Cold-Temperature Germination of Elytrigia repens X Pseudoroegneria spicata Hybrids

Abstract

The successful establishment of perennial grass seedlings on Artemisia rangelands may depend on germination in the early spring at cold seedbed conditions. To ascertain the feasibility of selecting for germination at low temperatures in a hybrid population, seeds for 30 RS hybrid [Pseudoroegneria spicata (Pursh) Love × Elytrigia repens (L.) Nevski] lines were germinated under a wide range of constant or alternating temperatures. The hybrid populations were characterized in 11 different, but related germination responses to incubation temperatures based on discriminate analysis of seedbed temperatures. Germination at very cold incubation temperatures was markedly reduced in all populations compared to germination at more moderate temperatures. A range of 0 to 16% germination existed among the hybrids at very cold temperatures after 4 weeks incubation. At the very cold temperature regime, crested wheatgrass [Agropryon desertorum (Fisch.) Schult.] had 1% germination and intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth and D.R. Dewey] had 3% germination. At cold temperatures, germination of one hybrid line exceeded that of the wheatgrasses. At cold fluctuating temperatures, 13 and 22 hybrid lines had higher germination than intermediate and crested wheatgrass, respectively. Results of this study indicate a high potential of selection among these hybrid lines for germination in rangeland seedbeds under cold temperature regimes.