting whereas the tester, KB4 manifested desirable mean for eleven characters which were leaf blade length, days to first flowering, days to 50% flowering, days to first fruiting, days to 50% fruiting, fruit length, fruit weight, fruit volume, fruit yield per plant, phenol content and crude protein. The cross Green Streaked x Balijana showed desirable mean for six traits among all the crosses which were leaf blade width, days to first flowering, days to 50% flowering, days to first fruiting, days to 50% fruiting and solasodine content. The highest yielder was M2 x KB4 among all the twenty four crosses. In regard to good general combining ability of the parents, the line Longai Long was observed to exhibit both positive and negative effects in desired direction for eleven traits. The lines found to be good general combiners for yield were Longai Purple Oblong and Barpeta and for earliness besides Long Long. The cross, HRS4 x Balijana was found to have the maximum number of positive and negative sca effects in favourable trend. The hybrid M2 x KB4 manifested highest average heterosis for fruit yield per plant followed by Longai Long x KB4 and HRS4 x Balijana. The cross M2 x KB4 produced the highest yield.
