Mining root traits for sunflower drought tolerance improvement by use of an automated phenotyping platform

Drought is a major limiting abiotic factor in production of sunflower (Helianthus annuus L.), one of the main oil crops, worldwide. Consequently, breeders are always in search of drought tolerant genotypes and getting more insight into mechanisms underlying drought tolerance. With the global environmental changes occurring, drought stress gained even more on its significance. Different and significant changes in plant morphology and metabolism occur in response to drought stress. Analysis of the root as a main plant organ for water uptake, was mainly neglected, mostly due to the diffi culties of reaching and examining it. Development of modern automated phenotyping platforms enable overcoming this problem. For the purpose of analyzing response of sunflower root system to water deprivation conditions, cultivated and wild sunflower genotypes were chosen from a vast sunflower collection located at the Institute of Field and Vegetable Crops (IFVCNS). Sunflower root architecture was analyzed by the use of the automated phenotyping platform GROWSCREEN-Rhizo located at the institute IBG-2: Plant Sciences at Forschungszentrum Jülich GmbH (FZJ). The aim of this study was to analyze the responses of different genotypes and genotypic constitutions to water defficiency conditions and to identify root trait(s) that could be used as a discriminant between genotypes that are tolerant and sensitive to low water availability