Phylogenomic Study of Monechma Reveals Two Divergent Plant Lineages of Ecological Importance in the African Savanna and Succulent Biomes.
Resource type
Journal article
Date published
June 11, 2020
Abstract
Monechma Hochst. s.l. (Acanthaceae) is a diverse and ecologically important plant group in sub-Saharan Africa, well represented in the fire-prone savanna biome and with a striking radiation into the non-fire-prone succulent biome in the Namib Desert. We used RADseq to reconstruct evolutionary relationships within Monechma s.l. and found it to be non-monophyletic and composed of two distinct clades: Group I comprises eight species resolved within the Harnieria clade, whilst Group II comprises 35 species related to the Diclipterinae clade. Our analyses suggest the common ancestors of both clades of Monechma occupied savannas, but both of these radiations (~13 mya crown ages) pre-date the currently accepted origin of the savanna biome in Africa, 5-10 mya. Diversification in the succulent biome of the Namib Desert is dated as beginning only ~1.9 mya. Inflorescence and seed morphology are found to distinguish Groups I and II and related taxa in the Justicioid lineage. Monechma Group II is morphologically diverse, with variation in some traits related to ecological diversification including plant habit. The present work enables future research on these important lineages and provides evidence towards understanding the biogeographical history of continental Africa.
Project(s)
“Establish and Improve baseline inventories for spatial data and biodiversity—Flora of Namibia Project”
Funder
| Funder name | Awards |
National Science Foundation, United States | DEB 1754845 - DEB 0919594 - DEB 1354964 |
Rancho Santa Ana Botanic Garden | |
Southern African Science Service Centre for Climate Change and Adaptive Land Management, South Africa | Task 060: “Establish and Improve baseline inventories for spatial data and biodiversity—Flora of Namibia Project” |
Journal title
Diversity
Volume
12
Issue
6
Publisher
MDPI AG
Place of publication
Basel, Switzerland
eISSN
1424-2818
Date accepted
June 5, 2020
Official URL
Related URL
Rights statement
In Copyright