Indexed on: 01 Jan '89Published on: 01 Jan '89Published in: Euphytica
Twenty seven clones of chrysanthemum, 19 of which were selected at low temperature, were flowered at 10, 14, 18 and 22°C. The number of days to flower in response to temperature could, for each genotype, be described by a parabola with the parameters: optimum temperature, days to flower at the optimum temperature and curvature which represents the sensitivity to temperature.The low-temperature selections did not have a reduced optimum temperature but reduced sensitivity to temperature accounted for most of the ability to flower at low temperature. The parameters may vary independently. Examples are given to show how these parameters can be combined to construct genotypes with a required temperature response.