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1722. Selenium delays leaf senescence in oilseed rape plants
- Creator:
- Rahmat, S., Hajiboland, R., and Sadeghzade, N.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- nitrát reduktázy, rychlost fotosyntézy, fluorescence chlorofylu, selen, řepka olejka, leaf photochemistry, nitrate reductase, photosynthetic rate, chlorophyll fluorescence, selenium, oilseed rape, 2, and 581
- Language:
- Multiple languages
- Description:
- Effect of selenium on leaf senescence was studied in oilseed rape plants treated with 10 μM Na2SeO4 at a rosette growth stage. In addition to developmental senescence, N deficiency and leaf detachment were used for induction of senescence. Nonphotochemical quenching declined in old leaves as senescence became more advancing but rose progressively in the plants supplied by Se. The total carbohydrate and protein pools decreased with leaf age, while increased by the Se treatment. However, during senescence induced by N deficiency, Se did not change remarkably the C and N metabolism, but delayed senescence mainly through protection of plants from photoinhibitory effects. After detachment, untreated leaves became chlorotic and necrotic, while the Se-treated ones remained fairly green. Our results demonstrated that Se delayed leaf senescence by a maintaining or even improving photochemical activities. During developmental senescence, the Se effect on the extending life span of the leaves was additionally linked to the metabolic regulation of senescence., S. Rahmat, R. Hajiboland, N. Sadeghzade., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1723. Selenium improves photosynthesis and protects photosystem II in pear (Pyrus bretschneideri), grape (Vitis vinifera), and peach (Prunus persica)
- Creator:
- Feng, T., Chen, S. S., Gao, D. Q., Liu, G. Q., Bai, H. X., Li, A., Peng, L. X., and Ren, Z. Y.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, foliar feeding, fruit tree, gas exchange, intercellular CO2 concentration, 2, and 581
- Language:
- Multiple languages
- Description:
- The effects of selenium on photosynthesis and Chl fluorescence in pear, grape, and peach were analyzed. The foliar spray of amino acid-chelated selenium solution was performed soon after fruit setting, totally six times, with an interval of ten days. After seven days from the last spray, the leaves in the middle of shoots were examined. Foliar spray of selenium increased the net photosynthetic rate in pear, grape, and peach. In contrast, the treatment decreased stomatal conductance, transpiration rate, and substomatal CO2 concentration in all the three species. The selenium treatment improved the maximum quantum yield of PSII, effective quantum yield of PSII, and photochemical quenching in all three species. Conversely, the selenium treatment reduced nonphotochemical quenching in all three species. We suggested that selenium can improve photosynthesis and protect PSII in fruit crops., T. Feng, S. S. Chen, D. Q. Gao, G. Q. Liu, H. X. Bai, A. Li, L. X. Peng, Z. Y. Ren., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1724. Self-sustaining infrapopulation or colony? Redial clonal groups of Himasthla elongata (Mehlis, 1831) (Trematoda: Echinostomatidae) in Littorina littorea (Linnaeus) (Gastropoda: Littorinidae) do not support the concept of eusocial colonies in trematodes
- Creator:
- Kirill Vladimirovič Galaktionov, Podvyaznaya, Irina M, Nikolaev, Kirill E, and Levakin, Ivan A
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- kasty, rozmnožování (biologie), castes, reproduction, rediae, parthenitae, Digenea, eusociality, germinal mass, allometry, developmental arrest, feeding behaviour, 2, and 59
- Language:
- English
- Description:
- Trematode sporocysts and rediae reproduce by parthenogenesis, forming clonal groups in the molluscan host. It has recently become popular to consider these groups as eusocial colonies, with division of labour between rediae morphs: small 'soldiers' incapable of reproduction defend the colony, while large rediae reproduce. Alternatively, clonal groups can be considered as self-sustaining infrapopulations. We tested these two hypotheses in the light of new data on rediae of Himasthla elongata (Mehlis, 1831) from snails Littorina littorea (Linnaeus) concerning ultrastructure, growth character and composition of their groups. Clonal groups under study contained rediae of different age and maturity stages: small (young) rediae, rediae with early cercarial embryos, rediae with late embryonic cercariae, rediae with fully formed motile cercariae, rediae with redial embryos and degenerating rediae. Small rediae had a reproductive organ, the germinal mass, whereas most large rediae with developing cercariae did not, which contradicts the eusocialconcept. Overall distribution of rediae by size and by gut to body length ratio was bimodal, which agrees with the eusocial concept ('soldiers' and 'reproductives' as modal size classes). On closer inspection, however, the bimodal size-frequency distributions (SFD) turned out to be the sum of unimodal SFD of rediae at various stages of maturity. The overall bimodality was determined by the character of redial growth resulting in a relatively low occurrence of intermediate morphs and by the developmental arrest in young rediae. The facts that small rediae can attack other rediae and concentrate in the anterior parts of the mollusc can be explained by age-related feeding preferences and niche segregation. They are unlikely to be associated with the 'colony' defence against invaders. To sum up, clonal groups of H. elongata rediae in our study represented self-sustaining infrapopulations., Kirill V. Galaktionov, Irina M. Podvyaznaya, Kirill E. Nikolaev, Ivan A. Levakin., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1725. Sequence of physiological responses in groundnut (Arachis hypogaea L.) subjected to soil moisture deficit
- Creator:
- Jeyaramraja, P. R. and Thushara, S. S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, drought susceptibility, drought tolerance, net photosynthesis, peanut, physiological mechanism, water-use efficiency, 2, and 581
- Language:
- Multiple languages
- Description:
- Responses of drought-tolerant (DT) and drought-susceptible (DS) pot-grown groundnut (Arachis hypogaea L.) varieties to changes in leaf relative water content (RWC) were studied. Water stress (WS) was imposed on 30-day-old plants for 2 weeks. Leaf RWC decreased significantly under WS conditions with simultaneous decrease in net photosynthetic rate (PN) and stomatal conductance (gs). Even though no significant difference was observed between DT and DS varieties with regard to RWC, DT varieties were able to maintain significantly higher PN than DS varieties. Higher values of water use efficiency (WUE) were also observed in DT varieties during WS conditions. The decline in PN due to WS could be attributed to both reduction in g s (i.e. stomatal limitation) and to reduction in chlorophyll content (Chl). No significant difference in leaf area index (LAI) was found between DT and DS types and LAI was not reduced by WS. Significant differences were found among the studied groundnut varieties, but not between DT and DS types, in terms of root, aboveground, and total dry mass. These growth parameters significantly decreased under WS conditions. Based on the results, a sequence of physiological responses in groundnut crop subjected to WS was postulated. and P. R. Jeyaramraja, S. S. Thushara.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1726. Sequestration of aristolochic acids from meridic diets by larvae of Battus polydamas archidamas (Papilionidae: Troidini)
- Creator:
- Pinto, Carlos F., Urzúa, Alejandro, and Niemeyer, Hermann M.
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, entomologie, Lepidoptera, Papilionidae, Battus polydamas archidamas, Aristolochia chilensis, aristolochic acids, sequestration of toxins, uptake of toxins, 2, and 59
- Language:
- English
- Description:
- Larvae of the butterfly, Battus polydamas archidamas (Papilionidae: Troidini) feed exclusively on aristolochic acid (AAs)-containing Aristolochia species (Aristolochiaceae). The distribution of sequestrated AAs in the tissues (body, integument and osmeterial secretions) of B. polydamas archidamas larvae during their development, when fed on a meridic diet containing either a higher or lower concentration of AAs (AAI and AAII) than occurs naturally in the aerial tissues of their host plant, was determined. Accumulation of AAs in the body and integument was proportional to the weight of larvae and greater in the larvae that fed on the diet containing the higher concentration of AAs. Phenolic AAs (AAIa and AAIVa) not present in the diets were found in all larval tissues examined. Integument and body extracts had a higher AAI/AAII ratio than in the original diet and also a relatively high AAIa/AAIVa ratio, suggesting a preferred AAII to AAIa transformation in those larval tissues. In the osmeterial secretion, the value of the AAI/AAII ratio was similar to that in the diets and the AAIa/AAIVa ratio close to 1, which suggests that hydroxylation of AAI to AAIVa and of AAII to AAIa occur to similar extents. The higher accumulation of AAs and the relatively higher proportion of AAI, one of the most toxic AAs, in the integument, suggest that their role is to deter attacks by natural enemies. and Carlos F. PINTO, Alejandro URZÚA, Hermann M. NIEMEYER.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1727. Serological diagnosis of cystic echinococcosis in cattle
- Creator:
- Bulashev, Aitbay K, Suranshiev, Zhanbolat A, Akibekov, Orken S, Akanova, Zhanara Zh, and Abulgazimova, Gulmira A
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- měchožil zhoubný, Echinococcus granulosus, protoscoleces, excretory-secretory antigen, monoclonal antibody, ELISA, 2, and 59
- Language:
- English
- Description:
- An IgM murine monoclonal antibody (MAb) was obtained against the excretory-secretory antigen (ES-Ag) of in vitro reared protoscoleces of Echinococcus granulosus (Batsch, 1786). Western blotting revealed that the MAb recognised a 20.6 kDa protein of this ES-Ag. The MAb was used in sandwich enzyme-linked immunosorbent assay (s-ELISA) for selective sensitisation of the solid phase with the protoscolex-specific protein from its ES-Ag and somatic antigen (S-Ag) to examine serum samples of 108 cows from a cystic echinococcosis (CE) endemic area for specific antibodies and to compare the results with those from necropsies and an indirect ELISA (i-ELISA). The sensitivity of s-ELISA/ES-Ag, s-ELISA/S-Ag and i-ELISA/S-Ag was 48%, 52% and 62%, respectively. The low sensitivity of the ELISA was probably caused by the fact that 13 cows (62%) were infected with sterile cysts (acephalocysts and/or calcified foci) only. A relatively high specificity (80%) of s-ELISA/ES-Ag was observed in cows with fertile cysts. It also detected antibodies in the serum of two cows that had recovered from the disease according to the necropsy. The i-ELISA/S-Ag gave false results in testing sera from a healthy animal and from a cow with tubercular foci. Further analysis will be necessary to define more precisely the value of this study, because the duration of antibody elimination from the bloodstream of recovered cattle remains unknown. The solution of this problem will increase the specificity of the proposed test in monitoring herbivorous animals for CE., Aitbay K. Bulashev, Zhanbolat A. Suranshiev, Orken S. Akibekov, Zhanara Zh. Akanova, Gulmira A. Abulgazimova., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1728. Seroprevalence and risk factors of infections with Neospora caninum and Toxoplasma gondii in hunting dogs from Campania region, southern Italy
- Creator:
- Machačová, Tereza, Eva Bártová, Kamil Sedlák, Slezáková, Radka, Marie Budíková, Piantedosi, Diego, and Veneziano, Vincenzo
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- toxoplazmóza, vlci, toxoplasmosis, wolves, Itálie jižní, Italy, Southern, neosporosis, IFAT, antibody titres, Canis lupus, 2, and 59
- Language:
- English
- Description:
- Hunting dogs have probably a higher level of exposure to Neospora caninum Dubey, Carpenter, Speer, Topper et Uggla, 1988 and Toxoplasma gondii Nicolle et Manceaux, 1908 than other canine populations for their different lifestyle. The aim of our survey was to determine the seroprevalence of N. caninum and T. gondii in hunting dogs from southern Italy and assess risk factors related to these protozoan infections. Blood samples were collected from 398 hunting dogs (19 different breeds, aged from 5 month to 14 years). The sera were screened by indirect fluorescence antibody test; a titre ≥ 50 was considered positive. Antibodies to N. caninum and T. gondii were detected in 59 (15%) dogs with titres from 50 to 3 200 and in 94 (24%) dogs with titres from 50 to 1 600, respectively, with co-infection in 25 (6%) dogs. Statistical difference (p ≤ 0.05) was found only for infection with T. gondii between two age groups: ≥ 2-4 years (16%) and ≥ 4-7 years (33%); other observed characteristics were without statistical significance. Our results suggest that the hunting dogs could play an important role in the transmission cycle of N. caninum between wild animals and livestock. This is the first detection of antibodies to T. gondii in hunting dogs in Italy., Tereza Machačová, Eva Bártová, Kamil Sedlák, Radka Slezáková, Marie Budíková, Diego Piantedosi, Vincenzo Veneziano., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1729. Seroprevalence of antibodies of Neospora spp. and Toxoplasma gondii in horses from southern Italy
- Creator:
- Eva Bártová, Machačová, Tereza, Kamil Sedlák, Marie Budíková, Mariani, Ugo, and Veneziano, Vincenzo
- Format:
- electronic, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- toxoplazmóza, toxoplasmosis, serological test, Equus caballus, risk factor, neosporosis, 2, and 59
- Language:
- English
- Description:
- The consumption of horse meat has been epidemiologically linked to clinical toxoplasmosis in humans and neosporosis that may cause clinical illness in horses. Here we determined seroprevalence of antibodies against Toxoplasma gondii Nicolle et Manceaux, 1908 and species of Neospora Dubey, Carpenter, Speer, Topper et Uggla, 1988 in horses from Italy. Blood samples were collected from 643 apparently healthy horses from 60 farms of 51 municipalities in southern Italy. The presence of antibodies against T. gondii and Neospora spp. were detected by indirect fluorescence antibody test (IFAT); a titre ≥ 50 was considered positive. The same sera were also tested for antibodies against Neospora spp. by a competitive-inhibition enzyme-linked immunosorbent assay (cELISA); samples with ≥ 30% inhibition were considered positive. Antibodies against T. gondii and Neospora spp. were detected in 19 (3.0%) and 15 (2.3%) horses by IFAT, respectively, without statistical difference between gender, age and breeds (p-value ≥ 0.05). Antibodies against species of Neospora were detected in 70 (10.9%) horses by cELISA with statistical difference in gender (6.0-18.5%, p-value ≥ 0.05) and breeds (0-19.4%, p-value ≥ 0.05). Although T. gondii infection rates were low, the risk of human infection should not be dismissed, particularly in Italy where consumption of raw or undercooked horse meat has a long tradition., Eva Bártová, Tereza Machačová, Kamil Sedlák, Marie Budíková, Ugo Mariani, Vincenzo Veneziano., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1730. Seroprevalence of Toxoplasma gondii in hunted wild boars (Sus scrofa) from southeastern France
- Creator:
- Roqueplo, Cédric, Blaga, Radu, Marié, Jean-Lou, Vallée, Isabelle, and Davoust, Bernard
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- toxoplazmóza, epidemiologie, prase divoké, toxoplasmosis, epidemiology, wild boar, Francie, France, agglutination test, wildlife, seroprevalence, 2, and 59
- Language:
- English
- Description:
- Toxoplasma gondii (Nicolle et Manceaux, 1908) is an obligate intracellular, parasitic protozoan within the phylum Apicomplexa that causes toxoplasmosis in mammalian hosts (including humans) and birds. Since meat of wild boar, Sus scrofa (Linnaeus), has been demonstrated to be a potential source of human infection, a careful evaluation of the prevalence of infection with T. gondii in hunted animals is needed to protect public health. In the Var area in southeastern France, we performed a spatio-temporal survey in order to investigate the prevalence of IgG antibodies in wild boars shot by hunters in the Canjuers military camp during two subsequent hunting seasons. Of 841 wild boars screened, antibodies (IgG) to T. gondii (modified agglutination test, cut-off 1 : 6) were found in 141 (16.8%) muscle extract samples. A significant association (p < 0.001) was found between positivity and age, but not gender, and hunting districts. The results obtained indicate that consumption of raw or undercooked meat from wild boars carries an important risk of infection with T. gondii. Wild boars may be considered as a bioindicator of parasite circulation in this ecosystem., Cédric Roqueplo, Radu Blaga, Jean-Lou Marié, Isabelle Vallée, Bernard Davoust., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public