Tolerance of Alfalfa Varieties Subjected to Salinity

Abstract

The aim of this study was to evaluate the salinity tolerance of alfalfa varieties, aiming at their inclusion in production systems that use water with high levels of salts for irrigation or saline soils. The experiment was conducted in a greenhouse, in a 3x5x3 factorial scheme, three alfalfa varieties (LE-N4, Crioula and DK-192), five salinity levels (0; 3.5; 5.0; 7.0; 10 .5 and 14.0 dS m-1) and three shoots of the aerial part, with four repetitions. For irrigation management, lysimeters were installed. Fresh and dry aboveground and root biomass, chlorophyll, water use efficiency and enzymatic activity were analyzed. The increase in salinity reduced fresh and dry aboveground and root biomass, chlorophyll and water use efficiency. Salinity altered the biochemical responses of the evaluated varieties. DK-192 showed higher production of fresh and dry aboveground biomass. LE-N4 was more sensitive to salt stress, significantly reducing production from a salinity level of 7.0 dS m-1. The increased catalase activity for Crioula and DK-192 under salt stress conditions contributed to the higher production of fresh and dry aboveground biomass.