Horticultural ex situ conservation of satiny willow (Salix pellita Anderss.)

Abstract

Salix pellita (satiny willow) is a state-threatened shrub willow species which is native to Minnesota and offers appealing ornamental traits. The natural distribution of this taxon in Minnesota is limited primarily by habitat loss. Because the disjunct populations of this species in Minnesota are in decline and because no prior efforts have been made to conserve this taxon, horticultural practices and cultivation could offer a preservation outlet for satiny willow. Stem cutting propagation was evaluated to develop an efficient protocol for the mass propagation of the species and to support the viability of diverse ex situ collections. Genetic variation between satiny willow populations was assessed using genotyping by sequencing (GBS) to characterize genetic diversity of satiny willow populations and subsequently design conservation strategies that capture the full spectrum of the taxon’s variability. Lastly, this project established a living collection to protect the unique genetics of the satiny willows of Minnesota while also generating plant material for future research. By integrating propagation practices, genetic diversity evaluations, and establishing a living collection, this project established a robust ex situ conservation framework for Salix pellita. The findings of this work will contribute to the conservation of satiny willow populations in Minnesota and serve as a model for conserving other threatened satiny willow populations outside of the state.