Exploring the utility of three nuclear regions to reconstruct reticulate evolution in the fern genus Asplenium  

作　　者：Harald SCHNEIDER Adriana NAVARRO-GOMEZ Stephen J. RUSSELL Stephen ANSELL Michal GRUNDMANN Johannes VOGEL 

机构地区：[1]State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China [2]Department of Life Sciences, Natural History Museum, London SW7 5BD, UK

出　　处：《Journal of Systematics and Evolution》2013年第2期142-153,共12页植物分类学报（英文版）

摘　　要：Three nuclear regions nuclear ribosomal internal transcribed spacer （nrlTS） and intron regions of two nuclear low-copy genes--gapCp, and pgiC, in combination with one chloroplast genome region were employed to explore patterns of reticulate evolution in the fern genus Asplenium. This is the one of the first studies using DNA sequences of multiple nuclear markers in ferns. All three nuclear markers amplified well with PCR and several copies were recovered by cloning PCR products. All three nuclear regions showed congruent results by recovering the neo-allotetraploid Asplenium adulterinum as the hybrid of diploid A. trichomanes and diploid A. viride. Conflicting results were obtained for several nodes. First, gapCp did not discriminate between A. aethiopicum andA. praegracile whereas the other markers recovered these two taxa as distinct. Conflicts among gene-trees were found in respect to A. monanthes, chloroplast and pgiC suggested a sister relationship ofA. monanthes and A. trichomanes but gapCp and nrITS nested A. monanthes within A. normale. Our resuks confirm： （i） the usefulness of several nuclear regions, in particular gapCp andpgiC, to unravel reticulate evolution in ferns and species differentiation and （ii） highlights the need to employ more than one nuclear region to obtain reliable hypotheses on reticulate events versus incomplete lineage sorting. Especially, if one assumes that the reticulation event might have occurred in the more distant past. Considering the expected high frequency of reticulate evolution in ferns, the establishment of robust and informative nuclear genomic markers is critical to achieve further progress in our efforts to elucidate fern evolution.Three nuclear regions nuclear ribosomal internal transcribed spacer （nrlTS） and intron regions of two nuclear low-copy genes--gapCp, and pgiC, in combination with one chloroplast genome region were employed to explore patterns of reticulate evolution in the fern genus Asplenium. This is the one of the first studies using DNA sequences of multiple nuclear markers in ferns. All three nuclear markers amplified well with PCR and several copies were recovered by cloning PCR products. All three nuclear regions showed congruent results by recovering the neo-allotetraploid Asplenium adulterinum as the hybrid of diploid A. trichomanes and diploid A. viride. Conflicting results were obtained for several nodes. First, gapCp did not discriminate between A. aethiopicum andA. praegracile whereas the other markers recovered these two taxa as distinct. Conflicts among gene-trees were found in respect to A. monanthes, chloroplast and pgiC suggested a sister relationship ofA. monanthes and A. trichomanes but gapCp and nrITS nested A. monanthes within A. normale. Our resuks confirm： （i） the usefulness of several nuclear regions, in particular gapCp andpgiC, to unravel reticulate evolution in ferns and species differentiation and （ii） highlights the need to employ more than one nuclear region to obtain reliable hypotheses on reticulate events versus incomplete lineage sorting. Especially, if one assumes that the reticulation event might have occurred in the more distant past. Considering the expected high frequency of reticulate evolution in ferns, the establishment of robust and informative nuclear genomic markers is critical to achieve further progress in our efforts to elucidate fern evolution.

关 键 词：fems gapCp GAPDH HYBRIDIZATION INTROGRESSION NRITS nuclear genes pgiC reticulate evolution. 

分 类 号：Q949.36[生物学—植物学] S682.11[农业科学—观赏园艺]