Search results for "SHO"
showing 10 items of 5071 documents
Alder pollen in Finland ripens after a short exposure to warm days in early spring, showing biennial variation in the onset of pollen ripening
2017
Abstract We developed a temperature sum model to predict the daily pollen release of alder, based on pollen data collected with pollen traps at seven locations in Finland over the years 2000–2014. We estimated the model parameters by minimizing the sum of squared errors (SSE) of the model, with weights that put more weight on binary recognition of daily presence or absence of pollen. The model results suggest that alder pollen ripens after a couple of warm days in February, while the whole pollen release period typically takes up to 4 weeks. We tested the model residuals against air humidity, precipitation and wind speed, but adding these meteorological features did not improve the model pr…
Scale dependence of species–area relationships is widespread but generally weak in Palaearctic grasslands
2021
Questions: Species–area relationships (SARs) are fundamental for understanding biodiversity patterns and are generally well described by a power law with a constant exponent z. However, z-values sometimes vary across spatial scales. We asked whether there is a general scale dependence of z-values at fine spatial grains and which potential drivers influence it. Location: Palaearctic biogeographic realm. Methods: We used 6,696 nested-plot series of vascular plants, bryophytes and lichens from the GrassPlot database with two or more grain sizes, ranging from 0.0001 m² to 1,024 m² and covering diverse open habitats. The plots were recorded with two widespread sampling approaches (rooted presenc…
Monuments Unveiled: Genetic Characterization of Large Old Chestnut (Castanea sativa Mill.) Trees Using Comparative Nuclear and Chloroplast DNA Analys…
2020
Large old trees are extraordinary organisms. They not only represent a historical, landscape and environmental heritage of inestimable value, but they also witness a long history of environmental changes and human interventions, and constitute an as yet poorly known reserve of genetic variability which can be considered a great resource for management programs of forest species. This is the first genetic study on Italian, large, old chestnut trees (Castanea sativa Mill.). Ninety-nine trees were surveyed and analysed. For each tree, more than one sample from canopy and root suckers was collected to test for the genetic integrity of the individuals. All samples were genotyped using nine nucle…
Potential of Crotalaria species as green manure crops for the management of pathogenic nematodes and beneficial mycorrhizal fungi
2004
On the basis of preliminary experiments, some Crotalaria species from Senegal were investigated to determine (1) their susceptibility to Meloidogyne javanica and M. incognita compared to a sensitive host (tomato), (2) their mycorrhizal and rhizobial responses, and (3) the effect of their cultivation on the mycorrhizal soil infectivity. The nematode invasion rates on Crotalaria spp. ranked from 0.17 to 7.17% and from 0.58 to 5.25%, respectively, for M. incognita and M. javanica, vs. 97% and 77% on tomato. Moreover, the inoculated J2 which invaded tomatoes developed into adult females, while those on Crotalaria spp. rarely developed beyond the third stage, confirming that all Crotalaria spp. …
Combined influence of bud load and bud position along the cane on vegetative and reproductive parameters of grape cv. Grillo
2019
Cultivar Grillo vines are characterized by problems with flower biology (the fertility of basal buds) and fructification (millerandage). In this study, to manage the variability in bunch weight with winter pruning and to program others canopy management practices (i.e. early defoliation), three different treatments of bud load were set up by leaving the cane with 3, 6 or 10 buds. The effects of bud load and cane length were studies regarding bud fertility, shoot leaf area, and the number of flowers and berries, as well as the relationship between leaf area and percentage of fruit set, leaf area/flower and percentage of fruit set, and the number of hens and chicks berries. Shoots in the dist…
Shoot Development and Non-Destructive Determination of Grapevine (Vitis vinifera L.) Leaf Area
2017
A non-destructive method for determination of grapevine total leaf area is described. It is based on a highly significant correlation found between shoot leaf area and shoot length of Syrah (Vitis vinifera L.). Total leaf area per vine may be determined by using the equations described, by choosing a representative number of primary and secondary shoots and by knowing the total number of shoots of the plant considered. The equation seemed independent of vigour and terroir and reasonably sensitive to changes in leaf area that occurred independent of altered shoot length. It also allowed for recognition of compensation as a result of canopy manipulation. It would therefore be particularly use…
Soil properties determine the elevational patterns of base cations and micronutrients in the plant-soil system up to the upper limits of trees and sh…
2018
Abstract. To understand whether base cations and micronutrients in the plant–soil system change with elevation, we investigated the patterns of base cations and micronutrients in both soils and plant tissues along three elevational gradients in three climate zones in China. Base cations (Ca, Mg, and K) and micronutrients (Fe, Mn, and Zn) were determined in soils, trees, and shrubs growing at lower and middle elevations as well as at their upper limits on Balang (subtropical, SW China), Qilian (dry temperate, NW China), and Changbai (wet temperate, NE China) mountains. No consistent elevational patterns were found for base cation and micronutrient concentrations in both soils and plant tissu…
Halophila stipulacea descriptors in the native area (Red Sea): A baseline for future comparisons with native and non-native populations
2018
Abstract Halophila stipulacea is a small tropical seagrass species native to the Red Sea. Due to its invasive character, there is growing interest in understanding its ability to thrive in a broad range of ecological niches. We studied temporal (February 2014 and July 2014), depth (5, 9, 18 m) and spatial (NB and SB) related dynamics of H. stipulacea meadows in the northern Gulf of Aqaba. We evaluated changes in density, morphometry, biomass, and biochemical parameters alongside the reproductive effort. In both sites, maximal growth and vegetative performance occurred in the summer with a marked increase of 35% in shoot density and 18% in biomass; PAR reduction with season and depth induced…
Water recycling in leaves of Lithops (Aizoaceae)
2016
Lithops plants consist of a pair of succulent leaves inserted on a short stem; each growing season young leaves develop in a cavity formed between the older pair. Young leaves can take up water from the older pair allowing the plant to maintain growth and leaf expansion even without external supply of water. Recycling water between vegetative organs is one of the possible adaptation strategies of plants under drought stress, but it had never been demonstrated experimentally in Lithops. The methodology used to verify the existence of water redistribution from old leaves to young leaves was fluorescence microscopy, using two dyes to follow the water pathway inside the plant: Sulforhodamine G …
Collateral sensitivity of natural products in drug-resistant cancer cells
2018
Cancer chemotherapy is frequently hampered by drug resistance. Concepts to combine anticancer drugs with different modes of action to avoid the development of resistance did not provide the expected success in the past, because tumors can be simultaneously non-responsive to many drugs (e.g. the multidrug resistance phenotype). However, tumors may be specifically hypersensitive to other drugs - a phenomenon also termed collateral sensitivity. This seems to be a general biological mechanism, since it also occurs in drug-resistant Escherichia coli and Saccharomyces cerevisiae. Here, we give a timely and comprehensive overview on hypersensitivity in resistant cancer cells towards natural produc…