In order to test the effects of irrigation depth on winter wheat photosynthesis, four treatments were applied in a field experiment using PVC growth tubes (identical amounts of water were applied on the land surface, and at 60, 75, and 90% of the depth for the winter wheat root distribution, denoted as D0, D60, D75, and D90, respectively). Compared to the surface irrigation treatment D0, the leaf area index, chlorophyll content, net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO2 concentration increased with irrigation depths. The values of these indicators obtained by the underground irrigation treatment D75 were higher than those of D60 and D90, and thus D75 was found to be the optimum irrigation depth. Furthermore, a positive but not significant correlation (r = 0.62) between carbon isotope discrimination (Δ13C) and grain yield was found. This study improves our understanding of the mechanism of underground water distribution control with depth, and the efficiency of
water-saving irrigation for winter wheat., L. J. Zheng, J. J. Ma, X. H. Sun, X. H. Guo, J. Jiang, R. Ren, X. L. Zhang., and Obsahuje bibliografii
In a field experiment, two winter wheat (Triticum aestivum L.) cultivars, Tainong 18 (a large-spike cultivar) and Jinan 17 (a multiple-spike cultivar), were treated with 78% (S1), 50% (S2), and 10% (S3) of full sunshine (S0, control) from anthesis to maturity to determine the responses of photosynthetic characteristics and antioxidative enzyme activities in a flag leaf. Compared with S0 treatment, the chlorophyll (Chl) content and maximal efficiency of photosystem II (PSII) photochemistry (Fv/Fm) of flag leaves were enhanced in treatments S1 and S2. From 0 to 7 d post flowering, the Chl content and Fv/Fm in S3 were also higher than those in S0, but significantly lower than those in controls, respectively. With the increase of shading intensity, the effective quantum yield of PSII (ΦPSII) was promoted; whereas, the ratio of Chl a/b declined. Compared with S0, treatments S2 and S3 significantly suppressed the activities of superoxide dismutase (SOD) and peroxidase (POD), net photosynthetic rate (PN), and contents of total soluble sugar, nevertheless, S1 treatment showed positive effects on the above parameters. Under the same shading condition, Jinan 17 had larger Chl content and higher activities of PSII and antioxidative enzymes, but lower malondialdehyde (MDA) content than Tainong 18. The results indicated that multiple-spike cultivar was more advantageous for the Huang-Huai-Hai Plain, where shading problem occurs later during the growth period, than the large-spike cultivar, because of the lesser damage in a flag leaf and better photosynthetic function of the former one. Wheat plants under S1 shading condition had relatively high activities of antioxidative enzymes and a low degree of membrane lipid peroxidation, which was in favor of stress resistance, maintaining high PN duration, and accumulation of photosynthates in wheat plants., C. Xu ... [et al.]., and Obsahuje bibliografii
The widespread Mediterranean Pinus pinea showed exceptionally low genetic diversity and low differentiation between traits in the adult phase. We explored the adaptation potential of seedlings from four main Iberian provenances during their regeneration phase. We assessed the variability of shoot growth, allometry, physiological traits, and phenotypic plasticity to the interactive effect of light and water environments during 8-month moderate water-stress cycle and after one-week heat wave. The effect of shade and drought was mainly orthogonal whatever the provenance. The inland La Mancha provenance showed higher shoot growth and biomass compared to the southern coastal Depresión-del-Guadalquivir provenance. Following the heat wave, La Mancha presented higher net photosynthetic rates, a lower decrease in maximal quantum efficiency of PSII, and a higher accumulated relative height growth, thus, showing an adaptive advantage. The observed differences corroborated the ecological grouping of the provenances along latitudinal and inland-coastal gradients. We confirmed the high adaptive plasticity of Pinus pinea to the unpredictable Mediterranean environment., M. Pardos, R. Calama., and Obsahuje bibliografii
The responses of photosynthesis and growth to increasing CO2 concentration ([CO2]) were investigated in Hippophae gyantsensis and H. rhamnoides subsp. yunnanensis, which are endemic at the Qinghai-Tibet Plateau and phylogenetically related, but distributed parapatrically in divergent regions. Seedlings of the two species were grown at ambient [AC; 360 μmol(CO2) mol-1] and elevated [EC; 720 μmol(CO2) mol-1] [CO2] in growth chambers. The responses to EC were significantly different between the two species. EC induced an increase in photosynthesis, stomatal conductance, intrinsic water-use efficiency, apparent quantum efficiency, total dry mass, and a decrease in photorespiration rate, maximum carboxylation rate of Rubisco, and maximum electron transport rate in H. gyantsensis compared to those in H. rhamnoides subsp. yunnanensis. Moreover, a significant increase in leaf nitrogen content and a decrease in root/shoot ratio was also observed in H. gyantsensis. H. gyantsensis showed a significantly higher specific leaf area than that of H. rhamnoides through treatments. Relative to H. rhamnoides subsp. yunnanensis, H. gyantsensis showed a greater potential to increase photosynthesis and growth to cope with the increasing [CO2] and it might expand its distribution range in the future., F. Ma, T. T. Xu, M. F. Ji, C. M. Zhao., and Obsahuje seznam literatury
We studied photosynthetic capacity, growth, sap flow, and water-use efficiency in young trees of ‘Pink Lady’ apple (Malus domestica) that were exposed to 60 d of moisture stress. Three irrigation schemes were tested in the greenhouse: well-watered control; drought; or alternate deficit irrigation (ADI). Compared with the drought-stressed plants, those treated via ADI showed better height growth, larger scion diameters, and greater total leaf area, as well as significantly increased gains in dry biomass and rootstock diameters. However, their performance was still significantly lower than that demonstrated by continuously well-watered plants. Sap flow was greater under ADI than under drought, but less than under control conditions. The average rate of net photosynthesis, total amount of irrigation water applied, and dry biomass gain had highly significant and positive linear correlations with long-term water-use efficiency (WUEL). The same was true between average stomatal conductance and WUEL. By contrast, instantaneous water-use efficiency (WUEI) was very significantly and negatively correlated with WUEL. In addition, values for WUEL were much higher from well-watered plants when compared with either drought-stressed trees or those treated per ADI. Therefore, our results indicate that, although ‘Pink Lady’ apple normally has high WUE, it still consumes a large amount of water. Therefore, the practice of ADI following a period of long-term drought could be used to improve growth and WUEL by this cultivar., X. P. Sun ... [et al.]., and Obsahuje bibliografii
The effects of ambient levels of ozone and summer drought were assessed on a poplar clone (Populus maximowiczii Henry X P. × berolinensis Dippel - Oxford clone) in an open top chamber experiment carried out at the Curno facilities (Northern Italy). Chlorophyll (Chl) a fluorescence parameters (from both modulated and direct fluorescence) were assessed at different hours of the day (predawn, morning, midday, afternoon, and evening), from June to August 2008. This paper compares the results from predawn (PD, before sunrise) and afternoon (AN, in full sunlight) measurements, in order to evaluate the role of high sunlight as a factor influencing responses to ozone stress. Sunlight affected the maximum quantum yield of primary photochemistry (decrease of Fv/Fm) thus indicating photoinhibition. The effective quantum yield (ΦPSII) and the photochemical quenching (qP) were enhanced in the afternoon with respect to the predawn, whereas the nonphotochemical quenching (NPQ) was reduced. The effect of ozone was detected with fluorescence on well watered plants in the first week of July, before the onset of visible symptoms. As far as Fv/Fm are concerned, the differences between ozone-treated and control plants were statistically significant in the predawn, but not in the afternoon. Ozone exerted only minor effects on drought exposed plants because of the reduced stomatal ozone uptake, but effects on the IP phase of the fluorescence transient were observed also in drought-stressed plants., R. Desotgiu ... [et al.]., and Obsahuje bibliografii
Retinol binding protein 4 (RBP4) is a novel adipokine which might be involved in the development of insulin resistance. The aim of the study was to investigate the expression of RBP4 mRNA in subcutaneous and visceral fat depots and the relationship between RBP4 plasma and mRNA levels relative to indices of adiposity and insulin resistance. In 59 Caucasian women (BMI 20 to 49 kg/m2 ) paired samples of subcutaneous and visceral fat were obtained for RBP4, leptin and GLUT 4 mRNA analysis using reverse transcription-quantitative PCR. Euglycemic hyperinsulinemic clamp and computed tomography scans were performed. RBP4 mRNA levels as well as GLUT 4 mRNA and leptin mRNA levels were lower (P<0.001, P<0.01 and P<0.001, respectively) in visceral compared to subcutaneous fat. No differences were found in RBP4 mRNA expression in the two fat depots or in RBP4 plasma levels between subgroups of non-obese subjects (n=26), obese subjects without metabolic syndrome (n=17) and with metabolic syndrome (n=16). No correlations between RBP4 mRNA or plasma levels relative to adiposity, glucose disposal rate and GLUT 4 mRNA expression in adipose tissue were found. There was a weak positive correlation between plasma RBP4 and plasma triglycerides (r = 0.30, p<0.05) and between plasma RBP4 and blood glucose (r = 0.26, p<0.05). Regardless of the state of adiposity or insulin resistance, RBP4 expression in humans was lower in visceral than in subcutaneous fat. We found no direct relationship between either RBP4 mRNA or its plasma levels and the adiposity or insulin resistance. and Obsahuje bibliografii a bibliografické odkazy
In the present study, we critically revised the recently proposed classification of the subfamily Leishmaniinae Maslov et Lukeš in Jirků et al., 2012. Agreeing with erection of the genus Zelonia Shaw, Camargo et Teixeira in Espinosa et al., 2017 and the subgenus Mundinia Shaw, Camargo et Teixeira in Espinosa et al., 2017 within the genus Leishmania Ross, 1908, we argue that other changes are not well justified. We propose to: (i) raise Paraleishmania Cupolillo, Medina-Acosta, Noyes, Momen et Grimaldi, 2000 to generic rank; (ii) create a new genus Borovskyia gen. n. to accommodate the former Leptomonas barvae Maslov et Lukeš, 2010 as its type and only species; (iii) leave the subfamily Leishmaniinae as originally defined, but establish two infrafamilies within it: Leishmaniatae infrafam. n. and Crithidiatae infrafam. n., Alexei Y. Kostygov, Vyacheslav Yurchenko., and Obsahuje bibliografii
A revisionary study revealed two species of monogeneans, Dactylogyrus crucis Rogers, 1967 and Dactylogyrus lythruri sp. n., parasitising Lythrurus Jordan (formerly a subgenus of Notropis Rafinesque, 1818). New records and updated taxonomy of seven of 12 known minnows of the genus of Lythrurus are provided for D. crucis. A record of Dactylogyrus attenuatus Mizelle et Klucka, 1953 (syn. Dactylogyrus umbratilus [Kimpel, 1939], nomen nudum) on Lythrurus umbratilis (Girard) is referrable to D. crucis. Dactylogyrus lythruri is described from eight species of Lythrurus. It most closely resembles Dactylogyrus beckeri Cloutman, 1987, but is distinguished by having a smaller base of the male copulatory organ (MCO) and lacking a ventral enlargement of the distal end of the basal process. Previous reports of Dactylogyrus banghami Mizelle et Donahue, 1944 and Dactylogyrus cf. beckeri Cloutman, 1987 from Lythrurus atrapiculus (Snelson) and Lythrurus bellus (Hay) from Alabama, and Dactylogyrus confusus Mueller, 1938 from L. umbratilis in Illinois are herein relegated to D. lythruri. Four species of Lythrurus appeared not to be infected with Dactylogyrus., Donald G. Cloutman, Andrew B. Adrian, Chris T. McAllister, Bruce W. Stallsmith, Thomas J. Fayton and Henry W. Robison., and Obsahuje bibliografii
The planthopper genus Pseudoparicana Melichar, 1914 is revised. Three previously known species, P. curvifera (Distant, 1907), P. sanguinifrons Muir, 1931 and P. tepida Melichar, 1914 are re-described and P. analoga Wang & Malenovský sp. n. is described as new. Lectotypes are designated for P. curvifera and P. tepida. An identification key and illustrations of diagnostic characters, including male and female genitalia, are provided for all taxa and the systematic position of this genus and the asymmetry of the genitalia of the species are briefly discussed. As far as known, the distribution of Pseudoparicana is restricted to New Guinea and the Aru Islands., Rong-Rong Wang ... [et al.]., and Obsahuje seznam literatury