Reconstruction of the evolutionary biogeography reveals the origin and diversification of Arisaema (Araceae)

ABSTRACT

Explaining where plants originated and how plants migrated between eastern Asia and other Northern Hemisphere regions is still challenging. The genus Arisaema is considered a good example to illuminate this process, due to its wide distribution in both the tropical and temperate zones. Based on comprehensive taxon sampling, the historical biogeography of Arisaema was conducted using the molecular data from four chloroplast DNA regions. The phylogeny of Arisaema was studied by using ML and BI methods. Divergence times of Arisaema species were estimated by the uncorrelated lognormal Bayesian method. The ancestral area reconstruction of Arisaema was performed with BioGeoBEARS and Bayes-DIVA. Our results indicated that the crown group of Arisaema originated in Southeast Asia ca. 31.28 Ma. After the initial origin, Arisaema was inferred to have become widespread in Southeast Asia. Members in Himalayas, Africa and North China, Japan, the Korean Peninsula region (NJK region) were derived from migrants originating in Southeast Asia. American members were derived from migrants originating in the NJK region. Arisaema originated in Southeast Asia during the Oligocene with the development of tropical rainforest and a warm, moist climate. During the Oligocene to Miocene, Southeast Asia was the original center for the diversification of Arisaema in the NJK region.

Keywords:
Arisaema; biogeography; origin; Eocene; Southeast Asia