First draft genome and genetic diversity analysis of the economically important and vulnerable tree species Saraca...

Saraca asoca(Roxb.) Wilde. (Ashoka tree), a culturally revered and pharmaceutically valuable species endemic to the Indian subcontinent, is currently listed as vulnerable on the IUCN Red List due to habitat loss and overharvesting. Saraca asoca is known for its extensive pharmacological properties. In particular, its bark is widely used in the treatment of menorrhagia, dysfunctional uterine bleeding, hemorrhagic dysentery, and other gynecological disorders, and it holds a prominent place in Ayurvedic medicine. Despite its longstanding use in traditional medicine, no genomic resources are available for this species. Here, we present the first draft genome of S. asoca, assembled using Illumina paired-end reads into a genome of 1.6 Gb, covering 76% of the estimated genome size. A total of 63,913 proteincoding genes were predicted. Pathway analysis identified key enzymes and regulators in flavonoid and phenylpropanoid biosynthesis pathways, including chalcone synthases, flavanone 3-hydroxylase, and UDP-glucosyltransferases. We analyzed the genetic diversity of 49 Saraca asoca samples from Kolluru and other locations in southern India using genotyping by sequencing (GBS). Analysis of 49 samples established genetic diversity relationships using a distance matrix. Population structure analysis revealed three distinct genetic clusters corresponding to geographic origin. A survey of simple sequence repeats (SSRs) identified 584,615 SSRs, with 236,123 sequences containing SSRs. This comprehensive genomic analysis of Saraca asoca provides critical insights for conservation efforts aimed at preserving this vulnerable species.