Early Identification of Intra- and Intergeneric Hybrids among Colchicaceous Ornamentals, Gloriosa spp., Littonia modesta Hook. and Sandersonia aurantiaca Hook., by Flow Cytometry and Random Amplified Polymorphic DNA Analyses

Plantlets derived from ovule culture following intra- or intergeneric crosses among Colchicaceous ornamentals, Gloriosa spp., Littonia modesta Hook, and Sandersonia aurantiaca Hook., were subjected to flow cytometry (FCM) and random amplified polymorphic DNA (RAPD) analyses in order to verify their hybridity. For crosses between plants with apparently distinct relative fluorescence intensity (RFI) of nuclei, i.e., intrageneric crosses between Gloriosa genotypes with different ploidy levels, and most intergeneric crosses, detection of hybrid plantlets could be readily accomplished by FCM analysis. The results of hybrid identification by RAPD analysis supported those of FCM analysis. In addition, RAPD analysis allowed the verification of the hybridity of intra- or intergeneric cross-derived plantlets, which could not be identified as hybrids by FCM analysis due to the similarity of RFI of the parents or appearance of the RFI peak in an unexpected position. Totally, 110 independent hybrid plantlets (60 intrageneric and 50 intergeneric hybrids) have so far been identified by FCM and/or RAPD analyses. Thus, FCM in combination with RAPD analyses offer simple and rapid means for the early detection of intrageneric and intergeneric hybrids in Colchicaceous ornamentals.