Joint selection for both extremes of mean performance and of sensitivity to a macroenvironmental variable

Abstract

A relationship is demonstrated between pattern of growth, as summarised by either the quadratic coefficient of the growth curve or the proportion of the final height achieved by the middle of the growing season, and environmental sensitivity of final height among the 60 D inbred lines derived from a cross between varieties 2 and 12 of Nicotiana rustica.The heritability and repeatability over diverse environments of the quadratic coefficient are both relatively high. Indirect selection for environmental sensitivity by selecting for the quadratic coefficient is, therefore, a practical alternative that overcomes many of the problems of direct selection reported by Brumpton, Boughey and Jinks (1977) and Jinks; Jayasekara and Boughey (1977). © 1978 The Genetical Society of Great Britain.