PENG, CHING-I1* AND TZEN-YUH CHIANG2. 1Herbarium, Institute of Botany, Academia Sinica, Nankang, Taipei, Taiwan 115; 2Department of Biology, National Cheng-Kung University, Tainan, Taiwan 700. - Hybridity and parentage of Begonia taipeiensis Peng (Begoniaceae) from Taiwan.
An unusual Begonia that sheds staminate flowers prematurely at
bud stage was collected from several localities in northern Taiwan.
Observations of morphology, pollen stainability, and seed set of this
species initially suggest a hybrid origin. Morphological comparisons,
distribution patterns, chromosome cytology, and experimental
hybridization show that such plants (2 n = 41) consist of
F1 hybrids between Begonia formosana (Hayata)
Masamune (n = 30) and B. aptera Blume ( n = 11),
both of which are widespread in Taiwan and sympatric in most of their
ranges. Such hybrids were named Begonia taipeiensis Peng.
Experimental hybridization between putative parental species
consistently resulted in germinable seeds and healthy F1
plants only when B. aptera was used as the pollen donor.
Molecular data obtained from sequences of rbcL-atpB spacer of
chloroplast DNA confirmed that recurrent unidirectional hybridization
between putative parents in the wild resulted in the formation of
B. taipeiensis.
Key words: Begonia aptera, Begonia formosana, Begonia taipeiensis, natural hybridization, Taiwan