Jatropha curcas L. has become an important source of oil production for biodiesel fuel. Most genetic studies of this plant have been conducted with Asian and African accessions, where low diversity was encountered. There are no studies of this kind focusing in the postulated region of origin. Therefore, five populations of J. curcas were studied in the state of Chiapas, Mexico, using amplified fragment length polymorphism (AFLP) markers. One hundred and fifty-two useful markers were obtained: overall polymorphism = 81.18% and overall Nei's genetic diversity (He) = 0.192. The most diverse population was the Border population [He: 0.245, Shanon's information index (I): 0.378]. A cluster analysis revealed the highest dissimilarity coefficient (0.893) yet to be reported among accessions. An analysis of molecular variance (AMOVA) revealed that the greatest variation is within populations (87.8%), followed by the variation among populations (7.88%). The PhiST value (0.121) indicated moderate differentiation between populations. However, a spatial AMOVA (SAMOVA) detected a stronger genetic structure

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<p>Aunado a la alta toxicidad de los productos químicos para el control fitosanitario de las enfermedades fúngicas a nivel de campo, el microorgansimso causante de enfermedad no es completamente eliminado, por lo que, productos de origen natural tanto vegetal como animal han generado interés para el control de plagas y enfermedades en las plantas. El presente trabajo tuvo como objetivo principal evaluar la actividad antifúngica de mieles de abeja en el crecimiento<em> in vitro</em> de <em>Colletotrichum gloeosporioides</em>. Se evaluaron nueve muestras de mieles, correspondientes a tres especies de abejas: <em>Melipona solani</em>, <em>M. beecheii y Scaptotrigona mexicana</em>. Se encontró que el diámetro de la colonia de <em>C</em>. <em>gloeosporioides</em> fue menor a mayor concentración de miel, con un 40% menos crecimiento de la colonia respecto al tratamiento testigo a los 12 días de incubación. En general la tasa de crecimiento de la colonia del hongo en las mieles correspondientes a los tres tipos de abeja fue en promedio de 40% menos que el testigo. El valor de porcentaje de inhibición observada en las mieles de abeja fue 70% mayor a lo obtenido con el fungicida Clorotalonil.</p>

Jatropha curcas is a plant that accumulates high-quality oil in its seeds, which is capable of being transformed into liquid biofuel. However, several aspects of its fl owering are still unknown, which is a key step in the production of fruits, seeds, and oil. Flowering is a complex process that is regulated by various factors at the molecular level, including microRNAs (miRNAs). Th ere is evidence suggesting that the miRNAs of the miR156 and miR172 families play a key role in the fl owering transition of plants. For this reason, the dynamics of miR156 and miR172 were studied during a production cycle of J. curcas. Our results reveal that J. curcas has a mechanism for the expression of these miRNAs that diff ers from that reported for the vast majority of angiosperms, since the expression of both families of miRNAs was positively correlated with the phenological state of J. curcas. We discuss the implications of these fi ndings and how the regulatory mechanisms of miR156 and miR172 diff er from what has been reported thus far.