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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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Author: Borah, Pulin × End date: 2014 × Start date: 2014 ×
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    ThesisItemOpen Access
    STUDIES ON COMBINING ABILITY AND GENETIC DIVERSITY OF PARENTAL LINES FOR EXPLOITATION OF HETEROSIS IN RICE (ORYZA SATIVA L
    (2014) Borah, Pulin
    The present investigation was conducted at Assam Agricultural University, Jorhat with three broad objectives - (i) to identify potential maintainer and restorer lines from local and improved germplasm, (ii) to study the genetic diversity of CMS, maintainer and restorer lines and (iii) to assess combining ability of CMS and restorer lines. Out of 79 lines evaluated, 22 restorers identified were for 1A, 13 for 3A, 3 for 4A and 10 for 5A based on pollen and spikelet fertility, whereas 3, 2 and 1 maintainers were obtained for IR68888A, IR79156A and IR80555A respectively. Morpho-physiological characterization of the genotypes revealed 6 characters as monomorphic, 12 as dimorphic and 32 as polymorphic. PCV and GCV were high for chaffs per panicle, grains per panicle, grain yield per plant, flag leaf area, culm length, days to first and 50% flowering. Narrow difference between PCV and GCV estimates suggested effective selection for these traits. High heritability coupled with high genetic advance was recorded for days to first flowering, days to 50% flowering, days to maturity, culm length, grains per panicle, flag leaf length, flag leaf breadth and flag leaf area. D² statistics grouped the genotypes into 9 clusters with the highest inter-cluster distance between clusters II-III and IV-IX. The most important characters contributing towards divergence were days to first flowering (40.91%) followed by culm length (17.88%), grains per panicle (9.9%) and panicle length (7.88%). At molecular level, 76 alleles were detected using 15 SSR markers with an average of 5.07 per marker. The Jaccard’s coefficient of similarity ranged from 0.758 to 0.111with an average of 0.385 suggesting diverse nature of the genotypes. The Mantel matrix correspondence test indicated that clusters produced based on morphological and SSR markers were not conserved. The line x tester analysis revealed preponderance of non-additive gene effects suggesting heterosis breeding as a suitable approach for yield improvement. Among the lines, 4A was the best general combiner for earliness, dwarfness and effective tillers per plant and 1A for grains per panicle. A good number of cross combinations had significant SCA effects in desirable directions. The degree of mid/better parent and standard heterosis varied with crosses and characters. Two for panicle length, 16 for effective tillers, one for grains per panicle, 44 for 1000-grain weight and one for biological yield exhibited significant heterobeltiosis as well as standard heterosis. The most productive 14 hybrids recorded 10.12% to 56.46% standard heterosis over Ranjit and could be chosen for evaluation in preliminary yield trials.