Almond agronomic response to long-term deficit irrigation applied since orchard establishment     

Gregorio Egea  Pedro A. Nortes  Rafael Domingo  Alain Baille  Alejandro Pérez-Pastor  María M. González-Real 《Irrigation Science》2013,31(3):445-454

This study assesses the long-term suitability of regulated (RDI) and sustained deficit irrigation (SDI) implemented over the first six growing seasons of an almond [Prunus dulcis (Mill.) D.A. Webb] orchard grown in a semiarid area in SE Spain. Four irrigation treatments were assessed: (i) full irrigation (FI), irrigated to satisfy maximum crop evapotranspiration (100% ET_c); (ii) RDI, as FI but receiving 40% ET_c during kernel-filling; (iii) mild-to-moderate SDI (SDI_mm), irrigated at 75–60% ET_c over the entire growing season; and (iv) moderate-to-severe SDI (SDI_ms), irrigated at 60–30% ET_c over the whole season. Application of water stress from orchard establishment did not amplify the negative effects of deficit irrigation on almond yield. Irrigation water productivity (IWP) increased proportionally to the mean relative water shortage. SDI_ms increased IWP by 92.5%, reduced yield by 29% and applied 63% less irrigation water. RDI and SDI_mm showed similar productive performances, but RDI was more efficient than SDI_mm to increase fruiting density and production efficiency (PE). We conclude that SDI_ms appears to be a promising DI option for arid regions with severe water scarcity, whereas for less water-scarce areas RDI and SDI_mm behaved similarly, except for the ability of RDI to more severely restrict vegetative development while increasing PE.  相似文献   

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species     

Alejandro Carlos Tozzini  María Fernanda Ceriani  María Verónica Saladrigas  H. Esteban Hopp 《Potato Research》1991,34(3):317-324

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).  相似文献   

Effects of adrenocorticotropic hormone challenge and age on hair cortisol concentrations in dairy cattle     

González-de-la-Vara Mdel R  Valdez RA  Lemus-Ramirez V  Vázquez-Chagoyán JC  Villa-Godoy A  Romano MC 《Canadian journal of veterinary research》2011,75(3):216-221

Dairy cattle suffer stress from management and production; contemporary farming tries to improve animal welfare and reduce stress. Therefore, the assessment of long-term hypothalamic-pituitary-adrenal function using non-invasive techniques is useful. The aims in this study were: to measure cortisol concentration in cow and calves hair by radioimmunoassay (RIA), to test cortisol accumulation in bovine hair after adrenocorticotropic hormone (ACTH) challenges, and determine the influence of hair color on cortisol concentrations. Fifteen Holstein heifers were allotted to 3 groups (n = 5 each): in control group (C), just the hair was sampled; in the saline solution group (SS), IV saline solution was administered on days 0, 7, and 14; and the ACTH group was challenged 3 times with ACTH (0.15 UI per kg of body weight) on days 0, 7, and 14. Serum samples from the SS and ACTH groups were obtained 0, 60 and 90 min post-injection. Serum cortisol concentration was greater 60 and 90 min after injection with ACTH. Hair was clipped on days 0, 14, 28, and 44. Hair cortisol was methanol extracted and measured by RIA. Hair cortisol was preserved for 11 mo. Hair cortisol concentrations in the ACTH group were greater than in the saline and control groups on days 14 and 28, but not on day 44. Concentrations were greater in calves than in cows and greater in white hair than in black hair. Cortisol accumulated in bovine hair after ACTH challenges, but the concentration was affected by both age and hair color. If hair color effects are taken into account, assessing cortisol concentration in hair is a potentially useful non-invasive method for assessing stress in cattle.  相似文献   

Frequency of removal reasons of sows in Southeastern Mexico   总被引：1，自引：1，他引：0  

Segura-Correa JC  Ek-Mex E  Alzina-López A  Segura-Correa VM 《Tropical animal health and production》2011,43(8):1583-1588

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Length of productive life of sows in four pig farms in the tropics of Mexico     

Segura-Correa JC  Ek-Mex EJ  Alzina-López A  Magaña-Monforte JG  Sarmiento-Franco L  Santos-Ricalde RH 《Tropical animal health and production》2011,43(6):1191-1194

The objective of this study was to determine the effect of some factors on the length of productive life (LPL), the number of parities (NP), and the culling interval (CI) of sows. The information from 2003 to 2009 of 3,746 sows with LPL and NP records and 5,819 sows with CI records from the four farms of Yucatan, Mexico was used. LPL was defined as the number of days between the first farrowing and culling or death and CI as the number of days between the last farrowing and culling. To determine the effects of farm, litter size at first farrowing (LSF1) and age at first farrowing (AF1) on LPL and NP, and of farm, LSF1 and culling reason on CI general linear models were used. Means and standard errors for LPL, NP, and CI were 496.4 ± 8.42 days, 3.35 ± 0.04 parities, and 48.3 ± 0.52 days, respectively. All factors had significant effects (P < 0.05) on LPL, NP, and CI. The sows from farm 2 stayed longer (806.0 days) and had more parities (5.25) than the sows from the other farms. Sows with the smallest litters (≤8 piglets) at first farrowing stayed the least time in the farm (675.1 days) and had the fewest parities (4.49). Gilts farrowing the first time before 331 days of age stayed longer time in the farm (726.4 days) and had more parities (4.81) in comparison with 331–348 and more than 348 days age groups. With respect to CI, the sows in farm 3 stayed the longest time in the farm. Sows with more than five parities were culled sooner after their last farrowing. In conclusion, differences between farms for LPL, PN, and CI were found. Females that farrowed at a short age and those with large litters stayed longer in the herd. Old sows and those culled for reproductive reasons stayed the least time in the herd after their last farrowing.  相似文献   

Surgical technique, postoperative complications and outcome in 14 dogs treated for hydrocephalus by ventriculoperitoneal shunting     

de Stefani A  de Risio L  Platt SR  Matiasek L  Lujan-Feliu-Pascual A  Garosi LS 《Veterinary surgery : VS》2011,40(2):183-191

Objective: To report frequency and type of complications, and outcome in dogs with severe neurologic signs secondary to internal, suspected obstructive hydrocephalus treated by ventriculoperitoneal (VP) shunting. Study Design: Case series. Animals: Dogs (n=14). Methods: Medical records (2001–2006) was reviewed for dogs that had VP shunting. Inclusion criteria were complete medical record, progressive forebrain signs unresponsive to medical treatment, normal metabolic profile, negative antibody titers and/or cerebrospinal PCR for Toxoplasma gondii, Neospora caninum, and canine distemper virus, magnetic resonance images of the brain, confirmed diagnosis of VP shunting, and follow‐up information. Results: Hydrocephalus was idiopathic in 5 dogs and acquired (interventricular tumors, intraventricular hemorrhage, inflammatory disease) in 9 dogs. Four dogs developed complications 1 week to 18 months postoperatively, including ventricular catheter migration, infection, shunt under‐drainage, kinking of the peritoneal catheter, valve fracture, and abdominal skin necrosis. Three of these dogs had 1 or more successful revision surgeries and 1 dog was successfully treated with antibiotics. All, but 1 dog, were discharged within 1 week of surgery, and had substantial neurologic improvement. Median survival time for all dogs was 320 days (1–2340 days), for dogs with idiopathic hydrocephalus, 274 (60–420) days and for dogs with secondary hydrocephalus, 365 (1–2340) days. Conclusions: VP shunting was successful in relieving neurologic signs in most dogs and postoperative complications occurred in 29%, but were resolved medically or surgically.  相似文献   

Germination differentiation patterns of wild and domesticated columnar cacti in a gradient of artificial selection intensity     

Susana Guill��n  Teresa Terrazas  Erick De la Barrera  Alejandro Casas 《Genetic Resources and Crop Evolution》2011,58(3):409-423

Germination of wild and managed populations of columnar cacti was compared to analyze differences associated to management intensity. The species studied: Polaskia chende, Escontria chiotilla, Myrtillocactus schenckii, Polaskia chichipe, and Stenocereus pruinosus are in a gradient from lower to higher management intensity, respectively. Within each species wild, silvicultural, and cultivated populations also represent a gradient from lower to higher management intensity. We hypothesized that seeds of plants under higher management intensity would require more water to germinate than others since managed environments are relatively wetter than unmanaged environments. Such pattern could be visualized within and among species according to management intensity. We tested germination of seeds from different populations of the different species to the water potentials: 0.0, ?0.2, ?0.4, ?0.6, ?0.8, and ?1.0 MPa. In all species studied seeds of managed populations had significantly more mass than seeds from wild populations. Each species had different susceptibility to water availability decrease, which could be related to particular adaptations to drought resistance. Stenocereus pruinosus and Polaskia chende were the most and least susceptible species, respectively. In control treatments of all species, seeds of managed populations had higher germination rate than seeds from wild populations, but when water availability decreased the pattern was the contrary. Our results suggest that artificial selection for larger fruits and heavier seeds in plants established in wetter environments have affected germination patterns. Although species have particular critical points of water availability for germination, differences in germination patterns are more pronounced according to management and artificial selection intensity.  相似文献   

Use of partition and redistribution indexes for heavy metal soil distribution after contamination with a multi-element solution     

Patricia Miretzky  Monica Rodriguez Avendaño  Carolina Muñoz  Alejandro Carrillo-Chavez 《Journal of Soils and Sediments》2011,11(4):619-627

Purpose  

Tessier's sequential extraction method is usually used to study metal parting among different phases in soils. The main objective of this study was to determine the redistribution of trace metals which were added simultaneously to a sandy loam soil by use of the fractional distribution and reduced partition indexes and the risk of assessment code (RAC).  相似文献   

Short-Term Effects of Arsenate-Induced Toxicity on Growth, Chlorophyll and Carotenoid Contents, and Total Content of Phenolic Compounds of Azolla filiculoides     

Gabriela S??nchez-Viveros  Ronald Ferrera-Cerrato  Alejandro Alarc??n 《Water, air, and soil pollution》2011,217(1-4):455-462

This study evaluated the toxic effects of arsenic (As) on the growth, total antioxidant activity, total content of phenolic compounds, and content of photosynthetic pigments of Azolla filiculoides. The aquatic fern was propagated and exposed to Yoshida nutrient solution contaminated with sodium arsenate (Na₂HAsO₄??7H₂O) at six concentrations (5, 10, 20, 30, 60, and 120???g?As?mL^?1), including the control without As contamination. Azolla cultures were kept under environmental chamber conditions?26??C, 12?h photoperiod and 80% HR for 96?h. Increased As concentrations (>30???g?mL^?1) significantly diminished growth of A. filiculoides and the total content of chlorophyll and total phenolic compounds, but significantly enhanced of total carotenoid?+?xanthophylls content. The concentrations of 5 and 10???g?As?mL^?1 significantly stimulated the growth of A. filiculoides. This aquatic fern tolerates As concentrations lower than 30???g?mL^?1, and its maximum As accumulation (28???g?g^?1 dry weight) was achieved when exposed to 60???g As mL^?1, but showing clear symptoms of As toxicity.  相似文献   

Metabolite Profiling of Rosemary Cell Lines with Antiproliferative Potential against Human HT-29 Colon Cancer Cells     

Urquiza-López  Araceli  Álvarez-Rivera  Gerardo  Ballesteros-Vivas  Diego  Cifuentes  Alejandro  Del Villar-Martínez  Alma Angélica 《Plant foods for human nutrition (Dordrecht, Netherlands)》2021,76(3):319-325

Plant Foods for Human Nutrition - Rosemary (Rosmarinus officinalis) is a culinary and medicinal plant used in food and pharmaceutical industry. The wide range of biological activities is mainly...  相似文献