In vitro germination and disinfestation of sweet cactus (Nopalea cochenillifera (L.) Salm Dyck)

Abstract

This work aimed to promote in vitro seed germination and disinfestation of the sweet cactus. Seeds were submerged in alcohol at 70% for 1 min. and then treated with sodium hypochlorite solution at different concentrations: 0.0; 0.5; 1.0 and 1.5%. After this treatment, the seeds were washed four times in distillated, deionized and autoclaved water. Seeds were inoculated in MS medium with different concentrations of sucrose (0.0, 2.5, 5.0, 7.5 and 10.0 g L-1). The experimental design was completely randomized in a factorial experiment 4 × 5, with five replicates for treatments. Contamination, germination and seedling growth were evaluated. The results of the analysis of variance indicate that there were no significant interactions among factors. There was no significance for sucrose concentrations on contamination but these treatments showed significant differences for seed germination and seedling growth (p ≤ 0.01). At higher sucrose concentrations there was lower germination and smaller seedlings. There were significant differences between the treatments with sodium hypochlorite for all traits analysed (p ≤ 0.01). There was low contamination with the increase in sodium hypochlorite concentrations with higher germination percentage and taller seedlings.