•Both species have low compensation point and low dark respiration.•R. nathaliae is more xeromorphic than R. serbica.•Fv/Fm and ΦPSII are resistant to the mild water stress due to high qP and ETR.•In ...severely dry leaf Fv/Fm and ΦPSII are reduced, excess energy dissipates as heat.•Carotenoids and phenolics in lower epidermis and hairs have sun-screen role.
Ramonda serbica and R. nathaliae are rare resurrection flowering plants of the northern hemisphere. Although their habitats on the north-exposed slopes of canyons and gorges are similar, those inhabited by R. nathaliae are more varied in terms of humidity, temperature and type of bedrock. These fine differences in ecological preference lead us to ask whether diploid R. nathaliae is ecologically more plastic than hexaploid R. serbica. Photosynthetic performance and fluorescence parameters are central in evaluating a plant's capacity to withstand extreme environmental conditions. We have compared the effects of various light intensities, CO2 concentrations and temperatures on the photosynthetic response of well hydrated plants of the two species. We also tracked changes in chlorophyll a fluorescence, photochemical efficiency and non-photochemical quenching during plant desiccation. The results have shown that both species have a low compensation point and low dark respiration that are indispensable for their survival at shaded and humid sites; only there are they able to maintain an appropriate equilibrium between positive net carbon gain and optimal water status. Under conditions of saturating light and CO2, net CO2 uptake was always higher in R. nathaliae that showed lower sensitivity to temperatures between 25°C and 40°C. Moreover, the leaves of R. nathaliae are amphistomatic, with smaller but more numerous stomata than those in the hypostomatic leaves of R. serbica. These xeromorphic characters of R. nathaliae suggest the better regulation of gas exchange and efficiency of water use, under the conditions of everyday short periods of direct sunlight and higher temperatures, making it possible for this species to inhabit more open, warm and dry habitats than R. serbica. Pronounced drought stress induced, in both species, strong decline in fluorescence parameters, photochemical quenching and chain electron transport rate. At the same time the exceptionally high non-photochemical quenching provided the main and highly effective mechanism of energy dissipation and protection against over-excitation. Although being homoiochlorophyllous, chloroplasts in desiccated plants are well protected from photodamage in two ways. First, the leaves are curled inward with the palisade tissue oriented to the inner side of the leaf. Second, the lower epidermis, that hence becomes exposed to sunlight, is densely covered with dark non-glandular hairs and is rich in carotenoids, anthocyanins and phenolics. All this protects desiccated plant tissues against excessive light induced damage.
Drosophila is among the most commonly used models for toxicity assessment of different types of nanoparticles. This study aims to examine the effects of a constant exposure to the low concentration ...of human food grade titanium dioxide nanoparticles (TiO2 E171) on Drosophila melanogaster wing morphology over multiple generations. Subsequently, the Geometric Morphometrics Analysis was employed to examine possible changes in the wing shape and size of the treated flies. The treatment resulted in the diminishment but not a disruption in the sexual dimorphism in wings. Consequently, the female flies were clearly separated from the male flies by the differences in wing morphology as in the control group. A splitting by generations was overly similar within the control and the treatment, but it was slightly more pronounced in the treatment. However, the observed generational differences seemed mostly random between generations, irrespective of the treatment. Specifically, the treated groups displayed slightly higher splitting by generations in females than in males. Regardless of the generation, the results show a clear splitting by the differences in the wing shape between the treated flies and the flies from control. The mean value of centroid size, which refers to the wing size, of both female and male wings was smaller in the treatment when compared to the control. The overall effect of TiO2 was to induce significant difference in Drosophila wing morphology but it did not alter the general wing morphology pattern. Therefore, the change in the wings occurred only within the normally allowed wing variation.
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•TiO2 treatment diminished but did not disrupt sexual dimorphism in wings.•The treated flies and the flies from control differed in wing size and shape.•Generational differences in wings seemed random, irrespective of TiO2 treatment.
The genus
includes three Paleoendemic and Tertiary relict species that survived in refugial habitats of the Balkan Peninsula (
and
) and the Iberian Peninsula (
). They are all "resurrection plants," ...a rare phenomenon among flowering plants in Europe.
and
are diploids (2
= 2
= 48), while
is a hexaploid (2
= 6
= 144). The two Balkan species occur in sympatry in only two localities in eastern Serbia, where tetraploid potential hybrids (2
= 4
= 96) were found. This observation raised questions about the existence of gene flow between the two species and, more generally, about the evolutionary processes shaping their genetic diversity. To address this question, genetic markers (AFLP) and an estimate of genome size variation were used in a much larger sample and at a larger geographic scale than previously. The combination of AFLP markers and genome size results suggested ongoing processes of interspecific and interploidy hybridization in the two sites of sympatry. The data also showed that interspecific gene flow was strictly confined to sympatry. Elsewhere, both
species were characterized by low genetic diversity within populations and high population differentiation. This is consistent with the fact that the two species are highly fragmented into small and isolated populations, likely a consequence of their postglacial history. Within sympatry, enormous variability in cytotypes was observed, exceeding most reported cases of mixed ploidy in complex plant species (from 2
to >8
). The AFLP profiles of non-canonical ploidy levels indicated a diversity of origin pathways and that backcrosses probably occur between tetraploid interspecific hybrids and parental species. The question arises whether this diversity of cytotypes corresponds to a transient situation. If not, the question arises as to the genetic and ecological mechanisms that allow this diversity to be maintained over time.
The aim of this study was to determine the concentrations of potentially toxic elements in soil samples and plant tissues of
Minuartia recurva
and
M. bulgarica
, predominantly or exclusively ...calcifuge species. Biological concentration (BCs) and translocation factors (TFs) were used to evaluate their accumulation potential. Considerable differences were observed between
M
.
recurva
and
M
.
bulgarica
assessions in terms of accumulation strategies of potentially toxic elements (PTEs). In
M
.
recurva
, most of the elements analyzed (Mn, Cu, Zn, Cd, and Co) were transported to the shoot, whereas in
M
.
bulgarica
, these elements remained predominantly in the roots. The Cu concentrations in the shoot samples of
M
.
recurva
from an abandoned iron-copper mine at Mt. Kopaonik were clearly above the notional hyperaccumulation threshold, characterizing this species as a possible Cu hyperaccumulator. Additionally, strong accumulation potential for Cr, Ni, Zn, Pb, and Cd was observed in
M
.
recurva
assessions, but without significant accumulation due to the low concentrations of these elements in the soils. The strong accumulation capacity and the different strategies in tolerance to PTEs indicate a potential of the two species for an application in phytoremediation:
M
.
recurva
for phytoextraction and
M
.
bulgarica
for phytostabilization.
Long term survival of plant populations relies on successful reproductive cycle to obtain generation turnover. Focusing on plant species of conservation concern, we brought together a group of plant ...conservationists from different countries to assess whether the already available information on plant reproductive biology and autecology is adequate for identifying which phases of single species life cycle might act as bottleneck.
We compiled a list of 80 plant species of conservation concern living on European cliffs and rocky slopes, for which biological and autecological information was collected from scientific literature, technical reports, and expert knowledge.
Results have shown that the available information on species reproductive biology and autecology is inadequate to identify bottlenecks in the life cycle of many species and to provide insights for the practical conservation of many more. Available knowledge is mainly referred to the flowering phase, less on seed production and much less on seedling establishment and on cloning. Meanwhile and noteworthy, flowering resulted to be the less critical phase for the fulfilment of the species life cycle.
Overall, with this perspective article we aim to encourage a constructive debate among the scientific community members and policymakers to set up novel concerted strategies for the conservation of plant species of conservation concern. The challenge of the discussion is the implementation of the current approach with new biological and ecological information to be exclusively targeted at identifying the constraints that limit the generation turnover and furnishing specific indications for active management.
•Most of the knowledge on plant life cycle does not focus on the critical phases.•Goals of biological studies are often independent from conservation purposes.•Available knowledge is insufficient to guide plant conservation practices.
Tribolium castaneum
(Herbst) and
Tribolium confusum
Jacquelin du Val (Coleoptera: Tenebrionidae) are widespread and serious pests of stored products. Various insecticides are applied aiming to ...effectively manage both species. Here, two insecticides are tested, the pyrethroid α-cypermethrin and the organophosphate pirimiphos-methyl, hypothesizing that they can lead to morphological changes in the certain body parts of the adult offspring of treated
T. castaneum
and
T. confusum
parental female adults. For this purpose, the geometric morphometric method to the elytra and hindwings was applied. Both males and females were included in the analysis. The results showed that adult individuals of
T. confusum
showed higher tolerance to both insecticides compared to
T. castaneum
adults. This finding is reflected in analyses of both pairs of wings in
T. confusum
where changes in shape were negligible. The hindwings of
T. castaneum
experienced deformations to both insecticides. More significant changes in wing shape were observed in the α-cypermethrin treatment compared to pirimiphos-methyl. In the case of
T. castaneum
, even the shortest exposure to insecticides (5 min) is enough to provoke shape changes in the hindwings. Deformities in offspring, caused after treatment of their parents with insecticides, could moderate the frequency of insecticidal applications in storages.
Aphidiinae are exclusive endoparasitoids of aphids and together with particular plant species form tritrophic complexes. Parasitoid wasps show different levels of host specificity, which is a very ...important fact since they have been used in biological control programs. We present a new approach to aphid parasitoid host specificity applied on 505 species from 38 genera, covering all valid species in the world fauna excluding synonyms. For this purpose, the artificial neural network visualization was performed to show the distribution and interconnections between and among members of five a posteriory selected groups of parasitoids. The results showed that about half of the analysed species (225) belong to the group of strict specialists, consisting of monophagous parasitoids that attack only one aphid species. The group of generalists assembled 58 species with mainly Palaearctic distribution. Between specialists and generalists are the oligophagous species which are clustered in three categories: narrow, moderate and broad oligophagous. Generally, host specificity in Aphidiinae is weakly connected with their phylogeny, suggesting that the parallel evolution of aphidiines must have occurred. Host specificity mainly depends on aphid hosts which follow host plant distribution.
Using CO1 sequence analysis, we investigated the relationships of Western Palearctic and Nearctic Cotesia that spin aggregated cocoons in the shape of a ball, and as adults are morphologically very ...similar. The analysis included the conceptual taxa C. tibialis, C. ofella, C. vanessae, C. ruficrus, C. xylina and C. yakutatensis, as well as the newly described species C. trivaliae sp. nov. The examined specimens of C. tibialis, C. ofella, C. vanessae, C. ruficrus and C. trivaliae sp. nov. were collected in several European countries, and C. xylina and C. yakutatensis in Canada and the USA. Molecular analyses showed that C. ruficrus is not closely related to the other studied taxa. Based on the genetic distances as well as biology and morphology, C. vanessae and C. ofella are confirmed as solid taxa. The species C. yakutatensis comprises two entities. Having 8 haplotypes, C. tibialis also emerges as a species complex, divided into two clusters. With 26 detected haplotypes, C. xylina shows the highest diversity, being composed of three segregates. The conceptual species C. tibialis, C. xylina and C. yakutatensis seem to be species complexes containing several candidates for recognition as distinct species. One from the European C. tibialis complex is here described as new, and the impediments to be overcome before the description of further species are outlined.
Cotesia tibialis is a gregarious koinobiont parasitoid of lepidopteran larvae. Due to the wide range of variability of some morphological traits, several new species were already described from the ...C. tibialis complex. Nixon left open the possibility that there are more by recognizing two seasonal forms. To investigate whether there are hidden taxa within C. tibialis, of 14 samples we analysed morphological characters such as the colouration of female hind femora and male antennae, and the colour and structure of the mass cocoons. The results of the analyses of the colouration of female hind femora and cocoons refute the previously defined forms within C. tibialis. Using the method of geometric morphometrics to investigate the shape of the females’ fore wings, we also did not find support of the existence of two seasonal forms of C. tibialis. Finally, applying the mitochondrial barcoding region COI the genetic differences between selected C. tibialis morphotypes were analysed. Based on both morphological and molecular analyses, one morphotype obtained from smoke-white cocoons was completely discriminated against all others, indicating that it is a potentially new species, or one of those already described which Nixon returned to C. tibialis as a synonym. The status of the other 13 morphotypes is still unclear and requires further analyses.
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