Influence of branch autonomy on fruit,scaffold, trunk and root growth during stage III of peach fruit development     

Marsal J  Basile B  Solari L  DeJong TM 《Tree physiology》2003,23(5):313-323

We studied the influence of branch autonomy on the growth of reproductive and vegetative organs by establishing different patterns of fruit distribution within and between large branch units (scaffolds) in mature peach trees (Prunus persica (L.) Batsch cv. 'Elegant Lady'). Different patterns of fruit distribution were established by defruiting either whole scaffolds (uneven fruit distribution between scaffolds; US) or several selected hangers (small fruiting branches) per tree (uneven fruit distribution between hangers; UH). The effects of these patterns were compared with the effects of an even fruit distribution treatment (EVEN) in which fruits were thinned to achieve maximum uniformity of fruit distribution within the canopy. The desired fruit loads were obtained by differentially thinning the remaining bearing parts. On a tree basis, the response of mean fruit mass to fruit load was strongly affected by fruit distribution. The steepest mean fruit mass to fruit load relationship was found in US trees, whereas the relationship in UH trees was intermediate between the US and EVEN trees. On a scaffold basis, differences in fruit size between EVEN and US trees with similar fruit loads, though statistically significant, were relatively small, indicating that scaffolds were almost totally autonomous with respect to dry matter partitioning to fruit during the final stage of peach fruit growth. Hangers also appeared to exhibit significant autonomy with respect to the distribution of dry matter during the final phase of fruit growth. Branch autonomy was evident in scaffold growth: defruited scaffolds in the US treatment grew more than fruited scaffolds, and fruit distribution treatments had little impact on scaffold cross-sectional area on a tree basis. On the other hand, as observed for fruit growth, branch autonomy did not appear to be complete because the fruited scaffolds grew more in US trees than in EVEN trees under heavy cropping conditions. However, the effect of fruit distribution occurred only over short distances, and was negligible on organs located farther away from the source of heterogeneity (fruits), such as the trunk and roots.  相似文献   

Association of the time that elapsed from last vaccination with protective effectiveness against foot-and-mouth disease in small ruminants     

Ehud Elnekave  Boris Even-Tov  Boris Gelman  Beni Sharir  Eyal Klement 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(1):87-92

Routine and emergency vaccination of small ruminants against foot-and-mouth disease (FMD) is mandatory in many endemic countries, yet data on the field effectiveness of the vaccines used is scarce. We conducted an investigation of a serotype O FMD outbreak that took place in a sheep and goat pen, and estimated the effectiveness of various routine vaccination statuses. We also evaluated the protection provided by colostrum administration and emergency vaccination. Animals which were routinely vaccinated twice were not clinically affected while disease incidence was observed among animals routinely vaccinated only once (p = 0.004 according to a two-sided Fisher''s exact test). In groups vaccinated only once, there was a significant association between the average time that elapsed since last vaccination and the disease incidence (n = 5; Spearman correlation coefficient: r_s = 1.0, p < 0.01). In addition, non-vaccinated lambs fed colostrum from dams vaccinated more than 2 months before parturition had a mortality rate of 33%. Administration of emergency vaccination 2 days after the occurrence of the index case was the probable reason for the rapid blocking of the FMD spread within 6 days from its onset in the pen.  相似文献   

Anti- and prooxidative properties of gallic acid in fenton-type systems     

Strlic M  Radovic T  Kolar J  Pihlar B 《Journal of agricultural and food chemistry》2002,50(22):6313-6317

The anti- and prooxidative properties of gallic acid in Fenton-type systems containing H(2)O(2) and Fe(III) were examined in pH 3-10 reaction media and at reaction temperatures of 20-50 degrees C. Although it is a free radical scavenger, gallic acid may exhibit prooxidative properties, as it promotes the production of hydroxyl radicals due to iron chelation. The overall effect is prooxidative if the ratio of the concentrations of gallic acid and Fe(III) in the reaction medium is smaller than 2. If the ratio is greater than 2, the overall effect of gallic acid presence is antioxidative due to free radical scavenging properties. The dependence of rates and of apparent activation energies of gallic acid consumption on pH in Fenton-type systems was also examined, and it is concluded that the rate-determining steps in acidic and alkaline media are different, the overall rate of gallic acid consumption being lowest at pH 7.  相似文献   

Modelling habitat and spatial distribution of an endangered longhorn beetle - A case study for saproxylic insect conservation     

Jörn Buse  Boris Schröder 《Biological conservation》2007,137(3):372-381

Saproxylic insects are characterised by their exceptional diversity and high proportion of threatened species. No recent studies have demonstrated the validity of habitat suitability analysis for scientifically based habitat management for these species. We studied the habitat requirements of the endangered longhorn beetle Cerambyx cerdo, a species with a supposed keystone function for the saproxylic insect community living on oaks. We used species distribution modelling based on datasets from Central Europe to understand the species-habitat relationships and to find the environmental variables responsible for habitat selection of C. cerdo. Our results show that the most important parameters, insolation, presence of oak sap, bark depth and the distance from the next colonised tree, are able to predict the presence of C. cerdo very well. A spatial validation procedure revealed very similar predictive power, indicating the general validity of our model. Tree-level parameters were shown to have a stronger effect on the occurrence probability than landscape-level predictors. To improve the tree-level conditions (e.g. insolation on the trunk) habitat management in the form of semi-open pasture landscapes is recommended from which many other taxa will also draw considerable benefit. The provision of such conditions over decades is the essential key in the conservation of this longhorn beetle species. The success of the European network of conservation areas “Natura 2000” heavily depends on broad biological knowledge of the designated protected species. The present paper shows that species distribution models can give valuable contributions for conservation in saproxylic insects.  相似文献   

Fucosylated Chondroitin Sulfates from the Sea Cucumbers Paracaudina chilensis and Holothuria hilla: Structures and Anticoagulant Activity     

Nadezhda E. Ustyuzhanina  Maria I. Bilan  Andrey S. Dmitrenok  Alexandra S. Silchenko  Boris B. Grebnev  Valentin A. Stonik  Nikolay E. Nifantiev  Anatolii I. Usov 《Marine drugs》2020,18(11)

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Antifungal activities of silver and selenium nanoparticles stabilized with different surface coating agents     

Karolina Vrande i&#x;  Jasenka &#x;osi&#x;  Jelena Ili&#x;  Boris Ravnjak  Ati&#x;a Selmani  Emerik Gali&#x;  Barbara Pem  Rinea Barbir  Ivana Vinkovi&#x; Vr ek  Tomislav Vinkovi&#x; 《Pest management science》2020,76(6):2021-2029

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Some factors affecting regional differentiation of the soils in the Republic of Benin (West Africa)     

Paul Faure  Boris Volkoff 《CATENA》1998,32(3-4)

Spatial distribution of the parent materials, color, clay-eluviated horizon thickness, textural profile type, presence and position of the ferruginous nodules and ferricretes in the profile are analyzed at a small scale using the thematic information content of the published 1:200,000 soil map of Benin. Analyses indicate that there is a regional differentiation of the soil cover which is first drawn on that of the geological provinces, sedimentary basins, great morpho-structural units, and then determined by the factors that control the preservation or the transformation and erosion of an ancient lateritic mantle. These factors are directly influenced by differential changes of the local base levels.  相似文献   

Real‐time PCR to study the effect of timing and persistence of fungicide application and wheat varietal resistance on Mycosphaerella graminicola and its sterol 14α‐demethylation‐inhibitor‐resistant genotypes     

Sameh Selim  Céline Roisin‐Fichter  Jean‐Baptiste Andry  Boris Bogdanow  Renée Sambou 《Pest management science》2014,70(1):60-69

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Verification of mitotic gynogenesis in ornamental (koi) carp (Cyprinus carpio L.) using microsatellite DNA markers     

Ahmed S Alsaqufi  Boris Gomelsky  Kyle J Schneider  Kirk W Pomper 《Aquaculture Research》2014,45(3):410-416

The Japanese ornamental (koi) carp is a popular decorative fish all over the world. In koi, clones have not yet been obtained, although production of fish with identical colour patterns could be of commercial interest. Mitotic gynogenetic progenies are essential for subsequent production of clones in fish. However, resulting late‐shocked progenies may be contaminated with meiotic gynogens from spontaneous suppression of the second meiotic division in eggs. In this study, microsatellite DNA markers were used to confirm mitotic gynogenetic origin of obtained late‐shocked progenies. Recombination rate (y) and mapping distance relative to centromere (M‐C) of 10 microsatellite loci were determined based on percentage of heterozygotes in meiotic gynogenetic progenies. The range of y varied from 0.01 to 0.96 and the M‐C map ranged from 0.5 to 48 cM. The mean value of y over the 10 loci was 0.481. Six loci, which had y 0.47 and higher, were used as markers in two late‐shocked gynogenetic progenies. Complete homozygosity was revealed at all six microsatellite loci indicating mitotic gynogenetic origin of analysed progenies.  相似文献   

Species selection maintains self-incompatibility     

Goldberg EE  Kohn JR  Lande R  Robertson KA  Smith SA  Igić B 《Science (New York, N.Y.)》2010,330(6003):493-495

Identifying traits that affect rates of speciation and extinction and, hence, explain differences in species diversity among clades is a major goal of evolutionary biology. Detecting such traits is especially difficult when they undergo frequent transitions between states. Self-incompatibility, the ability of hermaphrodites to enforce outcrossing, is frequently lost in flowering plants, enabling self-fertilization. We show, however, that in the nightshade plant family (Solanaceae), species with functional self-incompatibility diversify at a significantly higher rate than those without it. The apparent short-term advantages of potentially self-fertilizing individuals are therefore offset by strong species selection, which favors obligate outcrossing.  相似文献