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Generalized Height-Diameter Models for Pinus montezumae Lamb. and Pinus pseudostrobus Lindl. Plantations in Michoacan, Mexico
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作者 Jonathan Hernández-Ramos Valentín José Reyes-Hernández +3 位作者 Héctor Manuel De los Santos-Posadas Aurelio Manuel Fierros-González Enrique Buendía-Rodríguez Gerónimo Quiñonez-Barraza 《Open Journal of Forestry》 2024年第3期214-232,共19页
Tree height (H) in a natural stand or forest plantation is a fundamental variable in management, and the use of mathematical expressions that estimate H as a function of diameter at breast height (d) or variables at t... Tree height (H) in a natural stand or forest plantation is a fundamental variable in management, and the use of mathematical expressions that estimate H as a function of diameter at breast height (d) or variables at the stand level is a valuable support tool in forest inventories. The objective was to fit and propose a generalized H-d model for Pinus montezumae and Pinus pseudostrobus established in forest plantations of Nuevo San Juan Parangaricutiro, Michoacan, Mexico. Using nonlinear least squares (NLS), 10 generalized H-d models were fitted to 883 and 1226 pairs of H-d data from Pinus montezumae and Pinus pseudostrobus, respectively. The best model was refitted with the maximum likelihood mixed effects model (MEM) approach by including the site as a classification variable and a known variance structure. The Wang and Tang equation was selected as the best model with NLS;the MEM with an additive effect on two of its parameters and an exponential variance function improved the fit statistics for Pinus montezumae and Pinus pseudostrobus, respectively. The model validation showed equality of means among the estimates for both species and an independent subsample. The calibration of the MEM at the plot level was efficient and might increase the applicability of these results. The inclusion of dominant height in the MEM approach helped to reduce bias in the estimates and also to better explain the variability among plots. 展开更多
关键词 Random Covariate Random Effects Variance Structure Forest Inventories Forest Management Mixed Models
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Calibration of SWAT2009 Using Crop Biomass, Evapotranspiration, and Deep Recharge: Calera Watershed in Zacatecas, Mexico Case Study 被引量:1
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作者 Jose R. ávila-Carrasco Francisco Mojarro Dávila +10 位作者 Daniel N. Moriasi Prasanna H. Gowda Carlos Bautista-Capetillo Francisco G. Echavarria-Cháirez Jurgen D. Garbrecht Jean L. Steiner Terry A. Howell Edward T. Kanemasu Alan J. Verser Kevin Wagner Jairo Hernandez 《Journal of Water Resource and Protection》 2012年第7期439-450,共12页
Groundwater is the main source of water in the semi-arid Calera watershed, located in the State of Zacatecas, Mexico. Due to increasing population, rapid industrial growth, and increased irrigation to meet growing foo... Groundwater is the main source of water in the semi-arid Calera watershed, located in the State of Zacatecas, Mexico. Due to increasing population, rapid industrial growth, and increased irrigation to meet growing food demand, groundwater extraction in the Calera watershed are exceeding recharge rates. Therefore, development and evaluation of alter-native water management strategies are needed for sustainable development of the region. The Soil and Water Assessment Tool (SWAT) model was selected for this purpose as it has been used to simulate a wide range of agricultural production, the extensive testing and application in diverse watersheds worldwide, and the potential for future linkage of this model to groundwater models. However, crucial flow data which are commonly used for calibrating hydrologic models are not available in this watershed. This paper describes a novel calibration methodology that uses biomass and water balance approach which has potential for calibration of hydrologic models in ungauged or data-scarce watersheds, which are prevalent in many parts of the world. Estimated long-term annual average actual evapotranspiration (AET), and deep aquifer recharge rates and plant biomass values based on the expert knowledge of researchers and managers in the watershed were used as targets for calibration. The model performance was assessed using the Nash-Sutcliffe effi-ciency coefficient (NSE), coefficient of determination (R2), and percent bias (PBIAS, %) statistics. On average, the calibrated SWAT model yielded annual Nash-Sutcliffe efficiency coefficient values of 0.95, 0.99, and 0.85 for AET, recharge, and biomass, respectively. The coefficient of determination, values for AET, recharge, and biomass were 0.95, 0.94, and 0.99 respectively. The percent bias values of ±2.21%, ±0.18%, and ±0.96% for AET, recharge, and biomass, respectively, indicated that the model reproduced the calibration target values of the three water budget variables within an acceptable value of ± 10.0%. Therefore, it is concluded that the calibrated SWAT model can be used in evaluating alternative water management scenarios for the Calera watershed without further validation. Considering the relative ease in developing calibration data and excellent performance statistics, the calibration methodology proposed in this study may have the potential to be used for ungauged or data-scare agricultural watersheds that are prevalent in many parts of the world. 展开更多
关键词 SWAT Calera WATERSHED Scenarios RECHARGE EVAPOTRANSPIRATION RUNOFF Erosion
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Rapid HPLC Method for Determination of Rebaudioside D in Leaves of Stevia rebaudiana Bertoni Grown in the Southeast of Mexico 被引量:1
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作者 Irma Aranda-González Yolanda Moguel-Ordonez David Betancur-Ancona 《American Journal of Analytical Chemistry》 2014年第13期813-819,共7页
Stevia leaves contain glycosides on which biological activity and sweetening capacity has been reported. Besides the main glycosides—stevioside and rebaudioside A—there are minor glycosides that may contribute to th... Stevia leaves contain glycosides on which biological activity and sweetening capacity has been reported. Besides the main glycosides—stevioside and rebaudioside A—there are minor glycosides that may contribute to the activity and thus it is important to quantify them. Rebaudioside D is one of the minor glycoside present in S. rebaudiana leaves and there are no reports of a validated method to quantify it. Therefore a simple and sensitive high performance liquid chromatography (HPLC) method was validated for the determination of rebaudioside D in leaves of Stevia rebaudiana B. grown in the southeast of México. HPLC method was performed using a C18 column (250 mm × 4.6 mm, 5 μm) and UV detector set at 210 nm. The mobile phase consisted of 32:68 (v/v) mixture of acetonitrile and sodium phosphate buffer (10 mmol/L, pH 2.6), set to a flow rate of 1.0 ml/min. The calculated parameters were: sensitivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision. The retention time of rebaudioside D was found to be 3.47 min ± 0.04 (S.D.). The calibration curves were linear over the working range (25 - 150 μg/ml), with correlation coefficient ≥0.99 and determination coefficient ≥0.98. The calculated limit of detection (LOD) was 8.53 μg/ml, while the limit of quantitation (LOQ) was 25.85 μg/ml. The percent recoveries of fortified samples were 100% ± 10% and precision relative standard deviation was ≤2.79%. The criteria of validation showed accuracy, linearity, and precision;therefore the method is suitable for quantitative analysis of rebaudioside D in Stevia rebaudiana leaves. Rebaudioside D content (g/100g) in Morita II and Criolla varieties grown in the southeast of Mexico were 0.43 and 0.46, respectively with no significant differences (p > 0.05) between them. 展开更多
关键词 Rebaudioside D Stevia Rebaudiana HPLC VALIDATION
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Effects of corn gluten feed inclusion at graded levels in a corn-soybean diet on the ileal and fecal digestibility of growing pigs
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作者 Gerardo Mariscal Landin Tercia Cesaria Reis de Souza Ericka Ramirez Rodriguez 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2015年第1期63-68,共6页
Background: This study aimed to determine the effect of the inclusion of corn gluten feed (CGF) on the apparent and standardized ileal digestibility of protein and amino acids and the apparent ileal and total tract... Background: This study aimed to determine the effect of the inclusion of corn gluten feed (CGF) on the apparent and standardized ileal digestibility of protein and amino acids and the apparent ileal and total tract digestibility of energy in growing pigs. The study was performed using 16 barrows (weight, 45.3 ±4.5 kg) that were fitted with a T cannula at the terminal ileum. There were four treatments: a corn-soybean diet without CGF and three corn-soybean diets containing increasing levels of CGF (65, 130, and 195 g/kg). Data were analyzed according to a randomized complete block design, four blocks with four pigs each (one pig per treatment). The trend of the response (linear or quadratic) was determined using orthogonal contrasts, and when a linear effect was determined, a linear equation was obtained. Results: The results showed that the inclusion up to 195 g/kg of CGF in the corn-soybean diet did not diminish the ileal digestibility (apparent and standardized) of protein and amino acids (P 〉 0.05), except that of phenylalanine, cystine, and proline. A linear decrease (P 〈 0.05) per gram of CGF added to the diet in the apparent and standardized ileal digestibility of phenylalanine (0.011 and 0.015 percentage units, respectively), cystine (0.048 and 0.043 percentage units, respectively), and proline (0.045 and 0.047 percentage units, respectively) was noted. Similarly, ileal digestibility of dry matter and energy were adversely affected (reduced by 0.028 and 0.025 percentage units, respectively, per gram of CGF increment in the diet). A significant (P 〈 0.05) linear reduction in total tract digestibility with increase in CGF amount in the diet was observed for energy (0.027 percentage units), dry matter (0.027 percentage units), crude protein (0.020 percentage units), and neutral detergent fiber (0.041 percentage units) per gram of CGF added to the diet. Conclusion: CGF did not affect the ileal digestibility of protein and most amino acids but reduced the ileal and total tract digestibility of energy. 展开更多
关键词 Amino acids Corn gluten feed Energy Ileal digestibility Pigs Total tract digestibility
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Variable-top stem biomass equations at tree-level generated by a simultaneous density-integral system for second growth forests of roble, raulí,and coigüe in Chile
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作者 Carlos Valenzuela Eduardo Acuna +3 位作者 Alicia Ortega Geronimo Quinonez-Barraza Jose Corral-Rivas Jorge Cancino 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第3期993-1010,共18页
Variable-top stem biomass models at the tree level for second growth forests of roble (Nothofagus obliqua), rauli(Nothofagus alpina), and coigüe (Nothofagus dombeyi) were fitted by a simultaneous density-integral... Variable-top stem biomass models at the tree level for second growth forests of roble (Nothofagus obliqua), rauli(Nothofagus alpina), and coigüe (Nothofagus dombeyi) were fitted by a simultaneous density-integral system, which combines a stem taper model and a wood basic density model. For each model, an autoregressive structure of order 2 and a power equation of residual variance were incorporated to reduce residual autocorrelation and heteroscedasticity, respectively. By using dummy variables in the regression analysis, zonal effects on the parameters in the variable-top stem biomass equations were detected in roble. Consequently, equations for clusters of zones were obtained. These equations presented significant parameters and a high precision in both fitting and validation processes (i.e., CV<11.5% and CVp<11.9%, respectively), demonstrating that they are unbiased. The advantage of these types of functions is that they provide estimates of volume and biomass of sections of the stem, defined between any two points of the stem in the three species. Thus, depending on the final use of the wood and the dimensions of the tree, a stem fraction can be quantified in units of volume and the remaining fraction in units of weight. 展开更多
关键词 AUTOCORRELATION Density-integral DUMMY variables AUTOREGRESSIVE error structure HETEROSCEDASTICITY
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Estimation of endogenous protein and amino acid ileal losses in weaned piglets by regression analysis using diets with graded levels of casein
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作者 Tércia Cesária Reis de Souza Araceli Aguilera Barreyro Gerardo Mariscal-Landín 《Journal of Animal Science and Biotechnology》 SCIE CAS 2014年第1期74-79,共6页
Background: Many studies have investigated endogenous loss of proteins and amino acids (AAs) at the ileal level in growing pigs. However, only a few studies have researched this subject in piglets. Knowledge regard... Background: Many studies have investigated endogenous loss of proteins and amino acids (AAs) at the ileal level in growing pigs. However, only a few studies have researched this subject in piglets. Knowledge regarding AA ileal digestibility in piglets would be helpful during the formulation of diets for weaning piglets, rather than just using coefficients obtained in growing pigs. Therefore, in this study, we sought to estimate endogenous protein and AA ileal losses in piglets. Furthermore, apparent and true ileal digestibility (AID and TID) of protein and AAs from casein were measured. Results: The average flow of protein was 20.8 g/kg of dry matter intake (DMI). Basal protein loss, as estimated by regression, was 16.9 g/kg DMI. Glutamic acid, arginine, and aspartic acid (2.2, 1.4, and 1.2 g/kg DMI, respectively) were the AAs for which greater losses were seen. The AID of protein and AAs increased as the protein level in the diet increased. A higher increment in AID was observed between diets with 80 and160 g CP/kg of feed; this finding was mainly attributable to increases in glycine and arginine (46.1% and 18%, respectively). The TID of protein was 97.8, and the TID of AAs varied from 93.9 for histidine to 100.2 for phenylalanine. Conclusions: The basal endogenous protein loss in piglets was 16.9 g/kg DMI. Endogenous protein was rich in glutamic acid, aspartic acid, and arginine, which represented 32.7% of endogenous protein loss in weaning piglets. The TID of casein was high and varied from 93.0 for histidine to 100.2 for phenylalanine. 展开更多
关键词 Amino acid loss Ileal digestibility Protein loss Weaned piglets
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Spatial Distribution of Fuel Models Based on the Conditional-Fuel-Loading Concept
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作者 José Germán Flores Garnica 《Journal of Environmental Protection》 2018年第2期111-121,共11页
Fuel model mapping has followed in general two trends: 1) indirect inferences, where some factors, presumably associated with fuel production, are related to a given fuel model;and 2) experts consulting, which has bee... Fuel model mapping has followed in general two trends: 1) indirect inferences, where some factors, presumably associated with fuel production, are related to a given fuel model;and 2) experts consulting, which has been used to classify and to validate other people classifications. However, reliance on expert judgment implies a subjective approach. Thus, I propone the integration of geostatistic techniques and the Conditional-Fuels-Loading concept (CFL) to define a more objective perspective in the fuel-model mapping. The information used in this study was collected in a forest of Chihuahua, Mexico, where fuels were inventoried in 554 (1000 m2) sample plots. These sample plots were classified using the CFL;and ordinary kriging (Gaussian, spherical and exponential) was used to interpolate the fuel-model values. Using the Akaike’s Information Criterion the spherical model performed best. The methodology allowed a finer definition of spatial distribution of fuel models. Some advantages of the CFL are: 1) it is based on actual fuel loads, and not only on vegetation structure and composition;2) it is objective and avoids the bias of different classifiers (experts);and 3) it avoids the need of the advice of experts. 展开更多
关键词 Validation FUEL Mapping GEOSTATISTICS Ordinary KRIGING
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Structure and Density Analysis of a Semi Desert Ecosystem Disturbed by Fire
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作者 José Germán Flores Garnica 《Open Journal of Forestry》 2018年第2期155-166,共12页
In Mexico, forest ecosystems are disturbed by fires and generally these are considered to have negative impacts. However, it is important to consider that fire is an element of these ecosystems, and is important for i... In Mexico, forest ecosystems are disturbed by fires and generally these are considered to have negative impacts. However, it is important to consider that fire is an element of these ecosystems, and is important for its functionality. So it should be understood that in many cases the effects of a forest fire are beneficial, which can be determined through studies of population dynamics of these ecosystems. However, most of these studies currently focused only on aspects of species composition, with few cases concerning the analysis of the structure and density. In this study, a comparative analysis of the vegetation showed that conditions prevailing between burned and unburned areas of a site covered by microphyll desert species (shrubs and mesquite). The results suggest that the structure and density conditions of vegetation between burned and unburned areas are not statistically different. This is highlighted because one year after the fire occurred there is no evidence that fire had altered the structure and density of vegetation. Moreover, both in burned and unburned areas, vegetation had a healthy condition. Finally, although this may suggests that the fire was of low intensity, which resulted in a low impact on vegetation, in future studies it is recommended to determine if the same results are observed under different possible fire behavior and intensity. 展开更多
关键词 POPULATION Dynamic FOREST FIRE Semi-Desert
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Root colonization by mycorrhizal INIFAP<sup>MR</sup>in barley seed treated with fungicide
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作者 Oscar A. Grageda-Cabrera Sarahyt S. González-Figueroa +1 位作者 Mónica Guadalupe Lozano-Contreras Arturo Díaz-Franco 《Agricultural Sciences》 2013年第12期738-743,共6页
The effect of barley seed treated with chlorothalonil fungicide on mycorrhizal root colonization was evaluated. The treatments were: 1) Seed with Mycorrhizal INIFAP?, one, two and three doses, and uninoculated seed;2)... The effect of barley seed treated with chlorothalonil fungicide on mycorrhizal root colonization was evaluated. The treatments were: 1) Seed with Mycorrhizal INIFAP?, one, two and three doses, and uninoculated seed;2) Seed with and without fungicide. Monthly seed plantings were performed with different storage time, looking forward to assessing the colonization degree of the roots. As revealed by the results, the seed treated with chlorothalonil did not lower the root colonization by Mycorrhizal INIFAP?;the chlorothalonil treatment had a 32.63% average root colonization, whereas without chlorothalonil, it was 36.46%. When the seed was treated with root colonization by Mycorrhizal INIFAP?, this was lower in the treatment with one dose;no significant difference was revealed by the treatments with either double or triple doses.?The colonization percentage was progressively decreased by seed storage. The root colonization by Mycorrhizal INIFAP?, throughout the inoculated seed storage time, remained constant and unchanged for the first six months, but then decreased in 50% within a 10-month period for both treated and not treated fungicide seed. 展开更多
关键词 CHLOROTHALONIL HORDEUM vulgare Rhizophagus intraradices
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The Beneficial Effect of Trichoderma spp. in Seed Treatment of Four Maize (Zea mays L.) Genotypes
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作者 José Luis Arispe-Vázquez Abiel Sánchez-Arizpe +7 位作者 Daniel Alejandro Cadena-Zamudio Ma. Elizabeth Galindo-Cepeda David Heriberto Noriega-Cantú Oscar Guadalupe Barrón-Bravo Leslie Carnero-Avilés Juan Mayo-Hernández Susana Elizabeth Ramírez-Sánchez Adriana Antonio-Bautista 《American Journal of Plant Sciences》 2023年第6期625-637,共13页
Maize is the main crop for Mexicans;however, it is affected by species of fungi causing ear rot. This research aimed to evaluate the effect of T. asperellum T11, T. harzianum T1 4 y T. longibrachiatum T1 40 on some ag... Maize is the main crop for Mexicans;however, it is affected by species of fungi causing ear rot. This research aimed to evaluate the effect of T. asperellum T11, T. harzianum T1 4 y T. longibrachiatum T1 40 on some agronomic variables of four maize genotypes. The seeds of the genotypes H-515, Zapata 7, and H-507 were treated with a suspension of Trichoderma spp. to 1 × 10<sup>8</sup> spores mL<sup>-1</sup>, using a control (untreated seed), and Benomyl as chemical control. The planting was in Morelos, in a completely random block design with a factorial arrangement. The ear rot was natural. Data were obtained at the end of the crop cycle and processed in SAS 9.4<sup><sup>®</sup></sup>. H-515 genotype had the greatest effect on the treatment of maize seeds with Trichoderma spp. (5.562 kg);T. asperellum T11 was the strain that stood out with a mean yield of 50 ears in an area of 16 m<sup>2</sup> of 4.904 kg, and control of 4.448 kg. Our results are an economic option for farmers to contemplate the use of Trichoderma and obtain its benefits. 展开更多
关键词 SEEDS TREATMENT Trichoderma asperellum Ear Rot YIELD
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Potential Areas for Growing <i>Gmelina arborea</i>Roxb., under Rainfed Conditions in Tabasco, Mexico
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作者 Genovevo Ramírez Jaramillo Mónica Guadalupe Lozano-Contreras Jorge H. Ramírez Silva 《Agricultural Sciences》 2019年第9期1206-1216,共11页
Gmelina arborea Roxb. (Melina), also known as white teak, is a tropical tree of great importance with multiple benefits. It is a timber species with renewal capacity and accelerated growth, highly durable and high qua... Gmelina arborea Roxb. (Melina), also known as white teak, is a tropical tree of great importance with multiple benefits. It is a timber species with renewal capacity and accelerated growth, highly durable and high quantity and quality pulp production, widely used in commercial programs of reforestation. In view of a possible increase of Melina areas in the state of Tabasco Mexico, information was needed in relation with the physical environment and natural factors in order to locate the most suitable areas under rainfed conditions. In this way, decision makers will be provided with a basic tool to direct and promote commercial plantations in the best suitable areas. The software Arc/View version 3.3 was used to process and analyze the information. The optimum agroclimatic requirements of Melina were identified and each variable factor was matched with those found at ground level. A cartographic mapping was carried out to regionalize and locate the optimal and suboptimal zones. It was determined that there are 191,532 ha of high potential and 542,573 ha of medium potential production areas of Melina in Tabasco, Mexico under rainfed conditions. 展开更多
关键词 REGIONALIZATION Timber SPECIES Rapid Growth
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Potential for Growing <i>Salvia hispanica</i>L., Areas under Rainfed Conditions in Mexico
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作者 Genovevo Ramírez-Jaramillo Mónica Guadalupe Lozano-Contreras 《Agricultural Sciences》 2015年第9期1048-1057,共10页
The Salvia hispanica L. is an endemic species Mexican plant, which relevance relies upon its properties as a natural source of omega 3 (α-linolenic acid), soluble and insoluble fibers, proteins, plus some other signi... The Salvia hispanica L. is an endemic species Mexican plant, which relevance relies upon its properties as a natural source of omega 3 (α-linolenic acid), soluble and insoluble fibers, proteins, plus some other significant nutritional components. Due to the growing relevance generated by this crop, it became necessary to characterize its physical environment, as well as the natural factors related with its cultivation nationwide, aiming to find those most suitable for its production under rainfed conditions, looking forward to provide the basis to make a decision regarding where to target the agriculture promotion of such cropland. The software used for data process and analysis was the Arc/View 3.3 version. Thus, the crop requirements were recognized in order to analyze those most suitable for chia development in each one of its selected variables in the study hereby. The regionalization and mapping aimed to detect both the optimal and suboptimal potential areas for such crop were carried out, afterwards. It was finally determined that Mexico holds a total of 2,512,359 hectares with an optimal or high cultivation potential, whereas the areas with a medium or suboptimal potential are close to 3,658,089 hectares, which can be set under rainfed conditions. 展开更多
关键词 POTENTIAL RAINFED CONDITIONS CHIA
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Ultrastructural and Physiological Characterization of YELP, a Novel, Yellow, Chlorophyll-Deficient Cell Mutant Line That Develops Etioplast-Like Plastids in the Light
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作者 Betzaida Jiménez-Francisco Carlos Trejo +4 位作者 Hilda Araceli Zavaleta-Mancera Blanca Moreno-Gómez Edmundo García-Moya Florentino Víctor Conde-Martínez Gerardo Armando Aguado-Santacruz 《American Journal of Plant Sciences》 2016年第3期510-524,共15页
In this work, we present an ultrastructural and physiological description of a novel chlorophyll-deficient, yellow cell line of the grass Bouteloua gracilis that develops etioplast-like plastids in presence of light (... In this work, we present an ultrastructural and physiological description of a novel chlorophyll-deficient, yellow cell line of the grass Bouteloua gracilis that develops etioplast-like plastids in presence of light (YELP). These mutant cells were compared to the parental, wild-type, highly chlorophyllous cells from which they were isolated. Growth analysis, based on fresh and dry weights, indicated that YELP accumulates biomass at a slower rate than the parental, green cells. Besides, YELP developed very low levels of photosynthetic pigments, reaching only 9.3% and 38.4% of chlorophyll a and chlorophyll b, respectively, developed by the wild-type cells. Likewise, the accessory pigments, carotenes and xanthophylls, were only synthesized at 8.0% and 5.4%, respectively, of the levels reached by the green cells. Electron microscopy revealed remarkable differences in plastid ultrastructure between the wild-type and mutant cells. Plastids of YELP were heterogeneous and smaller than those found in wild-type cells. YELP plastids were abnormal with poorly developed membrane systems that prevented the accumulation of chlorophyll and accessory pigments in the mutant cell line. We expect this novel, mutant cell line will provide new tools for studying plastid development and differentiation. 展开更多
关键词 Cell Suspension Chloroplast Biogenesis Prolamellar Body ULTRASTRUCTURE
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Trichoderma spp.and Bacillus spp.as growth promoters in maize(Zea mays L.)
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作者 López-Valenzuela BE Armenta-Bojórquez AD +3 位作者 Hernández-Verdugo S Apodaca-Sánchez MA Samaniego-Gaxiola JA Valdez-Ortiz A 《Phyton-International Journal of Experimental Botany》 2019年第1期37-46,共10页
Microbes that are beneficial to plants are used to enhance the crop growth,yield and are alternatives to chemical fertilizers.Trichoderma and Bacillus are the predominant plant growth-promoting fungi and bacteria.The ... Microbes that are beneficial to plants are used to enhance the crop growth,yield and are alternatives to chemical fertilizers.Trichoderma and Bacillus are the predominant plant growth-promoting fungi and bacteria.The objective of this study was select,characterize,and evaluate isolates of Trichoderma spp.and Bacillus spp.native from the northern region of Sinaloa,Mexico,and assess their effect on growth promotion in maize(Zea mays L.).In greenhouse conditions,four Trichoderma isolates and twenty Bacillus isolates,as well as two controls,were tested in a completely randomized design with three replicates.We selected the two best strains of Trichoderma and Bacillus:TB=Trichoderma asperellum,TF=Trichoderma virens,B14=Bacillus cereus sensu lato and B17=Bacillus cereus,which were evaluated in the field in a completely randomized blocks in factorial arrangement design with three replicates applying different rates of nitrogen fertilizer(0,150 kg N/ha,and 300 kg N/ha).Treatments 5(B17=B.cereus)and 11(TF=T.virens)both fertilized with 150 kg N/ha showed similar yields and they did not reveal significant differences from the treatments fertilized with 300 kg N/ha.This indicated that treatment 5(B17=B.cereus with 150 kg N/ha)and treatment 11(TF=T.virens with 150 kg N/ha)were efficient as growth promoters,by not showing significant differences in root volume and dry weight of foliage.The results indicated a reduction of 50% in the rate of nitrogen to fertilizer required for maize(Zea mays L.)crops.These microorganisms Trichoderma and Bacillus could be an alternative to reduce the use of chemical fertilizers in maize. 展开更多
关键词 TRICHODERMA BACILLUS Native strains BIOFERTILIZERS
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Physiological Response of Advanced Lines of Rice under Water Deficit in Campeche, Mexico
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作者 Mónica Beatriz López-Hernández Jesús Arreola-Enríquez +4 位作者 Antonio Villalobos-González Luis Leonardo Pinzón-López Edwin Javier Barrios-Gómez Saúl Espinosa-Zaragoza Diana Sanzón-Gómez 《Agricultural Sciences》 2020年第10期932-945,共14页
Yields of rice (<em>Oryza sativa</em> L.) respond to complex interactions between the genotype and the environment;rice has the particularity of being a semi-aquatic crop, and as a result of this, it prese... Yields of rice (<em>Oryza sativa</em> L.) respond to complex interactions between the genotype and the environment;rice has the particularity of being a semi-aquatic crop, and as a result of this, it presents lower adaptation to the limiting water content of soil and is extremely sensitive to stress from drought;therefore, it is the most important limiting factor in rice production. The objective of this study was to research the physiological response of rice genotypes to water stress. The grain yield and its components, leaf area and transpiration efficiency under irrigation (I) and drought (D) were evaluated in eight advanced lines from the nursery of the Latin American Fund for Irrigated Rice (Fondo Latinoamericano para Arroz de Riego, FLAR) and a control variety of rice. The experiment was established in Campeche, in the 2015 autumn-winter cycle. The grain yield and its components, as well as the leaf area were greater under irrigation conditions than under drought. The transpiration from the water stress was reduced and the plants under drought increased their transpiration efficiency. The genotypes P-V 2006 and P-V 2009 were identified, with genealogies FL05392-3P-12-2P-2P-M and FL08224-3P-2-1P-3P-M, respectively, as the most outstanding compared to the rest of the genotypes in the grain yield and its components, leaf area, total root biomass, and transpiration efficiency. 展开更多
关键词 Oryza sativa L. YIELD DROUGHT
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Genetic variability of Rhizoctonia solani Kühn and its resistance to fungicides
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作者 Castillo RF Gallegos G +3 位作者 Flores OA Aguilar GC Rodriguez HR Hernandez CFD 《Studies in Fungi》 2020年第1期381-391,共11页
The aims of this study are to determine the population genetic structure of Rhizoctonia solani,associated with potato,and to assess its resistance degree to pencycuron and thiabendazole fungicides.A total of 57 strain... The aims of this study are to determine the population genetic structure of Rhizoctonia solani,associated with potato,and to assess its resistance degree to pencycuron and thiabendazole fungicides.A total of 57 strains of R.Solani were isolated from different potato crop fields in Mexico,and were classified according to their anastomosis group(AG)using the polymerase chain reaction(PCR)and restriction fragment length polymorphism(RFLP)-based analysis.Then,the amplified fragments were digested with four different endonucleases(Mse I,Ava II,Mun I and Hinc II).The Repetitive Element Sequence-Based PCR(rep-PCR)technique was used to determine the genetic diversity in R.solani populations.Results obtained by PCR-RFLP showed that 81%of the isolates were identified as belonging to AG-3 group,14%to AG1-1B and 5%to AG-11 group.In response to fungicides inhibition,IC_(50)between 0.014-0.039 mg a.i./L for pencycuron,and 0.82 to 2.91 for thiabendazole were determined,This IC_(50)value showed that the resistance factor(RF)values ranged from 1.4 to 3.945 and 0.27 to 0.97,respectively;this tendency suggests that isolates are susceptible to thiabendazole.The AG groups showed a heterogeneous resistance to pencycuron and thiabendazole,being more tolerant to these fungicides AG1-1B and AG-11 groups.The genetic analysis shows a low genetic diversity among(P-value 0.3225)and within(P-value 0.3275)populations;this can indicate a clonal reproduction and little parasexual cycle among the analyzed isolations. 展开更多
关键词 Anastomosis group GENETIC diversity GENETIC RESISTANCE Mexico PCR RFLP parasexual cycle REP PCR Wright’s statistics
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Determination of Rebaudioside A and Stevioside in Leaves of S.rebaudiana Bertoni Grown in Mexico by a Validated HPLC Method
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作者 Irma Aranda-Gonzalez Yolanda Moguel-Ordonez David Betancur-Ancona 《American Journal of Analytical Chemistry》 2015年第11期878-885,共8页
Stevia rebaudiana is a plant with high sweetening capacity due to its content of glycosides, mainly stevioside and rebaudioside A. Several techniques have been used to determine the concentrations of glycosides in Ste... Stevia rebaudiana is a plant with high sweetening capacity due to its content of glycosides, mainly stevioside and rebaudioside A. Several techniques have been used to determine the concentrations of glycosides in Stevia, although an HPLC method is recommended by the FAO/WHO-JECFA. Varieties of Stevia have been recently grown in Mexico, with no previous report of glycosides by a validated method. The aim of this study was to validate an isocratic HPLC method for content determination of main glycosides in the leaves of Stevia cultivated in Mexico. HPLC method was performed using a C18 column (250 mm × 4.6 mm, 5 μm) and UV detector set at 210 nm. The mobile phase consisted of 32:68 (v/v) mixture of acetonitrile and sodium-phosphate buffer (10 mmol/L, pH 2.6), set to a flow rate of 1.0 mL/min. Rebaudioside A and stevioside were determined in two Stevia varieties: Morita II and Criolla, and also validation parameters were calculated. Rebaudioside A content (g/100g) in Morita II was 15.15 ± 0.02 while stevioside was 3.97 ± 0.003;in the case of Criolla they were 4.03 ± 0.01 and 8.80 ± 0.14, respectively (p < 0.001). The recoveries of fortified samples were 100% ± 10% and precision RSD was ≤6.27%. The criteria of validation showed accuracy, linearity (≥0.99), and precision;therefore, the determination of glycosides was performed with reliability. 展开更多
关键词 Stevia rebaudiana Rebaudioside A STEVIOSIDE HPLC VALIDATION
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Root Sprouts of Domesticated Phaseolus coccineus L. Overwinter Plants and the Environment at Its Collection Sites
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作者 Ma. Luisa Patricia Vargas-Vázquez Jorge Alberto Acosta-Gallegos +1 位作者 Fabián Islas-Gutiérrez Enrique Buendía-Rodríguez 《Open Journal of Ecology》 2024年第5期508-521,共14页
Buds emerge from the roots of domesticated runner bean plants (Phaseolus coccineus L.) as sprouts and give the crop its persistence. This particularity of the species seems to be associated with the environment where ... Buds emerge from the roots of domesticated runner bean plants (Phaseolus coccineus L.) as sprouts and give the crop its persistence. This particularity of the species seems to be associated with the environment where the species was cultivated during long time. Data on regrowth traits were recorded on 70 accessions of domesticated P. coccineus after overwintering at a site in the central highlands of Mexico. The characteristics recorded included fresh weight of vegetative regrowth, root length, root crown diameter, and diameter of the main root. Most accessions that sprout the following spring, after the grain harvest of the previous year, come from temperate and semi-cold sites with cambisol and andosol soils in mixed Quercus pine forest and high mountain fir trees. Those that do not sprout are from sites of semiarid temperate climate, haplic phaeozem soil in shrub grasslands with deciduous broadleaved trees, and semiwarm subhumid climate, eutrophic regosol soil in deciduous broadleaved forest. Two types of roots were differentiated: branched and thickened taproots, also associated with a different climate, and the type of soil of the collection sites. 展开更多
关键词 P. coccineus Distribution Vegetation-Environment Interactions Drought-Alternative Species Root-Regrowth
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National assessment of the fragmentation,accessibility and anthropogenic pressure on the forests in Mexico 被引量:3
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作者 Rafael Moreno-Sanchez Juan Manuel Torres-Rojo +3 位作者 Francisco Moreno-Sanchez Sue Hawkins Justin Little Susan McPartland 《Journal of Forestry Research》 SCIE CAS CSCD 2012年第4期529-541,共13页
Forest managers and policy makers increasingly demand to have access to estimates of forest fragmentation, human accessibility to forest areas and levels of anthropogenic pressure on the remaining forests to integrate... Forest managers and policy makers increasingly demand to have access to estimates of forest fragmentation, human accessibility to forest areas and levels of anthropogenic pressure on the remaining forests to integrate them into monitoring systems, management and conservation plans. Forest fragmentation is defined as the breaking up of a forest unit, where the number of patches and the amount of expose edge increase while the amount of core area decreases. Forest fragmentation studies in Mexico have been limited to local or regional levels and have concen- trated only on specific forest types. This paper presents an assessment of the fragmentation of all forest types at the national level, their effective proximity to anthropogenic influences, and the development of an indica- tor of anthropogenic pressure on the forests areas. Broadleaf forests, tropical evergreen forests and tropical dry deciduous forests show the greatest fragmentation. Almost half (47%) of the tropical forests are in close effective proximity to anthropogenic influences and only 12% of their area can be considered isolated from anthropogenic influences. The values for the temperate forests are 23% and 29% respectively. Anthro- pogenic pressure in the immediate vicinity of anthropogenic activities is much higher in the tropical forests (75 in a scale 0-100) than in the tem- perate forests (30). When considering these results jointly, the tropical forests, and more specifically, the tropical evergreen forests and tropical dry deciduous forests are under the greatest pressure and risks of degra- dation. 展开更多
关键词 forest fragmentation effective proximity anthropogenicpressure Mexico forests GIS.
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National assessment of the evolution of forest fragmentation in Mexico 被引量:3
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作者 Rafael Moreno-Sanchez Francisco Moreno-Sanchez Juan Manuel Torres-Rojo 《Journal of Forestry Research》 SCIE CAS CSCD 2011年第2期167-174,共8页
This paper presents assessments of the fragmentation of the temperate and tropical forests in Mexico at the national level for two dates 1993 and 2002.The study was based on land use and vegetation cover data sets sca... This paper presents assessments of the fragmentation of the temperate and tropical forests in Mexico at the national level for two dates 1993 and 2002.The study was based on land use and vegetation cover data sets scale 1:250,000.Two broad forest types(Temperate Forests and Tropical Forests) and five more specific forest types(Broadleaf Forests,and Coniferous Forests;Tropical Dry Deciduous Forests,Tropical Sub-evergreen Forests,and Tropical Evergreen Forests) were defined to conduct the analyses.FragStats 3.3 was used to estimate nine metrics of the spatial pattern of the forests for each forest type and date considered.The results indicate that the land cover transitions that have occurred between 1993 and 2002 have resulted in more isolated forest patches with simpler shapes in both the Temperate and Tropical Forests.The remaining Tropical Forest patches have become smaller and more numerous.In contrast,the remaining Temperate Forest patches are fewer and on average larger.Of the more specific forest types defined in this study,the Broadleaf Forests have the highest indicators of fragmentation.However these forests are usually embedded or adjacent to Coniferous Forests.Of more concern for conservation purposes are the high values of fragmentation metrics found for the Tropical Evergreen Forests and Tropical Dry Deciduous Forests,because these forest types are usually surrounded by non-forest land covers or anthropogenic land uses. 展开更多
关键词 forest fragmentation Mexico FragStats.
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