Greenhouse testing of new wheat cultivars compared to those with known drought tolerance

Drought causes huge losses in crop production. With global climatic changes in prospect the extension of drought-prone areas is likely to grow in the future which will require the growing of drought resistant cultivars. In this study some physiological parameters of newly bred Hungarian cultivars were compared with those of drought tolerant or sensitive cultivars. The connection of these physiological parameters to the yield of the cultivars was also evaluated. Drought treatment decreased soil water content from 49-55% (control) to 13-17% (treated) of its water-holding capacity. As a result, there was a significant increase in midday water saturation deficiency (from 10-20% in control plants to 30-45% in treated ones) and a parallel decrease in transpiration rates and net CO2 assimilation. Analysis of averaged data of 3 consecutive years suggests that there is some correlation between net CO2 assimilation and sugar accumulation in flag leaves during the grain filling period with the yield of the different cultivars, however, there are other important factors influencing the yield which were not analysed in this study. The lowest yield reduction was found in Gk Pántlika, Mv Mariska, Mv Mambo and Mv Emese (7-10%), which proved to be drought tolerant cultivars from an agronomical point of view

Structural changes of the photosynthetic apparatus under osmotic stress in different Triticum aestivum and Aegilops biuncialis genotypes

The photosynthetic apparatus of three Aegilops biuncialis genotypes differing in the annual rainfall of their habitat (1050 mm, 550 mm and 225 mm), two drought resistant Triticum aestivum genotypes and one with high crossing efficiency (Mv9Kr1) were examined under the effect of osmotic stress brought about by PEG in the nutrient solution. Two Aegilops genotypes Ae.b.225 and Ae.b.550 proved to be relatively stable under osmotic stress showing only slight changes of Chi concentration of the leaves and relative amount of chlorophyll proteins (CPs) in the thylakoids. In spite of the structural stability, PEG treatment considerably lowered the yield of low temperature fluorescence emission. The relative increase of emission around 700 nm can be attributed to LHCII aggregation related quenching processes. More pronounced changes in the relative amount of CPs were observed in Triticum genotypes and in Ae.b. 1050. These changes, which included the relative decrease of PSII core complex and the relative increase of LHCII, reversed during the recovery period. Low temperature fluorescence yield decreased evenly throughout the spectrum and the lack of relative increase around 700 nm points to a quenching process other than LHCII aggregation. The Ae.b.1050 and Mv9Kr1 wheat genotypes proved to be the most susceptible to osmotic stress with more pronounced decrease of PSIICC and increase of LHCII, less fluorescence decline in the emission spectra, and slower recovery of these parameters

A szociálisprobléma-megoldás, az empátia és a szorongás kapcsolata serdülők körében

Személyközi problémáink módja és sikeressége nagymértékben meghatározza társas jóllétünket, hatással van tanulmányi-szakmai előmenetelünkre és pszichés egészségünkre (Chang, D’Zurilla és Sanna, 2004). A problémamegoldás sikeressége számos személyiségbeli és környezeti tényezőtől függ, melyek közül – az eddigi hazai (pl. Kasik, 2015) és nemzetközi (pl. Chang és mtsai, 2004) vizsgálatok alapján – már serdülőkorban is jelentős a szerepe az empátia és a szorongás egyes jellemzőinek, vagyis ezek fejlettsége meghatározó a problémamegoldás alakulásában és fordítva: mind a szorongás, mind az empátia függ a problémák megoldásának hatékonyságától. A tanulmányban ismertetett vizsgálat során serdülők (12–19 évesek) körében tártuk fel e három terület néhány részterületének kapcsolatrendszerét keresztmetszeti és longitudinális vizsgálat keretében. A vizsgálatok alapján az életkorral fokozatosan erősödik a kapcsolat a problémamegoldás pozitív orientációja és az empátia egyik kognitív részterülete, a nézőpontfelvétel/-váltás között. A negatív orientáció és az elkerülés, illetve az impulzivitás az empátia másik összetevőjével, a személyes distresszel mutat egyre szorosabb kapcsolatot. A negatív orientációra nagy hatással bír mindegyik életkori csoportban a vonásszorongás. A mindennapi pedagógiai gyakorlatban, valamint a jövőbeni kutatási-fejlesztési célok megfogalmazásakor és megvalósításakor egyaránt hasznosak lehetnek a feltárt összefüggések

Dynamic Viscosity Prediction of Blends of Paving Grade Bitumen with Reclaimed Bitumen

The recycling of reclaimed asphalt pavement is of significant economic and environmental benefits. In this case, however, the satisfactory performance of the final product needs scientific planning of the mixture and thorough quality control. Before its use, a number of tests must be performed to verify that the binder meets the relevant requirements and can be used in asphalt mixtures. The binder characteristics in the reclaimed asphalt pavement and the expected properties of the binder blend in the new asphalt mixture must be known. For its prediction and calculation, a European standard offers the calculation of the penetration or softening point of the binder blend in the mixture with reclaimed asphalt content. However, in some countries, the determination of paving grade bitumen types (categories) is based not on dynamic viscosity measured with DSR instrument, so other validated test and calculation methods are in force. A viscosity-based method has not yet been validated for paving grade bitumens standardized on a penetration basis, although this method is more advantageous in many aspects when monitoring daily production processes; it is much shorter and requires less material than measuring softening point or penetration. The article deals with the measurement of the dynamic viscosity of bitumen blends of asphalt mixtures made using reclaimed asphalts, determined with a dynamic shear rheometer at different frequencies (0.1–10.0 Hz sweep). Furthermore, the relationships between the different composition ratios of national paving grade bitumens classified on the bases of penetration level and bitumens from reclaimed asphalt pavement are examined