Adaptive divergence with gene flow in incipient speciation of Miscanthus floridulus / sinensis complex (Poaceae)
Type
ArticleAuthors
Huang, Chao-LiHo, Chuan-Wen
Chiang, Yu-Chung
Shigemoto, Yasumasa
Hsu, Tsai-Wen
Hwang, Chi-Chuan
Ge, Xue-Jun
Chen, Charles
Wu, Tai-Han
Chou, Chang-Hung
Huang, Hao-Jen
Gojobori, Takashi

Osada, Naoki
Chiang, Tzen-Yuh
KAUST Department
Biological and Environmental Sciences and Engineering (BESE) DivisionBioscience Program
Computational Bioscience Research Center (CBRC)
Bioscience Program
Date
2014-11-11Online Publication Date
2014-11-11Print Publication Date
2014-12Permanent link to this record
http://hdl.handle.net/10754/575622
Metadata
Show full item recordAbstract
Young incipient species provide ideal materials for untangling the process of ecological speciation in the presence of gene flow. The Miscanthus floridulus/sinensis complex exhibits diverse phenotypic and ecological differences despite recent divergence (approximately 1.59million years ago). To elucidate the process of genetic differentiation during early stages of ecological speciation, we analyzed genomic divergence in the Miscanthus complex using 72 randomly selected genes from a newly assembled transcriptome. In this study, rampant gene flow was detected between species, estimated as M=3.36x10(-9) to 1.20x10(-6), resulting in contradicting phylogenies across loci. Nevertheless, beast analyses revealed the species identity and the effects of extrinsic cohesive forces that counteracted the non-stop introgression. As expected, early in speciation with gene flow, only 3-13 loci were highly diverged; two to five outliers (approximately 2.78-6.94% of the genome) were characterized by strong linkage disequilibrium, and asymmetrically distributed among ecotypes, indicating footprints of diversifying selection. In conclusion, ecological speciation of incipient species of Miscanthus probably followed the parapatric model, whereas allopatric speciation cannot be completely ruled out, especially between the geographically isolated northern and southern M.sinensis, for which no significant gene flow across oceanic barriers was detected. Divergence between local ecotypes in early-stage speciation began at a few genomic regions under the influence of natural selection and divergence hitchhiking that overcame gene flow.Citation
Huang, C.-L., Ho, C.-W., Chiang, Y.-C., Shigemoto, Y., Hsu, T.-W., Hwang, C.-C., … Chiang, T.-Y. (2014). Adaptive divergence with gene flow in incipient speciation ofMiscanthus floridulus/sinensiscomplex (Poaceae). The Plant Journal, 80(5), 834–847. doi:10.1111/tpj.12676Sponsors
The work is supported by the International Research Intensive Centers of Excellence of Taiwan, the Supercomputing Research Center of National Cheng Kung University, and the Aim for the Top University Project of National Cheng Kung University. We thank Peter Raven (President Emeritus of Missouri Botanical Garden) for his valuable comments.Publisher
WileyJournal
The Plant Journalae974a485f413a2113503eed53cd6c53
10.1111/tpj.12676