Phenotypic variations of seedling root architectural traits of wheat species under different growth media

Abstract

Understanding of the behaviour and the function of root system architecture (RSA; the spatial configuration of a root system) is critically important to improve water and nutrient uptake of the plant. However, root traits are highly dependent upon the soil type and soil moisture content. Therefore, the present study, consisting of two experiments, was carried out under controlled environment conditions to identify) phenotypic variations of early seedling root architectural traits of three ancient wheat species together with modern bread wheat. In the first experiment, two week old vertically grown root systems on germination paper, soaked in nutrient media, were imaged and images were analysed using root phenotyping software RootNav. Seedling root architectural traits of two week old seedlings grown in compost and sand were compared in the second experiment where root samples were scanned and analysed using W|nRHIZO software. Both experiments were set up according to completely randomised design with 20 replicates. Number of seminal roots, total root length, maximum width, maximum depth, convex hull, tip angle of the seminal roots, emergence angle of the seminal roots were significantly different between genotypes in the first experiment where the greatest number of seminal roots and the Iargest tip angle leading to the widest root systems was observed in emmer 2. Spelt and bread wheat genotypes produced moderate numbers of seminal roots and deep-narrow root systems. There was a significant interaction between genotype and media for number of seminal roots, total root length, root volume, root diameter, root biomass, root to shoot ratio and specific root length in the second experiment.