Sexual dimorphism and sex ratio bias in the dioecious willowSalix purpureaL

Abstract

1Premise Sexual dimorphism in dioecious plant species is often not obvious or is 2 absent. Dioecious species populations also often exhibit deviations from expected sex ratios. 3Previous studies on members of the Salicaceae family have shown strong, partial, and no sexual 4 dimorphism. Some studies have shown sex-biased ratios in several Salix spp., however, S. 5 purpurea has never been examined for evidence of sexual dimorphism or for the presence of sex-6 ratio bias, and therefore a comprehensive phenotypic study is needed to fill this knowledge gap. 7 Methods This study examined a suite of morphological, phenological, physiological and wood 8 composition traits from multi-environment and multi-year replicated field trials in a diversity 9 panel of unrelated S. purpurea accessions and in full-sib F 1 and F 2 families produced through 1 0controlled cross pollinations to test for sexual dimorphism and sex ratio bias.

Integrative genomics reveals paths to sex dimorphism inSalix purpureaL.

“…Shrub willows ( Salix section Vetrix ) in particular, are grown throughout North America and Eurasia for bioenergy and bio-products 20 . Despite its commonality across the Salicaceae family, dioecy presents a challenge for breeding efforts and the cultivation of shrub willow, with sex showing linkage to biomass related traits, such as leaf area 21 and catkins showing distinct phenology and secondary metabolite profiles between sexes, affecting pollinator and pest attraction 22,23 . There is a strong interest in understanding the genetic mechanisms controlling sex determination in Salix , along with the gene pathways involved in sex dimorphism, in order to advance current breeding efforts and genetic studies to improve Salix as a bioenergy crop.…”

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

“…Six of the eight families were female biased -a feature prevalent in Salix. Of those studied here, S. purpurea (Gouker et al 2020), S. viminalis (Alström-Rapaport et al 1997, S. suchowensis (Yang et al 2020a), S. udensis (Ueno and Seiwa 2003), and S. integra (Tozawa et al 2009) have documented cases of sex ratio bias, yet this is the first time it has been reported in S. koriyanagi. The genetic basis of sex ratio bias could be a result of secondary sex dimorphisms, such as higher mortality rates in males, increased herbivory and pathogen resistance in females, or the presence of a sex distorter locus (Pucholt et al 2017a).…”

Warmer temperatures promote shrub radial growth but not cover in the central Canadian Arctic

“…Their growth chronologies exhibit a strong climate signal (temperature or precipitation), but only Forbes, Fauria, and Zetterbergs (2010) reported a long-term positive trend in S. lanata growth. Moreover, because Salix shrubs are dioecious, males and females may display differential climate sensitivity because females are thought to allocate more resources to reproduction (Sakai, Sasa, and Sakai 2006) and may have fewer resources left over for radial growth (Nissinen et al 2016;Gouker et al 2020; but see Schmidt et al 2010).…”