Molecular Diversity in Willow Clones Selected for Commercial Plantation

Twenty-five promising willow clones from six countries were selected after nursery screening. Molecular diversity among the clones was estimated using 16 RAPD and 14 SSR primers. A total of 363 markers were generated and out of which 351 were showing high (96.7%) rate of polymorphism. Out of 30, 18 primers showed 100% polymorphism. RAPD markers widely scored over SSR markers in polymorphic information content. UPGMA dendrogram based on both RAPD and SSR markers resolved into four major clusters. The similarity coefficient among 25 clones of willow ranged from 0.71 to 0.86. Maximum similarity (86%) was observed between 795 and PN-721 and SI-63-007 and V-99. Thus, these genotypes showed maximum degree of similarity in their genetic makeup. However, minimum values were observed between SE-69-002 and 84/11 (0.71) followed by SE-69-002 and 17-93-A (0.72). RAPD and SSR analysis proved helpful for estimating the magnitude of genetic diversity at molecular level. Clustering further indicated that the geographic distribution may not be the true index of genetic diversity in willow clones. On the basis of banding pattern RAPDs and SSRs were effectively used for molecular characterization of willow clones used in this study.