Genetic diversity and population structure of Indian willow (Salix tetrasperma Roxb.) along its distributional range in the Himalayan region

Indian willow (Salix tetrasperma) is distributed across India, South China, Indo Malaya to Java along the banks of rivers and streams in wet swampy areas. Different parts of the plant have been used as traditional medicine due to the presence of compounds such as catechol, salicin and their derivatives. Leaves of the plant are used as fodder while its wood is used as fuel, agricultural tools, furniture and soil binder on embankments. The genetic diversity and population structure of Indian willow populations of North India was examined using 25 microsatellites. The observed heterozygosity (0.70 ± 0.03) was higher than the expected heterozygosity (0.50 ± 0.015) and fixation index of populations (−0.39 ± 0.03) confirmed the outcrossing nature of the species. The genetic differentiation (Fst = 0.081) and gene flow among populations (Nm = 2.85) was moderate. Genetic distance was found significant with geographic distance (R2 = 0.11) as per Mantel test. Bayesian clustering pattern through STRUCTURE software showed existence of three gene pools which was further supported by principal coordinate and cluster analysis of molecular data. This study will be helpful in formulating conservation strategies and developing effective selection strategies for genetic improvement of Salix tetrasperma.