Interspecific Hybridization with Paspalum spp.1

The morphology and cytology of 11 interspecific Paspalum F1 hybrids are described. Species used were: dilatatum (common, sexual, and Var. pauciciliatum), pubiflorum, platyphyllum, urvillei, virgatum, and malacophyllum. The percent crossability and chromosome pairing relationships indiate that the species are not closely related. Hybrids obtained using P. dilatatum as the female parent appear to be developed from fertilization of an unreduced egg and all are apomictic. When P. dilatatum was used as the male parent, the mode of reproduction of the hybrids varied with the female parent. The prevalence of apomixis in the genus and the occurrence of the stable apomict, P. dilatatum, suggest that apomixis might have been an important factor in Paspalum speciation. The economic importance of the hybrids reported has not yet been shown, but the fact that apomixis was broken through interspecific hybridization is significant. Interspecific hybridization and the possible manipulation of apomixis offers a valuable approach to the improvement of plants in the Paspalum genus.