Rapid changes in pollen production in experimental outcrossing populations of wheat


Author for correspondence.


For evolutionary reasons, pollen production is expected to be modified when changes occur in plant mating systems. In this study, outcrossing was enforced through male-sterility in usually autogamous populations of winter wheat. The correlated changes in pollen production were studied after a 6-year period of natural evolution. Both the disappearance of individuals with the lowest pollen production and the increase in the production of fertile pollen per spike were observed in male-fertile plants. The results are interpreted as a selection on male function. Some morphological differences also appeared in evolved populations between male-fertile and male-sterile plants. These differentiations are discussed in light of resource allocation theory.