28 research outputs found
New molecular data attest to the absence of cospeciation patterns between Placobdella costata (Fr. MĂŒller, 1846) (Hirudinea) and freshwater turtles (Emys spp.) in Italy
The only Palearctic representative of the leech genus Placobdella Blanchard, 1893 is P. costata, an ectoparasite of freshwater
turtles. To date, no conclusive evidence about the possible presence of coevolutionary patterns between this leech and its turtle
hosts is available due to the paucity of DNA sequence data available for P. costata; moreover, comparative host data is also
mostly lacking, making any inferences more difficult. The discovery of new populations of the species in northern Italy and
Sicily allowed us to generate novel mitochondrial DNA sequences and to compare the topology of the resulting phylogenetic
trees with the phylogeny of the turtle hosts occurring in the study area, i.e., Emys orbicularis and E. trinacris. The branching
pattern of the phylogenetic tree for P. costata is not congruent with that of its turtle hosts, thus suggesting the lack of
coevolutionary or cospeciation phenomena between these taxa. The lack of a coevolutionary pattern might be ascribed to
the different dispersal ability of Placobdella costata and Emys spp. and to the host generality of the leech, as confirmed by the
occurrence of P. costata on aquatic turtles belonging to the genus Mauremys in areas where Emys spp. are rare or absent.
A single leech cytochrome c oxidase subunit 1 haplotype was found in each study region, and the overall nucleotide
diversity was very low throughout the investigated distribution. This apparent lack of a clear phylogeographical pattern was
unexpected in the P. costata populations occurring in the circum-Mediterranean areas, where the occurrence of high
haplotype and nucleotide diversity is customary for most terrestrial and freshwater species. Based on the available data, we
suggest a recent, post-glacial origin of the studied P. costata populations
New molecular data attest to the absence of cospeciation patterns between Placobdella costata (Fr. MĂŒller, 1846) (Hirudinea) and freshwater turtles (Emys spp.) in Italy
The only Palearctic representative of the leech genus Placobdella Blanchard, 1893 is P. costata, an ectoparasite of freshwater turtles. To date, no conclusive evidence about the possible presence of coevolutionary patterns between this leech and its turtle hosts is available due to the paucity of DNA sequence data available for P. costata; moreover, comparative host data is also mostly lacking, making any inferences more difficult. The discovery of new populations of the species in northern Italy and Sicily allowed us to generate novel mitochondrial DNA sequences and to compare the topology of the resulting phylogenetic trees with the phylogeny of the turtle hosts occurring in the study area, i.e., Emys orbicularis and E. trinacris. The branching pattern of the phylogenetic tree for P. costata is not congruent with that of its turtle hosts, thus suggesting the lack of coevolutionary or cospeciation phenomena between these taxa. The lack of a coevolutionary pattern might be ascribed to the different dispersal ability of Placobdella costata and Emys spp. and to the host generality of the leech, as confirmed by the occurrence of P. costata on aquatic turtles belonging to the genus Mauremys in areas where Emys spp. are rare or absent. A single leech cytochrome c oxidase subunit 1 haplotype was found in each study region, and the overall nucleotide diversity was very low throughout the investigated distribution. This apparent lack of a clear phylogeographical pattern was unexpected in the P. costata populations occurring in the circum-Mediterranean areas, where the occurrence of high haplotype and nucleotide diversity is customary for most terrestrial and freshwater species. Based on the available data, we suggest a recent, post-glacial origin of the studied P. costata populations
Use of 1-methylcyclopropene for the control of Botrytis cinerea on cut flowers
Cut flowers are marketed for their ornamental characteristics making post-harvest flower life an important determinant of crop value. Botrytis cinerea is one of the most significant post-harvest fungal pathogens causing losses in ornamental plants. Disease caused by this fungus seems to be enhanced by the presence of a ethylene hormone, that both the plant and the fungus are known to synthesize. The aim of the experiment was to determine if 1-methylcyclopropene (1-MCP), an ethylene antagonist, could be used to reduce B. cinerea damage to cut flowers. Six cultivars of four ornamental species: Dianthus caryophyllus âIdra di Muragliaâ, Rosa Ă hybrida âWhite Dewâ and âRitzâ, Ranunculus asiaticus âSaigonâ and âGreenâ, and Cyclamen persicum line âHalios Bianco Puro Compattoâ were given three concentrations of 1-MCP (0.38 ÎŒl L-1, 1.14 ÎŒL L-1, and 3.62 ÎŒL L-1) for 24 hours. Subsequently, 10 petals per cultivar were treated with a B. cinerea conidial suspension (5Ă103 conidia cm-2) and stored in air-tight vases. To evaluate B. cinerea development an arbitrary damage scale (1â7) was used. A high concentration of 1-MCP significantly reduced B. cinerea damage on D. caryophyllus âIdra di Muragliaâ and C. persicum âHalios White Pure Compactâ petals. In carnation, 1-MCP treatment slowed B. cinerea infection; its threshold level was reached three days after that of the control. In cyclamen, treated petals and control petals remained aesthetically good until day 53 and day 28 respectively. At low concentrations, 1-MCP slowed grey mould on R. Ă hybrida âRitzâ for up to three days beyond the control. On the two buttercup cultivars âGreenâ and âSaigonâ, 1-MCP treatments were not effective. In conclusion, 1-MCP limited pathogen development; its effect depended on the species and the 1-MCP concentration. Further investigations will be performed to improve methods to reduce B. cinerea development on the petals of cut flowers
Increasing plant longevity and associated metabolic events in potted carnation (Dianthus caryophyllus L. Clove Pink)
Osteological peculiarities of Bufo brongersmai (Anura: Bufonidae) and their possible relation to life in an arid environment
Osteological peculiarities of Bufo brongersmai (Anura: Bufonidae) and their possible relation to life in an arid environment. Zoological Studies 48(1): 108-119. The morphology of selected isolated skeletal elements of the northwestern African endemic toad Bufo brongersmai Hoogmoed 1972 is herein described and compared to those of other Bufo species inhabiting the same area and Europe. The osteological morphology of this species clearly differentiates it from others within the genus, and several diagnostic osteological characters are added to the specific diagnosis. In particular, the presence in adult individuals of a rather-large maxillary fontanella, which late in ontogeny is reduced to a few foramina, has not been observed in other species. These fontanellae, as well as the fenestrations on the sphenethmoid, together with other osteological traits, suggest a significant degree of hypo-ossification. This seems likely related to the rapid larval development that allows B. brongersmai to achieve higher reproductive fitness than other species in the highly ephemeral waters of the rocky, arid environment it inhabits. Other peculiar osteological traits could be related to the exploitation of small crevices to protect adults from overheating and desiccation
Habitat selection in a fossorial toad Pelobates fuscus insubricus (Amphibia: Pelobatidae): does the soil affect species occurrence?
For their rapid and alarming decline, the Italian populations of the Italian spadefoot toad (Pelobates fus-cus insubricus) are of high conservation importance. In this study we examined habitat use by the spadefoot toads
in north-west Italy, where one of the largest remaining populations lives. We used compositional analysis and logis-tic regression models to elaborate land-use and soil composition in order to determine the habitat preferences of the spadefoot toads. We found that the two main variables predicting the occurrence of spadefoot toads in the study area were the percentages of sandy-loam soil texture and the presence of Entisols. Our results showed that spadefoot toads preferred soils that keep soft and malleable structure: Entisols with sand texture, where sand represents the major component, and mature soils, with a high degree of pedogenesis and a relatively high natural fertility and humidity. Conversely, Pelobates fuscusavoids Inceptisols, probably too hard to be dug by the species. This study demonstrates that, at least in the Italian range, the choice of areas in which to reintroduce P. fuscus, or where re-create favourable habitats for it, must take into account the soil types, which, in intensely cultivated areas, seems to be decisive for the possibility of survival of the species in the medium and long time
On a new stochastic usage model (Non-time-homogeneous Poisson) for testing a multi-stage system to promote reliability growth
The effects of intra- and interspecific competitions on personality and individual plasticity in two sympatric brown frogs
We studied how individuals modify their behavior in response to inter- and intraspecific competitors and how these changes affected the pattern of variation between populations and species. As study models, we used tadpoles of two brown frogs, Rana latastei and R. dalmatina. Since R. latastei is always sympatric to R. dalmatina, whereas R. dalmatina is sympatric to R. latastei only in the periphery of its range, we predicted a stronger response to heterospecifics in R. latastei than in R. dalmatina and, within each species, in syntopic than in allotopic populations. To test these predictions, we raised tadpoles, from either syntopic or allotopic populations, in either syntopy or allotopy and repeatedly tested them in open field trials in the presence of a caged conspecific, a caged heterospecific, or an empty cage. As predicted, we found that, on average, R. latastei tadpoles modified their behavior across treatments more than R. dalmatina tadpoles and individuals from the syntopic population changed more than their conspecifics from the allotopic population. In both species, the pattern of variation at the individual level mirrored that at the population and species levels providing no evidence for an individual-by-environment interaction (I x E). Besides these differences, however, individuals of the two species also showed unpredicted and context-independent behavioral differences, suggesting that there might be more to interspecific behavioral variation than the effect of selection by heterospecific competitors.Significance statementDoes the distribution range of a species influence the evolution of plastic behaviors to heterospecific competitors? And how do differences in plasticity affect animal personality? To answer these questions, we raised tadpoles of two brown frog species, Rana dalmatina and R. latastei, and studied how the amount and the type of their swimming varied with the presence of the other species. R. latastei, whose small distribution range fully overlaps with that of R. dalmatina, plastically responds to it, whereas R. dalmatina, which is sympatric to R. latastei only in the periphery of its broader range, does not. These interspecific differences mirrored those among individuals: tadpoles of both species show repeatable behaviors, but only those of R. latastei plastically changed their behavior with the presence of the other species; however, neither R. latastei nor R. dalmatina show among-individual variation in plasticity
Use of 1-methylcyclopropene for the control of <i>Botrytis cinerea </i> on cut flowers
Cut flowers are marketed for their ornamental characteristics making post-harvest flower life an important determinant of crop value. Botrytis cinerea is one of the most significant post-harvest fungal pathogens causing losses in ornamental plants. Disease caused by this fungus seems to be enhanced by the presence of a ethylene hormone, that both the plant and the fungus are known to synthesize. The aim of the experiment was to determine if 1-methylcyclopropene (1-MCP), an ethylene antagonist, could be used to reduce B. cinerea damage to cut flowers. Six cultivars of four ornamental species: Dianthus caryophyllus âIdra di Muragliaâ, Rosa Ă hybrida âWhite Dewâ and âRitzâ, Ranunculus asiaticus âSaigonâ and âGreenâ, and Cyclamen persicum line âHalios Bianco Puro Compattoâ were given three concentrations of 1-MCP (0.38 ÎŒl L-1, 1.14 ÎŒL L-1, and 3.62 ÎŒL L-1) for 24 hours. Subsequently, 10 petals per cultivar were treated with a B. cinerea conidial suspension (5Ă103 conidia cm-2) and stored in air-tight vases. To evaluate B. cinerea development an arbitrary damage scale (1â7) was used. A high concentration of 1-MCP significantly reduced B. cinerea damage on D. caryophyllus âIdra di Muragliaâ and C. persicum âHalios White Pure Compactâ petals. In carnation, 1-MCP treatment slowed B. cinerea infection; its threshold level was reached three days after that of the control. In cyclamen, treated petals and control petals remained aesthetically good until day 53 and day 28 respectively. At low concentrations, 1-MCP slowed grey mould on R. Ă hybrida âRitzâ for up to three days beyond the control. On the two buttercup cultivars âGreenâ and âSaigonâ, 1-MCP treatments were not effective. In conclusion, 1-MCP limited pathogen development; its effect depended on the species and the 1-MCP concentration. Further investigations will be performed to improve methods to reduce B. cinerea development on the petals of cut flowers