Fisiologia de porta-enxertos de citros sob água salina em cultivo hidropônico.

Abstract

In order to study the physiological mechanisms for the establishment of salt stress in seedlings of citrus genotypes, during the rootstocks citrus phase, grown in a greenhouse with hydroponically system. The experiment was realized in a greenhouse at the Center of Science and Technology Agrifood - CCTA, of the Federal University of Campina Grande, UFCG, Pombal, PB, Brazil. It was studied, in a randomized block design, with a factorial scheme (2 x 13), two salinity levels (0.3 and 4.0 dS m-1) and 13 genotypes citrus rootstocks with three replications and four plants useful. At 90 days after sowing it was evaluated the gas exchange and chlorophyll fluorescence at 24 and 48 hours after salt stress beginner. The variables were subjected to the „F‟ test, comparing the means by Scott Knott test (p≤0.05). All rootstocks studied showed changes in their physiological activity, because the gas exchange or in efficiency of PSII demonstrating the rapid establishment of salt stress in these plants. Salinity did not affect gas exchange of the rootstocks Tangerineira „Sunki Comum‟ (TSKC) x Citrange Argentino (CTARG) – 019; limoeiro „Cravo‟ (LCR) x Poncirus trifoliata (TR) – 001 and Hibrido Trifoliado (HTR) – 116during the first 48 hours. The rootstocks Tangerineira „Sunki Comum‟ (TSKC) x Citrumelo Swingle (CTSW) - 033; the Tangerineira „Sunki Comum‟ (TSKC) x (limoeiro „Cravo‟ (LCR) x Poncirus trifoliata (TR)) – 040 and limoeiro „Volkameriano‟ (LVK)did not has changed their fluorescence using salt water in the nutrient solution during the first 48 hours.