Características fisiológicas envolvidas na resistência diferencial ao estresse salino em porta-enxertos de videira

Abstract

The high concentration of salts in the soil is one of the limiting factors of agricultural production. The ionic toxicity caused by salt stress in plants occurs as a result of the balance between the processes of absorption, accumulation and distribution of saline and toxic ions in the plant. The grapevine is one of the most widespread crops in the world, however, there is still no known genotypes that are resistant to salt stress. The present work aims to verify the performance and potential of grafted grapevine plants under salinity, in order to observe the influence of the use of rootstock, in an attempt to establish biochemical/physiological mechanisms granted by the associated rootstock. The grapevine seedlings were obtained by grafting the Vitória variety on three rootstock genotypes contrasting in Na+ and Cl- exclusion. The plants were irrigated daily, and supplemented with concentrated nutrient solution on alternate days. After 20 days of seedling transplanting, salt treatments of salt-free (Control - 0 mM) or added (50 mM and 100 mM NaCl) solution were started. The statistical design used was entirely randomized with treatments in a 3 x 3 factorial, three grapevine scion/vine rootstock combinations (Vitória/IAC 313, Vitória/IAC 572 and Vitória/SO4) and three NaCl concentrations, with three repetitions per treatment. The study found results that confirm the negative effect of salinity on grafted grapevine plants. This effect is related to the blockage in photosynthesis that can inhibit plant growth and also yield and production, this occurs mainly due to stomatal closure. In general, the results show characteristics associated with sensitivity and/or tolerance to salinity in grafted seedlings.