Phenotypic Plasticity: The Best Approach for Stress Selection

The abiotic stresses are the main factors associated to low productivity, since they are related to the
soil and the conditions of the environmental adversities. These are difficult to control factors and when
severely affects production dramatically. 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. Eleven sugarcane genotypes were evaluated under nonstress
and Al-stress conditions. 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 can be classified as tolerant or
sensitive to Al. The phenotypic plasticity is a simple form of analysis; however, it has great information
about the behavior of the genotype. We characterized genotypes associated with Al-stress. The
characterization of contrasting genotypes will be important for breeding programs involving sugarcane
yield in regions subjected to stress.