Resumen El género Trichoderma, descrito por Persoon y Rifai, con base en características morfo - fisiológicas, contaba con nueve especies; aunque no se diferenciaban satisfactoriamente. Las técnicas moleculares permitieron ratificar e identificar otras nuevas; actualmente, se notifican 453 especies de Trichoderma. La identificación polifásica se impone, debido a las complejidades del género. El trabajo tuvo como objetivo caracterizar aislados de Trichoderma tomando como base aspectos morfo-culturales y genéticos. Las descripciones morfológicas se realizaron por observaciones microscópicas de microcultivos, según Rifai, Gams y Bissett. La compatibilidad vegetativa se evaluó macroscópicamente, y se determinó el tipo de reacción (compatible o incompatible). La variabilidad genética se analizó por RAPD; utilizando el método Jaccard mediante el paquete estadístico FreeTree. Los aislados presentaron características morfológicas similares, aunque hubo diferencias en la coloración de las colonias y la morfometría de las estructuras fúngicas. Fueron compatibles con las especies T. viride, T. asperellum y T. atroviride, y entre ellos. Los RAPD generaron 92 bandas reproducibles, 65 fueron polimórficas (70,7 %). El agrupamiento por UPGMA mostró variabilidad intraespecífica, formándose cuatro grupos. Para T.13, T.17, T.75 y T.78 se detectaron bandas específicas, útiles para el diseño de cebadores específicos para la autenticación, protección y monitoreo en sistemas productivos.

Abstract The genus Trichoderma, described by Persoon and Rifai, on the basis of morpho-physiological characteristics, had nine species; however, they were not satisfactorily differentiated. The molecular techniques allowed to ratify and to identify other new ones; at present, 453 Trichoderma species are reported. The polyphasic identification is imposed, due to the complexities of the genus. The objective of this work was to characterize Trichoderma isolates based on morphological-cultural and genetic aspects. Morphological descriptions were made from microscopic observations of microcultures, according to Rifai, Gams and Bissett. The vegetative compatibility relationships were macroscopically evaluated, and the type of reaction (compatible or incompatible) was determined. The genetic variability was analyzed by RAPD; using the Jaccard method with the FreeTree statistical package. The isolates presented similar morphological characteristics, although there were differences in the colonies coloration and the fungal structures morphometry. They were compatible with T. viride, T. asperellum and T. atroviride species, and each other. RAPD generated 92 reproducible bands, 65 were polymorphic (70.7 %). Clustering by UPGMA showed intraspecific variability, forming four groups. For T.13, T.17, T.75 and T.78 specific bands were detected, useful for the specific primers design for authentication, protection and monitoring in productive systems.

ABSTRACTTernary spinel-like oxides such as CuFeMnO4, CoCuMnOxand CuCr2O4 are attractive materials due to their absorbent properties when used as pigments for selective surfaces thus improving solar heaters efficiency. These materials are obtained through sol-gel and sol-gel-combustion methods. This work proposes the synthesis of mixed oxides of Co, Cu and Mn by means of original one-step stoichiometric combustion methods starting from Mn(NO3)2,Co(NO3)26H2O, Cu(NO3)23H2O and Aspartic acid (Asp) or Lysine( Lys) as fuels. The resulting ashes after the combustion were calcined at 500 °C. The obtained ashes and the calcined powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and by Brunauer-Emmett-Teller method (BET), and TG-DTA analysis. In calcined powders obtained with Lys (CoCuMnOx-Lys), the phase corresponding to CoCuMnOx and others segregated phases were identified. However, in calcined powders obtained with Asp (CoCuMnOx-Asp) only the phase corresponding to CoCuMnOxwas identified. The sample CoCuMnOx-Lys presented an average crystallite size of 44 nm and a specific surface area of 23 m2/g while in CoCuMnOx-Asp, 54 nm and 13 m2/g values were obtained throughout FT-IR vibrational modes associated with spinel metallic oxides for both calcined powders (Asp and Lys) were observed. Additionally, by means of TEM, polyhedral particles with an average size of 20 to 100 nm were observed. In particular, it was determined in CoCuMnOx-Lys an average size of 44nm. According to the different fuels used (Asp and Lys), an evident variation in the obtained phases was observed. However, it was not obtained any difference in crystallite size and specific area surface values. It is of considerable importance the study of further syntheses processes to verify this trend.

Mexico is the center of origin and diversification of agave, a highly valued crop in the agroindustry, as well as in Mexican culture. Agaves present unique biological characteristics, such as their high tolerance to abiotic stress that allows them to grow under extreme environmental conditions, and their secondary metabolism that leads to the production of molecules of biotechnological interest. However, the necessary tools to carry out molecular physiology studies in Agave, and disclose the subjacent molecular basis of their particular metabolic capacity, have not been developed. Here we evaluate the performance of a series of commercially available methods for RNA extraction and mRNA purification that may be suitable for the construction of cDNA libraries derived from different A. tequilana tissues, a process described in detail. In addition, we report sequences and methods for the analysis of gene expression using RT-PCR for physiologically relevant agave genes. Expression of rbcS, encoding the small subunit of the RuBisCO; a gene encoding an NADP+ dependent malic enzyme; a gene encoding 1-SST fructosyltransferase; and a gene coding for a LEA-like abiotic stress related protein of A. tequilana, was analyzed using this methods. The methods set forth herein, and the libraries generated will subsequently be applied to molecular physiology, functional genomics, and transcriptome analysis of agaves.

México es el centro de origen y diversificación de los agaves, un cultivo agroindustrial con enorme valor cultural en este país. Los agaves poseen relevantes características biológicas como su gran tolerancia a estrés abiótico, que les permite desarrollarse bajo condiciones ambientales extremas; o su metabolismo secundario, mediante el cual producen moléculas de interés biotecnológico. Sin embargo, las herramientas necesarias para realizar estudios de fisiología molecular, o para determinar las bases moleculares sobre las que subyacen las particulares capacidades metabólicas de los agaves, no han sido desarrolladas. En este trabajo evaluamos la efectividad de métodos comerciales de extracción de ARN total y purificación de ARNm para la construcción de bibliotecas de ADNc a partir de diferentes tejidos de A. tequilana, proceso que describimos en detalle. También reportamos secuencias y métodos para análisis de expresión por RT-PCR de genes de agave importantes para su fisiología como rbcS, codificante de la sub-unidad pequeña de la RuBisCO; el de la enzima málica dependiente de NADP+; de la 1-SST fructosiltransferasa; y un gen de proteínas de estrés abiótico tipo LEA. Los métodos aquí reportados, y las bibliotecas generadas, podrán ser utilizados en estudios de fisiología molecular, genómica funcional, y análisis transcriptómico en agaves.