Biotemas (Mar 2012)
Leaf domatia morphology of Miconia sellowiana Naudin (Melastomataceae)
Abstract
Domatia are small cavities that shelter and provide an adequate physical microenvironment for arthropods, and are often found on leaves. Besides their ecological importance, few studies have described the structure of domatia. Miconia sellowiana has domatia on the abaxial surface of its leaves, and previous studies indicate that environmental factors influence the leaf morphology of this species. The goal of this study was to analyze the domatia morphology of M. sellowiana and to describe the environmental factors that possibly influence these structures. Leaves from two different vegetation types, grassland and Araucaria forest, were collected. Domatia thickness, area and dry weight, and leaf thickness were analyzed. The leaves have only one type of domatium, located on the abaxial surface of the leaf base. The anatomical structure of the domatia is less complex than the leaf blade, with a homogeneous mesophyll and without stomata. These features suggest that the photosynthetic capacity of the domatia is lower than the remaining part of the leaf blade. The only morphological variation of the domatia from the two areas was in size, with larger domatia in the grassland leaves. This might indicate the influence of environmental factors on the selection of host mites.
