Dissecting root trait variability in maize genotypes using the semi-hydroponic phenotyping platform

Abstract

The production of maize (Zea mays L.) is restricted by various edaphic stresses, including drought and low-fertility soil. Searching for genotypes with optimal root traits is a promising practice when breeding for improved adaptation to abiotic stress and resource-use efficiency. Using an established semi-hydroponic phenotyping technique, we assessed root trait variability across 174 maize genotypes including 113 cultivars and 11 breeding lines from northern China and 50 Serbian hybrids. Large variation in root architecture traits was observed among the tested genotypes 28 days after transplanting. Sixteen of the characterized traits had coefficients of variation greater than 0.25, especially local root traits. Root traits including total root length, root length at various depths, total shoot mass and nodal root angle, should be considered in maize breeding programs. Genotype ranking data based on a composite score was used to assist in the selection of genotypes with contrasting root architecture traits for future studies. This study identified genotypic variation in root architecture traits in a diverse genotypes of maize. The outcomes of this study could form a basis for maize breeding programs aimed at producing maize cultivars for improved adaptation to target environments.