Determination of the environmental sensitivity of selection lines by the selection environment

Abstract

SUMMARYThe parents chosen to continue 10 independent selection lines of Sc/zizophyllurn commune over eight successive generations of selection, along with unselected controls, have been retrospectively examined for their response to growth at 15°, 20°, 25°, 30° and 35°C. The regression of rate of growth on temperature was essentially linear over the range 15° to 30°C for all lines irs all generations as was also the regression of rate of growth on various biological assessments of the environments over the whole temperature range. Either regression, therefore, provided linear regression coefficients which adequately accounted for the relative sensitivities of the lines to temperature in each generation of selection. These measures of environmental sensitivity confirmed our earlier report that selection for high mean performance in a good environment or for low mean performance in a poor environment leads to selections that are more sensitive to environmental variation than selections for high mean performance in a poor environment or for low mean performance in a good environment. These differences in sensitivity emerge as correlated responses during selection and the magnitude of these correlated responses is higher in the good environment than in the poor environment irrespective of the direction of selection.The environmental sensitivity of selection lines can be modified in either direction as required by either selecting for sensitivity simultaneously with the selection for mean performance or by selecting for mean performance in an above or below average environment. The quality of environments in which artificial selection is usually carried out is likely to have led to high selections with maximum environmental sensitivity and low selections with minimum sensitivity.

Selection environment and environmental sensitivity in barley

“…The data presented are in good agreement with the model proposed by Jinks & Connolly (1975) and validated by Jinks & Pooni (1982) in Nicotiana rustica. Our study is only a partial test of the model as genotypes selected for low grain yield in both low or high yielding conditions were not available.…”

“…Jinks & Pooni (1982) reported that the relationship between selection environment and environmental sensitivity for final plant height in Nicotiana rustica is in agreement with the model. Crossa et al (1989) found that maize varieties selected for average performance across sites were not necessarily more stable than varieties selected for performance at specific sites.…”

“…They concluded that environmental sensitivity was reduced if selection and environment effects were in opposite directions; sensitivity was increased if selection and environment effects were in the same direction. The effect of the selection environment on environmental sensitivity was generalized by Jinks & Pooni (1982) on the basis that the genetic control of environmental sensitivity of a selected character and its mean performance were at least partly independent.…”

Selection for yield in Lolium perenne. II. performance of spaced plant selections under competitive conditions

“…Thus in Nicotiana rustica, JINKS and his co-workers (JINKS et al ., 1977 ;JINKS & POONI, 1982) have been able to establish lines with all combinations of high and low mean performance for flowering time and plant height with high and low sensitivity to environmental change, namely season or sowing date . Similarly, in Schizophyllum JINKS & CONNOLLY (1975) were able to select for differing growth rates in response to differing temperature regimes . From their studies they identified a number of situations under which selection should take place in order to achieve any desired combination of mean performance and sensitivity .…”

The measurement and interpretation of genotype by environment interaction in spring barley (Hordeum vulgare)

“…Examples are yield in maize (Eberhart and Russell, 1966) and final height in Nicotiana rustica (Jinks and Connolly, 1975). The present study was conducted on spring barley to assess the linear regression approach as a means of measuring a genotype's environmental sensitivity.…”