Bromegrass in Alaska. II. Autumn Food-Reserve Storage, Freeze Tolerance, and Dry-Matter Concentration in Overwintering Tissues as Related to Winter Survival of Latitudinal Ecotypes

Abstract

The objective of this study was to acquire improved understanding of factors that influence winter survival of bromegrass (Bromus spp.) at northern latitudes. Four bromegrass strains of diverse latitudinal origins were used: (a) native Alaskan pumpelly bromegrass (B. pumpellianus Scribn.) adapted at 61° to 65°N, (b) the Alaska hybrid cultivar Polar (predominantly B. inermis Leyss. x B. pumpellianus) selected at 61.6°N, and two smooth bromegrass (B. inermis) cultivars, (c) Manchar selected in the U.S. Pacific Northwest (43° to 47°N), and (d) Achenbach originating from Kansas (34° to 42°N)