著者

Yukihiro H. Kobayashi Shizuka Fuse Minoru N. Tamura

出版者

The Japanese Society for Plant Systematics

雑誌

Acta Phytotaxonomica et Geobotanica (ISSN:13467565)

巻号頁・発行日

vol.70, no.1, pp.1-17, 2019-02-28 (Released:2019-03-09)

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To evaluate the evolutionary relationships among species of Peperomia subg. Micropiper, a phylogenetic analysis based on the DNA sequences of plastid regions atpB-rbcL, psbK-I, rpL16, rpS16, trnG, trnK (including matK), trnL-L-F, and trnS-G was conducted using 20 species, in addition to four outgroup species. The trnK sequences of 46 species and trnL-L-F sequence of one species were quoted from GenBank and also included in the analysis. The results showed that P. subg. Micropiper includes seven major clades, which are also supported by morphological characteristics. They are recognized as sectionequivalent plant groups, namely Alatoid, Blandoid, Glabelloid, Glaucoid, Japonicoid, Lanceolatoid, and Rotundifolioid. A chromosome analysis of the subgenus yielded nine new counts: 2n = 22 (diploid) for P. alata, P. bicolor, P. diaphanoides, P. flexicaulis, P. hylophila, P. polystachya and P. prosterata, 2n = 44(tetraploid) for P. okinawensis and 2n = 132 (dodecaploid) for P. reticulata. Japonicoid, which occurs outside the Americas, i.e. in Asia, Africa, and the Pacific islands, is tetraploid, decaploid, and dodecaploid (not diploid), while the remaining six plant groups are native to the Americas and diploid (except Glaucoid, which is tetraploid). Further, P. diaphanoides is conspecific with P. glabella. Peperomia boninsimensis from the Ogasawara Islands, Japan, is more closely related to Polynesian species than to other Japanese species. Peperomia okinawensis should be regarded as a variety of P. japonica.