The use of midday leaf water potential for scheduling deficit irrigation in vineyards   总被引：1，自引：0，他引：1  

J. Girona  M. Mata  J. del Campo  A. Arbonés  E. Bartra  J. Marsal 《Irrigation Science》2006,24(2):115-127

Midday leaf water potential (Ψ_md) was monitored for 3 years at a commercial vineyard (cv. Pinot Noir) under four irrigation strategies. Three treatments were established based on irrigating vines with 4–6 mm/day, when daily measured Ψ_md was more negative than the pre-defined threshold. After the first experimental year, thresholds were adjusted for each treatment as: (1) Control (C), irrigated when Ψ_md was less than −0.6 MPa at the beginning of the season and gradually fell to −0.8 MPa at about mid-June, after which the threshold was maintained at −0.8 MPa until harvest. (2) Control–Deficit (CD), irrigated as C from bud-break to mid-June (around the middle of Stage II of fruit growth), and from then until harvest when Ψ_md decreased below −1.2 MPa. (3) Deficit–Deficit (DD), irrigated when Ψ_md was less than −1.0 from bud break to mid-May (about the middle of fruit growth Stage I), and after that time the Ψ_md threshold became −1.2 MPa until harvest. A fourth treatment was applied following a soil water budget approach (WB). All treatments were replicated five times but irrigation in the Ψ_md-based treatments were independently applied to each of the replicate plots, whereas irrigation for WB was applied equally to all replications. The more site-specific information obtained from Ψ_md thresholds in C provided substantial advantages for yield homogeneity and repeatability of results with respect to WB, thus demonstrating the method’s greater ability to account for spatial variability. Average applied water for the 3 years in C, CD, and DD was 374, 250, and 178 mm, respectively, while the yields were 11.8, 9.2, and 6.1 kg/vine, respectively. The CD treatment produced better juice quality than C, and was superior in other quality parameters to both C and DD. However, over the study period, an important carryover effect was observed in the yields and the grape size of CD, which tended to diminish from year to year relative to C.  相似文献   

Astaxanthin from Haematococcus pluvialis Prevents Oxidative Stress on Human Endothelial Cells without Toxicity     

Philippe Régnier  Jorge Bastias  Violeta Rodriguez-Ruiz  Noelia Caballero-Casero  Carmen Caballo  Dolores Sicilia  Axelle Fuentes  Murielle Maire  Michel Crepin  Didier Letourneur  Virginie Gueguen  Soledad Rubio  Graciela Pavon-Djavid 《Marine drugs》2015,13(5):2857-2874

Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI)+)/ion trap-MS) characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC) assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM). No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases.  相似文献   

Ripening-related defense proteins in Annona fruit     

Oscar Goñi  María T. Sanchez-Ballesta  Carmen Merodio  María I. Escribano 《Postharvest Biology and Technology》2010,55(3):169-173

In order to obtain a better understanding of the active defense strategy of cherimoya (Annona cherimola Mill.) fruit, hydrolytic and antifungal activity, as well as expression of proteins functionally and immunogenically related to the pathogenesis-related proteins chitinase (PR-Q) and 1,3-β-glucanase (PR-2), were estimated in fruit at different ripening stages. Increase in expression of the 27 kDa constitutive chitinase and the induction of two new proteins, a 26 kDa chitinase and a 51 kDa 1,3-β-glucanase were associated with enhanced in vitro hydrolytic and antifungal activity of the acidic protein extract in ripe fruit. Ripening modified the expression of constitutive basic isoenzymes, with a sharp decrease in both relative accumulation and hydrolytic activity. Likewise, a new basic 33 kDa chitinase was induced in the over-ripe fruit, concomitant with accumulation of a basic constitutive 76 kDa 1,3-β-glucanase. At this stage, the basic protein extract modified in vitro growth inhibition of Botrytis cinerea. Short-term high CO₂ treatment delayed fruit ripening and maintained a similar distribution of activity and isoenzymatic pattern in both protein fractions to that in unripe fruit. These results indicate that the changes in the pattern of defense proteins and hydrolytic activity in cherimoyas appear to be associated with ripening. Moreover, unlike the constitutively expressed isoenzymes, only the transitorily induced chitinases and 1,3-β-glucanases were associated with an active defense-related response.  相似文献   

Simultaneous determination of clofentezine,fenoxycarb and hexythiazox by HPLC on apples,pears and their pulps     

Carlo Bicchi  Angela D'Amato  Ivano Tonutti  Liliana Cantamessa 《Pest management science》1990,30(1):13-19

The simultaneous HPLC determination of clofentezine, fenoxycarb and hexythiazox in apples, pears and their pulps is described. The method is based on a clean-up procedure carried out on a Seppak C18 cartridge followed by HPLC analysis on an RP-18 column using acetonitrile + water as mobile phase. Average recoveries were 85.0% for clofentezine, 84.8% for fenoxycarb and 75.6% for hexythiazox on apple matrix; recoveries from pear matrix were in the same range. UV detection limits at 240 nm were 0.07 mg kg^?1 for clofentezine, 0.064 mg kg^?1 for fenoxycarb and 0.08 mg kg^?1 for hexythiazox.  相似文献   

Inhibition of pheromone action in Sesamia nonagrioides by Haloacetate analogues     

Magi Riba  Matilde Eizaguirre  Albert Sans  Carmen Quero  Angel Guerrero 《Pest management science》1994,41(2):97-103

The electrophysiological activity of some halogenated analogues of the major component of the sex pheromone of the corn stalk borer Sesamia nonagrioides Lef. (1) is presented. The analogues comprise a series of fluoro-, chloro- and bromoacetate analogues 4 – 10 as well as trifluoromethyl ketone 11. The fluoro derivatives 4 – 6 displayed remarkable electro-antennogram (EAG) intrinsic activities in comparison with the parent acetate 1, while the remaining analogues elicited significantly lower response. The compounds have also been tested as inhibitors of the sex pheromone perception in EAG and in the field. In the laboratory. fluoro analogues 4 – 6 were better inhibitors than chloro derivatives 7 – 9 , which in turn behaved similarly to the bromoacetate 10 . Trifluoromethyl ketone 11, however, was a poor inhibitor of the pheromone action. In the field, baits of mixtures of compounds 5 – 11 with the corn stalk borer pheromone in 10 :1 ratio inhibited the concomitant attraction of the clover cutworm moth Scotogramma irifolii Rott., while the difluoro analogue 5, trichloroacetate 9 and trifluoromethyl ketone 11 also diminished the number of catches of the armyworm Mythimna unipuncta Haw. The monofluoroacetate 4. trifluoro analogue 6 and bromo derivative 10 significantly disrupted the pheromone action of the corn borer, whereas trifluoromethyl ketone 11 synergistically increased the number of males attracted to the pheromone trap alone. Addition of 11 to baits containing the corn borer pheromone caught S. nonagrioides selectively with regard to the other habitat-sharing species M. unipuncta and S. trifolii.  相似文献   

Untersuchungen zum endophytischen Befall von Fusarium proliferatum (Matsushima) Nirenberg in geernteten Stangen von Spargel (Asparagus officinalis L.)     

Monika Goßmann  Sylvia Kleta  Hans-Ullrich Humpf  Carmen Büttner 《Gesunde Pflanzen》2005,57(2-3):53-58

Zusammenfassung Erstmalig wurden mit den vorliegenden Untersuchungen Spargelstangen zur Haupterntezeit auf endophytischen Pilzbefall untersucht. Sie zeigen, dass im Ernteprodukt zwar Fusarium proliferatum als potenzieller Mykotoxinbildner zu finden ist. Eine mögliche natürliche Kontamination mit Fumonisinen bestätigte sich nicht. Von den mit F. proliferatum infizierten Stangen wies nur eine Stange mit grau-rosa-orange farbenen Gewebeveränderungen an der Basis sichtbare Symptome auf. Allgemeine Rückschlüsse auf eine mögliche Gefährdung oder Nichtgefährdung des Verbrauchers beim Verzehr von mit F. proliferatum kontaminierten, symptomlosen Stangen können aus der Analyse nicht gezogen werden. Hierzu müssen weitergehende Untersuchungen zur Wirt-Pathogen-Interaktion erfolgen und die phänotypischen und genotypischen Einflussfaktoren in diesem Prozess noch näher untersucht werden.  相似文献   

Production of ex vivo lipopolysaccharide-induced tumor necrosis factor-α, interleukin-1β, and interleukin-6 is suppressed by trans-resveratrol in a concentration-dependent manner          下载免费PDF全文

Jean-Francois Marier  Keguan Chen  Peter Prince  George Scott  Jerome R.E. del Castillo    Pascal Vachon 《Canadian journal of veterinary research》2005,69(2):151-154

Trans-resveratrol is a biologically active compound present in certain foods that has anti-inflammatory and anticancer properties. These beneficial effects are derived from both the immune system and cytokines. The purpose of this study was to determine the immunomodulatory effect of trans-resveratrol on the ex vivo production of inflammatory and anti-inflammatory cytokines stimulated by lipopolysaccharides (LPS). Trans-resveratrol (0, 0.01, 0.1, 1, and 10 microM) was added to blood samples from male Sprague-Dawley rats (n = 6) along with 100 U of LPS (Escherichia coli serotype, 055B5). The samples were then incubated for 4 h at 37 degrees C and centrifuged. Finally, concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 in the plasma were analyzed using an enzyme-linked immunosorbent assay (ELISA). The production of inflammatory (TNF-alpha and IL-1beta) and anti-inflammatory (IL-6) cytokines was suppressed by trans-resveratrol in a concentration-dependent manner. These results support the hypothesis that the immunomodulatory effect of trans-resveratrol plays an important role in disease conditions that involve an overproduction of inflammatory cytokines.  相似文献   

Influence of pesticides on the activity and kinetics of invertase,urease and acid phosphatase enzymes     

Liliana Gianfreda  Filomena Sannino  Maria T. Filazzola  Antonio Violante 《Pest management science》1993,39(3):237-244

The effects of four pesticides (three herbicides, atrazine, paraquat, glyphosate, and an insecticide, carbaryl) on the activity and kinetics of an invertase (from yeast), a urease (from jack bean) and an acid phosphatase (from potato) were investigated. Glyphosate and paraquat showed a marked activation effect on invertase activity. From the dependence of V_max and K_m parameters on pesticide concentrations, a mixed-type activation mechanism was suggested. The kinetic behaviour of urease and acid phosphatase appeared to be uninfluenced by both pesticides. Methanol, used as solvent for both carbaryl and atrazine, inhibited invertase, urease and acid phosphatase with, respectively, competitive, non-competitive and uncompetitive mechanisms. The extent of the inhibition was different, as estimated by the values of the inhibition constant K₁. An additional inhibition effect of urease and invertase activities was achieved in the presence of carbaryl, whereas no influence was detected on the activity and kinetics of acid phosphatase. Finally, atrazine was shown to alter the kinetics of the enzymes only at higher concentrations.  相似文献   

Component population study of Acanthocephalus tumescens (Acanthocephala) in fishes from Lake Moreno,Argentina     

Rauque CA  Viozzi GP  Semenas LG 《Folia parasitologica》2003,50(1):72-78

Seasonal samples of all fish species from Lake Moreno were taken in order to determine the presence of paratenia, to evaluate the status of the hosts and to characterise the transmission of Acanthocephalus tumescens (von Linstow, 1896) at the component population level. Prevalence, mean abundance, mean intensity, numbers of gravid females, relative abundance of the different fish species, relative output of eggs and relative flow rates for each host species were computed. Acanthocephalus tumescens showed low host specificity, successfully parasitizing six out of eight fish species present in the lake. No paratenic infection was registered. If prevalence, mean abundance, and number of gravid females are considered, host species can be placed in a continuum from the most to least suitable as follows: Galaxias platei Steindachner, Diplomystes viedmensis (Mac Donagh), Oncorhynchus mykiss (Walbaum), Salvelinus fontinalis (Mitchill), Percichthys trucha (Cuvier et Valenciennes) and Galaxias maculatus (Jenyns). However, when parasite flow rates and egg output were calculated, including relative abundance of each fish species, the continuum was rearranged as follows: P. trucha, O. mykiss, G. platei / G. maculatus, S. fontinalis and D. viedmensis. The first four species would be the main contributors to the population of A. tumescens in this lake, P. trucha being the major one. Different regulatory and non-regulatory mechanisms are suggested.  相似文献   

Hip dysplasia in a 6-year-old Salz ram          下载免费PDF全文

Loste A  Ramos JJ  Sáez T  Sever R  Marca MC 《The Canadian veterinary journal. La revue veterinaire canadienne》2003,44(2):140-142

A 6-year old Salz ram was presented with a history of poor body condition, progressive gait abnormalities, pelvic limb lameness, and difficulty with copulation. Based on the history, clinical signs, hip palpation, and radiography, a diagnosis of hip dysplasia, previously unreported in sheep, was made.  相似文献