Recent approaches in screening methodology for drought resistance.

Abstract

Abstract Genetic progress in yield of staple crops is an urgent need in view of population growth. Predicted climate changes due to global warming necessitate that this progress is materialized in environments, which are affected more often by drought. Direct selection for yield under drought conditions is usually hampered by low heritability. Therefore, breeders rely on secondary traits with higher heritabilities to improve drought tolerance in agricultural crops. The present review gives an overview of methods that are applied for screening secondary traits. While for aboveground traits simple, reliable, fast, non-destructive and cost-effective methods that allow a high-throughput phenotyping are available, a bottleneck in drought research methods exists in the root zone, although there is evidence that roots are a key trait for superior drought avoidance. Still only few field screening techniques exist and most root screening is restricted to young plants and artificial growth media that limit inference to field grown adult plants. Spectral methods are identified as promising approach for both above- and belowground measurements and could bridge the gap between high throughput needs of breeding and complexity of plant physiological measurements.