45 research outputs found

    Application of photochemical parameters and several indices based on phenotypical traits to assess intraspecific variation of oat (Avena sativa L.) tolerance to drought

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    Functionality of the photosynthetic system under water stress is of major importance in drought tolerance. Oat (Avena sativa L.) doubled haploid (DH) lines obtained by pollination of F_{1} oat crosses with maize were used to assess the differences in plant genotypic response to soil drought. The investigations were based on the measurements of gas exchange and chlorophyll a fluorescence kinetics. Drought was applied to 17-day-old seedlings by withholding water for 14 days and subsequent plant recovery. Non-stressed optimally watered plants served as controls. Yield components were determined when plants reached full maturity. It was shown differences among the oat lines with respect to drought stress susceptibility (SI) and stress tolerance index mean productivity and drought susceptibility index. Sensitivity to drought of individual DH lines was significantly different, as demonstrated by the correlation between drought susceptibility index and yield components, such as dry weight (GW) or grain number (GN) of the harvested plants. GW and GN were lower in drought-sensitive genotypes exposed to drought stress compared to those resistant to drought. The principal component analysis allow to separate three groups of lines differing in their sensitivity to drought stress and indicated that tolerance to drought in oat has a common genetic background

    Chlorophyll a fluorescence parameters in the evaluation of oat DH lines yield components

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    Chlorophyll a fluorescence can provide insight into the ability of plants to tolerate environmental conditions that can damage photosynthetic apparatus and decrease yield. The aim of the study was to determine the relationship between chlorophyll a fluorescence parameters and yield components of oat DH lines. All DH lines significantly differed in chlorophyll a fluorescence parameters and yield components. The overall performance index of PSII photochemistry (PI), showed the highest variation between DH lines, whereas the lowest had the ratio of variable to maximum fluorescence (Fv/Fm). The highest differences were observed in the number of grains per plant (21.3 to 600). Thousand-grain weight varied from 17.82 g to 41.01 g and the biomass from 8.01 g to 29.31 g. The highest negative correlations were found between Fv/Fm, Area (pool size of electron acceptors from PSII), PI and grain number per plant and biomass. Positive correlations were observed between light energy absorption (ABS/CS), grain number per plant and biomass, as well as the amount of excitation energy trapped in PSII reaction centers (TRo/CS) and biomass. Principal component analysis of chlorophyll a fluorescence parameters, together with yield components, discriminated two oat DH lines groups according to their photosynthetic efficiency and yield

    Anatomical variations in the first dorsal compartment of the wrist: meta-analysis

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    Background: The first dorsal compartment of the wrist includes tendons of abductor pollicis longus (APL) and extensor pollicis brevis (EPB). However, many studies have showed multiple anatomical variations including anomalies in the number of both APL and EPB tendons and presence of intercompartmental fibro-osseous septum. Unfortunately, studies describing those variations are not consistent, hence, the aim of this study was to provide most accurate data about these anatomical variations in the population, using systematic review and meta-analysis. Material and methods: For this purpose, PubMed, Scopus, Web of Science, Embase and a number of minor online libraries were searched. Articles which included exact data about the number of APL or EPB tendons or a presence of intercompartmental septum were qualified for a more precise evaluation. Therefore, out of 1629 studies initially evaluated, 68 were finally included in this meta-analysis. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: A total of 5229 studied wrists have been included in this study. Double APL and single EPB are the most common variations of tendons in the first dorsal compartment, both in cadavers and patients with de Quervain’s disease, with no statistically significant differences between those two groups. Presence of intercompartmental fibro-osseus septum is much more common in patients with de Quervain’s disease than in cadavers. Conclusions: Our results should improve the awareness of anatomical variations in the first dorsal compartment, which in turn should have impact on treatment of de Quervain’s disease in clinical practice

    Glucose-6-phosphate dehydrogenase activity in stored blood

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    Autohydroliza skrobi wodorowej o ograniczonej zawartości wody

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    Preparations of hydrogen starch and superior starch of all 2.5% 10.5% and 30.5% humidity levels were heated each at 120°C, 140°C and 170°C. All macro- and microscopic appearance, solubility, reducing value specific rotation and content of free phosphorus were studied in resulting preparations. It was found that the process of autohydrolysis takes place also in grains of hydrogen starch of limited water content. Preparations obtained in our experiments are soluble in cold water.Skrobię wodorową oraz krochmal superior o różnej wilgotności: 2,5%, 10,5%, 30,5% ogrzewano w temperaturach: 120°C, 140°C i 170°C (tab. 1). Otrzymane preparaty badano pod względem wyglądu makro- i mikroskopowego (tab. 2, 3), rozpuszczalności (tab. 4), redukcyjności (tab. 5) oraz zawartości fosforu wolnego (tab. 6). Uzyskane wyniki świadczą, że nawet w ziarnach skrobi wodorowej o niskiej zawartości wody zachodzi proces autohydrolizy. świadczy o tym wzrost redukcyjności w wyniku hydrolitycznej depolimeryzacji cząstek tego polisacharydu oraz zwiększenie się zawartości fosforu wolnego wskutek hydrolizy wiązania estrowego kwasu amylofosforowego. Szybkość autohydrolizy zależy od zawartości wody w skrobi (zależność wprost proporcjonalna) i oczywiście od temperatury. Z przeprowadzonych badań wynika również, że zmieniając odpowiednio wilgotność i temperaturę skrobi wodorowej można otrzymać preparaty rozpuszczalne w zimnej wodzie. Preparaty te mogą mieć znaczenie praktyczne
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