The taxonomic status of the wild rice species Oryza ridleyi Hook. f. and O. longiglumis Jansen (Ser. Ridleyanae Sharma et Shastry) from

Abstract The taxonomic status of the two species O . ridleyi and O . longiglumis in Oryza series Ridleyanae was resolvedusing morphological and molecular markers. Cluster analysis using a similarity matrix based on 12 qualitativecharacters separated the O . ridleyi from the O . longiglumis samples and the O . ridleyi samples from Papua NewGuinea (PNG). O . ridleyi and O . longiglumis formed distinct groups upon cluster analysis based on 16quantitative characters. Canonical discriminant analysis showed significant differences between the two specieswith anther and ligule length and spikelet and leaf dimensions as the most discriminating characters. Clusteranalysis based on RAPD markers showed distinct clusters for O . longiglumis and O . ridleyi samples from differentgeographic origins. Hybridization studies revealed an F sterility barrier in interspecific hybrids and those obtained 1 from intraspecific crosses between O . ridleyi from Southeast Asia and PNG. Introduction (as noted by Vaughan 1990) indicated the possiblepresence of intermediates for this character uponIn a proposed taxonomic treatment of the genus examining a herbarium sample that did not complete-