In vitro assay of neutral electrolyzed water against Fusarium oxysporum and its application as germination pretreatment on tomato (Lycopersicon esculentum), lettuce (Lactuca sativa L.) and cucumber (Cucumis sativus) seeds.

Abstract

Seed germination is critical for seedling procedures, and new technologies are required to increase crop yields. Some substances are considered elicitors or stimulating agents because they promote seed germination as well as plant growth (like root and plumule length, and germination rate among others). Some of these, could be applied during plant growth, or in earlier phases before germination as seeds pretreatment. Neutral electrolyzed water (NEW) is a solution of oxidizing agents mainly studied for its antimicrobial power mainly applied to food pathogens, and in less reports to phytopathogens. The objective of this work is to evaluate the effect of NEW on germination and morphological parameters of tomato (Lycopersicon esculentum), cucumber (Cucumis sativus) and lettuce (Lactuca sativa L.) seeds as well as to evaluate the in vitro activity of NEW against F. oxysporum. Two experiments were carried out to determine the in vitro and in vivo effects of NEW in seed pretreatment and another in vitro experiment was also carried out to determine antifungal effect against F. oxysporum. NEW in vitro treatments at 50 mg/L decreased spore concentration greater than 4 log spores/mL. Germination parameters and morphological variables were analyzed after NEW pretreatments. For in vitro germination, NEW pretreatments up to 75 mg/L did not show effect on germination parameters however highest dose was slightly adverse (4 % against water control). For in vivo germination, NEW pretreatment of 100 mg/L had a stimulating effect on the germination rate in cucumber seeds (100 % FGP against 83 % FGP for water control). For tomato seeds germination neither stimulate nor adverse effect was observed (same percentage as water control). For lettuce seeds germination an inhibitory effect for 12 and 24 h of exposure time was achieved (73 % NEW treatment against 90 % of water control). For tomato and lettuce seeds, the NEW pretreatment of 50 mg/L during 12 h increased its germination capacity.