Genomic and transcriptomic resources for candidate gene discovery in the Ranunculids

Area of Science:

• Plant genetics
• Evolutionary biology
• Genomics

Background:

• *Thalictrum* species exhibit transitions from insect to wind pollination, linked to polyploidy and unisexual flowers.
• The genetic basis for these pollination syndrome shifts in *Thalictrum* remains largely unexplored.
• Understanding these genetic underpinnings is crucial for evolutionary studies.

Purpose of the Study:

• To generate a draft genome of *Thalictrum thalictroides*, an ancestral diploid, hermaphrodite, insect-pollinated species.
• To create floral transcriptomes for *T. thalictroides* and the wind-pollinated, andromonoecious *T. hernandezii*.
• To provide genomic and transcriptomic resources for identifying candidate genes involved in floral evolution and pollination shifts.

Main Methods:

• High-throughput sequencing (Illumina HiSeq 2000) was employed for genome and transcriptome generation.
• De novo assembly was performed to construct the draft genome and analyze transcriptomes.
• Comparative analysis of transcriptomic data from different pollination systems was utilized.

Main Results:

• A draft genome assembly for *T. thalictroides* was successfully generated, comprising 44,860 contigs with a total length of 243 Mbp.
• The genome assembly captured 84.5% of conserved embryophyte single-copy genes, indicating good completeness.
• Floral transcriptomes contained representations of most eukaryotic core genes, facilitating comparative analyses.

Conclusions:

• The generated genome and transcriptome data serve as valuable resources for candidate gene discovery in *Thalictrum* floral evolution.
• Potential candidate genes associated with distinct floral morphologies and pollination systems were identified.
• Single-copy gene analysis and SSR markers were developed for future population and phylogenetic studies.