Mapping the sex determination region in the Salix F1 hybrid common parent population confirms a ZW system in six diverse species

Authors: WILKERSON, DUSTIN - Cornell University; TASKIRAN, BIRCAN - Cornell University; Carlson, Craig; SMART, LAWRENCE - Cornell University

Submitted to: Genes, Genomes, Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2022
Publication Date: 3/25/2022
Citation: Wilkerson, D., Taskiran, B., Carlson, C.H., Smart, L. 2022. Mapping the sex determination region in the Salix F1 hybrid common parent population confirms a ZW system in six diverse species. Genes, Genomes, Genetics. 12(6). Article jkac071. https://doi.org/10.1093/g3journal/jkac071.
DOI: https://doi.org/10.1093/g3journal/jkac071

Interpretive Summary: Willows are wide-spread, diverse, and fast-growing plants used in both energy production and ecological restoration. Scientific resources are growing for willow, however, only a small portion of willow's 350 species have been evaluated for growth and disease resistance traits. To gain knowledge of this unseen potential, we developed a large population consisting of crosses between species. Sequencing of this population permitted an assessment of its diversity and the identification of new genes most likely to control important traits. These products benefit willow researchers by providing novel populations and traits for breeding purposes, and outlines new research methods for other scientists working on diverse crop plants. Importantly, the products of this research will especially benefits growers and stakeholders in the form of new and improved willow varieties.

Technical Abstract: Within the genus Salix, there are approximately 350 species native primarily to the northern hemisphere and adapted to a wide range of habitats. This diversity can be exploited to mine novel alleles conferring variation important for production as a bioenergy crop, but also to identify evolutionarily important genes, such as those involved in sex determination. To leverage this diversity, we created a mapping population by crossing 6 Salix species (Salix viminalis, Salix suchowensis, Salix integra, Salix koriyanagi, Salix udensis, and Salix alberti) to common male and female Salix purpurea parents. Each family was genotyped via genotyping-by-sequencing and assessed for kinship and population structure as well as the construction of 16 backcross linkage maps to be used as a genetic resource for breeding and selection. Analyses of population structure resolved both the parents and F1 progeny to their respective phylogenetic section and indicated that the S. alberti parent was misidentified and was most likely S.suchowensis. Sex determining regions were identified on Salix chromosome 15 in the female-informative maps for seven of the eight families indicating that these species share a common female heterogametic ZW sex system. The eighth family, S. integra × S. purpurea, was entirely female and had a truncated chromosome 15. Beyond sex determination, the Salix F1 hybrid common parent population (Salix F1 HCP) introduced here will be useful in characterizing genetic factors underlying complex traits, aid in marker-assisted selection, and support genome assemblies for this promising bioenergy crop.