title: Extreme multiple reticulate origins of the Pteris cadieri complex (Pteridaceae).
abstract: The Pteris cadieri complex displays extensive morphological variation and seems to have originated through hybridization. However, the members of this complex reproduce by apogamy, which usually limits genetic variation. To evaluate the hypotheses of hybrid origins, the pattern of evolution in this species complex is reconstructed. Multiple methodologies were used. Diploids, triploids, and tetraploids were identified by chromosome counts and flow cytometry. Nuclear DNA markers (cytosolic phosphoglucose isomerase gene, PgiC) were used, together with chloroplast DNA markers (atpB-rbcL spacer and rbcL gene) to infer the biparental and maternal lineages of the Pteris cadieri complex. The three cpDNA haplotype groups and five PgiC alleles found in this study indicate that the evolution of the Pteris cadieri complex has been extremely reticulate. Up to 11 taxa belonging to eight morphs were identified. By comparing genetic variation in the Pteris cadieri in two independent areas, Hainan and Taiwan, we inferred that hybridization has occurred independently in different areas. Furthermore, we found evidence for phenological divergence (evergreen and deciduous) within Taiwan. We propose that the Pteris cadieri complex originated from different genetic lineages through multiple hybridizations in different geographical areas, leading to its present morphological diversity.
authors.affiliation: Division of Botanical Garden, Taiwan Forestry Research Institute, Taipei 10006, Taiwan.
authors.forename: Yi-Shan
authors.initials: YS
authors.lastname: Chao
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Shi-Yong
authors.initials: SY
authors.lastname: Dong
authors.affiliation: Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
authors.forename: Yu-Chung
authors.initials: YC
authors.lastname: Chiang
authors.affiliation: Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
authors.forename: Ho-Yih
authors.initials: HY
authors.lastname: Liu
authors.affiliation: Division of Botanical Garden, Taiwan Forestry Research Institute, Taipei 10006, Taiwan.
authors.forename: Wen-Liang
authors.initials: WL
authors.lastname: Chiou
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D002678:Chimera / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics*; D019143:Evolution, Molecular; D005819:Genetic Markers / Q000235:genetics; D014644:Genetic Variation; D005843:Geography; D006824:Hybridization, Genetic; D010802:Phylogeny; D018515:Plant Leaves / Q000033:anatomy & histology / Q000145:classification; D006180:Proton-Translocating ATPases / Q000235:genetics*; D032495:Pteris / Q000145:classification* / Q000235:genetics*; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013624:Taiwan
chemical_list: D018742:DNA, Chloroplast; D005819:Genetic Markers; D006180:Proton-Translocating ATPases; C101625:RbcL protein, plastid; D012273:Ribulose-Bisphosphate Carboxylase