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
In this study,10 bacterial strains were isolated from the rhizosphere of coniferous trees on Mount Tla′loc in Mexico.The strains were characterized by their capacity to produce auxins,solubilize phosphates and stimul...In this study,10 bacterial strains were isolated from the rhizosphere of coniferous trees on Mount Tla′loc in Mexico.The strains were characterized by their capacity to produce auxins,solubilize phosphates and stimulate mycelial growth of the ectomycorrhizal fungus Suillus sp.All isolates were identified at the molecular level.Moreover,an experiment was established to evaluate the response of Pinus pseudostrobus seedlings to inoculation with the rhizobacteria strains.The isolated strains belonged to the species Cupriavidus basilensis,Rhodococcus qingshengii,R.erythropolis,Pseudomonas spp.,P.gessardii,Stenotrophomonas rhizophila and Cohnella sp.All of the strains produced auxins;the best producer was R.erythropolis CPT9(76.4 lg mL^-1).P.gessardii CPT6 solubilized phosphate at a significant level(443 lg mL^-1).The strain S.rhizophila CPT8 significantly increased the radial growth of the ectomycorrhizal fungus Suillus sp.by 18.8%.Five strains increased the dry mass of the shoots;R.qingshengii CPT4 and R.erythropolis CPT9 increased growth the most,by more than 20%.Inoculation with plant-growth-promoting rhizobacteria can be a very useful practice in a forest nursery to produce healthy,vigorous plants.展开更多
An in vitro gas production （GP） technique was used to investigate the effects of combining different doses of Salix babylonica extract （SB） with exogenous fibrolytic enzymes （EZ） based on xylanase （X） and cell...An in vitro gas production （GP） technique was used to investigate the effects of combining different doses of Salix babylonica extract （SB） with exogenous fibrolytic enzymes （EZ） based on xylanase （X） and cellulase （C）, or their mixture （XC; 1：1 v/v） on in vitro fermentation characteristics of a total mixed ration of corn silage and concentrate mixture （50：50, w/w） as substrate. Four levels of SB （0, 0.6, 1.2 and 1.8 mL g-1 dry matter （DM）） and four supplemental styles of EZ （1 μL g-1 DM; control （no enzymes）, X, C and XC （1：1, v/v） were used in a 4×4 factorial arrangement. In vitro GP （mL g-1 DM） were recorded at 2, 4, 6, 8, 10, 12, 24, 36, 48 and 72 h of incubation. After 72 h, the incubation process was stopped and supernatant pH was determined, and then filtered to determine dry matter degradability （DMD）. Fermentation parameters, such as the 24 h gas yield （GY24）, in vitro organic matter digestibility （OMD）, metabolizable energy （ME）, short chain fatty acid concentrations （SCFA）, and microbial crude protein production （MCP） were also estimated. Results indicated that there was a SBxEZ interaction （P〈0.0001） for the asymptotic gas production （b）, the rate of gas production （c）, GP from 6 to 72 h, GP2 （P=0.0095）, and GP4 （P=0.02）. The SB and different combination of enzymes supplementation influenced （P〈0.001） in vitro GP parameters after 12 h of incubation; the highest doses of SB （i.e., 1.8 mL g-1 DM）, in the absence of any EZ, quadratically increased （P〈0.05） the initial delay before GP begins （L） and GP at different incubation times, with lowering b （quadratic effect, P〈0.0001 ） and c （quadratic effect, P〈0.0001 ; linear effect, P=0.0018）. The GP was the lowest （P〈0.05） when the highest SB level was combined with cellulose. There were SBxEZ interactions （P〈0.001） for OMD, ME, the partitioning factor at 72 h of incubation （PF72）, GY24, SCFA, MCP （P=0.0143）, and pH （P=0.0008）. The OMD, ME, GY24 and SCFA with supplementation of SB extract at 1.8 mL g-1 DM were higher （P〈0.001） than the other treatments, however,PF72 was lower （quadratic effect, P=0.0194） than the other levels. Both C and X had no effect （P〉0.05） on OMD, pH, ME, GY24, SCFA and MP. The combination of SB with EZ increased （P〈0.001） OMD, ME, SCFA, PFz2 and GP24, whereas there was no impact on pH. It could be concluded that addition of SB extract, C, and X effectively improved the in vitro rumen fermentation, and the combination of enzyme with SB extract at the level of 1.2 mL g-1 was more effective than the other treatments.展开更多
Leaf rust(LR) and stripe rust(YR) are important diseases in wheat producing areas worldwide and cause severe yield losses under favorable environmental conditions when susceptible varieties are grown. We determined th...Leaf rust(LR) and stripe rust(YR) are important diseases in wheat producing areas worldwide and cause severe yield losses under favorable environmental conditions when susceptible varieties are grown. We determined the genetic basis of resistance to LR and YR in variety Borlaug 100 by developing and phenotyping a population of 198 F6 recombinant inbred lines derived from a cross with the susceptible parent Apav#1. LR and YR phenotyping were conducted for 4 and 3 seasons, respectively, at CIMMYT research stations in Mexico under artificial epidemics. Mendelian segregation analyses indicated that 3–5 LR and 2 YR genes conferred resistance in Borlaug 100. Lr46/Yr29(1 BL), Yr17(2 AS) and Yr30(3 BS) were present in the resistant parent and segregated in the RIL population based on characterization by molecular markers linked to these genes. When present alone, Lr46/Yr29 caused average 13% and 16% reductions in LR and YR severities, respectively, in RILs. Similarly, Yr17 and Yr30 reduced YR severities by 57% and 11%, respectively. The Yr30 and the Yr17 translocation were also associated with 27% and 14% reductions, respectively, in LR severity, indicating that the 3 BS and 2 AS chromosomal regions likely carry new slow rusting LR resistance genes, temporarily designated as Lr B1 and Lr B2, respectively. Additive effects of Yr30*Yr17, Yr29*Yr17 and Yr29*Yr30 on YR and LR were significant and reduced YR severities by 56%,55%, and 45%, respectively, and LR severities by 34%, 40%, and 45%, respectively. Furthermore, interaction between the three genes was also significant, with mean reductions of 70% for YR and 54% for LR severities. Borlaug 100, or any one of the 21 lines with variable agronomic traits but carrying all three colocated resistance loci, can be used as resistance sources in wheat breeding programs.展开更多
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
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
The study and characterization of biomolecules involved in the interaction between mycobacteria and their hosts are crucial to determine their roles in the invasion process and provide basic knowledge about the biolog...The study and characterization of biomolecules involved in the interaction between mycobacteria and their hosts are crucial to determine their roles in the invasion process and provide basic knowledge about the biology and pathogenesis of disease.Promising new biomarkers for diagnosis and immunotherapy have emerged recently.Mycobacterium is an ancient pathogen that has developed complex strategies for its persistence in the host and environment,likely based on the complexity of the network of interactions between the molecules involved in infection.Several biomarkers have received recent attention in the process of developing rapid and reliable detection techniques for tuberculosis.Among the most widely investigated antigens are CFP-10(10-kDa culture filtrate protein),ESAT-6(6-kD a early secretory antigenic target),Ag85 A,Ag85 B,CFP-7,and PPE18.Some of these antigens have been proposed as biomarkers to assess the key elements of the response to infection of both the pathogen and host.The design of novel and accurate diagnostic methods is essential for the control of tuberculosis worldwide.Presently,the diagnostic methods are based on the identification of molecules in the humoral response in infected individuals.Therefore,these tests depend on the capacity of the host to develop an immune response,which usually is heterogeneous.In the last 20 years,special attention has been given to the design of multiantigenic diagnostic methods to improve the levels of sensitivity and specificity.In this review,we summarize the state of the art in the study and use of mycobacterium biomolecules with the potential to support novel tuberculosis control strategies.展开更多
Their high bioactive compounds content and importance as dietary antioxidants has increased interest in Capsicum fruit. The fruit of seven Capsicum chinense Jacq. var. habanero genotypes grown in Yucatan, Mexico, were...Their high bioactive compounds content and importance as dietary antioxidants has increased interest in Capsicum fruit. The fruit of seven Capsicum chinense Jacq. var. habanero genotypes grown in Yucatan, Mexico, were analyzed to quantify their phenolic compounds, carotenoids and ascorbic acid contents, and to measure their free radical scavenging (ABTS assay) and antioxidant activities (β-carotene/linoleic acid assay). Phenolics (20.54 to 20.75 mg/100 g sample), carotenoids (1.00 to 1.26 mg/100 g sample) and ascorbic acid contents (187.24 to 281.73 mg/100 g sample) varied between genotypes. Trolox equivalent antioxidant capacity (TEAC) ranged from 1.55 to 3.23 mM/mg sample. During the 120-min decolorization trial, antioxidant capacity decreased over time in the studied genotypes. Values ranged from 36%to 57% β-carotene bleaching during the first 30 minutes. Fruit from all seven studied genotypes are good antioxidant sources and hold promise as natural ingredients in functional foods.展开更多
For the paper,Effects of cellulase and xylanase enzymes mixed with increasing doses of Salix babylonica extract on in vitro rumen gas production kinetics of a mixture of corn silage with concentrate,published in Journ...For the paper,Effects of cellulase and xylanase enzymes mixed with increasing doses of Salix babylonica extract on in vitro rumen gas production kinetics of a mixture of corn silage with concentrate,published in Journal of Integrative Agriculture 2015,Vol.14,No.1,on page 131-139,the authors'names and affiliated units should be.展开更多
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
Huanglongbing (HLB) or citrus greening is currently the most important citrus disease, caused by the bacterium </span><i><span style="font-family:Verdana;">Candidatus</span></i>...Huanglongbing (HLB) or citrus greening is currently the most important citrus disease, caused by the bacterium </span><i><span style="font-family:Verdana;">Candidatus</span></i><span style="font-family:Verdana;"> Liberibacter asiaticus (</span><i><span style="font-family:Verdana;">C</span></i><span style="font-family:Verdana;">Las). The impossibility of isolating it causes understanding its pathogenic mechanisms to be a complicated task. Recent studies identified 16 proteins with the signal peptide needed to be secreted in the plant and cause the disease. The present study aims to perform a bioinformatic analysis of these proteins with the function prediction approach by gene ontology (GO) and the detection of conserved domains. It was observed that of the 16 proteins analyzed not all are found in different infective strains reported in the literature. The GO analysis allowed us to relate different proteins with the biological process of energy and pathogenic activity, especially CLIBASIA_03315 and CLIBASIA_05115, respectively. The domain analysis allowed the observation of a </span></span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:""><span style="font-family:Verdana;">-CA domain, tentatively related to the damage caused to the chloroplast and a PAAR domain associated with the T6SS secretory system. Our results provide information on the possible function of potential pathogenicity effectors in </span><i><span style="font-family:Verdana;">C</span></i><span style="font-family:Verdana;">Las.展开更多
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
The objective of this study consisted of evaluating the effect of the application of chitosan(Q),1-methylcyclopropene(1-MCP)under two controlled temperatures on some physical,physiological,and chemical parameters cont...The objective of this study consisted of evaluating the effect of the application of chitosan(Q),1-methylcyclopropene(1-MCP)under two controlled temperatures on some physical,physiological,and chemical parameters contributing to the quality of Persian lime Citrus latifolia fruits.Eight treatments were evaluated,resulting from the combination of four senescence retardant applications(Q,1-MCP,1-MCP+Q,and without application)on fruits stored at two temperatures(12/20℃.Epidermis color(luminosity,chromaticity,and hue),fruit appearance,respiration,weight loss,total juice content,total soluble solids,and titratable acidity were registered during the study.The results indicate that the 1-MCP and Q combination favored fruit postharvest quality conditions such as reducing respiration rate;maintaining fruit good appearance,turgidity,and brighter fruit chromaticity;fruits treated with chitosan and stored at 12℃,favored total soluble solids.On the other hand,Variables such as weight loss,juice content,acidity,phenols,flavonoids,antioxidant activity,and hue values were favored by a 12℃ storing temperature regardless of the treatment.In general,the use of modified atmospheres,senescence retardants,and refrigeration as postharvest methods,can increase Persian lime shelf life.展开更多
Husk tomato production technology was developed utilizing plastic sheeting and drip irrigation based on the results of reference evapotranspiration and crop coefficients (Kc) proposed at different phenological stages....Husk tomato production technology was developed utilizing plastic sheeting and drip irrigation based on the results of reference evapotranspiration and crop coefficients (Kc) proposed at different phenological stages. The objectives of this study were as follows: 1) to evaluate the effect of plastic sheeting on the yield of husk tomato fruit with drip irrigation based on crop evapotranspiration;2) to validate the use of drip irrigation technology and plastic sheeting in husk tomato production using demonstration plots;and 3) to determine the profitability and economic viability of the product in the domestic market. The proposed Kc values were 0.25, 0.71 and 0.56 in the initial, intermediate and final stage of crop development, respectively. Irrigation rates ranged from 2.5 to 6 mm·day-1, which was equivalent to an irrigation time of 0.6 to 2.5 hr. Soil moisture tension was monitored with tensiometers at depths of 15 and 30 cm in a loamy eutricfluvisol. The use of plastic sheeting increased husk tomato yield by 56.2% and water productivity by 63.5% under drip irrigation conditions when basing irrigation levels on crop evapotranspiration. Soil matrix potential varied between depths of 15 and 30 cm based on irrigation or rainfall amounts and the use of plastic sheeting with values being higher when the plastic sheeting was used. The husk tomato fruit yield in validation plots was 46 and 54.6 t·ha-1 with water use efficiencies ranging from 16.1 to 19.1 kg·m-3. These results exceeded the national average of 14 t·ha-1 and water use efficiency of 2.54 kg·m-3. With this new technology, a cost benefit ratio of 3.6 is obtained, which represents an economically profitable margin for farmers in the region.展开更多
Adverse weather conditions and intensive use for fiber production have caused decline of natural populations of Agave lechuguilla. By these reasons, it is important to develop a sustainable management of this specie t...Adverse weather conditions and intensive use for fiber production have caused decline of natural populations of Agave lechuguilla. By these reasons, it is important to develop a sustainable management of this specie to avoid this situation. One of the first steps is to establish forest plantations as an alternative to restore A. lechuguilla habitat and increase its range while at the same time indirectly reducing erosion rates. The aim of this study was to identify the potential areas for establishment of plantations of A. lechuguilla in the State of Coahuila, Mexico. Areas for planting establishment were selected according to multi-criteria analysis using Geographic Information System (GIS) Idrisi32 Ver 2.0 and 3.2 Arc.View. The analysis was based on comparison of climate and soil requirements in contrast to environmental conditions of the tested area. The evaluated variables were: soil type, texture, depth, average annual temperature, annual precipitation, elevation and slope. Results derive in potential area maps, geo-referenced and their distribution by Agricultural Development District. An area of 5 million 159,273 hectares was determined with potential for establishment of A. lechuguilla forest plantations in the State of Coahuila. It was concluded that, use of GIS is a reliable tool to determine potential areas for A. lechuguilla forest plantations, where this specie has higher probability of success in survival and biomass production. This study will support programs aimed to strengthen the economy of rural producers and also recover and preserve the arid state.展开更多
Canola and oat forage potential may be affected by climatic conditions when sown early.The objective of this study was to evaluate the forage canola and oat potential in four early sowing dates(September 11 and 25;Oct...Canola and oat forage potential may be affected by climatic conditions when sown early.The objective of this study was to evaluate the forage canola and oat potential in four early sowing dates(September 11 and 25;October 9 and 23)during the 2012-2013 and 2013-2014 cycles in Matamoros,Coahuila,Mexico.Growth cycle duration,chemical composition,dry matter(DM),crude protein(CP),and net energy for lactation(NEL)yields were determined.High temperatures and long photoperiods affected crops seeded on September 11,accelerating growth and reducing canola(26.6%-31.7%)and oat(15.8%)DM yields.As of September 25,canola cv IMC 205 reached DM yields(7746 kg ha^(-1)-9276 kg ha^(-1))similar to those obtained by oat(8115 kg ha^(-1)-9507 kg ha^(-1)),while canola cv Hyola 401 obtained such yields only until October 23.Canola chemical composition was better than that found in oat,with higher CP,but lower acid detergent fiber(ADF)and neutral detergent fiber(NDF)contents.Canola equaled oat CP yields(972 kg ha^(-1)-1215 kg ha^(-1))in the first sowing date,while in the other three other canola sowings reached higher yields(1193 kg ha^(-1)-1889 kg ha^(-1)).As for NEL yields,no difference was observed between both species.The best sowing date for canola is from September 25 on,with CP production advantages over oat.展开更多
The activity of various biofertilizers on rice production (Sabanero A95) was evaluated in Palizada, Campeche, Mexico, in the wet season of 2009 (year one) and 2011 (year two). On year one, arbuscular mycorrhiza INIFAP...The activity of various biofertilizers on rice production (Sabanero A95) was evaluated in Palizada, Campeche, Mexico, in the wet season of 2009 (year one) and 2011 (year two). On year one, arbuscular mycorrhiza INIFAP? (Rhizophagus intraradices), Azospirillum brasilense plus arbuscular micorrhiza Rhizophagus sp., and chemical fertilizer (92, -92, -60 kg·ha-1) were evaluated, while on year two marine algae extracts, a consortium of growth promoting bacteria (Pseudomonas spp.) and a control (not fertilized) were evaluated. The results showed that there were no significant differences on grain yield among treatments during the year one. The average grain yield was 2,800 kg·ha-1. As for the year two, the highest grain yield was observed on plots fertilized with chemical fertilizer (3333 kg·ha-1), followed by plots treated with mycorrhiza INIFAP? (3000 kg·ha-1). The economic analysis for rice production in both years showed that the use of arbuscular mycorrhiza decreases the cost of production by 18.5% and 16.3%, which suggests that microbial inoculants might be good substitutes of chemical fertilizers in rice production.展开更多
文摘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.
基金Fok Ying Tung Eduction Foundation(94021)Beijng Municipal Natural Science Foundation(6061003)National Science Found for Distinguished Young Scholars(30425039)
基金supported by the project ‘‘Impact of Climatic Change and Agricultural Activity on the Emission of Greenhouse Gases and on the Microbial Resources of the Sierra Nevada,Mexico’’[‘‘Impacto del Cambio Climáticos y actividad agrícola en la emisión de gases de efecto invernadero y en los recursos microbianos de la Sierra Nevada,México’’] No.213059funded by the National Council of Science and Technology [Consejo Nacional de Ciencia y Tecnología(CONACy T)]
文摘In this study,10 bacterial strains were isolated from the rhizosphere of coniferous trees on Mount Tla′loc in Mexico.The strains were characterized by their capacity to produce auxins,solubilize phosphates and stimulate mycelial growth of the ectomycorrhizal fungus Suillus sp.All isolates were identified at the molecular level.Moreover,an experiment was established to evaluate the response of Pinus pseudostrobus seedlings to inoculation with the rhizobacteria strains.The isolated strains belonged to the species Cupriavidus basilensis,Rhodococcus qingshengii,R.erythropolis,Pseudomonas spp.,P.gessardii,Stenotrophomonas rhizophila and Cohnella sp.All of the strains produced auxins;the best producer was R.erythropolis CPT9(76.4 lg mL^-1).P.gessardii CPT6 solubilized phosphate at a significant level(443 lg mL^-1).The strain S.rhizophila CPT8 significantly increased the radial growth of the ectomycorrhizal fungus Suillus sp.by 18.8%.Five strains increased the dry mass of the shoots;R.qingshengii CPT4 and R.erythropolis CPT9 increased growth the most,by more than 20%.Inoculation with plant-growth-promoting rhizobacteria can be a very useful practice in a forest nursery to produce healthy,vigorous plants.
基金financial support from the IAEA, Vienna, Austria, Research Contract number MEX16307 within the D3.10.27 Coordinated Research Project
文摘An in vitro gas production （GP） technique was used to investigate the effects of combining different doses of Salix babylonica extract （SB） with exogenous fibrolytic enzymes （EZ） based on xylanase （X） and cellulase （C）, or their mixture （XC; 1：1 v/v） on in vitro fermentation characteristics of a total mixed ration of corn silage and concentrate mixture （50：50, w/w） as substrate. Four levels of SB （0, 0.6, 1.2 and 1.8 mL g-1 dry matter （DM）） and four supplemental styles of EZ （1 μL g-1 DM; control （no enzymes）, X, C and XC （1：1, v/v） were used in a 4×4 factorial arrangement. In vitro GP （mL g-1 DM） were recorded at 2, 4, 6, 8, 10, 12, 24, 36, 48 and 72 h of incubation. After 72 h, the incubation process was stopped and supernatant pH was determined, and then filtered to determine dry matter degradability （DMD）. Fermentation parameters, such as the 24 h gas yield （GY24）, in vitro organic matter digestibility （OMD）, metabolizable energy （ME）, short chain fatty acid concentrations （SCFA）, and microbial crude protein production （MCP） were also estimated. Results indicated that there was a SBxEZ interaction （P〈0.0001） for the asymptotic gas production （b）, the rate of gas production （c）, GP from 6 to 72 h, GP2 （P=0.0095）, and GP4 （P=0.02）. The SB and different combination of enzymes supplementation influenced （P〈0.001） in vitro GP parameters after 12 h of incubation; the highest doses of SB （i.e., 1.8 mL g-1 DM）, in the absence of any EZ, quadratically increased （P〈0.05） the initial delay before GP begins （L） and GP at different incubation times, with lowering b （quadratic effect, P〈0.0001 ） and c （quadratic effect, P〈0.0001 ; linear effect, P=0.0018）. The GP was the lowest （P〈0.05） when the highest SB level was combined with cellulose. There were SBxEZ interactions （P〈0.001） for OMD, ME, the partitioning factor at 72 h of incubation （PF72）, GY24, SCFA, MCP （P=0.0143）, and pH （P=0.0008）. The OMD, ME, GY24 and SCFA with supplementation of SB extract at 1.8 mL g-1 DM were higher （P〈0.001） than the other treatments, however,PF72 was lower （quadratic effect, P=0.0194） than the other levels. Both C and X had no effect （P〉0.05） on OMD, pH, ME, GY24, SCFA and MP. The combination of SB with EZ increased （P〈0.001） OMD, ME, SCFA, PFz2 and GP24, whereas there was no impact on pH. It could be concluded that addition of SB extract, C, and X effectively improved the in vitro rumen fermentation, and the combination of enzyme with SB extract at the level of 1.2 mL g-1 was more effective than the other treatments.
基金supported by the International Cooperation and Exchange of the National Natural Science Foundation of China(31861143010)Huazhong Agricultural University Scientific&Technological Self-innovation Foundation+3 种基金Australian Grains Research and Development Corporation(GRDC)with funding to the Australian Cereal Rust Control Program(ACRCP)CGIAR Research Program WHEAT(CRP-WHEAT)the Open Project of Qinghai Provincial Key Laboratory of Crop Molecular Breeding(2021-ZJ-Y05)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24030102)。
文摘Leaf rust(LR) and stripe rust(YR) are important diseases in wheat producing areas worldwide and cause severe yield losses under favorable environmental conditions when susceptible varieties are grown. We determined the genetic basis of resistance to LR and YR in variety Borlaug 100 by developing and phenotyping a population of 198 F6 recombinant inbred lines derived from a cross with the susceptible parent Apav#1. LR and YR phenotyping were conducted for 4 and 3 seasons, respectively, at CIMMYT research stations in Mexico under artificial epidemics. Mendelian segregation analyses indicated that 3–5 LR and 2 YR genes conferred resistance in Borlaug 100. Lr46/Yr29(1 BL), Yr17(2 AS) and Yr30(3 BS) were present in the resistant parent and segregated in the RIL population based on characterization by molecular markers linked to these genes. When present alone, Lr46/Yr29 caused average 13% and 16% reductions in LR and YR severities, respectively, in RILs. Similarly, Yr17 and Yr30 reduced YR severities by 57% and 11%, respectively. The Yr30 and the Yr17 translocation were also associated with 27% and 14% reductions, respectively, in LR severity, indicating that the 3 BS and 2 AS chromosomal regions likely carry new slow rusting LR resistance genes, temporarily designated as Lr B1 and Lr B2, respectively. Additive effects of Yr30*Yr17, Yr29*Yr17 and Yr29*Yr30 on YR and LR were significant and reduced YR severities by 56%,55%, and 45%, respectively, and LR severities by 34%, 40%, and 45%, respectively. Furthermore, interaction between the three genes was also significant, with mean reductions of 70% for YR and 54% for LR severities. Borlaug 100, or any one of the 21 lines with variable agronomic traits but carrying all three colocated resistance loci, can be used as resistance sources in wheat breeding programs.
文摘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.
文摘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.
基金Project supported by the Consejo Nacional de Ciencia y Tecnología(CONACYT,No.284118),México。
文摘The study and characterization of biomolecules involved in the interaction between mycobacteria and their hosts are crucial to determine their roles in the invasion process and provide basic knowledge about the biology and pathogenesis of disease.Promising new biomarkers for diagnosis and immunotherapy have emerged recently.Mycobacterium is an ancient pathogen that has developed complex strategies for its persistence in the host and environment,likely based on the complexity of the network of interactions between the molecules involved in infection.Several biomarkers have received recent attention in the process of developing rapid and reliable detection techniques for tuberculosis.Among the most widely investigated antigens are CFP-10(10-kDa culture filtrate protein),ESAT-6(6-kD a early secretory antigenic target),Ag85 A,Ag85 B,CFP-7,and PPE18.Some of these antigens have been proposed as biomarkers to assess the key elements of the response to infection of both the pathogen and host.The design of novel and accurate diagnostic methods is essential for the control of tuberculosis worldwide.Presently,the diagnostic methods are based on the identification of molecules in the humoral response in infected individuals.Therefore,these tests depend on the capacity of the host to develop an immune response,which usually is heterogeneous.In the last 20 years,special attention has been given to the design of multiantigenic diagnostic methods to improve the levels of sensitivity and specificity.In this review,we summarize the state of the art in the study and use of mycobacterium biomolecules with the potential to support novel tuberculosis control strategies.
基金This research was supported by the Fundación PRO-DUCE AC-Yucatán,México(Project“Determinación de las propiedades funcionales del chile habanero”).
文摘Their high bioactive compounds content and importance as dietary antioxidants has increased interest in Capsicum fruit. The fruit of seven Capsicum chinense Jacq. var. habanero genotypes grown in Yucatan, Mexico, were analyzed to quantify their phenolic compounds, carotenoids and ascorbic acid contents, and to measure their free radical scavenging (ABTS assay) and antioxidant activities (β-carotene/linoleic acid assay). Phenolics (20.54 to 20.75 mg/100 g sample), carotenoids (1.00 to 1.26 mg/100 g sample) and ascorbic acid contents (187.24 to 281.73 mg/100 g sample) varied between genotypes. Trolox equivalent antioxidant capacity (TEAC) ranged from 1.55 to 3.23 mM/mg sample. During the 120-min decolorization trial, antioxidant capacity decreased over time in the studied genotypes. Values ranged from 36%to 57% β-carotene bleaching during the first 30 minutes. Fruit from all seven studied genotypes are good antioxidant sources and hold promise as natural ingredients in functional foods.
文摘For the paper,Effects of cellulase and xylanase enzymes mixed with increasing doses of Salix babylonica extract on in vitro rumen gas production kinetics of a mixture of corn silage with concentrate,published in Journal of Integrative Agriculture 2015,Vol.14,No.1,on page 131-139,the authors'names and affiliated units should be.
文摘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.
文摘Huanglongbing (HLB) or citrus greening is currently the most important citrus disease, caused by the bacterium </span><i><span style="font-family:Verdana;">Candidatus</span></i><span style="font-family:Verdana;"> Liberibacter asiaticus (</span><i><span style="font-family:Verdana;">C</span></i><span style="font-family:Verdana;">Las). The impossibility of isolating it causes understanding its pathogenic mechanisms to be a complicated task. Recent studies identified 16 proteins with the signal peptide needed to be secreted in the plant and cause the disease. The present study aims to perform a bioinformatic analysis of these proteins with the function prediction approach by gene ontology (GO) and the detection of conserved domains. It was observed that of the 16 proteins analyzed not all are found in different infective strains reported in the literature. The GO analysis allowed us to relate different proteins with the biological process of energy and pathogenic activity, especially CLIBASIA_03315 and CLIBASIA_05115, respectively. The domain analysis allowed the observation of a </span></span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:""><span style="font-family:Verdana;">-CA domain, tentatively related to the damage caused to the chloroplast and a PAAR domain associated with the T6SS secretory system. Our results provide information on the possible function of potential pathogenicity effectors in </span><i><span style="font-family:Verdana;">C</span></i><span style="font-family:Verdana;">Las.
基金This work was supported by Fondos Fiscales-INIFAP through projects named“Desarrollo de productos alimenticios elaborados con hoja de Stevia rebaudiana Bertoni”Also,I.A.G.received a CONACYT’s scholarship during postgraduate studies.
文摘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.
基金funded by the National Institute of Forestry,Agriculture and Livestock Research(INIFAP)of MéxicoINIFAP provided the funds for research Project Number 14574034553“Evaluation of Rootstocks and Physiology of Citrus Production in Morelos,Guerrero and Oaxaca”.
文摘The objective of this study consisted of evaluating the effect of the application of chitosan(Q),1-methylcyclopropene(1-MCP)under two controlled temperatures on some physical,physiological,and chemical parameters contributing to the quality of Persian lime Citrus latifolia fruits.Eight treatments were evaluated,resulting from the combination of four senescence retardant applications(Q,1-MCP,1-MCP+Q,and without application)on fruits stored at two temperatures(12/20℃.Epidermis color(luminosity,chromaticity,and hue),fruit appearance,respiration,weight loss,total juice content,total soluble solids,and titratable acidity were registered during the study.The results indicate that the 1-MCP and Q combination favored fruit postharvest quality conditions such as reducing respiration rate;maintaining fruit good appearance,turgidity,and brighter fruit chromaticity;fruits treated with chitosan and stored at 12℃,favored total soluble solids.On the other hand,Variables such as weight loss,juice content,acidity,phenols,flavonoids,antioxidant activity,and hue values were favored by a 12℃ storing temperature regardless of the treatment.In general,the use of modified atmospheres,senescence retardants,and refrigeration as postharvest methods,can increase Persian lime shelf life.
文摘Husk tomato production technology was developed utilizing plastic sheeting and drip irrigation based on the results of reference evapotranspiration and crop coefficients (Kc) proposed at different phenological stages. The objectives of this study were as follows: 1) to evaluate the effect of plastic sheeting on the yield of husk tomato fruit with drip irrigation based on crop evapotranspiration;2) to validate the use of drip irrigation technology and plastic sheeting in husk tomato production using demonstration plots;and 3) to determine the profitability and economic viability of the product in the domestic market. The proposed Kc values were 0.25, 0.71 and 0.56 in the initial, intermediate and final stage of crop development, respectively. Irrigation rates ranged from 2.5 to 6 mm·day-1, which was equivalent to an irrigation time of 0.6 to 2.5 hr. Soil moisture tension was monitored with tensiometers at depths of 15 and 30 cm in a loamy eutricfluvisol. The use of plastic sheeting increased husk tomato yield by 56.2% and water productivity by 63.5% under drip irrigation conditions when basing irrigation levels on crop evapotranspiration. Soil matrix potential varied between depths of 15 and 30 cm based on irrigation or rainfall amounts and the use of plastic sheeting with values being higher when the plastic sheeting was used. The husk tomato fruit yield in validation plots was 46 and 54.6 t·ha-1 with water use efficiencies ranging from 16.1 to 19.1 kg·m-3. These results exceeded the national average of 14 t·ha-1 and water use efficiency of 2.54 kg·m-3. With this new technology, a cost benefit ratio of 3.6 is obtained, which represents an economically profitable margin for farmers in the region.
文摘Adverse weather conditions and intensive use for fiber production have caused decline of natural populations of Agave lechuguilla. By these reasons, it is important to develop a sustainable management of this specie to avoid this situation. One of the first steps is to establish forest plantations as an alternative to restore A. lechuguilla habitat and increase its range while at the same time indirectly reducing erosion rates. The aim of this study was to identify the potential areas for establishment of plantations of A. lechuguilla in the State of Coahuila, Mexico. Areas for planting establishment were selected according to multi-criteria analysis using Geographic Information System (GIS) Idrisi32 Ver 2.0 and 3.2 Arc.View. The analysis was based on comparison of climate and soil requirements in contrast to environmental conditions of the tested area. The evaluated variables were: soil type, texture, depth, average annual temperature, annual precipitation, elevation and slope. Results derive in potential area maps, geo-referenced and their distribution by Agricultural Development District. An area of 5 million 159,273 hectares was determined with potential for establishment of A. lechuguilla forest plantations in the State of Coahuila. It was concluded that, use of GIS is a reliable tool to determine potential areas for A. lechuguilla forest plantations, where this specie has higher probability of success in survival and biomass production. This study will support programs aimed to strengthen the economy of rural producers and also recover and preserve the arid state.
基金This research was funded by the Instituto Nacional de Investigaciones Forestales,Agrícolas y Pecuarias(México).
文摘Canola and oat forage potential may be affected by climatic conditions when sown early.The objective of this study was to evaluate the forage canola and oat potential in four early sowing dates(September 11 and 25;October 9 and 23)during the 2012-2013 and 2013-2014 cycles in Matamoros,Coahuila,Mexico.Growth cycle duration,chemical composition,dry matter(DM),crude protein(CP),and net energy for lactation(NEL)yields were determined.High temperatures and long photoperiods affected crops seeded on September 11,accelerating growth and reducing canola(26.6%-31.7%)and oat(15.8%)DM yields.As of September 25,canola cv IMC 205 reached DM yields(7746 kg ha^(-1)-9276 kg ha^(-1))similar to those obtained by oat(8115 kg ha^(-1)-9507 kg ha^(-1)),while canola cv Hyola 401 obtained such yields only until October 23.Canola chemical composition was better than that found in oat,with higher CP,but lower acid detergent fiber(ADF)and neutral detergent fiber(NDF)contents.Canola equaled oat CP yields(972 kg ha^(-1)-1215 kg ha^(-1))in the first sowing date,while in the other three other canola sowings reached higher yields(1193 kg ha^(-1)-1889 kg ha^(-1)).As for NEL yields,no difference was observed between both species.The best sowing date for canola is from September 25 on,with CP production advantages over oat.
文摘The activity of various biofertilizers on rice production (Sabanero A95) was evaluated in Palizada, Campeche, Mexico, in the wet season of 2009 (year one) and 2011 (year two). On year one, arbuscular mycorrhiza INIFAP? (Rhizophagus intraradices), Azospirillum brasilense plus arbuscular micorrhiza Rhizophagus sp., and chemical fertilizer (92, -92, -60 kg·ha-1) were evaluated, while on year two marine algae extracts, a consortium of growth promoting bacteria (Pseudomonas spp.) and a control (not fertilized) were evaluated. The results showed that there were no significant differences on grain yield among treatments during the year one. The average grain yield was 2,800 kg·ha-1. As for the year two, the highest grain yield was observed on plots fertilized with chemical fertilizer (3333 kg·ha-1), followed by plots treated with mycorrhiza INIFAP? (3000 kg·ha-1). The economic analysis for rice production in both years showed that the use of arbuscular mycorrhiza decreases the cost of production by 18.5% and 16.3%, which suggests that microbial inoculants might be good substitutes of chemical fertilizers in rice production.
