7-day soil drought followed by 7-day rehydration was applied to potted German chamomile (Chamomilla recutita) plants at the beginning of their generative stage. Plants of a wild type (WT), plus two diploid (2n) and two tetraploid (4n) genotypes were studied, in order to examine the alterations in chlorophyll (Chl) and carotenoids (Car) contents, and chlorophyll fluorescence (CF) parameters during water shortage and rehydration. The fresh mass of the anthodia after the recovery was also studied.
WT plants adjust better to water stress than modern breeding genotypes, because drought resulted in the low fall in leaf water content of WT, the lowest decrease in the fresh mass of its anthodia (a 41% decrease from the control), and the most elastic response of the photosynthetic apparatus. 4n C11/2 strain plants suffered from the highest reduction in anthodia yield (87%), and had the lowest constitutive pigment contents. It was also the only genotype which revealed nontypical alterations in various CF parameters obtained on a dark- and light-adapted leaf. During drought, a big increase was noticed in minimal, maximal, and variable fluorescence of PSII reaction centres in the dark- adapted (F0, Fm and Fv, respectively), and in the light-adapted state (F0', Fm' and Fv')., It was accompanied by the biggest decline in linear electron transport rate (ETR), quantum efficiency of PSII electron transport (ΦPSII) and photochemical quenching coefficient (qP). These alterations were prolonged to the stage when the normal leaf water content was retained. On the contrary, C6/2 strain plants had the highest constitutive Chl and Car contents, which additionally increased after rehydration, similarly to the values of F0, Fm and Fv, which reflects the high photosynthetic potential of this genotype. It was accompanied by the relatively high yield of its anthodia after drought. Considering the drop in the yield triggered by drought, it seems to be the only parameter which may be linked with the ploidy level.
Although the yield formation of chamomile strains cannot simply be estimated by CF assay, this technique may serve as an additional tool in the selection of plants to drought. The following circumstances should be submitted; namely: measurement at the proper developmental stage of plants, in different water regimes, and an analysis of various CF parameters. The increase in F0 and F0', and the reduction in ETR, Fv'/Fm', ΦPSII and qP values in response to water deficit should be an indicator of the impairment of the photosynthetic apparatus through drought., and R. Bączek-Kwinta ... [et al.].
In order to study a possible effect of mini-invasive heart intervention on a response of hypothalamo-pituitary-adrenal stress axis, we analyzed four stress markers (cortisol, cortisone, DHEA and DHEAS) in 25 sows using minimally invasive heart catheterisation as the stress factor. The marker levels were assessed in four periods of the experiment, (1) the baseline level on the day before intervention, (2) after the introduction of anesthesia, (3) after conducting tissue stimulation or ablation, and (4) after the end of the catheterisation. For statistical analyses we used the non-parametric Friedman test for four dependent samples (including all four stages of the operation) or three dependent samples (influence of operation only, baseline level was excluded). Statistically significant differences in both Friedman tests were found for cortisol and for cortisone. Significant differences for DHEA as well as for DHEAS were found for all tested stages but not for the effect of operation itself. We have concluded that cortisol levels are blunted by the influence of anesthesia after its administration, and therefore decrease back to the baseline at the end of the operation. The other markers (cortisone, DHEA and DHEAS) acted as balanced systems against the injurious stress effect., H. Skarlandtová, M. Bičíková, P. Neužil, M. Mlček, V. Hrachovina, T. Svoboda, E. Medová, J. Kudlička, A. Dohnalová, Š. Havránek, H. Kazihnítková, L. Máčová, E. Vařejková, O. Kittnar., and Obsahuje bibliografii
Action potentials (APs) and the force of isometric contractions of the right ventricular papillary muscles were measured in adult and newborn guinea-pigs. The measurements were carried out in the steady state with the rate of stimulation of 0.1, 1, and 2 Hz, and further some measurements were done in which Sr2+ was substituted for Ca2- The duration of APs of the newborn animals without pharmacological treatment was significantly shorter in comparison with that of the adults at all the used stimulation frequencies. An analogous sensitivity was found in the contractile force to increased stimulation frequency and when the steady state stimulation was discontinued by the insertion of interpolated extrasystoles in papillary muscles of adult or newborn animals. The biphasic contractions of papillary muscles were evoked in both groups of animals by the incomplete substitution of Sr2+ by Ca2+ in the presence of isoprenaline. The early component of the biphasic contractions had a faster course as compared to the late component and disappeared in the presence of caffeine in both groups of animals. Our results suggest that the heart cells of newborn guinea-pigs probably possess the sarcoplasmic reticulum (SR), whose function does not differ in quality from that of the adult guinea-pigs. The postnatal prolongation of APs is therefore not probably the result of postnatal development changes of the functions of SR, but could be related to changes in the relations between the surface and volume of the heart cell during its growth.
Two hundred and ninety-nine specimens of Atherina boyeri, collected from five Mediterranean sites (three from the open sea (Chioggia, Catania and Gaeta) and two from river mouths (the Birgi and S. Bartolomeo rivers) were analyzed in order to confirm previous genetic studies. Eigtheen loci were scored from 12 enzymatic systems, 3 of which were polymorphic: EST*, PGM* and PGI*. Mean Fst value (0.300, pFst and genetic distance revealed that samples from the river mouths (Birgi and S. Bartolomeo) were grouped separately from the open sea samples (Catania, Chioggia and Gaeta). These results are in agreement with the most recent classification, which considers A. boyeri as a complex of 3 different species.
Altogether 445 bats, representing nine species, caught during swarming in the Lodowa Cave in Mount Ciemniak, Western Tatra Mountains, southern Poland, were examined for ectoparasitic mites. In total, 259 spinturnicid (Spinturnix mystacina, S. andegavinus, S. kolenatii, S. plecotinus and S. myoti) and 95 argasid (Carios vespertilionis) mites were collected from seven bat species, Myotis myotis, M. mystacinus, M. brandtii, M. daubentonii, Eptesicus nilssonii, Plecotus auritus, and Vespertilio murinus. There were sex-based differences in the prevalence of mites in some hosts but no differences in their mean intensity and there was no observed relationship between the number of mites and the condition of the bats. The prevalence of mites differed significantly between years in E. nilssonii. The results suggested a very low mite load on swarming bats that had no impact on the body condition of bats.