Breeding for Stress-Tolerance or Resource-Use Efficiency?

Abstract

In plant breeding programs, it is not entirely clear whether the goal is to improve resource-use efficiency or the tolerance to low resource availability. The aim of this chapter was to verify the relationship between breeding for a tolerance to low levels of soil nutrients and for nutrient-use efficiency. The relationship between nutritional efficiency and the tolerance to nutritional stress was estimated by the Spearman ranking correlation between maize genotypes for the traits related to nitrogen, phosphorus and water-use efficiency and phenotypic plasticity indices. The lack of relationship between the traits, in both magnitude and significance, indicates that these traits are controlled by different gene groups. Consequently, simultaneous selection for both nutrient-use efficiency and tolerance to nutritional stress is possible if the mechanisms that confer efficiency and tolerance are not competitive.