title: The dual role of temperature in the regulation of the seasonal changes in dormancy and germination of seeds of Polygonum persicaria L.
abstract: The role of temperature in the regulation of seasonal changes in dormancy and germination was studied in seeds of Polygonum persicaria. Seeds were buried in the field and under controlled conditions. Portions of seeds were exhumed at regular intervals and germination was tested over a range of conditions. Seeds of P. persicaria exhibited a seasonal dormancy pattern that clearly showed the typical features of summer annuals, i.e. dormancy was relieved at low winter temperatures, the germination peak occurred in spring and dormancy was re-induced in summer. The expression of the dormancy pattern was influenced by the temperature at which germination was tested. At 30°C exhumed seeds germinated over a much longer period of the year than at 20° or 10°C. Nitrate added during the germination test occasionally stimulated germination. The seasonal changes in dormancy of buried seeds were regulated by the field temperature. Soil moisture and nitrate content did not influence the changes in dormancy. The fact that, on the one hand, field temperature determined the changes in dormancy and, on the other hand, germination itself was influenced by temperature, was used to describe the seasonal germination pattern of P. persicaria with a model. Germination of exhumed seeds in Petri dishes at field temperature was accurately described with this model. Germination in the field was restricted to the period where the range of temperatures over which germination could proceed (computed with the model) and field temperature overlapped.
authors.affiliation: Department of Plant Physiology, Agricultural University, Arboretumlaan 4, NL-6703 BD, Wageningen, The Netherlands.|Department of Vegetation Science, Plant Ecology and Weed Science, Agricultural University, Bornsesteeg 69, NL-6708 PD, Wageningen, The Netherlands.
authors.forename: Harro J
authors.initials: HJ
authors.lastname: Bouwmeester
authors.affiliation: Department of Plant Physiology, Agricultural University, Arboretumlaan 4, NL-6703 BD, Wageningen, The Netherlands.
authors.forename: Cees M
authors.initials: CM
authors.lastname: Karssen
keywords: Dormancy pattern; Germination; Model; Polygonum persicaria; Weed seeds