Protective Effect of Purple Lettuce (Lactuca sativa L.) Aqueous Extract on Physiological Quality of Lettuce Seedlings Subject to Salt Stress

Abstract

The salinity is an environmental stress that can affect germination of seeds. The lettuce has carotenoids, vitamin C, high level of phenolic compounds and high antioxidant activity, which can help reduce the stress caused by salt. The purple varieties still have a lots of anthocyanins, which gives them greater antioxidant power. The objective of this study was to evaluate the possible protective effect of purple lettuce leaf extract on the physiological quality during seed germination and early growth of lettuce seedlings subjected to salinity. Therefore, two experiments were conducted, one in the laboratory and the other in the greenhouse. In both experiments, lettuce seeds, cv. Regina, were subjected to irrigation with purple lettuce extracts, variety Batavia cacimba, and salt solutions during the early stages of seedling development, evaluating parameters related to germination and biomass production. The use of aqueous extract of purple lettuce promotes the germination, the first counting of germination, the shoot length and the dry mass of seedlings under laboratory conditions. The aqueous extract of purple lettuce, though not inhibit the effect of salt, it assists the initial development of lettuce seedlings. The salt affects the development of lettuce seedlings in the laboratory and in the greenhouse.