BRACE: A Method for High Throughput Maize Phenotyping of Root Traits for Short‐Season Drought Tolerance

Abstract

There is a need to develop new maize (Zea mays L.) breeding methodologies for the easier screening of quantitative traits that are largely influenced by the environment. Molecular laboratories initially intended to work with these challenging and economically important traits but have targeted genetically simple traits instead, often not a challenge to breeders. Root systems are important components of drought tolerance in maize genotypes. Phenotyping maize root systems without destroying experimental plots, however, is challenging. Our goal was to develop a nondestructive screening methodology for short‐season drought tolerance through BRACE, an index including root traits. Hybrids that represent a unique short‐season diverse maize sample were tested in eight water‐stressed and well‐watered environments, along with control commercial checks in 2013 and 2014. Short‐season drought tolerant hybrids were best for brace root count and spread width and root lodging resistance. We propose BRACE as a method for high throughput maize phenotyping leading to improvement in drought tolerance. Phenotyping of root traits associated with BRACE is simple, nondestructive, and can be performed in less than 2 min plot−1. BRACE could be a reliable method for large‐scale high throughput phenotyping of segregating generations for cultivar development under controlled drought stress environments in maize breeding programs. Validation of this method and further complimentary research across genetic materials is encouraged.