Tolerance of Spinach (Spinacia oleracea) Plants to Partial Defoliation     

Casierra-Posada  Fánor  Briceño-Pinzón  Iván David  Carreño-Patiño  Julio Alexander 《Gesunde Pflanzen》2021,73(4):427-434

Vegetables in the tropics are grown continuously throughout the year due to the favorable climate. Unfortunately, leafy vegetables are often damaged because of slugs and snails. These mollusks and other herbivores cause different levels of defoliation to plants which can significantly impact their growth, production, and quality of the harvested product. A study was carried out in order to artificially simulate the effect of a loss in foliar area caused by these pests. The impact of severe artificial defoliation in spinach plants (Spinacia oleracea) was evaluated in Tunja, Colombia. Under greenhouse conditions and after transplanting, the plants had 75% of their leaf area removed. This procedure was repeated weekly on newly emerging leaves while a control group of plants was left intact. 71 days after transplanting, the plants were harvested, and the leaf area and dry weight of the plants were measured with which some allometric variables were calculated to express growth. Variables such as the number of leaves, plant height, total dry weight, relative growth ratio, leaf weight ratio (LWR), and root to shoot ratio (R:S) were unaffected by defoliation while leaf area, leaf area ratio (LAR), and specific leaf area (SLA) were reduced with the partial removal of the leaf area. The partial defoliation resulted in an increased partial biomass of the leaves. These results suggest that spinach plants have a moderate tolerance to partial defoliation.

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Technologies used in the study of sperm function in cryopreserved fish spermatozoa          下载免费PDF全文

Elías Figueroa  Iván Valdebenito  Jorge G Farias 《Aquaculture Research》2016,47(6):1691-1705

Sperm cryopreservation has led to transcendental changes in the reproductive biotechnology of both mammals and fish, and is a basic tool for animal improvement. However, these protocols generate damage to cell structure and physiology, altering sperm function as a result of cryoinjuries during freezing and thawing. This review is a compilation of the techniques developed and standardised for assessing sperm function in cryopreserved fish semen. Recent studies have analysed sperm function objectively, applying cellular and molecular techniques to characterise cryodamage. The Computer Assisted Sperm Analysis system has facilitated the assessment of motility, while electron microscopy (SEM and TEM) and cryo‐microscopy have made it possible to study sperm morphology and ultra‐structure. The effects of cryodamage on nuclear DNA have also been analysed using various methods, including the comet Fluorescence in situ Hybridization test, TUNEL, Sperm Chromatin Structure Assay, specific DNA sequences using RT‐PCR and specific genes by qPCR. The latter technique is used to study the mitochondrial genome (mtDNA), together with some candidate genes which are associated with bioenergy activity and sperm motility. Other parameters assessed are mitochondrial membrane potential and ATP content using high performance liquid chromatography, nuclear magnetic resonance spectrometry and cell respiration. All this information makes it possible to establish study and assessment criteria for cryopreserved fish spermatozoa. This work focuses on the use of technologies to study of quality of fish spermatozoa during cryopreservation.  相似文献   

Association of phytoene synthase Psy1-A1 and Psy1-B1 allelic variants with semolina yellowness in durum wheat (Triticum turgidum L. var. durum)     

Karen M. Campos  Conxita Royo  Albert Schulthess  Dolors Villegas  Iván Matus  Karim Ammar  Andrés R. Schwember 《Euphytica》2016,207(1):109-117

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Assessment of cattle welfare at a commercial slaughter plant in the northwest of Mexico     

Miranda-de la Lama GC  Leyva IG  Barreras-Serrano A  Pérez-Linares C  Sánchez-López E  María GA  Figueroa-Saavedra F 《Tropical animal health and production》2012,44(3):497-504

Slaughter plants have been undergoing radical transformations in recent years due to the need to increase efficiency and incorporate new technologies for the improvement of the infrastructure, animal welfare, and product quality. The aim of this study was to assess the cattle welfare status during the unloading, lairage, stunning, bleeding and quantify bruising incidence at a commercial slaughter plant in the northwest of Mexico. We monitored 8,118 cattle during the unloading, lairage, stunning, bleeding, and carcass bruise incidence. Our results showed that in the unloading stage, 2% of the cattle vocalized, 5% were prodded with an electric goad, and 4% either slipped or fell. In the lairage stage, 12% of the animals vocalized, 80% prodded with an electric goad, and 8% of the animals slipped or fell. In the stunning stage, 10% of the animals vocalized, 67% prodded with an electric goad, and 15% of the animals slipped or fell. Ninety-five percent of the animals were stunned with a single shot, and 51% of the animals were effectively desensitized. Ninety-two percent of the carcasses had some type of bruise. Although the slaughter plant had adequate infrastructure and stringent operational standards, in all of the stages except unloading handling had an impact on the welfare of the animals being slaughtered.  相似文献   

Chromatographic fingerprinting of <Emphasis Type="Italic">Lupinus luteus</Emphasis> L. (Leguminosae) main secondary metabolites: a case of domestication affecting crop variability     

Claudia E. Osorio  Veronique S. E. Amiard  Javiera Aravena-Calvo  Joshua A. Udall  Jeff J. Doyle  Iván J. Maureira-Butler 《Genetic Resources and Crop Evolution》2018,65(4):1281-1291

Secondary metabolites (SMs), such as alkaloids and raffinose oligosaccharides (RFOs), play important roles in plant physiology. Although alkaloid and RFO phenotypic variation has been reported for yellow lupin (Lupinus luteus L.), most evaluations have used a reduced number of accessions; thus, limiting the understanding of accumulation patterns and variation ranges. The main goal of this research was to assess alkaloid and RFO content in a diverse L. luteus sample to understand possible SM accumulation patterns across this legume species. Eighteen yellow lupin accessions were analyzed using high performance thin layer chromatography to provide insights on seed and leaf RFO and alkaloid phenotypic variation. Co-dominant markers (170) were used to examine genetic relationships among L. luteus accessions and possible accumulation patterns across closely related genotypes. Significant differences were observed for seed and leaf RFOs. Total seed RFO accumulation ranged from 79.738 to 131.079 mg g^?1. Raffinose, stachyose, and verbascose were observed in all genotypes’ seeds, but at different RFO concentrations. Raffinose was the only RFO detected in leaves (2.793–0.4224 mg g^?1). Total alkaloid accumulation ranged from 0.22 to 15.12 and 0.00 to 8.007 mg g^?1 for seeds and leaves, respectively. Lupinine, sparteine, and gramine were observed in seeds and leaves, and showed a wide range of variation. Neighbor-Joining (NJ) analysis showed an apparent pattern of seed alkaloid accumulation, most likely due to domestication events. However, high RFO accumulating accessions were scattered across the NJ tree. Alkaloid and RFO significant phenotypic variation will not only help to understand the roles of these SMs in L. luteus, but also to uncover the genetic basis behind their accumulation.  相似文献   

Comparative Photocatalytic Performance on the Degradation of 2-Naphthol Under Simulated Solar Light Using α-Bi<Subscript>4</Subscript>V<Subscript>2</Subscript>O<Subscript>11</Subscript> Synthesized by Solid-State and Co-precipitation Methods     

Lucy T. González  C. Leyva-Porras  M. Sánchez-Domínguez  Iván J. Maza  F. E. Longoria Rodríguez 《Water, air, and soil pollution》2017,228(2):75

In this investigation, the photocatalytic activity of α-Bi₄V₂O₁₁ in the degradation of 2-naphthol under simulated solar light was evaluated. Bismuth vanadate α-Bi₄V₂O₁₁ was synthesized by the solid-state reaction method and by co-precipitation in aqueous media, with the aim of comparing their performance in the photodegradation of the aromatic pollutant. The latter method (co-precipitation) has not been previously reported for the synthesis of α-Bi₄V₂O₁₁. Structural evolution of the oxides precursors was determined by X-ray diffraction. Morphology and optical properties of the solids were analyzed by scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectroscopy (UV-vis), respectively. The results showed that at 800 °C, only α-Bi₄V₂O₁₁ was formed in both preparations. The SEM micrographs revealed that the powders were composed of agglomerates with sizes between 0.8–2 μm for those synthesized by co-precipitation and 2–10 μm for those obtained by solid-state reaction. The optical properties indicated that α-Bi₄V₂O₁₁ was activated with visible light during the photocatalytic process. The photocatalytic degradation of 2-naphthol was largely influenced at basic pH, degrading 79% of the contaminant in 240 min, with the powder obtained by co-precipitation; meanwhile, for the solid-state preparation, the degradation reached only 55%.  相似文献   

The effect of hedgerow loss on microclimate in the Mediterranean region: an investigation in Central Spain     

Iván A. Sánchez  Luis Lassaletta  Duncan McCollin  Robert G. H. Bunce 《Agroforestry Systems》2010,78(1):13-25

In Central Spain hedgerows are an important component of the landscape although many have been lost due to landscape planning and reallotment programmes. Loss of hedgerows can produce changes in environmental conditions that can be especially critical in summer, corresponding with the dry period in Mediterranean ecosystems. In order to show the effects of hedgerow removal on summer Mediterranean environmental conditions in rural landscapes, this paper describes a comparison of some key environmental conditions between areas where hedgerows are still present, compared to areas where they have been removed. Through a two-way ANOVA, it was found that temperatures in the hedgerows were significantly different from those in the fields, whilst air temperatures beneath the hedgerows were lower, and steadier, than those of surrounding areas. When temperatures of the fields were compared to those sites where hedgerows had been removed, significant differences in temperatures were detected belowground and sometimes at soil surface level but not at higher levels. The levels of soil water content and organic carbon were higher where hedgerows were still in place. These differences indicate potentially negative environmental impacts due to hedgerow removal. The implications of hedgerow conservation for environmental protection and for cropland productivity are discussed.  相似文献   

Improving the screening process for the selection of potato breeding lines with enhanced polyphenolics content     

Shiroma-Kian C  Tay D  Manrique I  Giusti MM  Rodriguez-Saona LE 《Journal of agricultural and food chemistry》2008,56(21):9835-9842

Efficient selection of potato varieties with enhanced nutritional quality requires simple, rapid, accurate, and cost-effective assays to obtain tuber chemical composition information. Our objective was to develop simple protocols to determine phenolics, anthocyanins, and antioxidant capacity in polyphenolic extracts of potatoes using Fourier transform infrared spectroscopy combined with multivariate techniques. Lyophilized potato samples (23) were analyzed. Polyphenolic compounds were extracted from potatoes and applied directly applied onto a three-bounce ZnSe crystal for attenuated total reflectance measurements in the infrared region of 4000 to 700 cm (-1). Robust models were generated (r > or = 0.99) with standard error of cross-validation values of 4.17 mg gallic acid equivalent/100 g (total phenolics), 0.87 mg pelargonidin-3-glucoside/100 g (monomeric anthocyanins), and 130.8 mumol Trolox equivalent/100 g (antioxidant capacity) potato powder. In addition, classification models discriminated potato samples at the species and variety level. Application of a simple infrared spectroscopic protocol allowed simultaneous rapid quantification of specific nutritional components in potatoes and efficient selection of value-added potato varieties.  相似文献   

Universal probe library assay for the detection of infectious pancreatic necrosis virus genogroups 1 and 5 in salmonid tissues          下载免费PDF全文

Ruben Avendaño‐Herrera  Jaime A Tobar  Iván Tobar  Claudia Fernández‐Caro 《Aquaculture Research》2017,48(4):1962-1967

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Pasture restoration improvement methods for temperate degraded pastures and consequences of the climatic seasonality on soil–pasture complex     

Constanza A. Descalzi  Ignacio F. López  Peter D. Kemp  José Dörner  Iván Ordóñez 《Journal of Agronomy and Crop Science》2020,206(1):130-147

Short persistence of renovated pastures is a major problem for pastoral production systems. Pasture species establishment, species performance and persistency and their relationships with soil–water attributes following pasture improvement methods were evaluated over two years. Fertilised naturalised pasture (FNP), non-fertilised naturalised pasture (NFNP), Lolium perenne–Trifolium repens cultivated pasture (CP), L. perenne–T. repens direct-drilled pasture (DP), and Bromus valdivianus, Holcus lanatus, Dactylis glomerata, L. perenne and T. repens direct-drilled pasture (DDP) were established as a randomised complete block design. Pastures were limed, fertilised and sheep-grazed. Plant growth compensatory mechanisms, by decreasing tiller number and increasing tiller size, equalised pasture yield during the establishment. In both years, the improved pastures yield was greater than that of NFNP. In the second year, DDP and FNP reached the higher pasture growth rate, with a seasonality diminishment. During the second summer, soil matrix potential at 0–20 cm soil profile exceeded the permanent wilting point, resulting in the pasture growth rate of NFNP and the sown pastures ranging from 0.0 to 3.6 kg DM/ha per day, while for FNP, it was 17.8 kg DM/ha per day. Sown species, fast-growing species spontaneous colonisation and growth were all stimulated in the improved pastures over species that tolerate stress, improving agronomical and ecological pasture features.  相似文献