Evolution of sexual systems and growth habit in Mussaenda (Rubiaceae): Insights into the evolutionary pathways of dioecy.

Autor: Duan T; Herbarium, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Guangdong Ocean University, Zhanjiang 524088, China., Deng X; Herbarium, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; State Academy of Forestry Administration, Beijing 102600, China., Chen S; Herbarium, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Beneficial Insects Institute, Fujian Agriculture and Forestry University, Fuzhou 350002, China., Luo Z; Herbarium, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China., Zhao Z; Herbarium, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China., Tu T; Herbarium, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China., Khang NS; Herbarium, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China., Razafimandimbison SG; Swedish Museum of Natural History, Department of Botany, Box 50007, SE-10405 Stockholm, Sweden., Zhang D; Herbarium, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China. Electronic address: dx-zhang@scbg.ac.cn.
Jazyk: angličtina
Zdroj: Molecular phylogenetics and evolution [Mol Phylogenet Evol] 2018 Jun; Vol. 123, pp. 113-122. Date of Electronic Publication: 2018 Feb 15.
DOI: 10.1016/j.ympev.2018.02.015
Abstrakt: Dioecy is a rare sexual system that is thought to represent an "evolutionary dead end". While many studies have addressed the evolution of dioecy and/or its relationship with the evolution of the woody habit, few have explored the relationship between dioecy and climbing habit, and their effects on diversification rates. Here, we study the evolution of sexual systems and growth habit in Mussaenda (Rubiaceae) using a robust phylogeny of the genus based on eight plastid regions and a broad sampling of taxa (92 of the 132 species were sampled). A time-calibrated tree was constructed to estimate diversification rates in different clades and its correlates with focal characters. More specifically, we assess evolutionary correlations between dioecy and climbing habit and their respective influences on diversification rates. Ancestral character state reconstructions revealed that distyly is the most likely ancestral state in Mussaenda. Distyly has subsequently given rise to dioecy, short-styled floral monomorphism, and long-styled floral monomorphism. Dioecy has evolved independently at least four times from distyly, and has reversed to homostylous hermaphroditism at least twice, which does not support the "evolutionary dead end" hypothesis. A significant correlation between the evolution of dioecy and climbing growth form was found in Mussaenda. It is possible that a strong association between high net diversification rates and dioecy may exist in Mussaenda, but no association was found with climbing habit.
(Copyright © 2018 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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