Aims Seed dormancy and the soil seed bank are crucial to plant regeneration strategy, especially in semiarid ecosystems with unpredictable precipitation. The aim of this study was to investigate how seed dormancy is controlled by environmental factors and how it is correlated with the soil seed bank and regeneration of the perennial legume Oxytropis racemosa, a dominant perennial herb in Mu Us Sandland of semiarid China. Methods Germination and imbibition experiments on fresh intact and scarified seeds of O. racemosa were used to identify physical dormancy (PY) in seeds of this species. Soil seed bank dynamics, timing of seedling emergence and the fate of buried seeds in the natural habitat were investigated. Important Findings PY was broken by mechanical scarification or wet heat/ice water cycles but not solely by dry heat or wet heat treatment. The soil seed bank exhibited seasonal changes in the number of seeds, which was highest in September and lowest in July. Seeds buried at different sand depths gradually lost dormancy; 20-42% of the seeds remained dormant after 20 months of burial. Dormancy break occurs gradually throughout the year. Our results indicate that O. racemosa exhibits hardcoatedness heterogeneity that spreads germination of a seed cohort between seasons and years in the semiarid environment, where the amount of precipitation during the growing season is highly variable.
|Number of pages||11|
|Journal||Journal of Plant Ecology|
|State||Published - May 23 2018|
Bibliographical noteFunding Information:
This research was supported by the Key Basic Research and Development Plan of P. R. China (2016YFC050080502) and the National Natural Science Foundation of P. R. China (31370705, 31570416). Conflict of interest statement. None declared.
© The Author(s) 2017. Published by Oxford University Press on behalf of the Institute of Botany, Chinese Academy of Sciences and the Botanical Society of China. All rights reserved.
- Oxytropis racemosa
- physical dormancy
- seedling emergence
- soil moisture
- soil seed bank
- soil temperature
- unpredictable rainfall
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Plant Science