Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 4, 2010
Publication Date: March 1, 2011
Citation: Bhattarai, K., Bushman, B.S., Johnson, D.A., Carman, J.G. 2011. Searls' Prairie Clover (Dalea searlsiae) for rangeland revegetation: phenotypic and genetic evaluations. Crop Science. 51:716-727. Interpretive Summary: There is a great need for legumes in revegetation programs in the western USA. We assessed genetic and phenotypic performance of collections of Searls' prairie clover (Dalea searlsiae), looking for its potential agronomic seed production and for its genetic diversity. There was wide variation in all the traits, and some performed as well as a closely related species currently used in agronomic seed production in the Midwest. Strong isolation by distance was found, and two genetic structured populations determined. Collection site precipitation was correlated to agronomic performance, providing us clue about which environmental characters condition adaptation.
Technical Abstract: Few 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 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 dameter, 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. Using AFLP markers, collections from northwestern Utah were genetically differentiated from those of southern Utah and Nevada. Strong isolation by distance among collections suggests that genetic drift and gene flow are important factors in determining population structure in Searls' prairie clover.