Variation in Saltgrass Growth and Time of Fall Dormancy Related to Geographical and Climatic Factors

Abstract

Development of a new turfgrass cultivar requires an evaluation of numerous traits as well as an understanding of environmental factors influencing those traits. Growth or ability to fill in gaps and time of fall dormancy (fall color retention) that indicates cold hardiness are important traits for turfgrasses. This study was initiated to characterize variation in saltgrass [Distichlis spicata L. (Greene)] growth and time of fall dormancy related to climatic and geographical factors at the source location (geographical location of clone origin). Growth traits and time of fall dormancy were measured on 52 saltgrass clones collected from 41 locations and established at one location (common garden) in Fort Collins, CO. Principal component analysis on the morphological traits extracted the first principal component that explained 78% of the variability. The first principal component and time of fall dormancy were related to climatic and geographical factors at the source locations. Variation in growth traits was related to seasonal climatic variables of summer drying and fall cooling that explained ≈50% of variability in morphological traits. Variation in time of fall dormancy was related to longitude of clone origin and minimum winter temperature. These two variables explained ≈60% of the total variability in time of fall dormancy. Information obtained in this study may help breeders identify the best environments for specific traits and suggests that cold tolerance could be a problem for some clones from western sources if established too far east.