Populus x euramericana cv. ‘Neva’ is an important tree species in northern China. In the study, we used its potted oneyear- old seedlings as experimental material and established three treatments (CK, 0.5X, and 1.0X) according to the concentrations of phenolic acids in order to examine the effects of different concentrations on the photosynthetic characteristics and growth of poplar. With increasing concentrations of phenolic acids, the net photosynthetic rate, stomatal limitation, transpiration rate, apparent quantum yield, photochemical quenching coefficient, electron transport rate, chlorophyll content, and total biomass decreased significantly. The intercellular CO2 concentration, light-compensation point, nonphotochemical quenching, malondialdehyde content, and root/shoot ratio increased significantly. Peroxidase and superoxide dismutase activities initially decreased and then increased. We concluded that phenolic acids significantly inhibited poplar’s photosynthesis and the higher phenolic acid concentration, the greater inhibition of photosynthesis occurred. This inhibition effect was mainly caused by nonstomatal factors. Phenolic acids induced noticeable photoinhibition, resulted in the irreversible damage of membrane structure, and then changed intracellular metabolic processes. To cope with phenolic acid stress, poplar seedlings increased dissipation of excess light energy and distributed relatively more biomass to underground parts within carbon allocation., D. F. Xie, G. C. Zhang, X. X. Xia, Y. Lang, S. Y. Zhang., and Obsahuje bibliografii
As a common waterfront and wet environment tree species, Salix babylonica shows a great potential for restoration of contaminated water or soil environments, such as phenol-polluted water. However, studies on such remediation effects have not been carried out yet. The objective of this study was to investigate the effects of phenols on photosynthesis of S. babylonica. Photosynthetic and chlorophyll fluorescence parameters of S. babylonica cuttings were determined in hydroponic experiment, where six phenol concentrations was used (0, 50, 100, 200, 400, and 800 mg L-1). Phenol presence inhibited photosynthesis of S. babylonica significantly, as the net photosynthetic rate (PN),
light-saturated net photosynthetic rate, apparent quantum yield, maximal quantum yield of PSII photochemistry, and effective quantum yield of PSII photochemistry declined significantly. The higher the concentration of phenol solution, the greater inhibition of photosynthesis occurred. Our data indicated that nonstomatal limitation was responsible for the reduction of PN. S. babylonica should be used to remediate phenol-contaminated water, when the concentration of phenol solution is lower than 200 mg L-1. Otherwise, the efficiency of photosynthesis of S. babylonica would decrease markedly. However, further study is needed to determine the maximum concentration of phenol that S. babylonica can tolerate to maintain normal photosynthetic activity., H. Li, G. C. Zhang, H. C. Xie, K. Li, S. Y. Zhang., and Obsahuje seznam literatury
Five new species of Mulcticola Clay et Meinertzhagen, 1938 are described and illustrated from Brazil. These new species and their hosts are: Mulcticola sicki sp. n. from the sand-coloured nighthawk, Chordeiles rupestris rupestris (Spix), Mulcticola bacurau sp. n. from the common pauraque, Nyctidromus albicollis (Gmelin), Mulcticola tendeiroi sp. n. from the long-trained nightjar, Macropsalis forcipata (Nitzsch), Mulcticola piacentinii sp. n. from the short-tailed nighthawk, Lurocalis semitorquatus semitorquatus (Gmelin) (type-host) and L. s. nattereri (Temminck), and Mulcticola parvulus sp. n. from the little nightjar, Setopagis parvula (Gould). These species were compared primarily with Mulcticola nacunda Carriker, 1945 from the nacunda nighthawk, Chordeiles nacunda nacunda (Vieillot), which is one of the species of Mulcticola previously recorded in the Neotropical region. All the five new species described herein differ from their congeners by exclusive characters such as the shape of anterior dorsal head plate, metasternal plate, subvulvar plates in females and genitalia in males. We increased the number of species in Mulcticola to 18 in total, with seven of them now known from the Neotropics. We present the main morphological characters to distinguish Mulcticola from other species of the Philopteridae parasitising Caprimulgiformes and also compile a detailed catalogue for species included in this louse genus., Michel P. Valim, Kamila M. D. Kuabara., and Obsahuje bibliografii
Babesiosis is an emerging zoonotic disease and various wildlife species are reservoir hosts for zoonotic species of Babesia Starcovici, 1893. The objective of the present study was to investigate the presence and prevalence of Babesia spp. in moose Alces alces (Linnaeus) in two regions of Norway. A total of 99 spleen samples were collected from animals of various ages from an area with the occurrence of the tick Ixodes ricinus (Linnaeus, 1758), and from an area where the ticks are known to be absent. Infection was detected by the amplification of different regions of the 18S rRNA gene by using two different PCR primer sets specific of Babesia. Babesia spp. were found in the spleen samples of four moose. All Babesia-infected animals were from an area where ticks occur, with an infection rate of 6% (4 of 70). Babesia-positive samples were obtained from a five-month old moose calf and three adults. Two Babesia species, Babesia capreoli (Enigk et Friedhoff, 1962) and a B. odocoilei-like, were identified. Co-infection with Anaplasma phagocytophilum was obtained in two animals. This is the first report of the occurrence of B. capreoli and B. odocoilei-like species in moose., Irma Pūraitė, Olav Rosef, Jana Radzijevskaja, Indrė Lipatova, Algimantas Paulauskas., and Obsahuje bibliografii
The aim of this review is to explain the functional significance of mantis peering behaviour from an entomological perspective. First the morphological and optical features of the mantis compound eye that are important for spatial vision are described. The possibility that praying-mantises use binocular retinal disparity (stereopsis) and other alternative visual cues for determining distance in prey capture, are discussed. The primary focus of the review is the importance of peering movements for estimating the distance to stationary objects. Here the following aspects are examined: (1) Direct evidence via object manipulation experiments of absolute distance estimation with the aid of self-induced retinal image motion; (2) the mechanism of absolute distance estimation (with the interaction of visual and proprioceptive information); (3) the range of absolute and relative distance estimation; (4) the influence of target object features on distance estimation; and (5) the relationship between peering behaviour and habitat structures, based on results of studies on three species of mantis., Karl Kral., and Obsahuje seznam literatury
a1_The infraspecific taxonomy of the European populations of the Large Blue (Maculinea arion) is confusing. Several subspecies have been described mostly based on external morphological features. In the Carpathian Basin two subspecies have been distinguished. Maculinea arion arion flies from mid-May to mid-June and Maculinea arion ligurica is on the wing from the end of June to mid-August. The two forms show some differentiation in habitat use, but occasionally can also share habitats with two peaks in the appearance of butterflies. Our aim was to study the level and structure of genetic variation in a set of populations of the two phenologically different M. arion. Imagos were collected from 8 localities between 2000 and 2006. Enzyme polymorphism was analysed at 13 enzyme loci using polyacrylamide gel electrophoresis. In the analysis of the data, we estimated the parameters of polymorphism. To study the pattern of genetic differentiation F-statistics, hierarchical F-statistics and AMOVA were computed. GeneClass and Structure were both applied to analyse the differentiation between the two phenologically different sets of populations. Cavalli-Sforza and Edwards' arc distances were calculated and a UPGMA dendrogram was constructed on the basis of the distance matrix. PCA analysis was also carried out using the allele frequencies of the individuals. The level of polymorphism was relatively high in M. arion. The results of all analyses indicated that the differences between the two sets of phenologically different populations accounted for a low percentage of the total differentiation. In addition, a sizeable amount of variation could be attributed to the differences among the samples collected from the same population in consecutive years. Thus, we concluded that the "spring" and "summer arion" could not be considered as separate ESUs, although we could attribute conservation value to both forms on the basis of, a2_their phenological differentiation and habitat use., and Judit Bereczki, János P. Tóth, Andrea Tóth, Edit Bátori, Katalin Pecsenye, Zoltán Varga.
Endemic Sicilian pond turtles Emys trinacris Fritz, Fattizzo, Guicking, Tripepi, Pennisi, Lenk, Joger et Wink were examined for the presence of haemogregarine parasites. The presence of haemogregarines, occurring mainly in the microgametocyte stage (13.2 ± 0.12 μm in length and 6.4 ± 0.52 μm in width), was observed in approximately 9% of the sampled E. trinacris. Based on the observed morphology and on the sequencing of nuclear 18S rDNA, we identified the parasite as Haemogregarina stepanowi Danilewsky, 1885. Morphometric study of uninfected and infected red blood cells has shown that H. stepanowi induces different changes in erythrocyte shape depending on the infective stage. The differential count of leukocytes in specimens infected with H. stepanowi showed no significant difference compared with healthy specimens. However, considering the health problems which might be induced by H. stepanowi in the closely related European pond turtle Emys orbicularis (Linneaus), monitoring of the health status of the infected Sicilian populations of E. trinacris is desirable. The restricted distribution of populations of Emys infected with haemogregarines in Sicily is quite puzzling and the possible human-mediated introduction of the parasite in Sicily is briefly discussed., Vincenzo Arizza, Francesco Sacco, Debora Russo, Rita Scardino, Marco Arculeo, Melita Vamberger, Federico Marrone., and Obsahuje bibliografii
Atmospheric CO2 concentration continues to rise and is predicted to reach approximately 700 ppm by 2100. Some predictions suggest that the dry season in West Africa could be extended with climate change. This study examined the effects of elevated CO2 concentration and water deficit on growth and photosynthesis of juvenile cacao. Light-saturated photosynthesis (Pmax), quantum efficiency, and intrinsic water-use efficiency increased significantly in response to elevated CO2, as did a range of growth and development responses (e.g. leaf area and leaf number), but the magnitude of the increase was dependent on the water treatment. Stomatal index was significantly greater in the elevated CO2 treatment; an atypical response which may be a reflection of the environment in which cacao evolved. This study shows a positive effect of elevated CO2 on juvenile cacao which may help to alleviate some of the negative impacts of water deficit stress., F. Lahive, P. Hadley, A. J. Daymond., and Obsahuje bibliografii
The objective of this study was to evaluate the significance of blue light (B) in the growth and photosynthetic capacity of cucumber. Gas exchange, chlorophyll (Chl) fluorescence kinetics, chloroplast ultrastructure, and leaf growth were investigated to explore the influence of three different light qualities of light emitting diodes (LEDs) on plant morphogenesis and the development of photosynthetic apparatus in cucumber (Cucumis sativus) leaves from emergence to full expansion under weak light [50 μmol(photon) m-2 s-1]. We found that B could significantly increase the leaf area (LA), shoot elongation, Chl a/b, net photosynthetic rate, and stomatal conductance (g s). In addition, the comparisons of maximal quantum yield of PSII photochemistry and the photosynthetic performance index between B-, W (white light)-, and R (red light)-grown leaves suggested that B was essential for the development of photosynthetic apparatus under weak light. B-grown leaves had the lowest Chl content under weak light, however, they had well-developed chloroplasts with the highest degree of stacked lamellae and the lowest starch accumulation. This could explain to a considerable extent the highest net photosynthetic rate per Chl unit. The results demonstrated that B optimized photosynthetic performance by improving the photosynthetic rate, increasing LA, and prolonging active photosynthesis duration under low irradiance. Therefore B is necessary to ensure healthy development of chloroplasts and highly efficient photosynthetic functions in cucumbers under a weak light environment. More importantly, our study also provided theoretical and technical support for the development of light environmental control technology., X. Y. Wang, X. M. Xu, J. Cui., and Obsahuje bibliografii
The purpose of the current investigation was to evaluate the influence of antimycin A (AA) as an activator of the alternative respiratory pathway (AP) on photosynthetic pigment composition and functional activity of the photosynthetic apparatus of wheat seedlings (Triticum aestivum L.) under exposure to high temperature as well as their acclimation. Our results indicated that a significant decrease (44-74%) of photosynthetic pigment contents was caused by a long-term exposure to high temperature (42°C), while the short-term exposure resulted in 20-46% decline. However, a combined effect of AA and long-term high temperature reduced the total pigment contents by 28-41%. Our results demonstrated that the reduction of the chlorophyll a/b ratio was less significant under the combined effect of AA and high temperature than that under the stressful condition without AA. We observed that short-term and long-term high temperature modified PSII functionality of the first leaves in wheat seedlings, which was manifested by the low maximal quantum yield of PSII photochemistry, maximum fluorescence yield in the dark-adapted state, and by high minimum fluorescence yield in the dark-adapted state. The quantum yield of PSII photochemistry decreased rapidly by 16-24% under the combination of AA and high temperature. Overall, these results suggest that the activation of the alternative pathway, induced by AA, contributed to the stabilization of the photosynthetic apparatus in wheat seedlings under high temperature., A. Batjuka, N. Škute, A. Petjukevičs., and Obsahuje bibliografii