Variability of outcrossing frequency in senecio vulgaris L.

Abstract

Using a marker gene controlling capitulum type, 30 lines derived from each, of a dune and a garden population of Senecio vulgaris L. were tested for their tendency to outcross. Compared with previous estimates of outbreeding in the species a relatively high degree of outcrossing was found in both experimental populations (an overall average of 22.4 per cent). It was shown that the dune population had a slightly greater mean outcrossing frequency than the garden population but, more importantly, had significantly more heritable variation (between lines) for this trait. In discussion, some reasons are advanced to account for the unexpectedly high level of outcrossing in both populations. It is suggested that the presence of significant genetic variation for outcrossing within the dune population may provide for adaptive flexibility in the native dune habitat where there is much spatial and temporal variation of the environment. © 1976 The Genetical Society of Great Britain.