Physiological and biochemical affectations in vitroplants of sugarcane in response to hydric and saline stress

Abstract

The agricultural production is negatively affected by biotic and abiotic stress, being responsible for great economic losses in the world. Sugarcane is the raw material for obtaining cane juice that is transformed into sucrose and the production of second generation ethanol. In the present study, the number of buds and leaves, the concentration of proline, chlorophyll a, b and total and the concentration of sugars in response to hydric and saline stress in two varieties of sugarcane in vitro were evaluated. Individualized buds of 5 cm in length of the MotzMex 91-207 and SP 71-6180 varieties of sugarcane were cultivated in vitro under water stress (PEG 6000) and saline (NaCl). The two varieties of sugar cane analyzed in vitro presented different responses to osmotic stress. The variety MotzMex 91-207 was better than the variety SP 71-6180 to respond to water stress with a greater accumulation of proline (82.34 mg g^-1 PS), did not present decrease in the chlorophyll a, b and total content and generated 20.8 buds per explant even under stress conditions. On the other hand, the response to salt stress with 50 mM NaCl in vitro was presented by the variety SP 71-6180, generating a greater accumulation of carbohydrates such as galactose, glucose and mannose.