Tolerância de genótipos de citros à salinidade in vitro e hodropônicos

Abstract

The objective of this study was to evaluate the salt tolerance of citrus genotypes, in the form of nucellar seedlings by using two methodologies. Therefore, we performed two experiments: The first in vitro culture in the laboratory and another in hydroponics under protected. The treatments consisted of two factors: salinity levels and genotypes of citrus. In vitro cultivation six genotypes [1 - ´Rangpur´ lemon, 2 - HTR-69, 3 - Poncirus trifoliata, 4 - x TSKC (LCR x TR) -59, 5 - 'Volkameriano' lemon and 6 - 'Cleopatra' mandarin ) underwent salinity culture medium promoted by the addition of NaCl (S1 0 dS m-1, S2 1 dS m-1, S3 2 dS m-1, S4 3 dS m-1, 4 dS m-1 and S6 5 dS m-1). In cultivation hydroponic three genotypes [1 ´Rangpur´ lemon, 2 HTR-069 and 3 TSKC x (LCR x TR)-059] were also subjected to salinity produced by NaCl (S1 0.30 dS m-1, S2 1.46 dS m-1, S3 2.43 dS m-1, S4 3.57 dS m-1, S5 4.53 dS m-1 and S6 4.93 dS m-1). We evaluated the number of leaves, plant height, number of dead leaves (in vitro culture) and stem diameter (in hydroponics). At the end of the experiment were also evaluated dry weight of root, stem, leaves and whole plant, besides the relative growth rate of plant height and stem diameter (in hydroponics). We also evaluated the relationship of the dry weight of roots and shoots and water content in the leaves (in hydroponics), which is used to perform the classification of genotypes by the method of relative income. In vitro cultivation genotypes ´Rangpur´ lemon and 'Volkameriano' were not significantly affected by salinity on growth variables and in hydroponics genotype Rangpur showed greater relative reduction for each unit increase in CEa (dS m-1 ) for plant height, number of leaves, stem diameter, relative growth rate of stem diameter and dry mass of roots.