Homoploid hybrid origin of Yucca gloriosa: intersectional hybrid speciation in Yucca (Agavoideae, Asparagaceae)

Ecology and Evolution

Jeremy D. Rentsch¹ 

[1] Department of Plant Biology, University of Georgia, Athens, Georgia

关键词: Hybrid index;    hybrid speciation;    microsatellite analysis;    Yucca;   

DOI  :  10.1002/ece3.328

来源: Wiley

【 摘 要 】

Abstract

There is a growing appreciation for the importance of hybrid speciation in angiosperm evolution. Here, we show that Yucca gloriosa (Asparagaceae: Agavoideae) is the product of intersectional hybridization between Y. aloifolia and Y. filamentosa. These species, all named by Carl Linnaeus, exist in sympatry along the southeastern Atlantic coast of the United States. Yucca gloriosa was found to share a chloroplast haplotype with Y. aloifolia in all populations sampled. In contrast, nuclear gene-based microsatellite markers in Y. gloriosa are shared with both parents. The hybrid origin of Y. gloriosa is supported by multilocus analyses of the nuclear microsatellite markers including principal coordinates analysis (PCO), maximum-likelihood hybrid index scoring (HINDEX), and Bayesian cluster analysis (STRUCTURE). The putative parental species share only one allele at a single locus, suggesting there is little to no introgressive gene flow occurring between these species and Y. gloriosa. At the same time, diagnostic markers are segregating in Y. gloriosa populations. Lack of variation in the chloroplast of Y. aloifolia, the putative maternal parent, makes it difficult to rule out multiple hybrid origins of Y. gloriosa, but allelic variation at nuclear loci can be explained by a single hybrid origin of Y. gloriosa. Overall, these data provide strong support for the homoploid hybrid origin of Y. gloriosa.

【 授权许可】

Unknown   
© 2012 The Authors. Published by Blackwell Publishing Ltd. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.