Chloroplast DNA phylogeography and cytotype geography in autopolyploid Plantago media

TY - JOUR

T1 - Chloroplast DNA phylogeography and cytotype geography in autopolyploid Plantago media

AU - Van Dijk, P.J.

AU - Bakx-Schotman, Tanja

N1 - Reporting year: 1997 Metis note: 2175; CTE; PVD ; TE file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs1997/VanDijk_ea_2175.pdf

PY - 1997

Y1 - 1997

N2 - In order to gain insight into the causes of parapatric diploid and tetraploid distributions in Plantago media chloroplast DNA (cpDNA) restriction site polymorphism was studied in 36 European populations. Parapatric distributions are often explained by adaptive differences between cytotypes to an underlying heterogeneity in environmental factors. Alternatively, such distribution patterns may be explained nonadaptively, through frequency-dependant production of hybrids with low fitness. However, nonadaptive explanations have been neglected in polyploid Literature. In this study nine chloroplast haplotypes were found. Their phylogeny suggests that tetraploids arose at least three times from diploids. In general, related haplotypes were also geographically clustered, although there were some marked geographical discontinuities. In the Pyrenees, diploids and tetraploids carried diverged haplotypes throughout their parapatric ranges. At the contact zone the level of cpDNA introgression in a mixed diploid- tetraploid population was low. It is discussed that the cpDNA phylogeography supports the nonadaptive hypothesis that parapatric cytotype distributions may be explained by postPleistocene range expansions followed by mutual minority cytotype exclusion, due to hybrid unfitness. [KEYWORDS: phylogeography; cpDNA; polyploidy; hybrid inviability; colonization; Pleistocene Gene flow; saxifragaceae; oaks]

AB - In order to gain insight into the causes of parapatric diploid and tetraploid distributions in Plantago media chloroplast DNA (cpDNA) restriction site polymorphism was studied in 36 European populations. Parapatric distributions are often explained by adaptive differences between cytotypes to an underlying heterogeneity in environmental factors. Alternatively, such distribution patterns may be explained nonadaptively, through frequency-dependant production of hybrids with low fitness. However, nonadaptive explanations have been neglected in polyploid Literature. In this study nine chloroplast haplotypes were found. Their phylogeny suggests that tetraploids arose at least three times from diploids. In general, related haplotypes were also geographically clustered, although there were some marked geographical discontinuities. In the Pyrenees, diploids and tetraploids carried diverged haplotypes throughout their parapatric ranges. At the contact zone the level of cpDNA introgression in a mixed diploid- tetraploid population was low. It is discussed that the cpDNA phylogeography supports the nonadaptive hypothesis that parapatric cytotype distributions may be explained by postPleistocene range expansions followed by mutual minority cytotype exclusion, due to hybrid unfitness. [KEYWORDS: phylogeography; cpDNA; polyploidy; hybrid inviability; colonization; Pleistocene Gene flow; saxifragaceae; oaks]

U2 - 10.1046/j.1365-294X.1997.00199.x

DO - 10.1046/j.1365-294X.1997.00199.x

M3 - Article

SN - 0962-1083

VL - 6

SP - 345

EP - 352

JO - Molecular Ecology

JF - Molecular Ecology

IS - 4

ER -