Stimulation and Promotion of Germination in Opuntia ficus-indica Seeds

Abstract

Opuntia ficus-indica seeds, as many other Opuntia species, show low germination capacity due mainly to their hard lignified integuments, the most inward of these is the funiculus that envelops the embryo, obstructing radicle protrusion. The purpose of this study was to accelerate the initiation of the germination process and to shorten their completion time by the action of physical and chemical agents. Germination assays were performed in Petri dishes and under controlled conditions at constant temperature (25°C) and photoperiodic regime of 14 hours light per day, continuous light, and continuous darkness. Aside from these environmental factors during the incubation period, we tested the effects of agents able to break different types of dormancy or inhibitory effects. All assays followed a completely randomized design with three replications of 25 seeds for each treatment. We found that chemical scarification of the seeds with concentrated H2S04 or with Schweizer reagent, followed by incubation of the treated seeds in solutions of H202, under photoperiodic conditions gave the highest germination percentage in the shortest time. None of the assays carried out to establish if different agents could remove the inhibitory effect of continuous darkness on seed germination during the incubation period were able to eliminate the mentioned effect.