Freeze Damage of Pinot noir (Vitis vinifera L.) as Affected by Bud Development, INA Bacteria, and a Bacterial Inhibitor

Spring freeze decreased the yield of field grown grapevines by 70%. The spring bud development of Pinot noir was characterized into seven stages after the initial budbreak, 96% of the buds attained full development in 44 days. Controlled freezing tests were used to determine bud hardiness. The T50 values (temperature when 50% of buds are damaged) for quiescent, swollen, bud urst, first, second, and third flat leaf bud stages were -14, -3, -2.2, -2, -1.7, and 1.1oC, respectively. The water content increased from 57 to 84% frorn the quiescent to the swollen bud stage, thereafter little change occurred. A high correlation was found between hardiness, water content, and stage of bud development. Genotype and culture age affected the ice nucleation activity of three Pseudomonas syringae strains (P. syringae is common bacteria found on grapevines). The cells attained stationary phase of growth after 60 hr. in culture. The INA (ice nucleation activity) of PssB15 occurred in the range of -2 to-4oC throughout the 7 days of evaluation. Pss2-3RNH INA was prevalent in 3-day-old cultures only. Pss2-3 was a poor ice nucleator. The INA of bacterial suspensions was directly proportional to concentrations ranging from 109 to 102 cells/ ml, which nucleated ice from -2.5 to -15.1oC. INA-bacteria at 108cells/ml incited freeze injury to grape leaf tissue specifically from -2 to -4oC. Frost Gard, a commercial chemical promoted as a freeze protectant, did not show antifreeze action (in water solutions) at concentrations of 0, 0.12, 0.25, 0.50, and 1%. At these concentrations, the water solutions froze at -11.6, -12.0, -11.8, -11.7, and -12.5oC, respectively, suggesting that the water ice nucleation temperature depended on the amount of impurities in the solutions. Frost Gard at 0.25, 0.50, and 1% had a strong bactericide effect on a bacterial suspension of 8 X 109 cells/ml. The same concentrations also lowered the nucleation temperature to -4.5, -6.9, and -5.2oC compared to the control suspension at -2.5oC. It was concluded that Frost Gard binds with the active site of nucleation since it strongly interacted with an inorganic ice nucleator. Frost Gard at 0.25% applied to grape leaf disks reduced the damaged area by 7% only at -2oC. Phytotoxicity due to Frost Gard was observed at rates above .25%. Grape cuttings were used to test the capacity of an antibiotic resistant strain of Pseudomonas syringaeto Page 1 of 2Grape Research Reports, 1988: Freeze Damage of Pinot noir translocate through the vascular tissue. The cuttings were placed in bacterial suspensions of ca. 102, 104, and 106 cells/ml for 24, 36, and 48 hr. Bacterial populations recovered were inversely proportional to the length of the cutting section regardless of the time of exposure to the inoculum. It was determined that the liquids moved faster through the vascular tissue than the bacteria

Bacanora and Sotol: So Far, So Close

El propósito de este trabajo es familiarizar al lector con algunos aspectos relacionados, no sólo con dos bebidas alcohólicas de profundo arraigo en la cultura rural del México norteño, sino también con Agave angustifolia, conocido en Sonora como “agave (o mezcal) bacanora”; y un grupo de especies del género Dasylirion, conocido en México como “sotoles”, y “desert spoon” o ¨cuchara del desierto¨ en los Estados Unidos de América. Ambas comparten múltiples características morfológicas, fisiológicas y ecológicas que les permiten vivir en ambientes áridos. De igual forma, también intenta señalar aspectos únicos de las dos denominaciones de origen que protegen la elaboración de esas bebidas y que han surgido en los albores de este siglo, así como a las normas que rigen su elaboración

Proximal chemical analysis and secondary metabolites in Washingtonia robusta fruit (Arecaceae): relevance for the feeding of wildlife and human

Background: Washingtonia robusta fruits are a staple for birds, small and medium-size mammals, and humans. However, quantitative data of their nutritional contribution has remained unknown. This is the first report on the phytochemical components found in fruit pulp and seeds. Questions: Does pulp compounds favor its consumption and contribute with nutrients for wildlife and humans? Do seed contents favor ecological interactions for germination and plantlet development? Species study: Washingtonia robusta H. Wendl. Study site and dates: Sierra El Aguaje, Sonora, Mexico, February - April 2016 Methods: Chemical and secondary metabolite analyses were carried out from extracts via phytochemical coloring tests and ultra-resolution liquid chromatography. Antioxidant activity was analyzed by DPPH. Results: Washingtonia robusta seeds contain 73 % sugars, 7.4 % protein, 8.4 % humidity, 4.3 % ashes, 8.7 % fat and 0.2 % calcium, while cyanogenic glycosides content was 0.8 mu g/g. Pulp has 71 % sugars, 10.8 % protein, 1.6 % humidity, 5.5 % ashes, 9.4 % fat and 1.5 % calcium, and cyanogenic glycosides reached 0.2 mu g/g. Alkaloids, tannins, saponins, phenols, and flavonoids were more abundant in seeds than in pulp. The DPPH assay expressed in Trolox equivalents indicated antioxidant capacity. Conclusions: Washingtonia robusta pulp is an important source of sugars and natural antioxidants for wildlife and human consumption. Occurrence of secondary metabolites prevents pathogens in seeds, also they could be beneficial for germination and initial plantlet development.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

A Novel Pectin Material: Extraction, Characterization and Gelling Properties

A novel pectin was acid extracted from chickpea husk (CHP). CHP presented a 67% (w/w) of galacturonic acid, an intrinsic viscosity of 374 mL/g and a viscosimetric molecular weight of 110 kDa. Fourier transform infrared spectroscopy spectrum of CHP indicated a degree of esterification of about 10%. The CHP-calcium system formed ionic gels with a storage (G′) modulus of 40 Pa and gel set time (G′ > G″) of 3 min at 1% (w/v), and a G′ of 131 Pa and gel set time of 1 min at 2% (w/v). The G′ of CHP gels was not greatly affected by temperature. The results attained suggest that chickpea husk can be a potential source of a gelling pectin material

Temperature response surfaces for mortality risk of tree species with future drought

Widespread, high levels of tree mortality, termed forest die-off, associated with drought and rising temperatures, are disrupting forests worldwide. Drought will likely become more frequent with climate change, but even without more frequent drought, higher temperatures can exacerbate tree water stress. The temperature sensitivity of drought-induced mortality of tree species has been evaluated experimentally for only single-step changes in temperature (ambient compared to ambient + increase) rather than as a response surface (multiple levels of temperature increase), which constrains our ability to relate changes in the driver with the biological response. Here we show that time-to-mortality during drought for seedlings of two western United States tree species, Pinus edulis (Engelm.) and Pinus ponderosa (Douglas ex C. Lawson), declined in continuous proportion with increasing temperature spanning a 7.7 °C increase. Although P. edulis outlived P. ponderosa at all temperatures, both species had similar relative declines in time-to-mortality as temperature increased (5.2% per °C for P. edulis; 5.8% per °C for P. ponderosa). When combined with the non-linear frequency distribution of drought duration—many more short droughts than long droughts—these findings point to a progressive increase in mortality events with global change due to warming alone and independent of additional changes in future drought frequency distributions. As such, dire future forest recruitment patterns are projected assuming the calculated 7–9 seedling mortality events per species by 2100 under business-as-usual warming occur, congruent with additional vulnerability predicted for adult trees from stressors like pathogens and pests. Our progressive projection for increased mortality events was driven primarily by the non-linear shape of the drought duration frequency distribution, a common climate feature of drought-affected regions. These results illustrate profound benefits for reducing emissions of carbon to the atmosphere from anthropogenic sources and slowing warming as rapidly as possible to maximize forest persistence.Peer reviewedPlant Biology, Ecology and Evolutio

Characterization of Cabernet Sauvignon Wines by Untargeted HS-SPME GC-QTOF-MS

Untargeted metabolomics approaches are emerging as powerful tools for the quality evaluation and authenticity of food and beverages and have been applied to wine science. However, most fail to report the method validation, quality assurance and/or quality control applied, as well as the assessment through the metabolomics-methodology pipeline. Knowledge of Mexican viticulture, enology and wine science remains scarce, thus untargeted metabolomics approaches arise as a suitable tool. The aim of this study is to validate an untargeted HS-SPME-GC-qTOF/MS method, with attention to data processing to characterize Cabernet Sauvignon wines from two vineyards and two vintages. Validation parameters for targeted methods are applied in conjunction with the development of a recursive analysis of data. The combination of some parameters for targeted studies (repeatability and reproducibility 0.99; retention-time reproducibility < 0.5% RSD; match-identification factor < 2.0% RSD) with recursive analysis of data (101 entities detected) warrants that both chromatographic and spectrometry-processing data were under control and provided high-quality results, which in turn differentiate wine samples according to site and vintage. It also shows potential biomarkers that can be identified. This is a step forward in the pursuit of Mexican wine characterization that could be used as an authentication tool

Maize bran gum: extraction, characterization and functional properties

Correspondance: [email protected] audienceA water-soluble maize bran gum (MBG) was alkali-extracted under mild conditions from maize bran. MBG presented an arabinoxylan (AX) content of 74% (w/w), a ferulic acid content of 0.34 mu g/mg MBG, an AIX ratio of 0.85 and an intrinsic viscosity of 208 ml/g. Gelling and emulsifying capabilities of MBG at different concentrations were investigated. Gels were obtained from this MBG by laccase covalent cross-linking of ferulic acid leading to the formation of diferulic (di-FA) and triferulic (tri-FA) acid. Gel hardness increased from 0.32 to 0.81 N as the MBG concentration changed from I to 2% (w/v) while the di-FA and tri-FA contents remained constant (0.030 and 0.015 mu g/mg MBG, respectively). The emulsion stability index (ESI) of oil-in-water containing different MBG concentrations was also investigated. ESI ranged from 0.01 to 0.20 as the MBG content in the mixture increased from 0% to 1% (w/v

Component Analysis and Free Radicals Scavenging Activity of Cicer arietinum L. Husk Pectin

A pectin (CAP) was extracted from the husk of Cicer arietinum L.. Monosaccharide analysis of CAP revealed the dominance of galacturonic acid and smaller amounts of galactose, arabinose, rhamnose, glucose, xylose and mannose. Viscosimetric analysis showed that the intrinsic viscosity ([η]) and the molecular weight (MW) of CAP were 296 mL/g and 105 kDa, respectively. The degree of esterification (DE = 10%) was determined by FTIR spectroscopy. CAP exhibited a dose-dependent free radical scavenging activity, as shown by its DPPH radical inhibition. At 1.0 mg/mL CAP exhibited a scavenging rate of 29% on DPPH radicals. The evaluation of antioxidant activity suggested that CAP had good potential for DPPH radical scavenging activity and should be explored as a novel potential antioxidant