The effect of cold exposure on seed dormancy and germination in a cold temperate eelgrass (Zostera marina) population

Research output: Working paperResearch

Seed dormancy is an adaptive trait that plays a key role in mitigation of unfavourable conditions for seedling establishment. In cold temperate eelgrass populations the potential role of cold exposure on dormancy release is presumed, but have not yet been tested. In this study we investigated the effect of temperature on dormancy relief and germination. Eelgrass seeds were stratified at 1, 3 and 7 °C for 30 and 60 days, and afterwards planted in sediment and left to germinate for 90 days at five different temperatures (3, 6.5, 9, 12 and 14.5 °C). Reduced temperature and increased duration of the stratification period had an additive effect on germination across the germination temperatures, indicating that the seed dormancy state had been relieved by cold exposure. At the optimum germination temperature of 9 °C, 29.8 % of the seeds stratified for 30 days germinated and 66.24% of those stratified for 60 days. Dormancy relief was also associated with increased seed vigour/performance, indicated from a shift towards a lower optimum germination temperature, increased rates of emergence and seedling growth was enhanced at 3 °C. These results may help to understand seed phenology and how interannual and long-term changes may affect the sexual recruitment of eelgrass populations. We point towards the necessity for more research into the effects of fluctuating temperatures and advise for similar studies into the effect of warm stratification on eelgrass populations at lower latitudes.
Original languageEnglish
Publication statusPublished - 2018

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