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

摘要

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