Effect of Salinity on Germination of Lettuce Cultivars Produced in Brazil

Abstract

The challenge of recovering degraded soils due to salinity excess leads to the search for more effective strategies that can overcome this problem. Among these, one of the approaches is the use of resistant plant varieties in affected areas. This study aimed to evaluate the influence of different doses of salts on seed germination and seedling formation of two lettuce cultivars (Hanson and H121) and to verify the existence of tolerance among the cultivars. A completely randomized design was used in a 2x5x4 factorial scheme, where the cultivars were evaluated under five distinct salt doses (0, 25, 50, 75 and 100 mol.m-3, conductivities of 0.0, 2.8, 5.4, ​​8.0 and 10.6 dS.m-1, respectively), with four replicates. In this sense, the following variables were evaluated: germination rate (GR), germination speed index (GSI), seedling height (SH), root length (RL) and percentage of dry matter in relation to fresh matter (DM%). As a result, the Hanson cultivar presented better performance than the H121, under all the different salt doses, in all the studied variables. Also, the EC of 2.8 dS.m-1 did not affect any of the studied variables, including both cultivars. However, EC above 2.8 dS.m-1had, significantly, reduced the development of the cultivars. The Hanson cultivar was influenced only in the variables SH, RL and DM%, where and DM% were influenced by EC values above 8.0 and 10.6 dS.m-1, respectively. The cultivar H121 was significantly influenced by all evaluate dvariables, which demonstrates its greater susceptibility to salinity.