Germination Responses to Light and Alternating Temperatures in European Populations of Dactyl1s Glomerata L.

Summary Basic patterns of germination response to light and alternating temperatures were relatively stable in three European populations of Dactylis glomerata L. during four years of cultivation in field plots. Small inconsistent quantitative differences were probably due to differences in the reproductive output of individual genotypes and seasonal variation in climatic factors. Germination responses were directly related to temperature conditions (over the range 6 to 26 °C) which prevailed during seed development and maturation. The relative effects of light and alternating temperatures were independent of maturation temperature suggesting a physiological link in the requirement for these factors.