Ceratopteris chunii and Ceratopteris chingii (Pteridaceae), two new diploid species from China, based on morphological, cytological, and molecular data

Jun-Hao Yu; Rui Zhang; Qiao-Ling Liu; Fa-Guo Wang; Xun-Lin Yu; Xi-Ling Dai; Yong-Bo Liu; Yue-Hong Yan

doi:10.1016/j.pld.2021.10.002

Ceratopteris chunii and Ceratopteris chingii (Pteridaceae), two new diploid species from China, based on morphological, cytological, and molecular data

Plant Divers. 2021 Nov 6;44(3):300-307. doi: 10.1016/j.pld.2021.10.002. eCollection 2022 May.

Authors

Jun-Hao Yu^{1

2}, Rui Zhang¹, Qiao-Ling Liu², Fa-Guo Wang³, Xun-Lin Yu⁴, Xi-Ling Dai², Yong-Bo Liu⁵, Yue-Hong Yan^{1

6}

Affiliations

¹ Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Shanghai 201602, China.
² College of Life Science, Shanghai Normal University, Shanghai, 200234, China.
³ Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
⁴ College of Forestry, Central South University of Forestry ＆ Technology, Changsha, Hunan, 410004, China.
⁵ State Environmental Protection Key Laboratory of Regional Eco-process and Function Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
⁶ Shenzhen Key Laboratory for Orchid Conservation and Utilization, National Orchid Conservation Center of China and the Orchid Conservation & Research Center of Shenzhen, Shenzhen, 518114, China.

Abstract

Understanding how natural hybridization and polyploidizations originate in plants requires identifying potential diploid ancestors. However, cryptic plant species are widespread, particularly in Ceratopteris (Pteridaceae). Identifying Ceratopteris cryptic species with different polyploidy levels is a challenge because Ceratopteris spp. exhibit high degrees of phenotypic plasticity. Here, two new cryptic species of Ceratopteris, Ceratopteris chunii and Ceratopteris chingii, are described and illustrated. Phylogenetic analyses reveal that each of the new species form a well-supported clade. C. chunii and C. chingii are similar to Ceratopteris gaudichaudii var. vulgaris and C. pteridoides, respectively, but distinct from their relatives in the stipe, basal pinna of the sterile leaf or subelliptic shape of the fertile leaf, as well as the spore surface. In addition, chromosome studies indicate that C. chunii and C. chingii are both diploid. These findings will help us further understand the origin of Ceratopteris polyploids in Asia.

Keywords: Ceratopteris; Chromosome; Cryptic species; Phylogeny; Taxonomy.