Phenological and physiological evaluation of first and second cropping periods of sorghum and maize crops     

Maria Antonia Machado Barbosa  Kacilda Naomi Kuki  Pedro Santos Peno Bengala  Emilly dos Santos Pereira  Angélica Fátima de Barros  Sebastián Giraldo Montoya  Leonardo Duarte Pimentel 《Journal of Agronomy and Crop Science》2020,206(2):263-276

Environmental conditions influence phenology and physiological processes of plants. It is common for maize and sorghum to be sown at two different periods: the first cropping (spring/summer) and the second cropping (autumn/winter). The phenological cycle of these crops varies greatly according to the planting season, and it is necessary to characterize the growth and development to facilitate the selection of the species best adapted to the environment. The aim of this study was to characterize phenological phases and physiological parameters in sorghum and maize plants as a function of environmental conditions from the first cropping and second cropping periods. Two parallel experiments were conducted with both crops. The phenological characterization was based on growth analyses (plant height, leaf area and photoassimilate partitioning) and gas exchange evaluations (net assimilation rate, stomatal conductance, transpiration and water-use efficiency). It was found that the vegetative stage (VS) for sorghum and maize plants was 7 and 21 days, respectively, longer when cultivated during the second cropping. In the first cropping, the plants were taller than in the second cropping, regardless of the crop. The stomatal conductance of sorghum plants fluctuated in the second cropping during the development period, while maize plants showed decreasing linear behaviour. Water-use efficiency in sorghum plants was higher during the second cropping compared with the first cropping. In maize plants, in the second cropping, the water-use efficiency showed a slight variation in relation to the first cropping. It was concluded that the environmental conditions as degree-days, temperature, photoperiod and pluvial precipitation influence the phenology and physiology of both crops during the first and the second cropping periods, specifically cycle duration, plant height, leaf area, net assimilation rate, stomatal conductance and water-use efficiency, indicating that both crops respond differentially to environmental changes during the growing season.  相似文献   

Synthesis and Antifouling Activity Evaluation of Analogs of Bromosphaerol,a Brominated Diterpene Isolated from the Red Alga Sphaerococcus coronopifolius     

Kyriakos C. Prousis  Stefanos Kikionis  Efstathia Ioannou  Silvia Morgana  Marco Faimali  Veronica Piazza  Theodora Calogeropoulou  Vassilios Roussis 《Marine drugs》2022,20(1)

Marine biofouling is an epibiotic biological process that affects almost any kind of submerged surface, causing globally significant economic problems mainly for the shipping industry and aquaculture companies, and its prevention so far has been associated with adverse environmental effects for non-target organisms. Previously, we have identified bromosphaerol (1), a brominated diterpene isolated from the red alga Sphaerococcus coronopifolius, as a promising agent with significant antifouling activity, exerting strong anti-settlement activity against larvae of Amphibalanus (Balanus) amphitrite and very low toxicity. The significant antifouling activity and low toxicity of bromosphaerol (1) motivated us to explore its chemistry, aiming to optimize its antifouling potential through the preparation of a number of analogs. Following different synthetic routes, we successfully synthesized 15 structural analogs (2–16) of bromosphaerol (1), decorated with different functional groups. The anti-settlement activity (EC₅₀) and the degree of toxicity (LC₅₀) of the bromosphaerol derivatives were evaluated using cyprids and nauplii of the cirriped crustacean A. amphitrite as a model organism. Derivatives 2, 4, and 6–16 showed diverse levels of antifouling activity. Among them, compounds 9 and 13 can be considered as well-performing antifoulants, exerting their activity through a non-toxic mechanism.  相似文献   

Oviposition‐deterrent effect of linalool – a compound of citrus essential oils – on female Mediterranean fruit flies,Ceratitis capitata (Diptera: Tephritidae)     

Stella A Papanastasiou  Charalampos S Ioannou  Nikos T Papadopoulos 《Pest management science》2020,76(9):3066-3077

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Influence of gamete density,salinity and temperature on the normal embryonic development of the mangrove oyster Crassostrea rhizophorae Guilding, 1828     

Antonia Euflosina Dos Santos  Iracema Andrade Nascimento 《Aquaculture (Amsterdam, Netherlands)》1985,47(4):335-352

Laboratory experiments were undertaken to determine the optimal environmental conditions and some of the other factors concerned in the development of Crassostrea rhizophorae embryos.Critical variables such as the number of spermatozoa per ovocyte during fertilization, the time of fertilization after gamete liberation, egg density, temperature and salinity were related to the proportion of normal D-larvae of C. rhizophorae in the resulting broods.The highest proportion of normal D-larvae was obtained at concentrations of 500–5000 spermatozoa/ovocyte, under conditions of 25‰ salinity at 25 ± 1°C. The optimal density of eggs, for the production of normal D-larvae, was 10⁴?4 × 10⁴ ovocytes/l. If fertilization was delayed for more than 45 min after liberation of spermatozoa the proportion of normal D-larvae was greatly reduced. The experiments demonstrated that the temperature for developing embryos should be below 30°C. At 20 and 25°C there was a high proportion of normal D-larvae 24 h after fertilization. The ideal salinity for embryonic development in C. rhizophorae was 25–37‰. Below a salinity of 16‰, less than 2.5% of the D-larvae were normal.  相似文献   

Citronella oil‐loaded electrospun micro/nanofibrous matrices as sustained repellency systems for the Asian tiger mosquito Aedes albopictus     

Konstantina Iliou  Stefanos Kikionis  Panos V Petrakis  Efstathia Ioannou  Vassilios Roussis 《Pest management science》2019,75(8):2142-2147

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Biological activity of immunostimulatory CpG DNA motifs in domestic animals   总被引：15，自引：0，他引：15  

Mutwiri G  Pontarollo R  Babiuk S  Griebel P  van Drunen Littel-van den Hurk S  Mena A  Tsang C  Alcon V  Nichani A  Ioannou X  Gomis S  Townsend H  Hecker R  Potter A  Babiuk LA 《Veterinary immunology and immunopathology》2003,91(2):89-103

Bacterial DNA contains a much higher frequency of CpG dinucleotides than are present in mammalian DNA. Furthermore, bacterial CpG dinucleotides are often not methylated. It is thought that these two features in combination with specific flanking bases constitute a CpG motif that is recognized as a "danger" signal by the innate immune system of mammals and therefore an immune response is induced when these motifs are encountered. These immunostimulatory activities of bacterial CpG DNA can also be achieved with synthetic CpG oligodeoxynucleotides (ODN). Recognition of CpG motifs by the innate immune system requires engagement of Toll-like receptor 9 (TLR-9), which induces cell signaling and subsequently triggers a pro-inflammatory cytokine response and a predominantly Th1-type immune response. CpG ODN-induced innate and adaptive immune responses can result in protection in various mouse models of disease. Based on these observations, clinical trials are currently underway in humans to evaluate CpG ODN therapies for cancer, allergy and infectious disease. However, potential applications for immunostimulatory CpG ODN in species of veterinary importance are just being explored. In this review, we will highlight what is presently known about the immunostimulatory effects of CpG ODN in domestic animals.  相似文献   

Volume Contents     

Antonia Srobarova  Antonio Moretti  Rosalia Ferracane  Alberto Ritieni  Antonio Logrieco 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(9):913-920

Volume Contents

Volume Contents  相似文献   

Assessment of relevant factors and relationships concerning human dermal exposure to pesticides in greenhouse applications     

Martínez Vidal JL  Egea González FJ  Garrido Frenich A  Martínez Galera M  Aguilera PA  López Carrique E 《Pest management science》2002,58(8):784-790

Principal component analysis (PCA) was applied to the gas chromatographic data obtained from 23 different greenhouse trials. This was used to establish which factors, including application technique (very small, small, medium and large drop-size), crop characteristics (short/tall, thin/dense) and pattern application of the operator (walking towards or away from the treated area) are relevant to the dermal exposure levels of greenhouse applicators. The results showed that the highest exposure by pesticides during field applications in greenhouses, in the climatic conditions and in the crop conditions typical of a southern European country, occurs on the lower legs and front thighs of the applicators. Similar results were obtained by hierarchical cluster analysis (HCA). Drop-size seems to be very important in determining total exposure, while height and density of crops have little influence on total exposure under the conditions of the present study. No pesticide type is a major factor in total exposure. The application of multiple regression analysis (MRA) allowed assessment of the relationships between the pesticide exposure of the less affected parts of the body with the most affected parts.  相似文献   

Field attraction of Cerambyx welensii to fermentation odors and host monoterpenes     

Israel Sánchez-Osorio  Gloria López-Pantoja  Antonia M. Paramio  José L. Lencina  Diego Gallego  Luis Domínguez 《Journal of pest science》2016,89(1):59-68

Cerambyx welensii Küster is one of the greatest threats to Quercus suber L. and Quercus ilex L. in Spain. Efficient control methods for this species are currently being tested, and the use of traps baited with food-related products for their monitoring and control has been proposed. Cerambyx welensii adults prefer to colonize old or decayed trees, in which cortical exudates frequently release fermentation odors. Fermentation-related compounds, such as ethanol, have been cited as attractants to various hardwood woodborers (as Cerambyx cerdo L.), used either alone or sometimes in combination with other host odors. In this work, we conducted field experiments to ascertain whether chemical blends mimicking fermentation odors were attractive for C. welensii. To this end, we used three types of traps (multiple funnel, cross-vane and single-funnel) baited with six synthetic blends including one or more fermentation-related chemicals (ethanol, ethyl acetate, 3-methyl-1-butanol, acetaldehyde, 2-methyl-1-propanol and 2-methyl-1-butanol), various food-related products (beer, melon and red wine mixed with peach juice) and host monoterpenes (α-pinene, β-pinene, limonene, α-phellandrene and camphene). At high release rates (5–11 g/day), various synthetic blends proved attractive irrespective of trap type. Our results contribute to understand the impact of volatile organic compounds in host selection by woodborers infesting deciduous trees. The results hold promise for optimizing trapping strategies to control C. welensii within an integrated pest management framework.  相似文献   

Maximum foraging ranges in solitary bees: only few individuals have the capability to cover long foraging distances   总被引：2，自引：0，他引：2  

Antonia Zurbuchen  Jeannine Klaiber  Silke Hein 《Biological conservation》2010,143(3):669-361

To preserve populations of endangered bee species, sound knowledge of their maximum foraging distance between nest and host plants is crucial. Previous investigations predicted maximum foraging distances of 100-200 m for small bee species and up to 1100 m for very large species based on mainly indirect methods. The present study applied a new and direct approach to experimentally investigate maximum foraging distances in solitary bees. One endangered and two common species of different body sizes, all of which restrict pollen foraging to a single plant genus, were established in a landscape lacking their specific host plants. Females were forced to collect pollen on potted host plants that were successively placed in increasing distance from fixed nesting stands. The maximum foraging distance recorded for the small Hylaeus punctulatissimus was 1100 m, for the medium sized Chelostoma rapunculi 1275 m and for the large Hoplitis adunca 1400 m, indicating that maximum foraging distances at species level have been underestimated. However, the capability to use resources on such a large spatial scale applied only to a small percentage of individuals as 50% of the females of H. punctulatissimus and H. adunca did not forage at distances longer than 100-225 m and 300 m, respectively. This finding suggests that a close neighbourhood of nesting and foraging habitat within few hundred meters is crucial to maintain populations of these species, and that threshold distances at which half of the population discontinues foraging are a more meaningful parameter for conservation practice than the species specific maximum foraging distances.  相似文献