Resumen

NUNEZ VAZQUEZ, Miriam et al. Brassinosteroids and its analogs enhance the seedling growth of two rice (Oryza sativa L.) genotypes under saline conditions. cultrop [online]. 2013, vol.34, n.1, pp. 74-80. ISSN 0258-5936.

Brassinosteroids are steroidal compounds which are required to plant growth and development and they are, also, implied in plant response to abiotic stress. The central objective of this paper was to evaluate if rice seed treatment with different concentrations of a natural brassinosteroid and an spirostane analog reduces the impact of salt stress in the seedling growth. Two experiments were performed, at the first one, a salt sensitive variety, J-104 was used and at the second one, a tolerant genotype, Ginés, was employed. In both experiments, the seeds were treated, for 24 hours, with different concentrations (0; 0,01; 0,1 y 1,0 µmol.L-1) of a natural brassinosteroid, 24-epibrassinolide, and an spirostanic analog of brassinosteroids, 25(R)-3a,5a, dihydroxy-5a-spirostan-6-one, which formulation is known as BIOBRAS-16. After germination, the seedlings were placed in pots containing Hoagland diluted nutritive solution with the addition or not of 100 mmol.L-1 sodium chloride. In the first experiment, the seedlings remaining during eleven days in a growth room with 12 h photoperiod and 25±2oC temperature; while in the second one, the seedlings were grown for thirteen days at a 28±2oC temperature. At the end of the experiments, root and shoot length and dry mass were evaluated. Results showed that 24-epibrassinolide and BIOBRAS-16 were able to reverse partially the seedling growth inhibition of both rice genotypes induced by the presence of sodium chloride; being the more effective treatments in the tolerant variety.

Palabras clave : growth; salt stress; rice.

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