Document Type

Article

Publication Title

International Journal of Plant Sciences

Abstract

We studied seed germination responses of 41 collections of Leymus cinereus (basin wildrye), a native perennial bunchgrass widely distributed in western North America. Collections made in 1987 and 1988 were largely nondormant in midautumn but relatively slow to germinate at optimal temperatures (mean germination time 6-16 d). Seeds germinated more quickly after a 2-wk chilling pretreatment (mean germination time 2-11 d). Mean germination time under conditions simulating prolonged snowpack (1⚬C) varied among collections from 6 to 12 wk and was negatively correlated with mean January temperature at the collection site. In dry-afterripening experiments with four 1992 collections, seeds showed only minor change in germination rate and percentage after time in dry storage, unlike seeds of Bromus tectorum (cheatgrass) and Elymus elymoides (squirreltail), which are facultatively fall-emerging. Field retrieval studies showed that L. cinereus seeds did not germinate in autumn even under conditions that triggered complete germination of B. tectorum and E. elymoides. Thus L. cinereus is primarily a spring-emerging species even though its seeds are mostly nondormant at dispersal. Its failure to germinate more quickly as a consequence of time in dry storage protects it from fall emergence under most weather scenarios. Timing of germination under snowpack is keyed to site-specific variation in snowpack duration, ensuring rapid emergence in very early spring. These results show the importance of rate as a mechanism that regulates germination phenology under semiarid conditions.

Pages

206-215

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DOI

https://doi.org/10.1086/297242

Volume

156

Issue

2

Publication Date

1995

Disciplines

Biology

ISSN

1058-5893

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Creative Commons Attribution-NonCommercial 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License

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