Genetic Diversity of the Narrow Endemic Allium aaseae (Alliaceae)

Smith, James F.; Pham, T. Vuong

doi:10.2307/2445848

Cited by 40 publications

(41 citation statements)

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“…In summary, the level of within-population RAPD diversity maintained by haynei/atrofusca is somewhat surprising, particularly if one considers their narrow geographical distribution. However, unexpectedly high levels of RAPD diversity have also been reported in the allogamous Allium aaseae, another monocot species with life history and geographical traits similar to the Iris taxa studied here (H = 0.274, P% = 0.522-0.672; Smith & Pham 1996). A similar pattern is seen in other nonmonocot species restricted in range (e.g.…”

Section: Intrapopulational Genetic Diversitysupporting

confidence: 75%

Patterns of genetic and phenotypic variation inIris hayneiandI. atrofusca(Irissect.Oncocyclus = the royal irises) along an ecogeographical gradient in Israel and the West Bank

et al. 2002

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Iris haynei and I. atrofusca are two closely related narrow endemics distributed vicariously along an ecogeographical north-south gradient in Israel and the West Bank. To obtain baseline information of the taxonomic status, conservation and population history of these taxa, we investigated patterns of phenotypic variation and the partitioning of genetic variation within and among populations using dominant random amplified polymorphic DNA (RAPD) markers. Multivariate (principal components analysis) and taxonomic distance analyses based on morphometric traits from eight populations revealed no unambiguous separation into two distinct groups. Results of genetic analyses for nine populations differed only slightly when either allele- or marker-based approaches were employed. Mean within-population diversity was high (0.258 for Nei's expected heterozygosity), but there was no significant relationship between genetic diversity and either population size or latitude. Although the range-wide estimate of GST ( approximately 0.20) revealed relatively high differentiation among populations this value was inflated because of a small, but significant, component of molecular variance among regions viz. taxa ( approximately 5%). Limited long-distance dispersal capabilities in conjunction with a linearized habitat distribution are proposed to contribute to the approximate isolation by distance pattern observed. It also appears that extant populations are currently deviating from equilibrium conditions because of primary divergence of a formerly more widespread ancestral population. Given the absence of deep genetic and phenotypic subdivision among northern (I. haynei) vs. central/southern (I. atrofusca) populations, we argue for a revision of their species status. Nonetheless, we recommend conservation attention to these geographically differentiated segments as separate management units, which can be seen as an instructive example of incipient species formation.

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Section: Intrapopulational Genetic Diversitysupporting

confidence: 75%

Patterns of genetic and phenotypic variation inIris hayneiandI. atrofusca(Irissect.Oncocyclus = the royal irises) along an ecogeographical gradient in Israel and the West Bank

et al. 2002

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“…C. brevifolia is thus another example of a narrow endemic island species with high diversity levels. This ample genetic diversity in Cyprus cedar could be interpreted according to the argument that maintaining high genetic diversity in a narrow endemic species is due to its origin from a widespread congener species (Smith and Pham 1996). This is probably true for C. brevifolia, since earlier phylogenetic studies on cedar species found a genetic relationship between C. brevifolia and several C. libani sources from Turkey (Scaltsoyiannes 1999; Fady et al 2000;Bou Dagher-Kharrat et al 2007).…”

Section: Discussionmentioning

confidence: 93%

High genetic diversity and significant population structure in Cedrus brevifolia Henry, a narrow endemic Mediterranean tree from Cyprus

et al. 2011

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Endemic island plant species with a narrow distribution are often, but not always, linked to low genetic variation within populations and a lack of differentiation among populations. Cedrus brevifolia is a narrow endemic island tree species of Cyprus. Its range is restricted to a single forest, divided into five neighbouring sites. This study, using biparentally inherited nuclear microsatellites and paternally inherited plastid (chloroplast) microsatellites, assessed the genetic variation of C. brevifolia within its sole population and the level of genetic differentiation among formed sites. The results from both markers showed high diversity (nuclear H T = 0.70; plastid H T = 0.93), strongly suggesting that the species did not experience severe bottleneck events or extensive genetic drift. Besides, the maintenance of a high genetic diversity in C. brevifolia may suggest that it originates from a widespread congener species. Significant genetic differentiation at nuclear (G ST = 0.052) and plastid (G ST = 0.119) markers was found among the formed sites. Remarkably, the relatively high genetic differentiation found at plastid markers was comparable to values observed in two widespread congener cedar species. The genetic differentiation probably occurred due to fragmentation of a previously uniform population. This would lead to the shaping of different genetic groups (Bayesian analysis) and to significant population substructure. Furthermore, significant values observed for both isolation by distance and large-scale spatial genetic structure could indicate ineffective gene flow among sites and the early geographical isolation of the more isolated sites from the core population.

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“…In a more recent paper. Smith and Vuong Pham (1996) applied RAPD data in a similar investigation of the rare Allium aaseae endemic to Idaho, USA, and its more common sister species A. simillimum. From 12 selected primers, 65 variable markers were scored in 14 populations from both species, but in this case the RAPD dendrogram did not confirm the species status of the populations, as determined by morphology.…”

Section: Infraspecific Applicationsmentioning

confidence: 99%

Applications and impact of molecular markers on evolutionary and diversity studies in the genus Allium

Klaas

1998

Plant Breeding

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Allium is a large variable genus containing %700 species, among them the economically important crops bulb onion, garlic and leek and many other crop species of minor or local importance. As the methods became available and more refined, systematic studies using biochemical and molecular markers were published to complement and offset the growing amount of data based on morphological, anatomical and other traditional approaches. Using isozymes and later restriction fragment length polymorphisms (RFLPs) and random amplified polymorphic DNAs (RAPDs), phylogenetic problems were addressed at all systematic levels of the genus and the interrelationships among crop species and their close relatives. The analysis of hybrid plants is another important application of molecular markers. Markers allow verification of the hybrid's cytoplasm, the composition of the nuclear genome, and investigation of introgression in backcrossing experiments.

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Genetic Diversity of the Narrow Endemic Allium aaseae (Alliaceae)

Cited by 40 publications

References 0 publications

Patterns of genetic and phenotypic variation inIris hayneiandI. atrofusca(Irissect.Oncocyclus = the royal irises) along an ecogeographical gradient in Israel and the West Bank

Patterns of genetic and phenotypic variation inIris hayneiandI. atrofusca(Irissect.Oncocyclus = the royal irises) along an ecogeographical gradient in Israel and the West Bank

High genetic diversity and significant population structure in Cedrus brevifolia Henry, a narrow endemic Mediterranean tree from Cyprus

Applications and impact of molecular markers on evolutionary and diversity studies in the genus Allium

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