SANKHYAN, H PSHARMA, JAI PAL2020-01-022020-01-022019-12http://krishikosh.egranth.ac.in/handle/1/5810139200ABSTRACT The present investigation entitled “Genetic Diversity of Indian Willow (Salix tetrasperma Roxb.)” was carried out in the Department of Tree Improvement and Genetic Resources, Dr Y. S. Parmar University of Horticulture and Forestry, Nauni, Solan (H.P.) during 2015-2019 to assess the genetic diversity among various genotypes through morphological and molecular markers. Genotypes of the species from northern India were evaluated in common garden experiment. These were grouped into five latitudinal and four altitudinal ranges for morphological study and five populations for studying population diversity and structure. The analysis of variance revealed significant differences among genotypes, sites, latitudes and altitude ranges for all the traits. The plant height, basal diameter and biomass characters were recorded maximum for Suhanpur site.Number of nodes, internodal length and root length was recorded maximum for Devamanal, Rupnagar and Chamba sites, respectively. Udaipur and Bhunter sites recorded maximum foliage durations and sprouting days, respectively. Whereas, Devamanal site showed longest lamina and leaf length and Udaipur recorded maximum breadth of lamina. Dasua recorded maximum petiole length and Udaipur highest leaf area. Numbers of leaf teeth were observed maximum for Jammu site. The variability estimates exhibited high variability, high heritability along with genetic advance as percentage of mean. Linear regression analysis depicted that only characters foliage duration, leaf area and root length were under the influence of latitude. Whereas basal diameter, internodal length, number of nodes, maximum breadth of lamina, leaf area and all the biomass characters were affected by altitude. Principal component analysis extracted 82.85 percent of the total variance in five components. In genetic divergence studies 21 sites could be grouped into three clusters based on Ward’s method, separating sites of Punjab and Rajasthan from others. UPGMA dendrogram categorized all the genotypes used into five, four and three clusters with RAPD, ISSR and SSR markers, respectively. RAPD primers viz., OPC-02, OPL-08, OPL-09, OPA-01, DECA7, OPS-07, OPA-02; ISSR primers viz., UBC835, 814, ISSR1, ISSR7, 840, ISSR94, ISSR98, ISSR91 and SSR primers viz., SB100, ORPM28, ORPM21, WPMS18, WPMS03, ORPM488, ORPM496, PTR1 were found to be desirable due to higher polymorphic information content, marker index, resolving power, expected heterozygosity and are further suggested for genetic differentiation studies in willows. Higher observed heterozygosity than expected heterozygosity and negative fixation index through SSR markers confirmed outcrossing nature of the species. Phi-statistics of ISSR and F- Statistics of SSR revealed more variation among individuals within populations than among populations. The genetic differentiation (Fst) was significant and moderate with ISSR (0.138) and SSR (0.081) markers. Pairwise population of gene flow (Nm) values based on Fst values among populations showed the effect of geographic distance on migration of alleles. Pairwise population matrix of Nei genetic distance was obtained maximum between JK and HP1 populations. Bayesian clustering pattern through STRUCTURE software was supported by scatter plot diagram of principal coordinate analysis and dendrogram of molecular and morphological data.ennullThesis