Characterization of Leaf Angle in Sorghum: A Deeper Analysis of the Genetics Underlying This Trait

Leaf angle refers to the inclination between the midrib of the leaf blade with respect to the vertical stem of a plant. This trait has been identified as one of the crucial components that determine grain yield in crops like corn, rice, wheat, oats, and barley. Modern maize hybrids, as well as rice, wheat, oat and barley varieties, have upright leaf angles. This plant architecture characteristic allows more light penetration into the canopy, which translates into higher crop yields. Leaf angle has not been exhaustively studied in sorghum but current knowledge demonstrates that it is controlled by genes localized on chromosomes 1, 2, 3, 4, and 7. The region on chromosome 7 has been consistently identified in GWAS and QTL studies and it has been narrowed down to a 1.68 Mb interval with approx. 200 annotated genes. Our research objectives were: i) to validate the previously identified region on chromosome 7, ii) to narrow down its physical interval containing putative candidate genes controlling leaf angle and iii) to identify novel regions associated with this trait by a multi-biparental population QTL approach.