Chloroplast DNA variation in <i>Epipactis atrorubens</i> populations from northern Greece

<p><i>Epipactis</i> Zinn. is a highly diverse genus, with numerous taxa naturally occurring throughout Europe. While their morphological variability has resulted in contradictory opinions about their taxonomy, the knowledge of the genetic variation of many of its species is limited. Such an example is <i>E. atrorubens</i> in the Balkan Peninsula. In this work, the cpDNA variation of seven <i>E. atrorubens</i> populations from northern Greece and of one population from Germany has been investigated by means of PCR-RFLP markers. Two regions of the cpDNA were studied (<i>trn</i>H-<i>psb</i>A, <i>trn</i>L intron) and four PCR-RFLP markers were employed (<i>trn</i>H-<i>psb</i>A/<i>Hae</i>III, <i>trn</i>H-<i>psb</i>A/<i>Hinf</i>I, <i>trn</i>H-<i>psb</i>A/<i>Vsp</i>I, <i>trn</i>L/<i>Mbo</i>I), which have revealed variation in other <i>Epipactis</i> species. The results demonstrate limited genetic variability in the studied populations, as only one haplotype was present in all the populations (both Greek and German), with the exception of Mt. Menikion (Greece) where a second haplotype was also recorded. This limited variation may be attributed to the properties of the genetic markers involved, to the conserved status of the two cpDNA regions in this species or to factors related to the biology and evolutionary history of <i>E. atrorubens</i>. The presence of a second haplotype only in Mt. Menikion could be attributed to a hybridisation event in the past and/or to the potential existence of a glacial refugium on this mountain.</p

Lessons from Red Data Books: Plant Vulnerability Increases with Floral Complexity

<div><p>The architectural complexity of flower structures (hereafter referred to as floral complexity) may be linked to pollination by specialized pollinators that can increase the probability of successful seed set. As plant—pollinator systems become fragile, a loss of such specialized pollinators could presumably result in an increased likelihood of pollination failure. This is an issue likely to be particularly evident in plants that are currently rare. Using a novel index describing floral complexity we explored whether this aspect of the structure of flowers could be used to predict vulnerability of plant species to extinction. To do this we defined plant vulnerability using the Red Data Book of Rare and Threatened Plants of Greece, a Mediterranean biodiversity hotspot. We also tested whether other intrinsic (e.g. life form, asexual reproduction) or extrinsic (e.g. habitat, altitude, range-restrictedness) factors could affect plant vulnerability. We found that plants with high floral complexity scores were significantly more likely to be vulnerable to extinction. Among all the floral complexity components only floral symmetry was found to have a significant effect, with radial-flower plants appearing to be less vulnerable. Life form was also a predictor of vulnerability, with woody perennial plants having significantly lower risk of extinction. Among the extrinsic factors, both habitat and maximum range were significantly associated with plant vulnerability (coastal plants and narrow-ranged plants are more likely to face higher risk). Although extrinsic and in particular anthropogenic factors determine plant extinction risk, intrinsic traits can indicate a plant’s proneness to vulnerability. This raises the potential threat of declining global pollinator diversity interacting with floral complexity to increase the vulnerability of individual plant species. There is potential scope for using plant—pollinator specializations to identify plant species particularly at risk and so target conservation efforts towards them.</p></div

Results of the best fitting (based on AIC) GLM showing the effects of the intrinsic and extrinsic variables on the Greek rare and threatened plants’ vulnerability.

<p>Results of the best fitting (based on AIC) GLM showing the effects of the intrinsic and extrinsic variables on the Greek rare and threatened plants’ vulnerability.</p

The Floral Complexity Index (FCI) values distributed across the Greek rare and threatened plants’ phylogeny.

<p>Grey bars indicate the relative magnitude of the FCI (highest value: 3.25, lowest: 1.15). Red rectangles mark the “more threatened” (CR, EN or EX) taxa.</p

Weights of the floral variables used in the Floral Complexity Index. For details on the estimation of the variable level values see S1 Text.

<p>^aBased on a scale of 1–3 (for floral depth, symmetry, corolla segmentation and functional reproductive unit) or a scale of 1–5 (for floral shape). See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138414#pone.0138414.s002" target="_blank">S1 Text</a>.</p><p>^bResulting from the floral variable weight (<i>w</i>) multiplied by the variable level’s value (<i>V</i>).</p><p>All terms are explained in the text.</p

Extrinsic vulnerability factors of the Greek rare and threatened plants.

<p>The effects of the extrinsic variables on plant vulnerability as included in the best fitted logistic GLM based on the backward AIC selection process. (a) Mean maximal distance (±SE); (b) mean minimum altitude (±SE); and (c) habitat. The variation of the latter is presented in a spinogram. The width of the columns corresponds to the relative frequency of the “more threatened” and “less threatened” plants in the dataset; the height of the cells represents the relative frequency of the response variable in every type of habitat. Colored cells denote statistical significance of the respective level (**: ≤ 0.01, ***: ≤ 0.001).</p