Whole-genome duplications are an important source of evolutionary novelties that change the mode and tempo at which genetic elements evolve within a genome. The Cucurbita genus experienced a wholegenome duplication ar...Whole-genome duplications are an important source of evolutionary novelties that change the mode and tempo at which genetic elements evolve within a genome. The Cucurbita genus experienced a wholegenome duplication around 30 million years ago, although the evolutionary dynamics of the coding and noncoding genes in this genus have not yet been scrutinized. Here, we analyzed the genomes of four Cucurbita species, in eluding a newly assembled genome of Cucurbita argyrosperma, and compared the gene con tents of these species with those of five other members of the Cucurbitaceae family to assess the evolutionary dynamics of protein-coding and long intergenic noncoding RNA (lincRNA) genes after the genome duplication. We report that Cucurbita genomes have a higher protein-coding gene birth-death rate compared with the genomes of the other members of the Cucurbitaceae family. C. argyrosperma gene families associated with pollination and transmembrane transport had significantly faster evolutionary rates. lincRNA families showed high levels of gene turnover throughout the phylogeny, and 67.7% of the lincRNA families in Cucurbita showed evidence of birth from the neofunctionalization of previously existing protein-coding genes. Collectively, our results suggest that the whole-genome duplication in Cucurbita resulted in faster rates of gene family evolution through the neofunctionalization of duplicated genes.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�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
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
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
Races belonging to the Ug99(TTKSK) lineage of the wheat stem rust fungus, carrying complex virulence combinations, and their migration to countries in Africa,Middle East and Asia continue to pose a significant threat ...Races belonging to the Ug99(TTKSK) lineage of the wheat stem rust fungus, carrying complex virulence combinations, and their migration to countries in Africa,Middle East and Asia continue to pose a significant threat to global wheat production.The rapid spread of additional races, e.g., TKTTF or the Digalu lineage, in several countries causing localized epidemics reminds us of the vulnerability of wheat germplasm to stem rust disease, a formidable foe referenced as early as biblical times.A global rust monitoring system reflecting increased surveillance efforts has identified 13 races within the Ug99 lineage in 13 countries and unrelated lineages are emerging, spreading and posing serious threats to wheat production.Race TKTTF has caused localized epidemics in Ethiopia and its variants have been recently implicated in stem rust outbreaks in Europe.Concerted research efforts have resulted in the identification of several new resistance genes and gene combinations for use in breeding.Combining multiple adult plant resistance(APR) genes in high-yielding backgrounds and discovery of new quantitative trait loci conferring stem rust resistance has progressed in the recent years, enhancing the durability of resistance.Effective gene stewardship and new generation breeding materials and cultivars that combine multiple race-specific or minor to intermediate effect APR genes,complemented by active surveillance and monitoring, have helped to limit major epidemics and increase grain yield potential in key target environments.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
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
Microbial inoculants are of great importance in agro-ecology and plants. However, the symbiotic effectiveness of strains may vary between species or within the same species. Aim of the study was to select experimental...Microbial inoculants are of great importance in agro-ecology and plants. However, the symbiotic effectiveness of strains may vary between species or within the same species. Aim of the study was to select experimental microbial strains of national origin, to know its impact on growth of sweet sorghum (Sorghum bicolor) in greenhouse and sterile soil. Five strains of arbuscular mycorrhizal fungi (AMF) and eight rhizobacteria (two of them mutagenized) were compared with non-inoculated plants as control. Variables measured were index of chlorophyll SPAD, plant height, stem diameter (from the middle section), fresh biomass from stem, leaf, panicle, radical, and stem sugars content (°Brix) of every two internodes. The results showed that in the majority of cases, microbial strains exceeded the values of variables compared with control plants. The highest values of chlorophyll (41.8 SPAD), stem diameter (13.5 mm) and total fresh biomass (144.3 g), were recorded with rhizobacterias BS410 (Herbaspirillum sp.), B2709 (Pseudomonas sp.) and B4M4 (Azospirillum sp.), respectively.展开更多
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
The protein intake of the population in the Yucatan Peninsula is based upon the different forms of beans naturally developed. The different ecotypes of creole beans that are grown traditionally have been displaced by ...The protein intake of the population in the Yucatan Peninsula is based upon the different forms of beans naturally developed. The different ecotypes of creole beans that are grown traditionally have been displaced by improved varieties, thereby turning into a risk of losing a valuable source of germ-plasma. The present study is aimed to identify, collect and preserve several bean species genetic resources grown in Campeche, Mexico, in addition to the development of an identification card with the main phenotypic characteristics and yield components. A total of 33 different samples were collected from nine different municipalities statewide;out of those, 15 were Phaseolus vulgaris and 18 Phaseolus lunatus. The collected samples diversity is reflected in the range of growth habits from the bush to the indeterminate climbing species, being these the most representative with about 29 samples, many of those because of the way the planting is carried out, which is traditionally performed in association with the cultivation of corn. Early samples were identified in this diversity with their cycle ranging from 60 to 120 days after emergence. Samples of Phaseolus lunatus with 1.35 to 2.86 t/ha yield potential were also obtained.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 co展开更多
Mexico is the main producer,consumer and exporter of avocado in the world,being Michoacan the main producer state contributing more than 80%of the national production.There are phytopathogens that decimate the product...Mexico is the main producer,consumer and exporter of avocado in the world,being Michoacan the main producer state contributing more than 80%of the national production.There are phytopathogens that decimate the production causing the death of the tree.Root samples were collected in avocado trees that showed the characteristic symptomatology of the disease known as avocado sadness,the sampling was carried out in four of the main avocado producing towns,in the state of Michoacan,Mexico.The isolation consisted in sowing root tissue in Petri dishes with V8R-PARPH culture medium,subsequently they were identified morphologically and for species level it was determined by molecular biology,with the PCR-ITS technique.Pathogenicity tests were performed in triplicate with avocado seedlings with more than six leaves.After 24 hours,the inoculated plants expressed decay in the apical part,after 120 hours the leaves showed yellowing and after 15 days there was a generalized wilt on the stem and leaves,re-isolating the phytopathogen Phytopythium vexans.This study confirms the first report of the oomycete P.vexans affecting avocado trees in the most important producing region of the Mexican Republic.展开更多
Some intensive dairy operations in Mexico are contributing to large,negative environmental impacts,especially in regions dominated by high concentrations of animals.Excessive manure inputs plus additional nitrogen(N)f...Some intensive dairy operations in Mexico are contributing to large,negative environmental impacts,especially in regions dominated by high concentrations of animals.Excessive manure inputs plus additional nitrogen(N)fertilizer has,in some cases,resulted in background nitrate–nitrogen(NO3–N)levels in irrigation water that are so high,it is not safe for human consumption.One reason is that commercial farmers in this region are currently not using any method to rapidly calculate N budgets based on their practices,N inputs and/or crop N uptake.The Nitrogen Index,a quick tool that can be used to conduct an assessment within a few minutes,was developed for Mexico,but needed further testing under commercial field operations.We conducted studies in 2010 and 2011 and collected soil and crop information from several commercial farming operations to test the tool.The index accurately assessed(Po0.0001)residual soil nitrate after harvesting corn(Zea mays L.)and oats(Avena sativa L.);and also accurately assessed the N uptake of these crops(Po0.01).The Mexico N Index is a tool that can be used to quickly conduct N balances,show when N is being over-applied,and help reduce over-application,thus reducing N losses to the environment and improving management of dairy forage systems in Mexico.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
Symptoms of Tar Spot Complex (TSC) in corn appear in the form of black spots surrounded by a chlorotic halo known as fish-eye. The crop with these symptoms was found at San Pablo Autopan, Estado de Mexico. The stromal...Symptoms of Tar Spot Complex (TSC) in corn appear in the form of black spots surrounded by a chlorotic halo known as fish-eye. The crop with these symptoms was found at San Pablo Autopan, Estado de Mexico. The stromal region of foliar lesions was cut longitudinally, showing perithecia, asci and ascospores typical of Phyllachora maydis. The results were confirmed by PCR-ITS with ITS 1 and ITS4 initiators, cloned by pJET, before being sequenced and compared against NCBI’s data base. Phyllachora identity was confirmed. This is the first report where TSC pathogen has been detected under conditions that had not been previously reported, for instance, at 2600 meters above the sea level.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
The research was done at Havana Biofabric, Mayabeque Province. The vitro plants of banana （Musa sp） used came from the clone Enano Guantanamero （viand type）. They come from multiplication phase in a Murashige and ...The research was done at Havana Biofabric, Mayabeque Province. The vitro plants of banana （Musa sp） used came from the clone Enano Guantanamero （viand type）. They come from multiplication phase in a Murashige and MS （Skoog medium）. The objective of this work was to study the potentialities of HA （humic acids） for stimulation of rooting and cell division process, searching for completely synthetic hormone substitution due to its high cost. The multiplication medium contained thiamine （2 mg·L^-1）, myo-inositol （100 mg·L^-1）, sugar （30mg·L^-1）. By the use of HA, five treatments were used with total substitution of auxin and cytokinin （TI： HA （10 mg.Ll）; （T2： HA （20 mg·L^-1）; （T3： HA （30mg·L^-1）; （T4： HA （40 mg·L^-1）; （T5： HA （50 mg·L^-1） and the control with 6BAP （benzil amino purine） （4 mg·L^-1） ＋ IBA （indol butyric acid） （0.65 mg·L^-1）, pH of the medium was adjust just before agar were add. The results showed that in the explants under HA treatments, elongation and cell multiplication were favored confirmed by explants great high, root number and length due to dry mass. The total protein content, reduced carbohydrate and peroxidases enzymatic activity were determine. The use of Vermicompost HA in the in vitro micropropagation of banana allow the elimination of rooting phase saving materials and be able to pass explants directly to Acclimatization phase.展开更多
文摘Whole-genome duplications are an important source of evolutionary novelties that change the mode and tempo at which genetic elements evolve within a genome. The Cucurbita genus experienced a wholegenome duplication around 30 million years ago, although the evolutionary dynamics of the coding and noncoding genes in this genus have not yet been scrutinized. Here, we analyzed the genomes of four Cucurbita species, in eluding a newly assembled genome of Cucurbita argyrosperma, and compared the gene con tents of these species with those of five other members of the Cucurbitaceae family to assess the evolutionary dynamics of protein-coding and long intergenic noncoding RNA (lincRNA) genes after the genome duplication. We report that Cucurbita genomes have a higher protein-coding gene birth-death rate compared with the genomes of the other members of the Cucurbitaceae family. C. argyrosperma gene families associated with pollination and transmembrane transport had significantly faster evolutionary rates. lincRNA families showed high levels of gene turnover throughout the phylogeny, and 67.7% of the lincRNA families in Cucurbita showed evidence of birth from the neofunctionalization of previously existing protein-coding genes. Collectively, our results suggest that the whole-genome duplication in Cucurbita resulted in faster rates of gene family evolution through the neofunctionalization of duplicated genes.
基金Fok Ying Tung Eduction Foundation(94021)Beijng Municipal Natural Science Foundation(6061003)National Science Found for Distinguished Young Scholars(30425039)
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�
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financial support particularly from the DGGW Project managed by Cornell University and funded by the Bill and Melinda Gates Foundation and the UK Department for International Development, as well as the Indian Council of Agricultural Research, USAID, USDA-ARS and GRDC-Australia
文摘Races belonging to the Ug99(TTKSK) lineage of the wheat stem rust fungus, carrying complex virulence combinations, and their migration to countries in Africa,Middle East and Asia continue to pose a significant threat to global wheat production.The rapid spread of additional races, e.g., TKTTF or the Digalu lineage, in several countries causing localized epidemics reminds us of the vulnerability of wheat germplasm to stem rust disease, a formidable foe referenced as early as biblical times.A global rust monitoring system reflecting increased surveillance efforts has identified 13 races within the Ug99 lineage in 13 countries and unrelated lineages are emerging, spreading and posing serious threats to wheat production.Race TKTTF has caused localized epidemics in Ethiopia and its variants have been recently implicated in stem rust outbreaks in Europe.Concerted research efforts have resulted in the identification of several new resistance genes and gene combinations for use in breeding.Combining multiple adult plant resistance(APR) genes in high-yielding backgrounds and discovery of new quantitative trait loci conferring stem rust resistance has progressed in the recent years, enhancing the durability of resistance.Effective gene stewardship and new generation breeding materials and cultivars that combine multiple race-specific or minor to intermediate effect APR genes,complemented by active surveillance and monitoring, have helped to limit major epidemics and increase grain yield potential in key target environments.
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.
文摘Microbial inoculants are of great importance in agro-ecology and plants. However, the symbiotic effectiveness of strains may vary between species or within the same species. Aim of the study was to select experimental microbial strains of national origin, to know its impact on growth of sweet sorghum (Sorghum bicolor) in greenhouse and sterile soil. Five strains of arbuscular mycorrhizal fungi (AMF) and eight rhizobacteria (two of them mutagenized) were compared with non-inoculated plants as control. Variables measured were index of chlorophyll SPAD, plant height, stem diameter (from the middle section), fresh biomass from stem, leaf, panicle, radical, and stem sugars content (°Brix) of every two internodes. The results showed that in the majority of cases, microbial strains exceeded the values of variables compared with control plants. The highest values of chlorophyll (41.8 SPAD), stem diameter (13.5 mm) and total fresh biomass (144.3 g), were recorded with rhizobacterias BS410 (Herbaspirillum sp.), B2709 (Pseudomonas sp.) and B4M4 (Azospirillum sp.), respectively.
文摘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.
文摘The protein intake of the population in the Yucatan Peninsula is based upon the different forms of beans naturally developed. The different ecotypes of creole beans that are grown traditionally have been displaced by improved varieties, thereby turning into a risk of losing a valuable source of germ-plasma. The present study is aimed to identify, collect and preserve several bean species genetic resources grown in Campeche, Mexico, in addition to the development of an identification card with the main phenotypic characteristics and yield components. A total of 33 different samples were collected from nine different municipalities statewide;out of those, 15 were Phaseolus vulgaris and 18 Phaseolus lunatus. The collected samples diversity is reflected in the range of growth habits from the bush to the indeterminate climbing species, being these the most representative with about 29 samples, many of those because of the way the planting is carried out, which is traditionally performed in association with the cultivation of corn. Early samples were identified in this diversity with their cycle ranging from 60 to 120 days after emergence. Samples of Phaseolus lunatus with 1.35 to 2.86 t/ha yield potential were also obtained.
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 co
文摘Mexico is the main producer,consumer and exporter of avocado in the world,being Michoacan the main producer state contributing more than 80%of the national production.There are phytopathogens that decimate the production causing the death of the tree.Root samples were collected in avocado trees that showed the characteristic symptomatology of the disease known as avocado sadness,the sampling was carried out in four of the main avocado producing towns,in the state of Michoacan,Mexico.The isolation consisted in sowing root tissue in Petri dishes with V8R-PARPH culture medium,subsequently they were identified morphologically and for species level it was determined by molecular biology,with the PCR-ITS technique.Pathogenicity tests were performed in triplicate with avocado seedlings with more than six leaves.After 24 hours,the inoculated plants expressed decay in the apical part,after 120 hours the leaves showed yellowing and after 15 days there was a generalized wilt on the stem and leaves,re-isolating the phytopathogen Phytopythium vexans.This study confirms the first report of the oomycete P.vexans affecting avocado trees in the most important producing region of the Mexican Republic.
文摘Some intensive dairy operations in Mexico are contributing to large,negative environmental impacts,especially in regions dominated by high concentrations of animals.Excessive manure inputs plus additional nitrogen(N)fertilizer has,in some cases,resulted in background nitrate–nitrogen(NO3–N)levels in irrigation water that are so high,it is not safe for human consumption.One reason is that commercial farmers in this region are currently not using any method to rapidly calculate N budgets based on their practices,N inputs and/or crop N uptake.The Nitrogen Index,a quick tool that can be used to conduct an assessment within a few minutes,was developed for Mexico,but needed further testing under commercial field operations.We conducted studies in 2010 and 2011 and collected soil and crop information from several commercial farming operations to test the tool.The index accurately assessed(Po0.0001)residual soil nitrate after harvesting corn(Zea mays L.)and oats(Avena sativa L.);and also accurately assessed the N uptake of these crops(Po0.01).The Mexico N Index is a tool that can be used to quickly conduct N balances,show when N is being over-applied,and help reduce over-application,thus reducing N losses to the environment and improving management of dairy forage systems in Mexico.
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.
文摘Symptoms of Tar Spot Complex (TSC) in corn appear in the form of black spots surrounded by a chlorotic halo known as fish-eye. The crop with these symptoms was found at San Pablo Autopan, Estado de Mexico. The stromal region of foliar lesions was cut longitudinally, showing perithecia, asci and ascospores typical of Phyllachora maydis. The results were confirmed by PCR-ITS with ITS 1 and ITS4 initiators, cloned by pJET, before being sequenced and compared against NCBI’s data base. Phyllachora identity was confirmed. This is the first report where TSC pathogen has been detected under conditions that had not been previously reported, for instance, at 2600 meters above the sea level.
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.
文摘The research was done at Havana Biofabric, Mayabeque Province. The vitro plants of banana （Musa sp） used came from the clone Enano Guantanamero （viand type）. They come from multiplication phase in a Murashige and MS （Skoog medium）. The objective of this work was to study the potentialities of HA （humic acids） for stimulation of rooting and cell division process, searching for completely synthetic hormone substitution due to its high cost. The multiplication medium contained thiamine （2 mg·L^-1）, myo-inositol （100 mg·L^-1）, sugar （30mg·L^-1）. By the use of HA, five treatments were used with total substitution of auxin and cytokinin （TI： HA （10 mg.Ll）; （T2： HA （20 mg·L^-1）; （T3： HA （30mg·L^-1）; （T4： HA （40 mg·L^-1）; （T5： HA （50 mg·L^-1） and the control with 6BAP （benzil amino purine） （4 mg·L^-1） ＋ IBA （indol butyric acid） （0.65 mg·L^-1）, pH of the medium was adjust just before agar were add. The results showed that in the explants under HA treatments, elongation and cell multiplication were favored confirmed by explants great high, root number and length due to dry mass. The total protein content, reduced carbohydrate and peroxidases enzymatic activity were determine. The use of Vermicompost HA in the in vitro micropropagation of banana allow the elimination of rooting phase saving materials and be able to pass explants directly to Acclimatization phase.
