Incidence of galls on fruits of Parkinsonia praecox and its consequences on structure and physiology traits in a Mexican semi-arid region

Abstract

Galls are atypical plant growths that provide nourishment, shelter, and protection to the inducer or its progeny. Fruit and flowers are poorly represented as host organs for galling insects. Our main question was: Do morphological traits, anatomical features and physiological characteristics differ between galled and healthy fruits of Parkinsonia praecox ? Galled and healthy fruits of P. praecox were characterized in terms of morphological traits (length, diameter, thickness, water and biomass content); anatomical features (trichomes, stomatal and pavement cells), and physiological characteristics (stomatal conductance, gs). We found that galled fruits were induced by Asphondylia sp. (Diptera: Cecidomyiidae). Thickness, diameter, and water content values of galled fruits were greater compared to healthy fruits. Length, biomass, and pavement cells density of healthy fruits were higher. The density of trichomes on galled fruits was higher, while the stomatal density and pavement cell size were not statistically different between galled and healthy fruits. Furthermore, the gs rates of galled fruits were almost 3 times higher than in healthy fruits. Incidence of galls on fruits on P. praecox modified the original morphology and anatomy of healthy fruits that stimulate physiological mechanisms to increase the water continuum from the host plant to the gall.