RESUMO
Warmer temperatures predicted as a result of climate change will have an impact on milpa. An experiment was carried out with induced passive heat with the objective of simulating the increase in temperature on the physiological, morphological, and yield parameters of milpa from different climates of San Luis Potosí, Mexico. Two different environments, Open-top chambers (OTC) and control, and three milpas, from warm-dry, temperate, and hot and humid climates, were studied. A total of 12 experimental units of 13.13 m2 were used in the random design, with a factorial arrangement of 2 × 3 and two replications. Abiotic variables (minimum, maximum, and mean daily temperatures and accumulated heat units) were determined and compared between the two environments and confirmed that the OTC increased the abiotic variables. The growth and development parameters increased under the warming effect. Furthermore, the milpa from hot and humid climate was the least affected. In contrast, the warming considerably delayed yield parameters. The squash suffered the most, while the bean benefited the most. The warming affected the chlorophyll fluorescence and gas exchange differently for each crop. However, at an early stage, the maximum photochemical efficiency (Fv/Fm) and non-photochemical quenching (qN) for bean and maize were reduced, while at a late stage, they were Fv/Fm, photochemical quenching (qP), and qN for maize; stomatal conductance and transpiration rate of the squash were improved under the warming treatments. In conclusion, the warming delayed the yield and photosynthetic parameters, while growth and development benefited. The milpa systems were differently affected by warming.
RESUMO
Vanilla planifolia Jacks. ex Andrews es una orquídea de gran importancia económica, que presenta problemas de sobreexplotación y amenaza en su hábitat original. Por lo cual, el objetivo de esta investigación fue establecer un protocolo de micropropagación in vitro evaluando el efecto diferentes extractos orgánicos. El cultivo in vitro se inició a través de la germinación de semillas que dieron lugar a la formación de protocormos. Los protocormos se cultivaron en medios MS suplementados con extractos naturales: MPL (plátano), MPI (piña), MCO (agua de coco) y medio control, para promover la morfogénesis. Posteriormente, para inducir la rizogénesis de los brotes y la aclimatación, se utilizaron tratamientos con auxinas (AIA y AIB). Los resultados mostraron que la germinación inició a los 60 días de cultivo in vitro, y que la adición de los extractos orgánicos promovió la diferenciación de los brotes, resultando más eficiente el tratamiento MPI. Además, la adición de 0.5 mg L-1 de AIA promovió el enraizamiento y la pre aclimatación in vitro. Estos resultados sugieren que los extractos orgánicos promueven la morfogénesis de vainilla, sin necesidad de emplear reguladores de crecimiento sintéticos en las primeras etapas de la micropropagación in vitro.
Assuntos
Orchidaceae , Técnicas In Vitro , Germinação , MéxicoRESUMO
This article analyzes the relationship between the configuration and spatial reorganization of land-use and land-cover in the Pujal-Coy project area, Huasteca Potosina region, eastern San Luis Potosí, Mexico, as well as the relationship between these changes and the environmental conditions prevailing in the area. Land-use and land-cover changes were determined through the analysis and interpretation of satellite images from different dates. The changes identified in the different study periods were correlated with the prevailing physical factors. The results show that the spatial configuration of farming activities, initially induced by the implementation of a regional development project, is highly correlated to the presence of limiting factors such as soil type, slope, and climate. Particularly, the former represents the element that has led to the establishment of the current distribution pattern of farming activities.
