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Vicente Torres-Olivar Antonio Cárdenas-Flores Ricardo Hugo Lira-Saldivar José Humberto Valenzuela-Soto Marco Antonio Castillo-Campohermoso 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2018,68(2):97-103
Purpose: The aim of this study was to realize whether soil mulching, with different plastic mulch colors, is a suitable practice for the culture of pickling cucumber.Materials and Methods: The crop was cultured or not with black, silver/black, white/black, and aluminum/black plastic films, treatments were evaluated in randomized complete block design, to determine their effect on soil temperature, gas exchange, nutrient concentration, growth, and fruit yield.Results and Conclusions: Black, silver/black, and aluminum/black plastic mulches were higher (p?≤?0.05) in plant height, leaf area, and shoot dry weight than bare soil at 15 days after sowing, whose results were similar than using white/black film. Maximum, minimum, and mean soil temperatures were higher with all plastic mulches except for aluminum/black, in which the maximum soil temperature was similar to the one in bare soil. There was no difference in net photosynthesis and there was very little difference in nutrient concentration between plants in plastic mulches and plants in bare soil; however, early and total yield showed a higher (p?≤?0.05) yield in all plastic mulches, and lower with bare soil and white/black plastic mulch. Our results confirm that soil mulching impacts the pickling cucumber yield. We suggest a carefull selection of the color plastic mulch. 相似文献
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Corella-Madueño MA Harris MK Fu-Castillo AA Martínez-Téllez MA Valenzuela-Soto EM Gálvez-Ruiz JC Vargas-Arispuro I 《Pest management science》2011,67(12):1522-1527
BACKGROUND: Plant volatiles have complex intra‐ and interspecific effects in the environment that include plant/herbivore interactions. Identifying the quantity and quality of volatiles produced by a plant is needed to aid the process of determining which chemicals are exerting what effects and then examining whether these effects can be manipulated to benefit society. The qualitative characterization of volatile compounds emitted by pecan, Carya illinoinensis (Wang.) K. Koch, was begun in order to establish a database for investigating how these volatiles affect Acrobasis nuxvorella Nuenzig, a monophagous pest of pecan. Headspace solid‐phase microextraction combined with gas chromatography–mass spectrometry was used for the analysis of the volatile constituents of pecan during three phenological stages (dormant buds, intact new shoot growth and intact nutlets) of the Western Schley and Wichita cultivars. RESULTS: About 111 distinct compounds were identified from the two cultivars, accounting for ~99% of the headspace volatiles. The chromatographic profiles of both varieties revealed variations in the volatile composition and proportion between cultivars, with a predominance of terpene hydrocarbons, of the sesquiterpenes class, as well as monoterpenes. CONCLUSION: The significantly higher responsiveness recorded for the larvae of A. nuxvorella to C. illinoinensis shoots indicates that the larvae may be activated by terpenes emanating from the new shoot growth. This is the first study that has examined volatiles of pecan in Mexico. Copyright © 2011 Society of Chemical Industry 相似文献
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Jesus Aaron Salazar-Leyva Jaime Lizardi-Mendoza Juan Carlos Ramirez-Suarez Elisa Miriam Valenzuela-Soto Josafat Marina Ezquerra-Brauer Francisco Javier Castillo-Yañez 《Journal Of Aquatic Food Product Technology》2013,22(7):1144-1154
ABSTRACTResponse surface methodology was employed to optimize the immobilization yield of acidic proteases from Monterey sardine (Sardinops sagax caeurelea) using partially deacetylated chitin as immobilization support. A rotatable central composite design was applied to evaluate the effects of immobilization conditions such as enzyme loading (X1), immobilization pH (X2), and tripolyphosphate concentration (X3) on the immobilization yield. The analysis of variance revealed that the established model was significant (p < 0.05), and the adjustment of the quadratic model with the experimental data was satisfactory. Under optimal conditions (X1 = 0.05 mg/mL, X2 = 3.16, and X3 = 0.75%), an immobilization yield of 79.1% was achieved; a value that was in accordance with the predicted one. 相似文献
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Villalba-Villalba Ana Gloria Pacheco-Aguilar Ramón Ramirez-Suarez Juan Carlos Valenzuela-Soto Elisa Miriam Castillo-Yáñez Francisco Javier Márquez-Ríos Enrique 《Fisheries Science》2011,77(4):697-705
Vermiculated sailfin catfish (Pterygoplichthys disjunctivus, Weber, 1991), a member of the Loricariidae family and an invasive species of several inland waters around the world, possess
an enormous digestive tract representing about 10% of fish weight. Thus, the aim of this study was to partially characterize
proteases from their digestive tracts. Azocasein digestion of the crude extract of intestine at different pH values and temperatures
revealed the presence of alkaline proteases with optimum activities at pH 9.0 and 50°C. Incubation assays of the crude extract
with inhibitors such as phenyl methyl sulfonyl fluoride, N-α-p-tosyl-l-lysine chloromethyl ketone, N-tosyl-phenyalanine chloromethyl ketone, benzamidine, pepstatin A and ethylenediamine tetra-acetic acid showed that trypsin
and chymotrypsin are the main alkaline proteinases present. Zymography showed that the crude extract of Pterygoplichthys
disjunctivus viscera contained proteases with molecular masses ranging from 21.5 to 116 kDa. Trypsin and chymotrypsin were inhibited by
the following ions in decreasing order: Hg2+, Fe2+, Cu2+, Li+, Mg2+, K+, while Mn2+, and Ca2+ had no effect. Activities decreased continuously as the NaCl concentration increased from 0 to 30%. These results constitute
important background information for future studies and for the potential biotechnological use of the crude digestive extract
from this invasive species. 相似文献
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Ana Gloria Villalba-Villalba Juan Carlos Ramírez-Suárez Ramón Pacheco-Aguilar Elisa Miriam Valenzuela-Soto María Elena Lugo-Sánchez Ciria Guadalupe Figueroa-Soto 《Fish physiology and biochemistry》2013,39(2):121-130
Pterygoplichthys disjunctivus viscera chymotrypsin was purified by fractionation with ammonium sulfate (30–70 % saturation), gel filtration, affinity, and ion exchange chromatography. Chymotrypsin molecular weight was approximately 29 kDa according to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), shown a single band in zymogram. Electrofocusing study suggested being an anionic enzyme (pI ≈ 3.9), exhibiting maximal activity at pH 9 and 50 °C, using Suc-Ala-Ala-Pro-Phe-p-nitroanilide (SAAPNA) as substrate. Enzyme was effectively inhibited by phenyl methyl sulfonyl fluoride (PMSF) (99 %), and N-tosyl-l-phenylalanine chloromethyl ketone (TPCK) (94 %). Enzyme activity was affected by the following ions in decreasing order: Hg2+, Fe2+, Cu2+, Li1+, Mg2+, K1+, Mn2+, while Ca2+ had no effect. Chymotrypsin activity decreased continuously as NaCl concentration increased (from 0 to 30 %). K m and V max values were 0.72 ± 1.4 mM and 1.15 ± 0.06 μmol/min/mg of protein, respectively (SAAPNA as substrate). Results suggest the enzyme has a potential application where low processing temperatures are needed, such as in fish sauce production. 相似文献
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Gorgonio López-Tolentino Adrián Méndez-Prieto A. Javier Lozano-del Río Ricardo H. Lira-Saldivar José H. Valenzuela-Soto 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(1):77-84
The use of plastic mulch is associated with a higher increase in yield of vegetables. However, at the end of the growing season for each crop, plastic mulching can create environmental pollution that can cause negative impacts on the environment that could be solved by the use of degradable plastics. The aim of this study was to determine the effect of oxo-degradable plastic mulches on soil temperature, growth, gas exchange, and cucumber crop yield. The study was conducted in two locations in the northeast of Mexico during the spring and summer of 2013. The plastic mulch colors with additives were blue, green, and red and each color having 8% and 12% of pigment and 22% and 23% of Titanium dioxide (Rutile). The resultant treatments were compared with the black plastic mulch, which is the standard plastic in the world, and bare soil in a randomized complete block design with three replications in two locations. The mean soil temperature at both locations was statistically higher in black plastic mulch, followed by the oxo-degradable plastics mulches and lowest in the control. Gas exchange was not affected by plastic mulches. SPAD units as the index of chlorophyll content in leaves were very little affected by plastic mulch. Both, commercial and total yield were statistically similar in the oxo-degradable plastic mulches and the black plastic mulch, and lowest in the control. Plastics with higher concentrations of pigment registered higher degradation in both locations. Our results suggest that different plastic mulches impact positively on the yield of cucumber crop. The benefit in yield by the different plastic mulches in the conditions of this study was due to their soil warming ability that results in improved soil temperature, leaf area, and plant dry weight. 相似文献
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