Genome- Wide Association Studies of Root System Architecture Governing Agronomic Productivity in Sorghum

Sorghum is a major crop for food, feed and industrial processes in the US and on the global market. It is a particularly relevant crop under the current pressures of climate change and food security because it is adapted to cultivation under low water and nutrient conditions. However, compared to other major crops, sorghum productivity is relatively low, and historic increases in sorghum yield have been minimal. Recently, it has been established that root architecture plays a critical role for crop yield potential and stability, especially under limiting environments, such as drought and low nutrient availability. Our preliminary analysis of root architecture traits among sorghum varieties has revealed a potential for genetic improvement of root architecture for sorghum agronomic productivity in sustainable agriculture. Current challenge remains in identification of root architecture features and their genetic control which have been limited by the phenotyping technologies available, as well as the application of emerging and potentially useful genome-wide association studies of root architecture. GrassRoots Biotechnology will apply a novel, high through-put and accurate imaging and analysis platform, RootXpose, for imaging roots targeting three dimensions and for measuring complex root traits for 242 sorghum genotypes of a minicore collection from 58 Countries from ICARISAT. Well also develop genome-wide association studies tools in sorghum to determine the genetics of root traits, and identify root traits that correlate with agronomic performance. Collectively, this project will set foundations to enhance sorghum productivity through modifying its root architecture traits for sustainable agriculture and increase the profitability and market share of this crop.