Morphology and distribution leaf galls of Anacardium occidentale L. (Anacardiaceae) / Morfologia e distribuição de galhas foliares de Anacardium occidentale L. (Anacardiaceae)

Abstract

Galls are structures that show specific associations between the inductor and the host plant, which morphological, anatomical and chemical changes of the plant tissues are highlighted. This paper aimed to describe the morphology and distribution of leaf galls in Anacardium occidentale L. (Anacardiaceae). 294 leafs were collected from the branches apical portion of individuals located in the Federal University of Tocantins - Araguaina Campus, TO. Morphological analyzes were performed using stereoscopic microscope, caliper and specific bibliography. It was determined the number of galls on the foliar limb followed by the number of galls per limb and its length linear regression analysis. Conical type galls were observed crossing the leaf blade, green-colored glabrous when young and orange-red when mature, with isolated/grouped distribution and full adherence; internally it presented a lobe and inducer’s larvae (Cecidomyiidae). The distribution of galls in the limb showed significant differences (p <0.001), in descending order there was a higher number of galls between the veins (57.1%) on the secondary vein (35.7%) on the edge (6.3%) and the central vein (1.2%); Linear regression analysis showed weakly positive (r2 = 0.03; Pearson's correlation coefficient = 0.2025), suggesting that oviposition is associated in part with the foliar limb size and that other variables can be decisive. These are the first records of galls in A. occidentale in the State of Tocantins.