Interspecific hybridization between Scirpus mariqueter Ts. Tang & F.T. Wang and S. planiculmis F. Schmidt and their selfing

Abstract

Self-pollination and bidirectional interspecific crosses were carried out in Scirpus mariqueter Ts. Tang & F.T. Wang and S. planiculmis F. Schmidt. Self-pollination experiments suggest that S. mariqueter is a completely self-compatible species despite that its flowers are protogynous, whereas S. planiculmis is a predominantly outcrossing species, possessing a low level of self-compatibility. For the interspecific crossing experiments, hybrid seeds were obtained from bidirectional pollination. However, only 4% of the hybrid seeds from the cross of S. mariqueter ♀×S. planiculmis ♂ germinated successfully, with hybrid offsprings exhibiting similar morphological characters to the maternal parent S. mariqueter, while hybrid seeds from the cross of S. planiculmis ♀×S. mariqueter ♂ were unviable. These results suggest asymmetrical gene flow from S. planiculmis to S. mariqueter and the existence of some post-pollination reproductive barriers between these two Scirpus species.