El Ultrasonido y control oxidativo en el establecimiento de portainjertos ‘Velvick’ y ‘Duke 7’

The in vitro establishment of Persea americana is limited by microbial contamination and oxidation, both of which are genotype-dependent processes. This study evaluated disinfestation and oxidative control in ‘Velvick’ and ‘Duke 7’ rootstocks using two factorial experiments: a 2×2 experiment comparing silver nanoparticles (AgNPs) with a sequential chemical protocol (SCP) and a 2×4 experiment analyzing antioxidant systems with ultrasonic agitation. A third experiment evaluated meristematic apices of ~400 μm. SCP was the most effective treatment for ‘Velvick’, achieving 75% establishment and reducing fungal and bacterial contamination to 20%; by contrast, in ‘Duke 7’, establishment was 48%, with high bacterial contamination. AgNPs were less efficient in both rootstocks. In ‘Velvick,’ ascorbic acid (800 mg L-1) and L-cysteine (50 mg L-1) reduced oxidation from 82% to 20% and promoted greater growth, whereas in ‘Duke 7’, oxidation remained high (61%), with no improvement in development. Ultrasonic agitation enhanced SCP activity. However, more than 90% of the 400 μm apices darkened completely before 15 days. In conclusion ‘Velvick’ responds best to ultrasound-assisted chemical disinfestation and to antioxidants at 800 mg L-1 ascorbic acid or 50 mg L-1 L-cysteine, and ‘Duke 7’ requires additional adjustments.