Effects of temperature on seed dormancy and germination of the coastal dune plant Viola grayi : germination phenology and responses to winter warming

Autor: Yoshihiro Sawada, Asumo Kuroda
Rok vydání: 2022
Předmět:
Zdroj: American Journal of Botany. 109:237-249
ISSN: 1537-2197
0002-9122
DOI: 10.1002/ajb2.1802
Popis: PREMISE In temperate sand dunes, rising air temperature owing to climate change could not only further elevate surface soil temperatures during summers but also drastically change the range of soil temperatures in other seasons. Winter warming may shift the timing of seed germination of dune species that require cold stratification for dormancy release. METHODS We assessed the effects of temperature on dormancy and germination of Viola grayi seeds and evaluated whether winter warming could affect its germination phenology by conducting germination experiments and analyzing soil temperature data in cold and warm winters. RESULTS Viola grayi seeds were dormant when dispersed in spring. One-month moist-chilling treatment (4°C) effectively released dormancy, while short, intermittent lower temperatures (alternating 20/5°C) did not. Continuous higher temperatures induced secondary dormancy in non-dormant seeds. During a cold, snowy winter, the surface soil temperatures of the sand dune remained at 0-2°C for approximately one month owing to the accumulated snow, while the period of such stable low soil temperatures was much shorter during a warm, less snowy winter, and the highest soil temperature class reached 20-25°C. These results suggest that dispersed seeds germinate in the following spring after winter chilling, but they may remain dormant after warm winters. CONCLUSIONS With winter warming, prolonged seed dormancy and associated germination delay could occur in V. grayi seeds. Assessing the minimum requirements for dormancy release and the potential to form persistent soil seed banks is important for judging the necessity and urgency of conservation efforts for temperate dune species. This article is protected by copyright. All rights reserved.
Databáze: OpenAIRE
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