Investigation into the relationships and ancestry of Vulpia and Festuca.

The relationships between the European species of Vulpia were investigated by interspecific hybridisation and consequent meiotic analysis, hybrid fertility and morphological survey of the F1 hybrids. The relationship between the genus Vulpia and the Festuca rubra aggregate was investigated by the examination of both naturally occurring and artificially produced intergeneric hybrids. Embryo culture was used for both interspecific and intergeneric crosses and the germination of the hybrid embryos by this method proved successful. Of 47 cross combinations (including reciprocals) attempted hybrid plants were obtained for 20 different crosses. Crossability and hybrid fertility were not found to be obvious indicators of taxonomic distance and unilateral incompatibility was found both in crosses with a self-incompatible species as the female parent and a self-compatible species as the male parent and in crosses where both parental species were self-compatible. Analysis of bivalent pairing at meiosis revealed genome relationships in hybrids between diploid species. However no conclusions could be made as to the possible ancestors of tetraploid V. fasciculata. Artificial hybrids were made between V. sicula, the presumed link species between the annual species of Vulpia and the perennial fescues, and F. rubra and the meiotic analysis of the F1 hybrid revealed similarities between at least part of the V. sicula genome and a genome of F. rubra. Conclusions as to genome homology could not be made from the cytological analysis of the other intergeneric hybrids.