Inter-intraspecific variation of chloroplast DNA of European Plantago spp.

Abstract

Inter-and intraspecific chioroplast DNA variation in four species of Plantago (P. lanceolata, P. major, P. media and P. coronopus) were analysed by comparing DNA fragment patterns produced by seven restriction endonucleases. Plant material was collected in seven European countries. Only 21.3 per cent of the 409 restriction sites were shared by all four species. Phylogenetic analysis, performed by constructing the most parsimonious trees, showed that genetic differentiation in cpDNA was very high among P. lanceolata, P. coronopus and the species pair P. media and P. major, which were more closely related.At the intraspecific level, four restricted site mutations were detected. Most of the variation was due to numerous small length mutations, one of which (70 bp) discriminated between the two subspecies of P. major (i.e. ssp. major and ssp. pleiosperma). This mutation was used successfully to show that, in Denmark, cpDNA introgression occurs from pleiosperma into major in the areas where the two subspecies grow together, whereas previous studies of the same subspecies in the Netherlands suggested introgression in the reverse direction. In P. lanceolata, five distinct types of cpDNA genome could be distinguished, one of these being widely distributed. Therefore, DNA variation was present both between and within populations. In P. media, three distinct cpDNA genomes were found, one being specific to diploid and tetraploid material from the Pyrenees, suggesting multiple origins of the autotetraploids in this species. Whereas cpDNA variation was observed in the two outcrossing species of Plantago (P. media and P. lanceolata) no variation was detected in the two autogamous subspecies of P. major. This suggests that chioroplast DNA variation may be related to nuclear genome diversity.

Contrasting the distribution of chloroplast DNA and allozyme polymorphism among local populations of Silene alba: implications for studies of gene flow in plants.

“…While there is no evidence of paternal leakage in this sample, a much larger study would be It is necessary to first consider the nature of the markers themselves. To date, length variants comprise a relatively large proportion of the intraspecific cpDNA polymorphisms that have been documented (2,11,12) and were the subject of this study. It has been suggested that cpDNA length polymorphisms have limited utility for the study of population genetic processes (11).…”

“…The chloroplast genome is generally highly conserved and it is not yet clear whether intraspecific variation of the sort needed for studies of population structure is sufficiently common for cpDNA to be a widely used tool in plant population biology. There is a small but growing literature showing that intraspecific cpDNA variation can be detected in a variety of species and that such variation generally shows considerable spatial structure (1,2,4,(9)(10)(11)(12). However, comparisons to nuclear variation are limited.…”

Introgressive hybridization between Plantago major L. taxa

“…Intermedia there, was not observed in a few individuals identified morphologically as major from sites where the two taxa were growing together. The study suggested that hybridization may have occurred between the two taxa and these individuals with morphological characters of major and without the larger 70-bp DNA fragment length resulted from natural successive hybridization and backcrossing onto intermedia mothers, with the more outcrossing major acting as pollen donors, resulting in an introgression from intermedia to major (Hooglander et al, 1993). However, Wolff and Schaal (1992) by comparing chloroplast DNA (cpDNA) found three mutations in Dutch populations, which discriminated intermedia from major.…”

“…In Plantago, maternally inherited chloroplast DNA (cpDNA) was analyzed by comparing DNA fragment patterns produced by seven restriction endonucleases in four species of Plantago (Hooglander et al, 1993). In this study it was shown that the larger 70 bp DNA fragment, present in Netherlands P. major ssp.…”

A population genetic analysis of chloroplast DNA in Phacelia

“…Population analyses based upon the chloroplast genome are beginning to be applied to problems in intraspecific phylogeography in plants (Soltis et al, 1992;Hooglander et al, 1993;Mayer & Soltis, 1994) in ways analogous to the use of mitochondrial DNA (mtDNA) in studies of animals (Avise et a!., 1987). In addition, data from cpDNA have been used to examine population structure within species (Neale et al, 1988;Milligan, 1991;Soltis et a!., 1992;McCauley, 1994;Petit et a!., 1994), haplotype diversity within and between populations (Milligan, 1991;Hong et a!., 1993;Byrne & Moran, 1994), and to search for correlations between chloroplast variation and morphological (Terauchi et a!., 1991) or breeding system (Wolff & Schaal, 1992) characteristics.…”