Abstract
To investigate patterns in seed germination and survival at three different soil depths over a long time span, seeds of Rumex obtusifolius, Polygonum longisetum and Oenothera biennis were examined as a function of season (spring, autumn) and soil depth (3, 10, 30 cm). Buried seeds were exhumed after 3 years and subjected to two different temperature treatments. These were gradually increasing and decreasing temperatures, starting at 5 and 35°C, respectively. Treatments commenced after a 5-day acclimation to the initial starting temperature with light. With increasing burial depth, diurnal temperature fluctuations decreased and seed survival increased. Seed dormancy patterns changed with season and burial depths for all the species. Polygonum seeds germinated between 15 and 35°C in spring, but not in autumn. Rumex seeds germinated between 15 and 25°C in both spring and autumn. The optimal germination temperature for Oenothera seeds differed between spring (>30°C) and autumn (ca 30°C). Seed dormancy and survival are controlled by soil temperature fluctuations that differ with soil depth and seeds appear to have season-sensing and burial-depth detecting mechanisms based upon temperature fluctuations.
Highlights
Seed dormancy has an important role in plant survival via the alteration of seed germination patterns and various types of seed dormancy have been reported, in particular for weeds[1,2]
The magnitude of diurnal temperature fluctuations differs with soil depth[5] and seed dormancy cycles differ with the depth at which the seed is buried
To investigate changes in seed survival and seed germination patterns at different burial depths and in different seasons, I studied the temperature treatments required for seed germination in three common weed species
Summary
Seed dormancy has an important role in plant survival via the alteration of seed germination patterns and various types of seed dormancy have been reported, in particular for weeds[1,2]. Since light does not usually penetrate the soil beyond a few centimeters, the seed dormancy cycle is mostly determined by diurnal and seasonal temperature fluctuations[3,4]. Diurnal temperature fluctuations often break dormancy in many species and decreases with increasing soil depth[6]. Due to decreasing diurnal temperature fluctuations, the percentage of seeds that are dormant increases with increasing depth of burial[1,7]. To investigate changes in seed survival and seed germination patterns at different burial depths and in different seasons, I studied the temperature treatments required for seed germination in three common weed species. R. obtusifolius is European origin and O. biennis is North American origin. Nowadays both species are widespread in temperate zones in the Northern Hemisphere. The flowering periods of those three species are usually from June to October in northern Japan
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
