Shiga T., and Y. Kadono, 2007. Nuphar xfluminalis, a new hybrid from central Japan. Acta Phytotaxonomica et Geobotanica 58(1): 43-50.
Abstract
We investigated morphology, allozyme variation and pollen viability in 9 populations of Nuphar japonica, N. submersa, and unidentified intermediate plants. A phenogram based on cluster analysis using 10 morphological characters revealed three cluster groups. Groups 1 and 3 had distinctive morphological characteristics and corresponded to the published descriptions of N. japonica and N. submersa, respectively, whereas Group 2 showed intermediate values in most characteristics between the two species. In allozyme study, many morphologically intermediate plants showed additive combinations of species-specific alleles in two loci (lap1 and mdh3) from the two species. Pollen viability was significantly lower in intermediate plants than in the two species. Based on these evidences, we concluded that the intermediate plant was of hybrid origin between the two species and is described as N. xfluminalis.
Key words:
allozymes, hybridization, Nuphar japonica, Nuphar submersa, Nuphar xfluminalis, pollen fertility