A relationship between seedling growth rates and latitude of origin of cocksfoot populations

Abstract

Growth rates of vegetative seedling plants of 15 cocksfoot (Dactylis glomerata L.) populations were measured in long days at near optimum temperature. Relative growth rate of the plant tops was greater in populations from high than in those from low latitudes of origin (r = 0.85; P < 0.001).

In a second experiment, the populations from low latitudes were found to initiate inflorescences earlier than those from high latitudes. It is suggested that environmental conditions which maximize population differences in time of floral initiation also maximize differences in growth rates during the vegetative phase of growth.