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Mexico City, Mexico

Universidad Autónoma Chapingo is an agricultural college located in Texcoco, Mexico State in Mexico. The university is a federally funded public institution of higher education. It offers technical and full bachelor’s degrees as well as having scientific and technological research programs. Many of these programs are related to agriculture, forestry and fishing.The school began as the Escuela Nacional de Agricultura which was founded in 1854 at the Monastery of San Jacinto in Mexico City. The school was moved in 1923 to the President Álvaro Obregón ex Hacienda of Chapingo. Postgraduate studies were added in 1959. The school received autonomous status in 1978. It offers courses of study in Forestry, Agricultural Economics, Agricultural Industries, Irrigation, Rural Sociology and more.The main attraction for visitors at this school is its murals. In the old hacienda chapel, which is now the University Ceremonies Room is a mural by Diego Rivera called “Tierra Fecundada” . This work was begun in 1924 and completed in 1927. Covering an area of over 700m2, the work divides into three parts. The left panel depicts man’s struggle to have land, the right panel shows the evolution of Mother Nature and the center shows the communion between man and earth. It is considered to be one of Rivera’s best works. More recently, the school acquired an unnamed mural by Luis Nishizawa. This work was produced during his last year at the Escuela Nacional de Artes Plasticas of UNAM and depicts the agriculture of Mexico in both the past and the present. The work is six meters high, nine meters wide and in the form of a triangle. It is placed in a building that is commonly called “El Partenon.”The school is also home to the National Museum of Agriculture. The 2,000 m2 facility presents the development of agriculture in Mexico from the pre-Hispanic past to the present day. The collection has about 4,000 objects relating to technology, agronomy including farming implements and photographs by Hanz Gutmann. Wikipedia.

Arce-Cervantes O.,Metropolitan Autonomous University | Mendoza G.,Metropolitan Autonomous University | Miranda L.A.,Chapingo Autonomous University | Meneses M.,Postgraduate College | Loera O.,Metropolitan Autonomous University
Journal of Agricultural Science and Technology | Year: 2013

Production of lignocellulolytic enzymes by the thermotolerant Fomes sp. EUM1 was determined in solid cultures using corn stover (CS) as a sole substrate or supplemented with 20 % wheat bran (CS+WB). This supplementation increased (P< 0.05) enzymatic activity per gram of initial dry matter (gdm) for xylanases and cellulases: 160 IU g dm-1 and 37 IU g dm-1, respectively; while laccases reached a similar yield (3.3 IU g dm-1) for both cultures. Nevertheless, laccases showed different stability patterns at 39°C and pH 6: half-life time (t1/2) was doubled in extracts from CS+WB (23.5 h); whereas t1/2 for the other enzymes from both cultures showed no difference. Both extracts by Fomes sp. EUM1 and a commercial enzymatic product were used on forages: corn stover, (CS), sugarcane bagasse (SCB), and alfalfa hay (AH). The fractional rate of gas production (FR; ml g-1 h-1) increased (P< 0.05) at 9 hours in CS compared to the sample without enzymes. The use of any enzymes favoured higher maximum gas volume (Vm; h-1) on SCB. The in vitro digestibility (IVD) of CS after using the commercial product was 12% higher, while our extracts from CS and CS+WB showed 16 and 21% improvements (P< 0.05), respectively, suggesting a higher specificity of these enzymes produced on the same substrate (CS). In addition to the proven stability, the versatility of extracts from CS and CS+WB was confirmed by the increase in IVD values for SCB (up to 100%) in relation to the control without enzymes.

Hsieh H.-Y.,University of Michigan | Liere H.,University of Wisconsin - Madison | Soto E.J.,Chapingo Autonomous University | Perfecto I.,University of Michigan
Ecology and Evolution | Year: 2012

Trait-mediated indirect interactions (TMII) can be as important as density-mediated indirect interactions. Here, we provide evidence for a novel trait-mediated cascade (where one TMII affects another TMII) and demonstrate that the mechanism consists of a predator eavesdropping on chemical signaling. Ants protect scale insects from predation by adult coccinellid beetles - the first TMII. However, parasitic phorid flies reduce ant foraging activity by 50% - the second TMII, providing a window of opportunity for female beetles to oviposit in high-quality microsites. Beetle larvae are protected from ant predation and benefit from living in patches with high scale densities. We demonstrate that female beetles can detect pheromones released by the ant when attacked by phorids, and that only females, and especially gravid females, are attracted to the ant pheromone. As ants reduce their movement when under attack by phorids, we conclude that phorids facilitate beetle oviposition, thus producing the TMII cascade. © 2012 The Authors.

Cruz-Hipolito H.,University of Cordoba, Spain | Dominguez-Valenzuela J.A.,Chapingo Autonomous University | Osuna M.D.,Finca la Orden Valdesequera Research Center | De Prado R.,University of Cordoba, Spain
Plant and Soil | Year: 2012

Background and aims: In this study, we describe the molecular, physiological and agronomic aspects involved in the resistance to acetyl coenzyme A carboxylase inhibiting herbicides (ACCase) observed in one biotype of Phalaris paradoxa from Mexico. Methods: Dose-response Assays: The herbicide rate inhibiting plant growth of each biotype by 50% with respect to the untreated control, ED 50. Enzyme purification and ACCase assays to determine herbicide rate inhibiting the enzyme of each biotype by 50% with respect to the untreated control, I 50. Absorption and Translocation Assays with [ 14C]diclofop-methyl. Metabolism of diclofop-methyl and its metabolites were identified by thin-layer chromatography. Study of target site resistance mechanism at enzyme and molecular levels. Results: In this work, it has been studied the whole-plant response of Phalaris paradoxa biotypes from Mexico resistant (R) and susceptible (S) to ACCase-inhibiting herbicides: aryloxyphenoxypropionate (APP), cyclohexanedione (CHD) and phenylpyrazoline (PPZ), and the mechanism behind their resistance were studied. To analyse the resistance mechanism, the enzyme ACCase activity was investigated. Results from biochemical assays indicated a target-site resistance as the cause of reduced susceptibility to ACCase inhibitors. The absorption, translocation and metabolism were similar between R and S biotypes. A point mutation never described before was detected within the triplet of glycine at the amino acid position 2096 (referring to EMBL accession no. AJ310767) and resulted in the triplet of serine. This new mutation could explain the loss of affinity for the ACCase-inhibiting herbicides. Conclusions: We found a new mutation, which had never been described before. This mutation was detected within the triplet of glycine at the amino acid position 2096. This new mutation confers cross-resistance to three different chemical groups of ACCase-inhibiting herbicides. © 2011 Springer Science+Business Media B.V.

Cruz-Hipolito H.,University of Cordoba, Spain | Rojano-Delgado A.,University of Cordoba, Spain | Dominguez-Valenzuela J.A.,Chapingo Autonomous University | Heredia A.,University of Malaga | And 2 more authors.
Plant and Soil | Year: 2011

Glyphosate tolerance by Clitoria ternatea, Neonotonia wightii and Amaranthus hybridus was studied in whole plants from Mexico. Experiments in a controlled growth chamber showed both legumes to be highly tolerant of glyphosate, with and ED50 values of 600. 18 g ae ha-1 for C. ternatea and 362. 94 g ae ha-1 for N. wightii. On the other hand, A. hybridus was highly susceptible to the herbicide (ED50 = 42. 22 g ae ha-1). Shikimate accumulation peaked 96 h after treatment in the tolerant plants and the susceptible weed under 500 g ae ha-1 glyphosate. The shikimic acid content of whole leaves was 4. 0 and 5. 0 times higher in the susceptible weed than in N. wightii and C. ternatea, respectively. 14C-glyphosate absorption and translocation tests showed A. hybridus to absorb 30% more herbicide than the legumes 24 h after glyphosate foliar application. 14C-glyphosate translocation as measured by quantified autoradiography revealed increased translocation of the herbicide to untreated leaves and roots in A. hybridus relative to the two legumes. The cuticular surface of A. hybridus exhibited very low wax coverage relative to the epicuticular surface of N. wightii and, especially, C. ternatea. No significant degradation of glyphosate to aminomethylphosphonic acid and glyoxylate metabolites was detected among the tolerant leguminous plants or the susceptible weed population. These results indicate that the high glyphosate tolerance of Clitoria ternatea and Neonotonia wightii is mainly a result of poor penetration and translocation of the herbicide to apical growing points in their plants. © 2011 Springer Science+Business Media B.V.

Cruz-Hipolito H.,University of Cordoba, Spain | Osuna M.D.,Finca la Orden Valdesequera Research Center | Dominguez-Valenzuela J.A.,Chapingo Autonomous University | Espinoza N.,Agricultural Research Institute INIA | De Prado R.,University of Cordoba, Spain
Journal of Agricultural and Food Chemistry | Year: 2011

Whole-plant response of two suspected resistant Avena fatua biotypes from Chile and Mexico to ACCase-inhibiting herbicides [aryloxyphenoxypropionate (APP), cyclohexanedione (CHD), and pinoxaden (PPZ)] and the mechanism behind their resistance were studied. Both dose-response and ACCase enzyme activity assays revealed cross-resistance to the three herbicide families in the biotype from Chile. On the other hand, the wild oat biotype from Mexico exhibited resistance to the APP herbicides and cross-resistance to the CHD herbicides, but no resistance to PPZ. Differences in susceptibility between the two biotypes were unrelated to absorption, translocation, and metabolism of the herbicides. PCR generated fragments of the ACCase CT domain spanning the potential mutations sited in the resistant and susceptible biotypes were sequenced and compared. A point mutation was detected in the aspartic acid triplet at the amino acid position 2078 in the Chilean biotype and in isoleucine at the amino acid position 2041 in the Mexican wild oat biotype, which resulted in a glycine triplet and an asparagine triplet, respectively. On the basis of in vitro assays, the target enzyme (ACCase) in these resistant biotypes contains a herbicide-insensitive form. This is the first reported evidence of resistance to pinoxaden in A. fatua. © 2011 American Chemical Society.

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