Eutrema giganteum (Brassicaceae), a new species from Sichuan, southwest China

By

Hao, Guoqian
Zhang, Changbing
Al-Shehbaz, Ihsan A., (Ihsan Ali) 1939-
Guo, Xinyi
Bi, Hao
Wang, Junyin
Liu, Jianquan

Type

Article

Date of Publication

2017

Original Publication

PhytoKeys

Volume

82

Pages

15-26

Subjects

Brassicaceae , Cruciferae , Eutrema yunnanense , molecular phylogeny

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers [2010]-

Identifiers

DOI: https://doi.org/10.3897/phytokeys.82.12329

 

Abstract

Eutrema giganteum (Brassicaceae), a new species from Hengduan Mountains in Sichuan Province, southwest China, is described, and its relationships to the closely related E. yunnanense is discussed based on morphological, cytological, and molecular data. It is similar morphologically to E. yunnanense but is readily distinguished by having robust (vs. slender), erect (vs. decumbent), and branched (vs. mostly simple), and rather tall stems (60–110 cm vs. 20–60 cm); curved (vs. straight), smooth (vs. torulose), and shorter fruit (5–8 mm vs. 8–15 mm); and fewer ovules per ovary (1–4 vs. 6–10). All examined individuals from different populations of E. giganteum clustered into a single clade sister to E. yunnanense in phylogenetic analyses using the combined nuclear ITS and plastid DNA datasets. Our cytological studies revealed that the chromosome number of E. giganteum is 2n = 44, with a genome size of 1160 (±8) Mb, while that of E. yunnanense is 2n = 28, with a genome size of 718 (±15) Mb. Multiple lines of evidence support the recognition of E. giganteum as a distinct species well differentiated from E. yunnanense.