Searls Prairie Clover (Dalea searlsiae) for Rangeland Revegetation: Phenotypic and Genetic Evaluations

Abstract

ABSTRACTFew North American legumes are available for use in rangeland revegetation in the western USA, but Searls prairie clover [Dalea searlsiae (A. Gray) Barneby] is one that holds promise. Commercial‐scale seed production of this species could address the issues of unreliable seed availability and high seed costs associated with its wildland seed collection. To evaluate its utility for revegetation, we collected Searls prairie clover at 20 locations across Utah and Nevada. Amplified fragment length polymorphisms (AFLP) and morphological and phenotypic traits (measured in common‐garden plots) were used to clarify the role of evolutionary forces responsible for its genetic structure. Collections were evaluated for dry‐matter yield, inflorescence weight, number of inflorescences, plant height, foliage diameter, flowering date, acid‐detergent fiber, neutral‐detergent fiber, and crude protein at two common‐garden locations in northern Utah. Collections from southern Utah and eastern Nevada exhibited high phenotypic values, whereas collections from western Nevada and northwestern Utah had low phenotypic values. Collections from northwestern Utah were genetically differentiated from those of southern Utah and Nevada via AFLP markers. Strong isolation by distance between collections suggests that genetic drift and gene flow are important factors in determining population structure in Searls prairie clover.