Toward “Smart Canopy” Sorghum: Discovery of the Genetic Control of Leaf Angle Across Layers

Abstract

Leaf angle across the sorghum canopy is genetically controlled by both common and layer-specific loci, which holds potential for the development of an optimized canopy associated with higher yields.

Field-based remote sensing models predict radiation use efficiency in wheat

“…Thus, it will be possible to increase RUE by designing a new wheat ideotype with a ‘smart canopy’ for wheat with erect flag leaves to allow light penetration to lower (and usually shaded) parts of the canopy and to avoid light saturation, similarly to what has been proposed for sorghum canopies ( Mantilla-Perez et al , 2020 ). Evidence found in wheat canopies indicates that erectophile genotypes can have up to 11% higher biomass and 24% higher yields compared with planophile genotypes ( Richards et al , 2019 ); therefore, the addition of erectophile genotypes and the use of remote sensing models that correlate NPQ and PRI can become important in wheat physiological breeding to increase RUE, biomass, and yield, especially because wheat is grown under contrasting light environments across different latitudes, which leaves the door open to further increase the genetic gains of these traits.…”

3D reconstruction identifies loci linked to variation in angle of individual sorghum leaves

“…More pessimistically the same result could be interpreted as many of the identified associations representing false positive associations. There is indeed evidence that genetic variants associated with upper and mid-level leaf angle in sorghum are only partially overlapping [26]. However, in this case we examined the angle of three sequential leaves rather than distinct parts of the sorghum canopy.…”

“…We demonstrate that leaf angle measurements collected in this fashion can be used to identify both known and novel loci in the sorghum genome influencing overall leaf angle or the angle of individual sorghum leaves. 3D reconstruction and leaf angle measurement -as well as the measurement of other leaf properties including length, width, and curvature -across multiple stages of development can enable a more comprehensive understanding of the genetic determinants of sorghum canopy architecture and aid breeding or engineering of more productive and resource use efficient "smart canopies" [26]. [35] was used to identify significant associations of SNP markers with variation in leaf angle aggregated across all three time points.…”

“…Analysis with GEMMA [35], a mixed linear model based algorithm, did not identify any significant markers for the automated 2D angles (Figure S9) but for 3D derived angles, identified a single large peak for leaf angle located on chromosome 7 between 59.8 MB and 59.9 MB. This position corresponds to the genomic location of dwarf3 (Sobic.007G163800), an ATP-binding cassette (ABC) transporter involved in auxin export [36] which has been previously associated with variation in leaf angle in sorghum RIL populations [21] and an association study [26]. As dwarf3 is a large effect locus with functionally variable alleles segregating at high frequencies in this population, we speculated that the effects of additional loci on may angle might be masked in the MLM-based GWAS results (Figure2A).…”

“…Efforts have been made to automate the scoring of sorghum leaf angle. Leaf angle can be roughly estimated under field conditions by examining the overall width of rows of sorghum plants, a trait which can be measured from current robotic platforms [26]. When working with individual plants in a greenhouse setting, depth camera data collected from 12 viewing angles was sufficient to reconstruct sorghum plant meshes from a panel of 99 recombinant inbred lines, enabling the detection of the known effect of the dwarf3 gene on leaf angle via QTL mapping [27].…”