Indicadores fisiológicos do estresse salino em limeira ácida ‘Tahiti’ sobre porta-enxertos em dois anos

Abstract

Citrus is cultivated in all regions of Brazil, it is an important segment of production in the country. However, its productivity is low compared to its potential. This may be associated with the use of unproductive rootstocks, or even to the negative impacts of water and soil salinity. Therefore, the aim of this study was to identify, through physiological aspects, indicators of tolerance to saline stress in the 'Tahiti' acid lime grafted on different rootstocks derived from progenies during the production period. To this end, an experiment was carried out on Embrapa Semiárido experimental farm, which is located in the municipality of Nossa Senhora da Glória- Sergipe, this was arranged in four randomized blocks with subdivided plots, where in the plot there were 13 citrus rootstocks, corresponding to the ‘Santa Cruz Rangpur’ lime, three 'Citrandarins', the ‘Tropical Sunki’ mandarin and eight citrus hybrids generated by the Citrus Breeding Program of Embrapa Mandioca e Fruticultura, all grafted with the 'Tahiti' acid lime, and in the subplot three electrical conductivities of irrigation water (0.14; 2.4 and 4.8 dS m-1 ). The effect of salinity was evaluated by gas exchange and chlorophyll a fluorescence, becoming evident that salt stress causes deleterious effects on plant physiology, causing them to dissipate energy to keep their biochemical activities within the normal range, genotypes 12 [TSKC x (LCR x TR) - 059], 11 [TSKC x (LCR x TR) – 040] and 5 ‘Tropical Sunki’ mandarin showed higher tolerance to the environment with the highest salinities.