Stereometric analysis of Amazon rainforest Anacardium occidentale L. leaves.

MAIN CONCLUSION: AFM, profilometry and SEM measurements on both sides of the Anacardium occidentale L. leaf reveal that ultrastructure presented some singularities due to their different morphologies and roughness. The advanced stereometry and power spectrum density of both sides of the Anacardium occidentale L. leaf were carefully studied. We use three different microscopy techniques such as scanning electron microscopy, profilometry, and atomic force microscopy for a complete description of the leaf surface morphology. The morphology of the adaxial and abaxial sides revealed a surface composed of striated cuticles and stomata cells, respectively. The height parameters obtained by profilometry revealed that the abaxial side was rougher. However, both sides presented similar Gaussian height distribution and asymmetry. The advanced stereometric parameters obtained by the topographic maps of AFM revealed that the two sides have some singularities due to their different morphologies and roughness, but with similar microtextures. However, average PSD spectra showed that adaxial and abaxial sides are dominated by relatively low and high spatial frequencies, showing that the microtextures, unlike what was shown in stereometric parameters, are different. These results revealed that leaves surface morphology under different aspects and scales and the quantitative parameters confirmed the different spatial patterns displayed, which can be of great interest for the study of the biological behavior of plants from their leaves.

The ultrastructure of shelled and unshelled cashew nuts.

Cashew nuts have many attributes, including sensory, nutritional and health appeal, which contribute to their worldwide acceptance. We demonstrate details of the microstructure of shelled and unshelled cashew kernels with regard to pericarp and cotyledon organization. This study also provides evidence of the colonization of these kernels by filamentous fungi. Nuts were examined by scanning electron and confocal scanning laser microscopy. Staining with acridine orange was performed. A tight lignified palisade layer adjacent to the exocarp surface explains the hardness of the shell's pericarp. The mesocarp contains large secretory cavities that confer a spongy property to this tissue. Papillose cells, which are responsible for secreting CNSL (cashew nutshell liquid), were observed to cover the inner wall of these cavities. Lipid components are readily released from the parenchyma and appear as oil droplets. The outer surface of the shelled samples exhibited a dense Aspergillus infestation.