Knowledge about short-term climate change adaptation strategies for Mediterranean vineyards is needed in order to improve grapevine physiology and yield-quality attributes. We investigated effects of kaolin-particle film suspension on water relations, photosynthesis and oxidative stress of field-grown grapevines in the Douro region (northern Portugal) in 2012 and 2013. Kaolin suspension decreased leaf temperature by 18% and increased leaf water potential (up to 40.7% in 2013). Maximum photochemical quantum efficiency of PSII was higher and the minimal chlorophyll fluorescence was lower in the plants sprayed by kaolin. Two months after application, net photosynthesis and stomatal conductance at midday increased by 58.7 and 28.4%, respectively, in treated plants. In the same period, kaolin treatment increased photochemical reflectance, photosynthetic pigments, soluble proteins, soluble sugars, and starch concentrations, while decreased total phenols and thiobarbituric acid-reactive substances. Kaolin application can be an operational tool to alleviate summer stresses, which ameliorates grapevine physiology and consequently leads to a higher yield., L.-T. Dinis, A. C. Malheiro, A. Luzio, H. Fraga, H. FerreiraI. Gonçalves, G. Pinto, C. M. Correia, J. Moutinho-Pereira., and Obsahuje bibliografii
Using measures of gas exchange and photosynthetic chain activity, we found some differences between grapevine inflorescence and leaf in terms of photosynthetic activity and photosynthesis regulations. Generally, the leaf showed the higher net photosynthesis (PN) and lower dark respiration than that of the inflorescence until the beginning of the flowering process. The lower (and negative) PN indicated prevailing respiration over photosynthesis and could result from a higher metabolic activity rather than from a lower activity of the photosynthetic apparatus. Considerable differences were observed between both organs in the functioning and regulation of PSI and PSII. Indeed, in our conditions, the quantum yield efficiency and electron transport rate of PSI and PSII were higher in the inflorescence compared to that of the leaf; nevertheless, protective regulatory mechanisms of the photosynthetic chain were clearly more efficient in the leaf. This was in accordance with the major function of this organ in grapevine, but it highlighted also that inflorescence seems to be implied in the whole carbon balance of plant. During inflorescence development, the global PSII activity decreased and PSI regulation tended to be similar to the leaf, where photosynthetic activity and regulations remained more stable. Finally, during flowering, cyclic electron flow (CEF) around PSI was activated in parallel to the decline in the thylakoid linear electron flow. Inflorescence CEF was double compared to the leaf; it might contribute to photoprotection, could promote ATP synthesis and the recovery of PSII., M. Sawicki, B. Courteaux, F. Rabenoelina, F. Baillieul, C. Clement, E. Ait Barka, C. Jacquard, N. Vaillant-Gaveau., and Obsahuje bibliografii
Příspěvek shrnuje výsledky analýz environmentálních dat z lokality Ledčice a hodnotí jejich přínos k poznání této památky v souvislosti s výsledky terénního výzkumu. Z hlediska archeobotaniky lze za nejvýznamnější označit nález révy vinné, známé zatím jen z malého počtu raně středověkých nalezišť spjatých se sídly společenské elity. Osteologický materiál je zastoupen pouze nálezy domácích kopytníků (tur, prase, ovce/koza, kůň). Kromě druhového složení byly hodnoceny i tafonomické charakteristiky souboru. and The work summarizes the results of analyses of environmental data from the Ledčice site and evaluates their contribution to our understanding of this monument in connection with the results of terrain excavations. Most significant from an archaeobotanical perspective is the find of grapevine, of which only a small number have heretofore been found at early medieval sites associated with the social elite. Osteological material is represented only by finds of domesticated ungulates (cattle, pig, sheep/goat, horse). Analyzed in addition to the species composition were the taphonomic characteristics of the assemblage.