Verma, J.S.Rawat, Naveen Singh2016-06-102016-06-102014-09http://krishikosh.egranth.ac.in/handle/1/67154Thesis-PhDThe present study was carried out with 21 oat varieties over two seasons of Rabi 2010-11 and Rabi 2011-12. Data were recorded for 33 morpho-physiological characteristics (21 visually assessed and 12 measurable). Among the twenty one visually assessed characteristics, three were monomorphic, three were dimorphic and fifteen were polymorphic. Out of 12 measurable characteristics, two were monomorphic, three were dimorphic and seven were polymorphic. The COYD analysis with respect to 12 measurable traits indicated that all the varieties were clearly distinct from each other. COYD analysis was supported with MJRA analysis where the slope of the MJRA curve and regression probability was calculated, which indicated that characteristics under study were not completely independent rather they are interacting with each other as well as with the environment. The COYU analysis revealed that all the varieties were more or less uniform for measurable characteristics. Statistical analysis for stability, comparing respective values of PCV and GCV based on morphological data showed same magnitude for seven measurable characteristics. This indicated that environmental influence was less for the expression of these characters. High heritability coupled with high to moderate genetic advance for most of the measurable characteristics indicating their consistency and stability over the years and their utility in varietal characterization. Out of the 21 oat varieties under study, 14 varieties could establish distinctiveness by unique morpho-physiological profiles on the basis of proposed grouping characteristics (six). The seven remaining varieties (OL-9, SKO-20, Sabzar, JO-03-91, JO-1, JHO-99-1 and HJ-8) were discriminated further when certain morpho-physiological characteristics i.e., primary grain: hairiness of base, primary grain: length of lemma, panicle: orientation of branches other than grouping characteristics taken. Principal component analysis indicated that first eight components accounted for more than 90% of the total genetic variation. The characters contributing more positively with the PC1 and exhibited maximum variability among the varieties were leaf length, leaf: stem ratio, plant height and 1000-grain weight. Cluster analysis through D2 statistics sequestrated 21 varieties into 5 clusters during both the year and in pooled analysis. It would appear logical to affect crosses between genotypes belonging to the clusters separated by high estimated statistical distance. In pooled analysis maximum inter-cluster distance (99.60) between cluster II and V followed by 95.29 between cluster II and IV were found. From the cluster mean value of pooled analysis, the promising cluster identified for desirable characteristics were cluster IV for maximum plant height, cluster II for late time of panicle emergence, cluster III for high green fodder yield and dry matter yield, cluster II for late maturity and cluster V for early maturity. On the basis of present study, 33 morpho-physiological characteristics studied could be used for the development of DUS descriptors in oat. Results of PCA and D2 analysis indicated substantial variation among the varieties with respect to different characteristics which can be implicated in the oat breeding programmes for the development of improved cultivars.enplant morphology, plant physiology, genetic diversity, oats, avena sativa, seasonal behaviour, cluster analysis, principal component analysis, cultivarsThesis