Molecular phylogeny and taxonomy of Hosta (Asparagaceae) on Shikoku Island, Japan, including five new species, one new subspecies, and two new status assignments

By

Yahara, Tetsukazu 1954-
Hirota, Shun
Fujii, Seiko
Kokami, Yasushi
Fuse, Kengo
Sato, Hiroyuki
Tagane, Shuichiro
Suyama, Yoshihisa

Type

Article

Date of Publication

2023

Original Publication

PhytoKeys

Volume

235

Pages

137--187

Subjects

anacladogenetic speciation , Flowering season , MIG-seq , next generation sequencing , reproductive isolation , threatened species

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers [2010]-

Identifiers

DOI: https://doi.org/10.3897/phytokeys.235.99140

 

Abstract

Japan has 16 native species of the genus Hosta Tratt. (Asparagaceae). A recent study on Hosta based on field surveys and molecular phylogenetic analyses resulted in the discovery of six unknown taxa in Kochi Prefecture, Shikoku Island, southwestern Japan. We aimed to identify these unknown taxa. Therefore, we constructed a finely resolved phylogeny for 320 Hosta samples collected from the Honshu, Shikoku, and Kyushu Islands using multiplex inter-simple sequence repeat genotyping by sequencing (MIG-seq). Based on this phylogenetic analysis and related morphological observations, we describe five new species, H. longipedicellatasp. nov., H. minazukiflorasp. nov., H. polyneuronoidessp. nov., H. samukazemontanasp. nov., and H. takiminazukiflorasp. nov. and one new subspecies, H. takiminazukiflora subsp. grandissubsp. nov. In addition, we propose two new status assignments, H. tardiva subsp. densinerviacomb. and stat. nov. and H. scabrinerviastat. nov. We also propose classifying H. kikutii var. tosana as a species, H. tosana. Further studies that combine MIG-seq with careful morphological observations are needed for Hosta plants on all Japanese islands, which may result in the discovery of even more undescribed species.