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274752. Effects of temperature on the activity of antioxidant enzymes in larvae of Bactrocera dorsalis (Diptera: Tephritidae) parasitized by Diachasmimorpha longicaudata (Hymenoptera: Braconidae): optimizing the mass rearing of this braconid by varying the temperature
- Creator:
- Cai, Pumo , Wang, Yong , Yi, Chuandong , Zhang, Qiwen , Xia, Huimin , Lin, Jia , Zhang, Hehe , Yang, Jianquan , Ji, Qinge , and Chen, Jiahua
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- Diptera, Tephritidae, Bactrocera dorsalis, Hymenoptera, Braconidae, Diachasmimorpha longicaudata, parasitoid, altering temperatures, mass-reared, and activity of antioxidants
- Language:
- English
- Description:
- Diachasmimorpha longicaudata is the most widely used endoparasitoid in biocontrol programmes against various species of tephritids and is continuously mass-reared under laboratory conditions at a constant temperature; however, little is known about how varying the temperature might affect the effectiveness of the mass rearing of immature D. longicaudata. This study aimed to determine the optimum temperature for the development of larvae D. longicaudata the larvae of its host, Bactrocera dorsalis. Third-instar B. dorsalis were exposed for 4 h to five pairs of parasitoids, and then they were kept at one of six temperatures ranging from 19°C to 34°C. The activities of three major antioxidant enzymes (CAT, POX, SOD) were individually measured 4, 24, 48 and 72 h after exposure to each of the six temperatures. The results were as follows: for CAT the highest CAT activities were recorded at 25°C (intervals 5-24 h and 25-48 h), at 28°C (interval 0-4 h) and at 31°C (interval 49-72 h), and for POX and SOD identically at 25°C (intervals 0-4 h, 5-24 h) and at 31°C (intervals 25-48 h, 49-72 h), respectively. Subsequently, the effects keeping the parasitized larvae at these different temperatures on the biological attributes of D. longicaudata reared under laboratory conditions were investigated. The percentage of their eggs that hatched, percentage of adults that emerged, pupal weight and longevity were significantly greater than that recorded for the control when the parasitized host larvae were kept at 28°C for 4 h, 25°C for 5 and 48 h and 31°C for 49 and 72 h.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
274753. Effects of temperature on the phenology of germination of Isoëtes echinospora
- Creator:
- Čtvrtlíková, Martina, Znachor, Petr, Nedoma, Jiří, and Vrba, Jaroslav
- Type:
- article, model:article, and TEXT
- Subject:
- aquatic macrophyte, quillwort, reproduction, ontogeny, and germination
- Language:
- English
- Description:
- Isoëtes echinospora, a submerged aquatic quillwort, is native in northern latitudes and a rare glacial relict in mountain lakes in temperate Central Europe. A relic population of this quillwort in the Plešné jezero lake has recovered recently from a 30-year period of failure to reproduce caused by acidification. Early ontogenetic stages of the quillwort are considered to be the most vulnerable to environmental changes. Therefore, the objective of this study was to investigate the phenology of germination of I. echinospora. In a two-year experiment, we examined the time course of germination of micro- and macrospores and establishment of sporelings under (i) natural in situ conditions in the Plešné jezero lake and (ii) at various temperatures (6–17 °C) in the laboratory. We developed a mathematical model that describes the temperature-specific temporal changes in the early ontogeny of I. echinospora. Our experiments clearly show that spores do not germinate at once but gradually over time if exposed to favourable temperatures. Generally, percentage germination tended to increase during the course of a season under most temperature regimes but was inhibited at the lowest temperature. With increasing temperature, microspores germinated earlier and more successfully than macrospores, as described by the model. Sporelings also developed faster at the higher temperature. However, the highest temperature used in the experiments (17 °C) desynchronized the phenology of germination in I. echinospora as it resulted in the two types of spore not being available for fertilization at the same time. Thus, climate change might affect interactions between temperature and the phenology of quillwort reproduction and threaten the survival of this species in Central Europe.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
274754. Effects of thallus temperature and hydration on photosynthetic parameters of Cetraria islandica from contrasting habitats
- Creator:
- Hájek, J., Barták, M., and Gloser, J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll fluorescence, Cladonia rangiferina, high and low attitude, high and low temperature, iceland moss, irradiance response curves, lichens, Pseudevernia furfuracea, and shade acclimation
- Language:
- Multiple languages
- Description:
- Two methods of induced in vivo chlorophyll (Chl) fluorescence were used to investigate the effects of varying thallus temperature and hydration on the performance of photosynthetic apparatus of a foliar lichen Cetraria islandica: slow Chl fluorescence induction kinetic with the analysis of quenching mechanisms, and rapid irradiance response curves of photosynthesis derived from quantum yield of photochemical reactions of photosystem 2 (Φ2) recorded at increasing irradiances. We compared responses of photosynthetic apparatus in populations of C. islandica growing in lower altitude (LAP: 1 350 m a.s.l.) and in higher altitude (HAP: 2 000 m a.s.l.). At each altitude, the samples were collected both in fully irradiated sites (HI) and in shade (LI). Temperature optimum of photosynthetic processes was the same for LAP and HAP thalli of LI populations (18 °C), while it was significantly lower for HI HAP (14 °C). Gradual dehydration of fully hydrated thalli led to initial increase (up to 20 % of water saturation deficit, WSD) in FV/FM and Φ2, no change at 20-50 % WSD, and a dramatic decrease of the parameters within 50-80 % of WSD. LI HAP of C. islandica was the best adapted population to low temperature having higher rates of photochemical processes of photosynthesis than HI HAP within temperature range of -5 to +5 °C. The differences between populations were apparent also in Chl content and thallus morphology. and J. Hájek, M. Barták, J. Gloser.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
274755. Effects of the applícation of cement kiln exhausts on leaf biochemistry in certain legume crops
- Creator:
- Saralabai, V.C. and Vivekanandan, M.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- ascorbic acid, enzymes, growth characters, N-compounds, photosynthetic rate, photosystem 2, saccharides, stomatal resistance, superoxide dismutase, and transpiration rate
- Language:
- Multiple languages
- Description:
- Application of the electrostatic precipitator (ESP) dust to soil and leaves of Cajanus cajan, Vigna mungo, Vigna radiata, Vigna catjung and Glycina max increased biomass, chloroplast pigments, Chemical constituents and enzyme activities of leaves, besides crop productivity evidently indicating that the dust acted as a fertilizer. The net photosynthetic rate, photosystem 2 activity and rate of transpiration were not altered in špite of the dust forming a thin uniform coating ověř the leaf surface. The contents of intermediary N-compounds like allantoin, allantoic acid and total ureides of the leaves, which might serve as an indirect evidence of symbiotic N2-fixation, were higher in the treated plants. There were increments in free proline, soluble proteins, total nitrogen, nitrates, nitrites, soluble sugars and phenols in the treated plants. The concentrations of ffee amino acids, soluble starch, total sucrose and water soluble SH compounds of the leaves of the control and treated plants did not show any significant difference. The activity of superoxide dismutase was significantly higher which possibly indicated its role in alleviation of H2O2 and Oj toxicity. Enzymes like nitráte reductase, nitrite reductase, glutamine S3mthetase, acid and alkaline phosphatases, carbonic anhydrase, catalase, glutathione reductase and ascorbate peroxidase also functioned normally. In the treated plants, the concentration of ascorbic acid was significantly higher in the roots and nodules indicating the possible role of ascorbic acid in stress alleviation.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
274756. Effects of the cold pressor test on cardiac autonomic control in normal subjects
- Creator:
- Mourot, Laurent, Bouhaddi, M., and Regnard, J.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, spektrální analýza, fraktály, physiology, spectrum analysis, fractals, heart rate variability, detrended fluctuation analysis, cold pressor test, 14, and 612
- Language:
- English
- Description:
- The cold pressor test (CPT) triggers in healthy subjects a vascular sympathetic activation and an increase in blood pressure. The heart rate (HR) response to this test is less well defined, with a high inter-individual variability. We used traditional spectral analysis together with the non-linear detrended fluctuation analysis to study the autonomic control of HR during a 3-min CPT. 39 healthy young subjects (23.7 ± 3.2 years, height 180.4 ± 4.7 cm and weight 73.3 ± 6.4 kg) were divided into two groups according to their HR responses to CPT. Twenty subjects have a sustained increase in HR throughout the test with reciprocal autonomic interaction, i.e. increase in sympathetic activity and decrease vagal outflow. In the 19 remainders, HR decreased after an initial increase, with indication of involvement of both sympathetic and vagal outflow. Baseline evaluation of the subjects revealed no difference between the two groups. Nevertheless, a higher sympathetic activity at the skin level during CPT was present in the group with decreased HR. Further studies are needed to explain why healthy subjects react differently to the CPT and if this has potential clinical implications., L. Mourot, M. Bouhaddi, J. Regnard., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
274757. Effects of the Gabčíkovo hydroelectric-station on the aquatic vegetation of the Danube river (Slovakia)
- Creator:
- Oťaheľová, Helena and Valachovič, Milan
- Type:
- article and TEXT
- Subject:
- macrophytes, aquatic habitats, vegetation succession, Gabčíkovo hydropower station, Danube river, and Slovakia
- Language:
- English
- Description:
- Vegetation in the river Danube was studied in 1972–2001 to document the changes associated with the construction of a water reservoir. Before 1993, only a single species of aquatic plant, Potamogeton pectinatus, was known to occur in the main channel of the river Danube, which forms the frontier between Slovakia and Hungary. In the 1980s the building of the Gabčíkovo hydroelectric power station started and was finished in 1993. At present, five different aquatic habitats occur in the study area. (i) In the upper part of the Čunovo reservoir, there are stands of reed; Zannichellia palustris and Elodea nuttallii were the first other macrophytes to colonize this area where there are now 11 species. (ii) The Old Danube consists of shallows and margins of the original riverbed, which since 1992 (1851–1811 river km) were occupied predominantly by Zannichellia palustris. The adjacent pools were colonized by Elodea nuttallii, Potamogeton species, Batrachium trichophyllum, Ceratophyllum demersum and Lemnaceae species, and Phalaris arundinacea dominates the littoral areas. (ii) The bypass canal harbours only the moss Cinclidotus riparius growing on the boulders. (iv) Two seepage canals were rapidly overgrown by macrophytes, many species of which were threatened species in Slovakia (Apium repens, Groenlandia densa, Hippuris vulgaris, Chara species). (v) Succession occurred in river arms on the left bank after the damming of the river which resulted in changes in spatial distribution and species composition of macrophytes; a North- American alien species Elodea nuttallii spread rapidly there.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/
274758. Effects of the interaction between ozone and carbon dioxide on gas exchange, ascorbic acid content, and visible leaf symptoms in rice leaves
- Creator:
- Imai, K. and Kobori, K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- dark respiration, net photosynthesis, Oryza sativa, photochemical oxidant, and stomatal conductance
- Language:
- Multiple languages
- Description:
- Tropospheric ozone (O3) decreases photosynthesis, growth, and yield of crop plants, while elevated carbon dioxide (CO2) has the opposite effect. The net photosynthetic rate (PN), dark respiration rate (RD), and ascorbic acid content of rice leaves were examined under combinations of O3 (0, 0.1, or 0.3 cm3 m-3, expressed as O0, O0.1, O0.3, respectively) and CO2 (400 or 800 cm3 m-3, expressed as C400 or C800, respectively). The PN declined immediately after O3 fumigation, and was larger under O0.3 than under O0.1. When C800 was combined with the O3, PN was unaffected by O0.1 and there was an approximately 20 % decrease when the rice leaves were exposed to O0.3 for 3 h. The depression of stomatal conductance (g s) observed under O0.1 was accelerated by C800, and that under O0.3 did not change because the decline under O0.3 was too large. Excluding the stomatal effect, the mesophyll PN was suppressed only by O0.3, but was substantially ameliorated when C800 was combined. Ozone fumigation boosted the RD value, whereas C800 suppressed it. An appreciable reduction of ascorbic acid occurred when the leaves were fumigated with O0.3, but the reduction was partially ameliorated by C800. The degree of visible leaf symptoms coincided with the effect of the interaction between O3 and CO2 on PN. The amelioration of O3 injury by elevated CO2 was largely attributed to the restriction of O3 intake by the leaves with stomatal closure, and partly to the maintenance of the scavenge system for reactive oxygen species that entered the leaf mesophyll, as well as the promotion of the PN. and K. Imai, K. Kobori.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
274759. Effects of the interaction between ozone and carbon dioxide on gas exchange, photosystem II and antioxidants in rice leaves
- Creator:
- Kobayakawa, H. and Imai, K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, ascorbic acid, chlorophyll II fluorescence, elevated CO2, glutathione, net photosynthesis, Oryza sativa, ozone, quantum efficiency, respiration, and stomatal conductance
- Language:
- Multiple languages
- Description:
- To understand the interactive effects of O3 and CO2 on rice leaves; gas exchange, chlorophyll (Chl) fluorescence, ascorbic acid and glutathione were examined under acute (5 h), combined exposures of O3 (0, 0.1, or 0.3 cm3 m-3, expressed as O0, O0.1, or O0.3, respectively), and CO2 (400 or 800 cm3 m-3, expressed as C400 or C800, respectively) in natural-light gas-exposure chambers. The net photosynthetic rate (PN), maximum (Fv/Fm) and operating (Fq'/Fm') quantum efficiencies of photosystem II (PSII) in young (8th) leaves decreased during O3 exposure. However, these were ameliorated by C800 and fully recovered within 3 d in clean air (O0 + C400) except for the O0.3 + C400 plants. The maximum PSII efficiency at 1,500 μmol m-2 s-1 PPFD (Fv'/Fm') for the O0.3 + C400 plants decreased for all measurement times, likely because leaves with severely inhibited PN also had a severely damaged PSII. The PN of the flag (16th) leaves at heading decreased under O3 exposure, but the decline was smaller and the recovery was faster than that of the 8th leaves. The Fq'/Fm' of the flag leaves in the O0.3 + C400 and O0.3 + C800 plants decreased just after gas exposure, but the Fv/Fm was not affected. These effects indicate that elevated CO2 interactively ameliorated the inhibition of photosynthesis induced by O3 exposure. However, changes in antioxidant levels did not explain the above interaction. and H. Kobayakawa, K. Imai.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
274760. Effects of the interaction between vapor-pressure deficit and salinity on growth and photosynthesis of Cucumis sativus seedlings under different CO2 concentrations
- Creator:
- Shibuya, T., Kano, K., Endo, R., and Kitaya, Y.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- vlhkost vzduchu, humidity, poptávka po odpařování, výměna plynu, analýza růstu, reakce na stres, vodní potenciál, evaporative demand, gas exchange, growth analysis, stress response, water potential, 2, and 581
- Language:
- Multiple languages
- Description:
- We studied growth and photosynthesis of cucumber (Cucumis sativus) seedlings under two vapor-pressure deficit levels (VPD; 0.4 and 3.0 kPa), two salinity levels (0 mM and 34 mM NaCl), and two CO2 concentrations ([CO2]; 400 and 1,000 μmol mol-1). Relative growth rate (RGR) decreased with increasing VPD, but the causal factor differed between salinity levels and CO2 concentrations. Under ambient [CO2], RGR decreased with increasing VPD at low salinity mainly due to decreased leaf area ratio (LAR), and decreased net assimilation rate (NAR) at high salinity. The decrease in intercellular [CO2] (Ci) with decreasing stomatal conductance caused by high VPD did not significantly limit net photosynthetic rate (PN) at low salinity, but PN was potentially limited by Ci at high salinity. At high [CO2], high VPD reduced LAR, but did not affect NAR. This is because the decrease in Ci occurred where slope of PN-Ci curve was almost flat., T. Shibuya, K. Kano, R. Endo, Y. Kitaya., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public