Germination and early growth of Acacia berlandieri Benth. (Fabaceae) under infestation by Stator pruininus Horn (Bruchidae)

Abstract

It is well known that bruchids and legumes generally have ecological relationships, such as parasitism and predation; however, little is known about the effects of such relationships on the initial life cycle stages of wild legumes. This study evaluates the effect of Stator pruininus infestation on the germination and early growth of Acacia berlandieri. Germination tests were performed under controlled conditions on healthy seeds, seeds with physical scarification, chemical scarification, damage from larvae, and seeds with eggs. A one-way analysis of variance was used to analyze the germination of seeds (percentage, rate, and mean germination time), as well as the early growth of the seedlings (survival, size, and biomass). The percentage of germination in all of the seed categories was greater than 85%, with significant differences (p < 0.05) between seed categories. However, there were no significant differences between seed categories in germination rate or average germination time (p > 0.05). In the early growth of the seedlings, there were significant differences (p < 0.001) between seed categories in the size of the seedling, stem, and root, and in the aboveground and belowground biomass. Based on these results, S. pruininus is not a predator of A. berlandieri, but the damage done to the cotyledons by this insect species can reduce seedling growth and accumulation of biomass in the first days of growth.