Root system of Quercus suber L. seedlings in response to herbaceous competition and different watering and fertilisation regimes     

Elena Cubera  Gerardo Moreno  Alejandro Solla  Manuel Madeira 《Agroforestry Systems》2012,85(2):205-214

Different management practices are commonly applied to increase pasture yield of Mediterranean open woodlands, but the consequences of increasing competition for soil resources with these practices on tree recruitment are still unknown. In a greenhouse study, belowground competition of Quercus suber L. seedlings growing together with natural (Oak_NP) or improved pasture (Oak_IP) was evaluated, and their root systems compared with those of seedlings growing in bare soil (Oak_BS). Two watering levels and two regimes of P₂O₅ fertilisation were also tested. Because of competition, the Oak_IP seedlings had their fine root mass density, coarse root length, and shoot mass reduced by up to 40, 36, and 39%, respectively, when compared to Oak_NP seedlings. Oak_NP and Oak_BS seedlings showed similar average root density parameters and shoot mass values, indicating that Q. suber seedlings growing with natural pasture is a low competitive system. High availability of water and phosphorus did not mitigate the strength of competition between herbaceous plants and oak seedlings, and favoured the pasture to the detriment of the trees. Our findings suggest that P₂O₅ fertilisation and irrigation practices performed to improve herbaceous productivity will negatively influence recruitment of Q. suber seedlings.  相似文献   

Chemical control of sprouting in white potatoes     

Gerardo Perlasca 《American Journal of Potato Research》1956,33(4):113-133

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Lethal and sublethal effects of withanolides from Salpichroa origanifolia and analogues on Ceratitis capitata     

Bado S  Mareggiani G  Amiano N  Burton G  Veleiro AS 《Journal of agricultural and food chemistry》2004,52(10):2875-2878

Biological effects on Ceratitis capitata were evaluated for several withanolides isolated from Salpichroa origanifolia (Solanaceae), (20S,22R,24S,25S,26R)-5alpha,6alpha:22,26:24,25-triepoxy-26-hydroxy-17(13-->18)-abeo-ergosta-2,13,15,17-tetraen-1-one (salpichrolide A, 1), (20S,22R,24S,25S,26R)-22,26:24,25-diepoxy-5alpha,6beta,26-trihydroxy-17(13-->18)-abeo-ergosta-2,13,15,17-tetraen-1-one (salpichrolide C, 2), (20S,22R,24S,25S,26R)-5alpha,6alpha;22,26:24,25-triepoxy-15,26-dihydroxy-17(13-->18)abeo-ergosta-2,13,15,17-tetraen-1-one (salpichrolide G, 3), and (20S,22R,24S,25S,26R)-5alpha,6alpha:22,26:24,25-triepoxy-1,26-dihydroxy-17(13-->18)-abeo-ergosta-2,13,15,17-tetraene (salpichrolide B, 5), and for chemically modified analogues. Influence of chemical modifications on development delay was analyzed. The compounds were incorporated into the larval diet and the adults' drinking water. Significant development delays from larvae to puparia were observed in treatments with the natural withanolides salpichrolides A, C, and G (1-3) at a concentration of 500 ppm. Salpichrolide B (5) was the most toxic compound, the highest mortality (95%) being observed at the larval stage. Exposure of adults to drinking water containing natural withanolides 1-3 and 5 produced mortality in all cases.  相似文献   

Genetic diversity of introduced and local Spanish persimmon cultivars revealed by RAPD markers   总被引：2，自引：1，他引：2  

María Badenes  Ana Garcés  Carlos Romero  Miguel Romero  Joan Clavé  Mercé Rovira  Gerardo Llácer 《Genetic Resources and Crop Evolution》2003,50(6):579-585

Persimmon culture has become an alternative for fruit growers in Italy, Israel and Spain. However, there is some confusion concerning cultivar identification in non-Asian countries were the species was introduced. Authenticating the identity of germplasm resources of persimmon would be a great value for breeding. Due to the floral biology of the persimmon species the expected genetic variability is high. RAPD markers were chosen for this study of persimmon germplasm resources in Spain. Nineteen markers were obtained from 8 primers. The average of 2.4 markers/primer was higher than that obtained in other woody fruit species. The availability of data referenced from isozymes and pomological traits revealed complete agreement among groups identified by RAPDs, isozymes and pomological traits. Results suggest that RAPD technology is adequate for fingerprinting persimmon and the data is consistent with persimmon's hypothetical origins, adaptation history and previous classification by isozymes or pomological traits. Many synonyms have been identified, mostly in cultivars from local surveys, suggesting that a few new genotypes arose in Spain since the species was introduced to Europe. By means of RAPD markers, a better identification of the European persimmon germplasm is available.  相似文献   

Effects of biochar addition to estuarine sediments     

Gerardo Ojeda  Joana Patrício  Stefania Mattana  Abilio J. F. N. Sobral 《Journal of Soils and Sediments》2016,16(10):2482-2491

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Natural Folates from Biofortified Tomato and Synthetic 5-methyl-tetrahydrofolate Display Equivalent Bioavailability in a Murine Model     

Fabiola Castorena-Torres  Perla A. Ramos-Parra  Rogelio V. Hernández-Méndez  Andrés Vargas-García  Gerardo García-Rivas  Rocío I. Díaz de la Garza 《Plant foods for human nutrition (Dordrecht, Netherlands)》2014,69(1):57-64

Folate deficiency is a global health problem related to neural tube defects, cardiovascular disease, dementia, and cancer. Considering that folic acid (FA) supply through industrialized foods is the most successful intervention, limitations exist for its complete implementation worldwide. Biofortification of plant foods, on the other hand, could be implemented in poor areas as a complementary alternative. A biofortified tomato fruit that accumulates high levels of folates was previously developed. In this study, we evaluated short-term folate bioavailability in rats infused with this folate-biofortified fruit. Fruit from tomato segregants hyperaccumulated folates during an extended ripening period, ultimately containing 3.7-fold the recommended dietary allowance in a 100-g portion. Folate-depleted Wistar rats separated in three groups received a single dose of 1 nmol of folate/g body weight in the form of lyophilized biofortified tomato fruit, FA, or synthetic 5-CH₃-THF. Folate bioavailability from the biofortified tomato was comparable to that of synthetic 5-CH₃-THF, with areas under the curve (AUC_0–∞) of 2,080?±?420 and 2,700?±?220 pmol?·?h/mL, respectively (P?=?0.12). Whereas, FA was less bioavailable with an AUC_0–∞of 750?±?10 pmol?·?h/mL. Fruit-supplemented animals reached maximum levels of circulating folate in plasma at 2 h after administration with a subsequent steady decline, while animals treated with FA and synthetic 5-CH₃-THF reached maximum levels at 1 h. Pharmacokinetic parameters revealed that biofortified tomato had slower intestinal absorption than synthetic folate forms. This is the first study that demonstrates the bioavailability of folates from a biofortified plant food, showing its potential to improve folate deficiency.  相似文献   

Cytokine-enhanced vaccine and interferon-β plus suicide gene as combined therapy for spontaneous canine sarcomas     

Finocchiaro LM  Villaverde MS  Gil-Cardeza ML  Riveros MD  Glikin GC 《Research in veterinary science》2011,91(2):230-234

Eleven soft tissue- and five osteosarcoma canine patients were subjected to: (i) periodic subcutaneous injection of irradiated xenogeneic cells secreting hGM-CSF and hIL-2 mixed with allogeneic or autologous tumor homogenates; and (ii) injections of cIFN-β and HSVtk-carrying lipoplexes and ganciclovir, marginal (after surgery) and/or intratumoral (in the case of partial tumor resection, local relapse or small surface tumors). This treatment alone (4 patients) or as surgery adjuvant (12 patients), was safe and well tolerated. In those patients presenting local disease (6/11), the suicide gene plus cIFN-β treatment induced local antitumor activity evidenced by the objective responses (3 complete, 2 partial) and stable diseases (2). In addition, the treatment prevented or delayed local relapse, regional metastases (lymph nodes developed only in 3/16) and distant metastases (0/16), suggesting a strong systemic antitumor immunity. The most encouraging result was the long survival times of 10 patients (>1 year, with good quality of life).  相似文献   

The effect of flushing and stimulus of estrogenized does on reproductive performance of anovulatory-range goats   总被引：1，自引：1，他引：0  

De Santiago-Miramontes MA  Luna-Orozco JR  Meza-Herrera CA  Rivas-Muñoz R  Carrillo E  Véliz-Deras FG  Mellado M 《Tropical animal health and production》2011,43(8):1595-1600

This study was conducted to determine whether flushing or the stimulus of estrogenized goats is necessary to achieve a high reproductive response in anestrous goats on rangeland. Does were feed-supplemented on rangeland (flushed, n = 20). Other group was exposed to estrogenized does during the mating period (stimulated, n = 20). A third group was both supplemented and stimulated (stimulated–flushed, n = 20) and other group grazed on rangeland only (control, n = 18). More goats in the stimulated and stimulated–flushed groups showed estrus during the first 5 days of joining (45% and 60%, respectively) than the control and flushed groups (11% and 5%, respectively; P < 0.05). Flushing did not improve prolificacy and reduced (P < 0.05) kidding rates (40% and 35% for the flushed and stimulated–flushed groups, respectively) compared to 67% and 55% for the control and stimulated groups, respectively. This experiment demonstrates potential shortcomings of use of flushing in range goats with inadequate nutrition during gestation.  相似文献   

Occurrence of Helicobacter pullorum in turkeys     

Zanoni RG  Piva S  Rossi M  Pasquali F  Lucchi A  De Cesare A  Manfreda G 《Veterinary microbiology》2011,149(3-4):492-496

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Restoring abandoned pasture land with native tree species in Costa Rica: Effects of exotic grass competition and light     

Gerardo CelisShibu Jose 《Forest Ecology and Management》2011,261(10):1598-1604

Understanding the early establishment requirements and performance of tropical tree seedlings is essential to ensuring the success of restoration plantings. This study was designed to characterize growth and light requirements of six common neotropical tree species Pseudosamanea guachapele (Fabaceae), Tabebuia impetiginosa (Bignoniaceae), Ceiba pentandra (Bombacaceae), Pachira quinata (Bombacaceae), Dalbergia retusa (Fabaceae), and Tabebuia rosea (Bignoniaceae) in an abandoned pasture under contrasting light environments and grass competition. Field studies were conducted in the pastures of the Santa Ana Conservation Center in Costa Rica. Two differing grass competition sites were selected, one dominated by a tall grass, Hyparrhenia rufa and another dominated by a short grass, Cynodon mlenfluensis. Three light treatments were created (2, 37 and 100% light) using either neutral shade cloth (2 and 37%) or no shade cloth (100%). Growth characteristics and biomass partitioning of the seedlings were measured. Species differed in their relative growth rates (RGRs). The light × species interaction was significant at both sites. While all species had similar performance under 100% light on both short grass and tall grass sites, species growth differences were evident under 37 and 2% light levels. For example, at the short grass site, T. rosea had higher RGR than D. retusa and P. quinata under 2% light whereas both Tabebuia species performed better than other species at the tall grass site. The general trend was to increase root mass ratio and decrease leaf mass ratio with increasing levels of light. As an initial step for restoring abandoned pasture lands we recommend using all these species in direct and moderate light conditions. Incorporating all species will create a more heterogeneous environment. Choosing light demanding species that can tolerate grass competition may help ensure success in the early stage of restoration.  相似文献