Phenotypic Plasticity of Sugarcane Genotypes under Aluminum Stress

The expand agricultural production to new crop areas in the tropical regions is an important strategy to supply the huge demand for food and renewable energy sources. However toxic aluminum (Al) present in tropical soils is a limiting factor for agricultural production. The objective of this study was to identify Al-tolerant and Al-sensitive sugarcane genotypes, based on phenotypic plasticity, and to determine the correlation between the traits associated with Al stress. Eleven sugarcane genotypes were evaluated under non-stress and Al-stress conditions. The experiment was conducted using randomized complete block design with three replications in a factorial scheme. The study was carried out at Department of Crop Science, Federal University of Viçosa, between January and May 2014. Genetic variability regarding Al tolerance was observed among the sugarcane genotypes by phenotypic plasticity. Al-stress caused a reduction in the primary root length and in the shoot dry weight, but an increase in the lateral root length. There was a difference between the genotypes related to Al accumulation in the roots and shoot, suggesting the existence of distinct tolerance mechanisms. Based on phenotypic plasticity, genotypes RB966928, RB867515, RB008041, and RB935744 were characterized as tolerant, and RB937570, RB92579, and RB928064 sensitive to Al. We characterized genotypes and elucidated the correlation between features associated with Al-stress. The characterization of contrasting genotypes will be important for breeding programs involving sugarcane yield in regions subjected to stress.