Quantitative genetic analysis of dispersal in epiphyas postvittana. I. genetic variation in flight capacity

Abstract

The genetic basis for determination of flight capacity in the light brown apple month, Epiphyas postvittana (Walker) (Tortricidae), was investigated by means of heritability estimation, artificial selection and crossbreeding, using samples from two natural populations. The mean heritabilities estimated by offspring-parent regression were 0.559 for offspring on female parents and 0.427 for offspring on male parents. These results were largely consistent with those estimated from paternal half-sibs and with realized heritabilities calculated from selected generations, although the heritability of flight capacity varied, to some extent, with the populations and temperatures to which the individuals were subjected. These estimates indicate the existence of additive genetic variance for flight capacity in the natural populations. The response pattern in the selection experiment indicates that the genetic effect on flight capacity in this species is mainly additive, though the phenotype performance of flights in F, progeny from crossbreeding ‘long-fliers’ with ‘short-fliers’ suggests a weak dominance of short-flying genes and a slight maternal effect. © 1992 The Genetical Society of Great Britain.