MORPHOLOGICAL ESTIMATION OF THE ORIGIN OF RHODODENDRON TRANSIENS AND ITS CULTIVARS
Rhododendron transiens Nakai classified as subsection Tsutsusi is one of the native azalea species in Japan, although its taxonomic position is still uncertain. It has been found in suburban forests in Kanto region (surrounded area of Tokyo) and many cultivars were produced since the Edo era (1603-1867). Recently, its wild population is critically endangered. To determine the origin of wild R. transiens and its cultivars, we investigated 14 morphological characters of wild R. transiens and its cultivars together with their close-related species, R. kaempferi Planch in the same subsection, and R. macrosepalum Maxim, R. ripense Makino and their cultivars, which are classified as subsection Macrosepala. Significant correlation was found between number and size of stomata. R. transiens represented intermediate characteristics between R. kaempferi and R. macrosepalum/R. ripense complex in this leaf micromorphology. Principal component analysis by 14 morphological characters showed that R. transiens and its cultivars located between R. kaempferi and R. macrosepalum/R. ripense/their cultivars. These results suggested that R. macrosepalum and/or R. ripense may be related to the origin of R. transiens. Molecular marker analysis is under investigation.
Miyano, M., Nakayama , A., Handa, T. and Kurashige, Y. (2014). MORPHOLOGICAL ESTIMATION OF THE ORIGIN OF RHODODENDRON TRANSIENS AND ITS CULTIVARS. Acta Hortic. 1025, 123-126
principal component analysis, endangered species, conservation, genetic resources