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Taxonomic position and phylogeny of the genus Vargasiella (Orchidaceae, Vandoideae) based on molecular and morphological evidence.

Szlachetko DL, Górniak M, Kolanowska M, Mytnik-Ejsmont J, Kowalkowska AK, Rutkowski P, Koliński T - PLoS ONE (2014)

Bottom Line: The outcomes from the morphological studies indicated significant differences between Vargasiella, Warrea and Warreopsis.The molecular analysis and morphological data suggest that Vargasiella and Warrea could have evolved from a common ancestor.Accumulation of morphological differences and acceleration of the evolution of Vargasiella were more intensive than in other Warreinae and this could probably be synchronized with adaptation to different climatic conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Taxonomy and Nature Conservation, The University of Gdańsk, Gdańsk, Poland.

ABSTRACT
Since the description of the Neotropical genus Vargasiella in 1952, its taxonomic position has remained unclear, mainly due to a lack of sufficient data. In this study, the taxonomic position of Vargasiella was revised based on the outcomes of macro- and micromorphological studies, analyses of selected molecular markers and ecological methods of niche distribution modeling. The phylogenetic relationships were inferred using three DNA markers: matK, trnL-F and ITS sequences. The morphological studies included the analysis of macromorphological features of herbarium specimens as well as micromorphological examination of preserved flowers. The ecological niche modeling was applied to identify the distribution of the suitable niches of the studied taxa. The relationships between Vargasiella and most similar taxa remain unresolved based on the molecular analysis. The outcomes from the morphological studies indicated significant differences between Vargasiella, Warrea and Warreopsis. Moreover, a niche shift in response to changing climate after the last glacial maximum is observed in Vargasiella, while no substantial changes in the occupied habitats were identified in the other related taxa. The clocktree of the Zygopetaleae estimated from the matK gene indicated that the most recent common ancestors of Vargasiella, Warrea and Warreopsis originated in the Miocene, while the divergence time for Vargasiella and Warrea was assessed at approximately 5.4 Ma ago. Vargasiella seems to be an outshoot of the main branch of evolution of the Zygopetaleae. It is noteworthy that the Vargasiella-Warrea dichotomy could have taken place later than the divergence of Warreopsis from the mutual lineage. The molecular analysis and morphological data suggest that Vargasiella and Warrea could have evolved from a common ancestor. Accumulation of morphological differences and acceleration of the evolution of Vargasiella were more intensive than in other Warreinae and this could probably be synchronized with adaptation to different climatic conditions.

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Warrea hookeriana (Rchb.f.) Rolfe.(A,B) Rostellum remnant, front view. (C-E) Various views of pollinarium. (F) Viscidium, bottom view. (G) Pollinia, various views (cult. Glasnevin BG, K).
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pone-0098472-g009: Warrea hookeriana (Rchb.f.) Rolfe.(A,B) Rostellum remnant, front view. (C-E) Various views of pollinarium. (F) Viscidium, bottom view. (G) Pollinia, various views (cult. Glasnevin BG, K).

Mentions: Several differences were observed in the morphology of the lip and gynostemium between V. peruviana (Fig. 7A-H), Warrea costaricensis Schltr. (Fig. 8A-D) and W. warreana (Lodd. ex Lindl.) C. Schweinf. (Fig. 8E-F). In both Warrea species the central, single callus starts from the smooth lip base (Fig. 8A, E), but the surface of the lip apex is deeply undulate (Fig. 8A, F). The gynostemium is erect, rather short, clavate (Fig. 8B, G, Fig. 9), with a short column foot. The tegula is thin, narrowing gradually towards the apex (Fig. 8B-C, G-H, Fig. 9C, D, E). The rather large, elliptic and deeply concave stigma is partially hidden by the rostellum (Fig. 8B-C, G-H). The four ellipsoid-ovoid pollinia are arranged in two unequal pairs (Fig. 8D, I, Fig. 9G).


Taxonomic position and phylogeny of the genus Vargasiella (Orchidaceae, Vandoideae) based on molecular and morphological evidence.

Szlachetko DL, Górniak M, Kolanowska M, Mytnik-Ejsmont J, Kowalkowska AK, Rutkowski P, Koliński T - PLoS ONE (2014)

Warrea hookeriana (Rchb.f.) Rolfe.(A,B) Rostellum remnant, front view. (C-E) Various views of pollinarium. (F) Viscidium, bottom view. (G) Pollinia, various views (cult. Glasnevin BG, K).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4043880&req=5

pone-0098472-g009: Warrea hookeriana (Rchb.f.) Rolfe.(A,B) Rostellum remnant, front view. (C-E) Various views of pollinarium. (F) Viscidium, bottom view. (G) Pollinia, various views (cult. Glasnevin BG, K).
Mentions: Several differences were observed in the morphology of the lip and gynostemium between V. peruviana (Fig. 7A-H), Warrea costaricensis Schltr. (Fig. 8A-D) and W. warreana (Lodd. ex Lindl.) C. Schweinf. (Fig. 8E-F). In both Warrea species the central, single callus starts from the smooth lip base (Fig. 8A, E), but the surface of the lip apex is deeply undulate (Fig. 8A, F). The gynostemium is erect, rather short, clavate (Fig. 8B, G, Fig. 9), with a short column foot. The tegula is thin, narrowing gradually towards the apex (Fig. 8B-C, G-H, Fig. 9C, D, E). The rather large, elliptic and deeply concave stigma is partially hidden by the rostellum (Fig. 8B-C, G-H). The four ellipsoid-ovoid pollinia are arranged in two unequal pairs (Fig. 8D, I, Fig. 9G).

Bottom Line: The outcomes from the morphological studies indicated significant differences between Vargasiella, Warrea and Warreopsis.The molecular analysis and morphological data suggest that Vargasiella and Warrea could have evolved from a common ancestor.Accumulation of morphological differences and acceleration of the evolution of Vargasiella were more intensive than in other Warreinae and this could probably be synchronized with adaptation to different climatic conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Taxonomy and Nature Conservation, The University of Gdańsk, Gdańsk, Poland.

ABSTRACT
Since the description of the Neotropical genus Vargasiella in 1952, its taxonomic position has remained unclear, mainly due to a lack of sufficient data. In this study, the taxonomic position of Vargasiella was revised based on the outcomes of macro- and micromorphological studies, analyses of selected molecular markers and ecological methods of niche distribution modeling. The phylogenetic relationships were inferred using three DNA markers: matK, trnL-F and ITS sequences. The morphological studies included the analysis of macromorphological features of herbarium specimens as well as micromorphological examination of preserved flowers. The ecological niche modeling was applied to identify the distribution of the suitable niches of the studied taxa. The relationships between Vargasiella and most similar taxa remain unresolved based on the molecular analysis. The outcomes from the morphological studies indicated significant differences between Vargasiella, Warrea and Warreopsis. Moreover, a niche shift in response to changing climate after the last glacial maximum is observed in Vargasiella, while no substantial changes in the occupied habitats were identified in the other related taxa. The clocktree of the Zygopetaleae estimated from the matK gene indicated that the most recent common ancestors of Vargasiella, Warrea and Warreopsis originated in the Miocene, while the divergence time for Vargasiella and Warrea was assessed at approximately 5.4 Ma ago. Vargasiella seems to be an outshoot of the main branch of evolution of the Zygopetaleae. It is noteworthy that the Vargasiella-Warrea dichotomy could have taken place later than the divergence of Warreopsis from the mutual lineage. The molecular analysis and morphological data suggest that Vargasiella and Warrea could have evolved from a common ancestor. Accumulation of morphological differences and acceleration of the evolution of Vargasiella were more intensive than in other Warreinae and this could probably be synchronized with adaptation to different climatic conditions.

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