SHIH, BING-LING1,2*, YUEN-PO YANG1, AND SHU-MIAW CHAW2. 1Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 80424;, 2Institute of Botany, Academia Sinica, Taipei 11529, Taiwan. - Origin of a Rhododendron hybrid in alpine Taiwan: evidence from nuclear and chloroplast phylogeny.
In Taiwan the two Taiwan endemic species, Rhododendron
pseudochrysanthum and R. hyperythrum , are sympatric in
the northeastern and central alpine ridges. A natural hybrid
putatively originated from these two species was recognized based on
field observations and morphological studies. In its leaf-shape, the
hybrid resembles the putative parents but with the lower surface being
gray to brownish indumentum, which is intermediate between those of
the former parent (sparse gray) and the latter (dense rust-brown).
Six additional taxa represent other three subgenera of
Rhododendron were also sampled, and nuclear ITS as well as
chloroplast maturase K (cp matK) sequences were employed to examine
relationships between the hybrid and its proposed parents. The
ITS-based analyses strongly supported that the hybrid originates from
interbreed of parental populations in Mt. Nanhu, and the hybrid origin
is likely very recent. Indels found in the ITS provided reliable
information as to the possible parental parent. We are in the process
of assembling the cp matK data. A more thorough assessment as to the
maternal and parental parents will be presented.
Key words: hybrid origin, ITS, matK, Phylogeny, Rhododendron