TY - JOUR
T1 - Phylogeny and biogeography of the genus Stevia (Asteraceae: Eupatorieae)
T2 - an example of diversification in the Asteraceae in the new world
AU - Soejima, Akiko
AU - Tanabe, Akifumi S.
AU - Takayama, Izumi
AU - Kawahara, Takayuki
AU - Watanabe, Kuniaki
AU - Nakazawa, Miyuki
AU - Mishima, Misako
AU - Yahara, Tetsukazu
N1 - Funding Information:
We would like to thank M. Ito, T. Kajita, S. Kobayashi, T. Miyake, and K. Ooi for their help with fieldwork in Mexico; K. Oyama for logistical support in Mexico; Y. Nagatani and the late G. Hashimoto for their assistance with locating Brazilian populations of Stevia; H. Shibuya, M. Miya, and D. Honda for advice regarding statistical analyses; and E. Kamitani for assistance with DNA sequencing. We would also like to thank the following herbaria for access to herbarium materials: the National Herbarium of Mexico at the UNAM (MEXU), the University of Texas Herbarium (TEX), and the Goro Hashimoto Herbarium (São Paulo, Brazil). The present study was supported in part by a Grant in Aid for Scientific Research (No. 14405014), which was provided by the Ministry of Education, Science, and Culture, Japan.
Publisher Copyright:
© 2017, The Botanical Society of Japan and Springer Japan.
PY - 2017/11/1
Y1 - 2017/11/1
N2 - The genus Stevia comprises approximately 200 species, which are distributed in North and South America, and are representative of the species diversity of the Asteraceae in the New World. We reconstructed the phylogenetic relationships using sequences of ITS and cpDNA and estimated the divergence times of the major clade of this genus. Our results suggested that Stevia originated in Mexico 7.0–7.3 million years ago (Mya). Two large clades, one with shrub species and another with herb species, were separated at about 6.6 Mya. The phylogenetic reconstruction suggested that an ancestor of Stevia was a small shrub in temperate pine–oak forests and the evolutionary change from a shrub state to a herb state occurred only once. A Brazilian clade was nested in a Mexican herb clade, and its origin was estimated to be 5.2 Mya, suggesting that the migration from North America to South America occurred after the formation of the Isthmus of Panama. The species diversity in Mexico appears to reflect the habitat diversity within the temperate pine–oak forest zone. The presence of many conspecific diploid–polyploid clades in the phylogenetic tree reflects the high frequency of polyploidization among the perennial Stevia species.
AB - The genus Stevia comprises approximately 200 species, which are distributed in North and South America, and are representative of the species diversity of the Asteraceae in the New World. We reconstructed the phylogenetic relationships using sequences of ITS and cpDNA and estimated the divergence times of the major clade of this genus. Our results suggested that Stevia originated in Mexico 7.0–7.3 million years ago (Mya). Two large clades, one with shrub species and another with herb species, were separated at about 6.6 Mya. The phylogenetic reconstruction suggested that an ancestor of Stevia was a small shrub in temperate pine–oak forests and the evolutionary change from a shrub state to a herb state occurred only once. A Brazilian clade was nested in a Mexican herb clade, and its origin was estimated to be 5.2 Mya, suggesting that the migration from North America to South America occurred after the formation of the Isthmus of Panama. The species diversity in Mexico appears to reflect the habitat diversity within the temperate pine–oak forest zone. The presence of many conspecific diploid–polyploid clades in the phylogenetic tree reflects the high frequency of polyploidization among the perennial Stevia species.
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U2 - 10.1007/s10265-017-0955-z
DO - 10.1007/s10265-017-0955-z
M3 - Article
C2 - 28536984
AN - SCOPUS:85019928072
SN - 0918-9440
VL - 130
SP - 953
EP - 972
JO - Journal of Plant Research
JF - Journal of Plant Research
IS - 6
ER -