Draft genome of a high value tropical timber tree, Teak (Tectona grandis L. f): insights into SSR diversity, phylogeny and conservation

Teak (Tectona grandis L. f.) is one of the precious bench mark tropical hardwood having qualities of durability, strength and visual pleasantries. Natural teak populations harbour a variety of characteristics that determine their economic, ecological and environmental importance. Sequencing of whole nuclear genome of teak provides a platform for functional analyses and development of genomic tools in applied tree improvement. A draft genome of 317 Mb was assembled at 151× coverage and annotated 36, 172 protein-coding genes. Approximately about 11.18% of the genome was repetitive. Microsatellites or simple sequence repeats (SSRs) are undoubtedly the most informative markers in genotyping, genetics and applied breeding applications. We generated 182,712 SSRs at the whole genome level, of which, 170,574 perfect SSRs were found; 16,252 perfect SSRs showed in silico polymorphisms across six genotypes suggesting their promising use in genetic conservation and tree improvement programmes. Genomic SSR markers developed in this study have high potential in advancing conservation and management of teak genetic resources. Phylogenetic studies confirmed the taxonomic position of the genus Tectona within the family Lamiaceae. Interestingly, estimation of divergence time inferred that the Miocene origin of the Tectona genus to be around 21.4508 million years ago.