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María C. Lobato Milagros F. Machinandiarena Cecilia Tambascio Guillermo A. A. Dosio Daniel O. Caldiz Gustavo R. Daleo Adriana B. Andreu Florencia P. Olivieri 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):155-163
The utilization of phosphites (Phi) could be considered as another strategy to be included in integrated disease management
programmes to reduce the intensive use of fungicides and production costs. The aim of the present work was to analyze whether
the beneficial effects of phosphite treatment previously observed in potato plants grown under greenhouse conditions, were
reflected after harvest of field grown potatoes, both in disease protection and in yield. In addition, biochemical compounds
possibly involved in induced defence responses by Phi, like phytoalexins, pathogenesis related proteins and oxidative stress
enzymes were measured. Foliar applications of KPhi to field grown crops resulted in post-harvest tubers with a reduced susceptibility
to Phytophthora infestans, Fusarium solani and Erwinia carotovora infections, suggesting that this compound induced a systemic defence response. An increase in phytoalexin content in P. infestans inoculated tubers obtained from Phi-treated plants suggests their participation in the defence response. Chitinase content
increased 72 h after wounding or inoculation with P. infestans in tubers from KPhi-treated plants compared to wounded or infected tubers from non-treated plants. Contrary to this, the
isoforms of β-1,3-glucanases analyzed did not increase in the tubers of Phi-treated plants. The increment in peroxidase and
polyphenol oxidase activities indicated that these enzymes could be part of the Phi defence mechanism. No negative effects
were observed in potato yield at harvest, measured as total tuber weight and dry matter, after foliar KPhi treatment. This
suggests that the energetic cost involved in the defence response activation would not be detrimental to plant growth. 相似文献
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Spontaneously occurring neoplasms and non-neoplastic proliferative changes of the pancreatic cells in aging Sprague-Dawley and Long-Evans rats were examined for the presence and distribution of pancreatic hormones using immunocytochemical techniques. Islet cell tumors were indistinguishable in the two rat strains. They were composed principally of insulin-containing beta cells, but had additional and variable small proportions of cells that stained for somatostatin, glucagon, or rarely, pancreatic polypeptide. The heterogeneity in these spontaneous islet cell neoplasms was similar to that reported in humans as well as those induced in rats by streptozotocin. Hyperplasia of the islet cells also mainly affected the beta cells, but the overall pattern of immunocytochemical staining usually remained similar to that of normal islets, a point of distinction from islet cell neoplasms. In addition, rats with exocrine atrophy and fibrosis were found to have considerable disruption and focal proliferation of the islets. 相似文献
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Bijay Tamang Michael G. Andreu Christina L. Staudhammer Donald L. Rockwood Shibu Jose 《Agroforestry Systems》2012,86(2):255-266
Agroforestry systems have received global attention lately as a strategy for carbon mitigation but still are one of the least studied systems. This study was conducted in south Florida to develop biomass equations for windbreak grown cadaghi (Corymbia torelliana) trees and to estimate biomass in various aged windbreaks. Trees were selected for destructive sampling based on diameter at breast height (DBH) distribution from five windbreaks. Crown biomass was estimated using randomized branch sampling (RBS) and trunk biomass by taking disks every 1.5?m along the stem. Separate nonlinear equations were developed for crown, trunk and whole tree biomass estimation using DBH and height as predictors. Results indicated that DBH alone was sufficient to predict aboveground biomass, but including height in the models gave better results. Average oven-dry whole tree biomass ranged between 6 and 935?kg for 2- and 20-year-old windbreaks. Oven-dry whole tree biomass per100?m windbreak length in the same windbreaks ranged between 166 and 26,605?kg. Because fast-growing cadaghi is efficient and can produce significantly more biomass in a short period versus other windbreak species, landowners can expect higher returns from biomass or carbon trade over a shorter period, where available, to offset the cost of land occupied by the windbreaks. 相似文献
35.
Mar Cerdán Antonio Sánchez‐Sánchez Juana D. Jordá Margarita Juárez Juan Sánchez‐Andreu 《植物养料与土壤学杂志》2013,176(6):859-866
The objective of this work was to study the effect of root and foliar application of two commercial products containing amino acids from plant and animal origin on iron (Fe) nutrition of tomato seedlings cultivated in two nutrient media: lime and normal nutrient solutions. In the foliar‐application experiment, each product was sprayed with 0.5 and 0.7 mL L–1 2, 7, 12, and 17 d after transplanting. In the root application experiment, 0.1 and 0.2 mL L–1 of amino acids products were added to the nutrient solutions. In both experiments, untreated control plants were included as well. Foliar and root application of the product containing amino acids from animal origin caused severe plant‐growth depression and nonpositive effects on Fe nutrition were found. In contrast, the application of the product from plant origin stimulated plant growth. Furthermore, significantly enhanced root and leaf FeIII‐chelate reductase activity, chlorophyll concentration, leaf Fe concentration, and FeII : Fe ratio were found in tomato seedlings treated with the product from plant origin, especially when the amino acids were directly applied to the roots. These effects were more evident in plants developed under lime‐induced Fe deficiency. The positive results on Fe uptake may be related to the action of glutamic acid, the most abundant amino acid in the formulation of the product from plant origin. 相似文献
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Journal of Plant Diseases and Protection - Phosphites have low-toxicity on the environment and show high efficacy in controlling oomycete diseases in plants, both by a direct and an indirect... 相似文献
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Florida citrus and vegetable crops generate billions of dollars in revenue every year. However, wind, freezing temperatures,
hurricanes, and diseases negatively impact production. Windbreaks located perpendicular to the prevailing wind can increase
farm production simply by reducing wind and modifying microclimate. Windbreaks can also help in managing pathogens such as
citrus canker (Xanthomonas campestris pv. citri). To study the modification of wind speed, temperature, and relative humidity on the leeside of single-row tree windbreaks
in southern Florida, automated weather stations were installed in 2007/2008 at 2 m above the ground along transects perpendicular
to a eastern redcedar (Juniperus virginiana) and three cadaghi (Corymbia torelliana) (WB1–WB3) windbreaks. All windbreaks reduced wind speed, with minimum wind speed (~5% of the open wind speed) at two times
the distance of windbreak height (2H, where H = windbreak height in m) on the leeside of a E. redcedar (~17% porosity) and
at 4H (~3–30% of the open wind speed) and 6H (<50% of the open wind speed) on the leeside of cadaghi windbreaks WB1 (~22%
porosity) and WB2 (~36% porosity), respectively, when the wind direction was nearly perpendicular to the windbreaks. Wind
speed reduction was observed up to 31 times the windbreak height (31H). Cadaghi windbreaks reduced wind speed on the leeside
even during a tropical storm event. Temperatures on the leeside of the windbreaks were warmer during the day and cooler near
the windbreaks at night compared to temperature in the open fields. This study demonstrates that single-row tree windbreaks
can reduce wind and modify the microclimate to enhance crop production for Florida growers. 相似文献
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Sánchez J Cabrer JM Rosselló CA Palou A Picó C 《Journal of agricultural and food chemistry》2008,56(13):5096-5101
The effect of fiber and fat contents of food and of age and sex of animals on the formation of hemoglobin adducts of acrylamide (AA-Hb) in blood has been studied. The results suggest that the absorption of acrylamide (AA) present in food is not affected by the fiber or fat contents of food. However, AA-Hb resulting from the intake of an aqueous solution of AA is dependent on the age and sex of rats: AA-Hb levels were higher in females than in males (3.53- and 2.55-fold higher, respectively, for AA doses of 25 and 100 mg/kg) and in younger than in older rats (30.1% higher in 1.5 month old as compared to 14 month old rats). In males, AA-Hb levels found after the oral administration of AA in an aqueous solution were significantly lower than those found after dietary or intravenous administration. In conclusion, these results show the existence of significant differences in AA bioavailability from an aqueous solution depending on the sex and age of animals. If similar differences also occur in humans, they would be relevant to assess the exposure of different subpopulations to AA. 相似文献
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M. C. Lobato F. P. Olivieri E. A. González Altamiranda E. A. Wolski G. R. Daleo D. O. Caldiz A. B. Andreu 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(3):349-358
Phosphites (Phi) are alkali metal salts of phosphorous acid, with the ability to protect plants against different pathogens.
In this research, the effect of Phi applied to potato plants on severity of three important potato diseases in Argentina was
assessed. Seed tubers and foliage of potato cvs Shepody and Kennebec were treated with Phi to assess effects on resistance
against Phytophthora infestans, Fusarium solani and Rhizoctonia solani. Protection resulting from Phi treatment in seed tubers was high against P. infestans, intermediate against F. solani, and low against R. solani. In addition, seed tubers treated with calcium or potassium phosphites (CaPhi and KPhi, respectively) at 1% of commercial
product emerged earlier than untreated ones. When Phi were foliarly applied two or four times at different doses, high levels
of protection against P. infestans were achieved in both cultivars. Higher protection was observed in Kennebec when CaPhi was applied, while in Shepody this
was true for KPhi. Expression of β-1,3-glucanases was induced at different times after treatment but no correlation between
β-1,3-glucanases expression and foliar protection level was found. On the other hand, Phi positive protection effects did
not produce negative effects in plant growth. Leaves from CaPhi-treated plants showed a darker green colour than leaves from
control plants; also an increase in Rubisco protein and a delay in crop senescence was observed. 相似文献
40.
Soraya Constán-Nava Andreu Bonet Estrella Pastor María José Lledó 《Forest Ecology and Management》2010
Ailanthus altissima is an invasive tree species which has colonized numerous ecosystems and affected ecosystem processes worldwide. Despite its importance as an invasive species and the high economic costs incurred from its spread, there is a lack of long-term management planning for its control. Although mechanical disturbance is commonly applied, the effect that this treatment may have exhausting its resprouting ability and also its joint effect with phytochemical treatments are poorly understood, especially in Mediterranean environments. We tested three treatments (plus a control) aimed to reduce A. altissima growth in Mediterranean forests throughout 5 years of study. The treatments (one cut stump, double cut stump and cut stump with glyphosate application) were repeated annually. General plant performance (biomass, height and resprout-type density) was measured yearly during the study. Water potential and stomatal conductance were also measured at the end of the study to evaluate particular ecophysiological factors which might affect the response of A. altissima to assayed treatments, together with leaf area index. Our results show that only the cut stump with glyphosate application treatment was able to reduce the long-term growth and spread of A. altissima. The treatments applied favoured collar sprout growth in response to disturbance events (treatments) opposite to the control, where new sprouts grew mainly from the root. Treated resprouts displayed ecophysiological changes depending on the assayed treatment. To our knowledge, this is the only study testing the long-term effect of both physical disturbance and phytochemical application on A. altissima growth. Our study further refines our knowledge on the effects of repeating both commonly and newly used treatments, improving our management techniques to reduce the presence and growth of this invasive tree. 相似文献