Assessment of morphological and genetic variability through genic microsatellite markers for essential oil in Sandalwood (Santalum album L.).

Abstract

Sandalwood (Santalum album L; family Santalaceae) is a highly significant aromatic oil yielding tree. It is valued for two important traits, heartwood and essential oil obtained from the heartwood. This study was proposed to assess the morphological and genetic variability of sandalwood accessions. For this, genotypes were randomly selected (n = 177) from the 14 populations from three states in southern India. The total heartwood oil content and quality was estimated by UV method and GC-MS. Total 14 oil-specific genic SSR markers were procured to evaluate the genetic diversity among the sandalwood accessions. Total core size, heartwood content, and oil of S. album ranged from 4.4 to 19.1cm; 0.0 to 17.3cm; and 0.0 to 5.96% with covariance 27.61, 85.25, and 73.12% followed by mean 9.74, 3.77, and 2.71, respectively. Genetic diversity estimates were highly polymorphic in terms of Na 7.28, Ne 5.89, He 8.0 PIC 0.891, with little Ho, and F-0.922. AMOVA revealed that minimal genetic variation among populations and highest variation was found among individuals with Nm (58.4). The UPGMA reveals the cluster favored the grouping pattern by the PCA analysis. Structure and PCA analysis clustered the entire populations into two major groups with F ST 0.046 in which population of Kerala and Karnataka were pure and Telangana accessions were found admixtures. No significant correlation (r 2 = 0.23, P = 0.00) was observed between heartwood oil and genetic structures. A high degree of transferability of genic markers would facilitate the assessment of novel genotypes for future tree improvement and conservation of Sandalwood populations.