A convenient screening test system and a model for thermal germination responses of wild plant seeds: behaviour of model and real seeds in the system

Abstract

Abstract A convenient test system for screening the thermal germination behaviour of seeds was developed for both basic and applied research in seed germination ecophysiology. Only two temperature‐controlled facilities, a test period of about a month and a relatively small number of sample seeds arc needed to obtain information on the thermal‐germination parameters of individual seed populations, such as lower or higher limit temperatures, and thermal times required for germination. In the test system, the germination performances of sample seed populations were compared under two temperature regimes: a gradually increasing temperature regime and a gradually decreasing temperature regime, in which the seeds were subjected to gradually changing temperatures in the range of 4 36°C. In order to assess the effects of various values for thermal‐germination parameters on the patterns of germination performance in the system, the behaviour of model seeds characterized by a definite set of thermal germination parameters were investigated. Referring to the results of the simulations, the actual germination patterns of some wild‐seed populations in the test system were interpreted in terms of thermal‐germination parameters.