Variation in root system architecture in the parents of two MAGIC wheat populations for selection in breeding

Root system architecture is a target for modern breeding because of the need to develop crops with roots that use soil nutrients and water more effectively. Breeding for root traits requires phenotypic diversity in populations amenable to QTL identification to provide markers to large breeding programs that do not have direct root phenotyping platforms. Our collaboration with BASF aims to understand the dynamics of root growth in seventeen parents of two Multiparent advanced generation intercross (MAGIC) wheat populations using the non-invasive, high throughput phenotyping platform, GrowScreen-PaGe. Seeds were pre-germinated on filter paper, and transferred to germination paper supplied with the nutrient solution. The system allows the development and quantification of roots on the paper over time. This system has been developed in house at Forschungzentrum Juelich. Root system architecture components such as lengths of seminal and lateral roots, seminal root angle, root system width and depth were analyzed. The data sets were completed by shoot traits, such as leaf lengths, and shoot biomass as well as root biomass. Substantial variation in root and shoot traits were recorded in both sets of MAGIC parent lines. Low to moderate heritability and repeatability were recorded for most traits. Our results indicate that GrowScreen-PaGe system is suitable to detect phenotyping variation in MAGIC wheat populations for characterizing early seedling root traits