Preharvest Application of Hydrogen Sulfide and Nitric Oxide Improves Floral Traits and Postharvest Performance of Cut Gladiolus Inflorescences.

Gladiolus is a well-known bulbous plant producing impressive cut spikes. Hydrogen sulfide (H₂S) and nitric oxide (NO) are vital signaling molecules required for the proper functioning of plant metabolism. Preharvest applications of these molecules to crops have gained attention in recent years due to their positive role in tackling abiotic stresses, although, their role in geophytes is comparatively less studied. We assessed the effects of preharvest H₂S and NO treatments on development, flowering, harvest and postharvest performance of gladiolus inflorescences. NO and H₂S + NO treatments increased preharvest performance of plants associated with corm production, inflorescences length and harvest time. Individual and combined treatments improved postharvest vase life (VL) up to 3.4 days. Total soluble proteins (TSP) were increased in response to H₂S, NO and H₂S + NO treatments by 39%, 43%, and 55%, respectively compared to the controls. Soluble sugars (SS) were increased after NO and H₂S + NO treatments by up to 25% and 42%, respectively. Postharvest catalase (CAT) activity was higher by 65%, 68%, and 76% after H₂S, NO and H₂S + NO treatments, respectively. Malondialdehyde (MDA) was decreased by all preharvest treatments by up to 88%, although, only the combined H₂S + NO treatment reduced H₂O₂ and superoxide dismutase (SOD) activity. The results confirm that preharvest treatments with H₂S, NO and H₂S + NO may positively affect growth, floral traits and postharvest performance of cut gladiolus inflorescences. [ABSTRACT FROM AUTHOR]