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Biogeography of the Phalaenopsis amabilis species complex inferred from nuclear and plastid DNAs.

Tsai CC, Chou CH, Wang HV, Ko YZ, Chiang TY, Chiang YC - BMC Plant Biol. (2015)

Bottom Line: Demographic growth associated with the climatic oscillations in the Würm glacial period followed the species splits.Nevertheless, a subsequent population slowdown occurred in the late LGM due to extinction of regional populations.The reduction of suitable habitats resulted in geographic fragmenttation of the remaining taxa.

View Article: PubMed Central - PubMed

Affiliation: Crop Improvement Division, Kaohsiung District Agricultural Improvement Station, Pingtung, 900, Taiwan. tsaicc@mail.kdais.gov.tw.

ABSTRACT

Background: Phalaenopsis is one of the important commercial orchids in the world. Members of the P. amabilis species complex represent invaluable germplasm for the breeding program. However, the phylogeny of the P. amabilis species complex is still uncertain. The Phalaenopsis amabilis species complex (Orchidaceae) consists of subspecies amabilis, moluccana, and rosenstromii of P. amabilis, as well as P. aphrodite ssp. aphrodite, P. ap. ssp. formosana, and P. sanderiana. The aims of this study were to reconstruct the phylogeny and biogeographcial patterns of the species complex using Neighbor Joining (NJ), Maxinum Parsimony (MP), Bayesian Evolutionary Analysis Sampling Trees (BEAST) and Reconstruct Ancestral State in Phylogenies (RASP) analyses based on sequences of internal transcribed spacers 1 and 2 from the nuclear ribosomal DNA and the trnH-psbA spacer from the plastid DNA.

Results: A pattern of vicariance, dispersal, and vicariance + dispersal among disjunctly distributed taxa was uncovered based on RASP analysis. Although two subspecies of P. aphrodite could not be differentiated from each other in dispersal state, they were distinct from P. amabilis and P. sanderiana. Within P. amabilis, three subspecies were separated phylogenetically, in agreement with the vicariance or vicariance + dispersal scenario, with geographic subdivision along Huxley's, Wallace's and Lydekker's Lines. Molecular dating revealed such subdivisions among taxa of P. amabilis complex dating back to the late Pleistocene. Population-dynamic analyses using a Bayesian skyline plot suggested that the species complex experienced an in situ range expansion and population concentration during the late Last Glacial Maximum (LGM).

Conclusions: Taxa of the P. amabilis complex with disjunct distributions were differentiated due to vicariance or vicariance + dispersal, with events likely occurring in the late Pleistocene. Demographic growth associated with the climatic oscillations in the Würm glacial period followed the species splits. Nevertheless, a subsequent population slowdown occurred in the late LGM due to extinction of regional populations. The reduction of suitable habitats resulted in geographic fragmenttation of the remaining taxa.

No MeSH data available.


Ancestral distributions reconstructed by RASP. Phylogenetic relationships of the 39 accessions in the P. amabilis species complex, plus the three outgroups P. schilleriana, P. stuartiana and P. philippinensis, obtained from sequence comparisons of the cpDNA trnH-psbA spacer sequence and generated by BEAST. Bayesian credibility values (PP) are indicated above the branch on one of the post-burn Bayesian trees. The distribution areas of extant accessions of P. amabilis species are marked in capitals A–J (A: Bantam, Java, Indonesia; B: Mentawai Is., Sumatra, Indonesia; C: Brooks Point, Palawan, the Philippines; D: Sabah, Indonesia; E: East Timor; F: Celebes, Molucca Is., Indonesia; G: Kaiser Wilhelms, New Guinea; H: Mindanao, the Philippines; I: Manila, Luzon, Fuga Is., and Calayan Is. in the Philippines; J: southern Taiwan), respectively. The grey circles indicate the vicariance events and the circles with dashed line indicate the long-distance dispersal (LDD) events obtained from the RASP analysis, respectively
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Fig3: Ancestral distributions reconstructed by RASP. Phylogenetic relationships of the 39 accessions in the P. amabilis species complex, plus the three outgroups P. schilleriana, P. stuartiana and P. philippinensis, obtained from sequence comparisons of the cpDNA trnH-psbA spacer sequence and generated by BEAST. Bayesian credibility values (PP) are indicated above the branch on one of the post-burn Bayesian trees. The distribution areas of extant accessions of P. amabilis species are marked in capitals A–J (A: Bantam, Java, Indonesia; B: Mentawai Is., Sumatra, Indonesia; C: Brooks Point, Palawan, the Philippines; D: Sabah, Indonesia; E: East Timor; F: Celebes, Molucca Is., Indonesia; G: Kaiser Wilhelms, New Guinea; H: Mindanao, the Philippines; I: Manila, Luzon, Fuga Is., and Calayan Is. in the Philippines; J: southern Taiwan), respectively. The grey circles indicate the vicariance events and the circles with dashed line indicate the long-distance dispersal (LDD) events obtained from the RASP analysis, respectively

Mentions: In the trnH-psbA spacer, 11 variable sites and 6 indels were found among the species/subspecies of the P. amabilis complex. The phylogeny inferred from the plastid DNA was largely consistent with those from the ITS data and provided better resolution in the geographic subdivision. The Phalaenopsis amabilis complex consisted of two clades with high bootstrapping supports in both NJ and MP phylogenetic trees, one for P. amabilis with its subspecies and P. sanderiana and the other for P. aphrodite (Figs. 2b and 3). The clade including P. amabilis/P. sanderiana consisted of two geographic groups (Fig. 2b), however, the Timor population was not closely related to P. amabilis ssp. rosentromii but was related to the Mentawei Island population (Fig. 2b)Fig. 3


Biogeography of the Phalaenopsis amabilis species complex inferred from nuclear and plastid DNAs.

Tsai CC, Chou CH, Wang HV, Ko YZ, Chiang TY, Chiang YC - BMC Plant Biol. (2015)

Ancestral distributions reconstructed by RASP. Phylogenetic relationships of the 39 accessions in the P. amabilis species complex, plus the three outgroups P. schilleriana, P. stuartiana and P. philippinensis, obtained from sequence comparisons of the cpDNA trnH-psbA spacer sequence and generated by BEAST. Bayesian credibility values (PP) are indicated above the branch on one of the post-burn Bayesian trees. The distribution areas of extant accessions of P. amabilis species are marked in capitals A–J (A: Bantam, Java, Indonesia; B: Mentawai Is., Sumatra, Indonesia; C: Brooks Point, Palawan, the Philippines; D: Sabah, Indonesia; E: East Timor; F: Celebes, Molucca Is., Indonesia; G: Kaiser Wilhelms, New Guinea; H: Mindanao, the Philippines; I: Manila, Luzon, Fuga Is., and Calayan Is. in the Philippines; J: southern Taiwan), respectively. The grey circles indicate the vicariance events and the circles with dashed line indicate the long-distance dispersal (LDD) events obtained from the RASP analysis, respectively
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4537552&req=5

Fig3: Ancestral distributions reconstructed by RASP. Phylogenetic relationships of the 39 accessions in the P. amabilis species complex, plus the three outgroups P. schilleriana, P. stuartiana and P. philippinensis, obtained from sequence comparisons of the cpDNA trnH-psbA spacer sequence and generated by BEAST. Bayesian credibility values (PP) are indicated above the branch on one of the post-burn Bayesian trees. The distribution areas of extant accessions of P. amabilis species are marked in capitals A–J (A: Bantam, Java, Indonesia; B: Mentawai Is., Sumatra, Indonesia; C: Brooks Point, Palawan, the Philippines; D: Sabah, Indonesia; E: East Timor; F: Celebes, Molucca Is., Indonesia; G: Kaiser Wilhelms, New Guinea; H: Mindanao, the Philippines; I: Manila, Luzon, Fuga Is., and Calayan Is. in the Philippines; J: southern Taiwan), respectively. The grey circles indicate the vicariance events and the circles with dashed line indicate the long-distance dispersal (LDD) events obtained from the RASP analysis, respectively
Mentions: In the trnH-psbA spacer, 11 variable sites and 6 indels were found among the species/subspecies of the P. amabilis complex. The phylogeny inferred from the plastid DNA was largely consistent with those from the ITS data and provided better resolution in the geographic subdivision. The Phalaenopsis amabilis complex consisted of two clades with high bootstrapping supports in both NJ and MP phylogenetic trees, one for P. amabilis with its subspecies and P. sanderiana and the other for P. aphrodite (Figs. 2b and 3). The clade including P. amabilis/P. sanderiana consisted of two geographic groups (Fig. 2b), however, the Timor population was not closely related to P. amabilis ssp. rosentromii but was related to the Mentawei Island population (Fig. 2b)Fig. 3

Bottom Line: Demographic growth associated with the climatic oscillations in the Würm glacial period followed the species splits.Nevertheless, a subsequent population slowdown occurred in the late LGM due to extinction of regional populations.The reduction of suitable habitats resulted in geographic fragmenttation of the remaining taxa.

View Article: PubMed Central - PubMed

Affiliation: Crop Improvement Division, Kaohsiung District Agricultural Improvement Station, Pingtung, 900, Taiwan. tsaicc@mail.kdais.gov.tw.

ABSTRACT

Background: Phalaenopsis is one of the important commercial orchids in the world. Members of the P. amabilis species complex represent invaluable germplasm for the breeding program. However, the phylogeny of the P. amabilis species complex is still uncertain. The Phalaenopsis amabilis species complex (Orchidaceae) consists of subspecies amabilis, moluccana, and rosenstromii of P. amabilis, as well as P. aphrodite ssp. aphrodite, P. ap. ssp. formosana, and P. sanderiana. The aims of this study were to reconstruct the phylogeny and biogeographcial patterns of the species complex using Neighbor Joining (NJ), Maxinum Parsimony (MP), Bayesian Evolutionary Analysis Sampling Trees (BEAST) and Reconstruct Ancestral State in Phylogenies (RASP) analyses based on sequences of internal transcribed spacers 1 and 2 from the nuclear ribosomal DNA and the trnH-psbA spacer from the plastid DNA.

Results: A pattern of vicariance, dispersal, and vicariance + dispersal among disjunctly distributed taxa was uncovered based on RASP analysis. Although two subspecies of P. aphrodite could not be differentiated from each other in dispersal state, they were distinct from P. amabilis and P. sanderiana. Within P. amabilis, three subspecies were separated phylogenetically, in agreement with the vicariance or vicariance + dispersal scenario, with geographic subdivision along Huxley's, Wallace's and Lydekker's Lines. Molecular dating revealed such subdivisions among taxa of P. amabilis complex dating back to the late Pleistocene. Population-dynamic analyses using a Bayesian skyline plot suggested that the species complex experienced an in situ range expansion and population concentration during the late Last Glacial Maximum (LGM).

Conclusions: Taxa of the P. amabilis complex with disjunct distributions were differentiated due to vicariance or vicariance + dispersal, with events likely occurring in the late Pleistocene. Demographic growth associated with the climatic oscillations in the Würm glacial period followed the species splits. Nevertheless, a subsequent population slowdown occurred in the late LGM due to extinction of regional populations. The reduction of suitable habitats resulted in geographic fragmenttation of the remaining taxa.

No MeSH data available.