Dissection of Leaf Angle Variation in Maize through Genetic Mapping and Meta‐Analysis

Abstract

Core Ideas Twelve QTL were discovered for maize leaf angle variation in the lower canopy. A consistently detected QTL explained 10 to 17% of the phenotypic variance on chromosome 1. Meta‐analysis identified 58 genomic bins containing 33 candidate genes. Maize (Zea mays L.) hybrids have transitioned to upright leaf angles (LAs) over the last 50 yr as maize yields and planting densities increased concurrently. Genetic mapping and a meta‐analysis were conducted in the present study to dissect genetic factors controlling LA variation. We developed mapping populations using inbred lines B73 (Iowa Stiff Stalk Synthetic), PHW30 (Iodent, expired plant variety protection inbred), and Mo17 (Non‐Stiff Stalk) that have distinct LA architectures and represent three important heterotic groups in the United States. These populations were genotyped using genotyping‐by‐sequencing (GBS), and phenotyped for LA in the F2 and F2:3 generation. Inclusive composite interval mapping across the two generations of the mapping populations revealed 12 quantitative trait loci (QTL), and a consistent QTL on chromosome 1 explained 10 to 17% of the phenotypic variance. To gain a comprehensive understanding of natural variations underlying LA variation, these detected QTL were compared with results from 19 previous studies. In total, 495 QTL were compiled and mapped into 143 genomic bins. A meta‐analysis revealed that 58 genomic bins were associated with LA variation. Thirty‐three candidate genes were identified in these genomic bins. Together, these results provide evidence of QTL controlling LA variation from inbred lines representing three important heterotic groups in the United States and a useful resource for future research into the molecular variants underlying specific regions of the genome associated with LA variation.

Mapping of QTL for Grain Yield Components Based on a DH Population in Maize

“…maizegdb.org). Among them, the gene ZmLG1 controls the angle of maize leaves and changes the plant architecture, thereby increasing photosynthetic efficiency and crop yield 33 . ZmMHA2 was identified as a functional Fe transporter that promotes Fe uptake and plays an essential role in plant growth and development 34 , while ZmAST91 could significantly improve crop stress resistance under abiotic stresses 35 .…”

Maize Introgression Library Provides Evidence for the Involvement ofliguleless1in Resistance to Northern Leaf Blight

“…In maize, mutations in lg1 result in more upright leaves (Moreno et al 1997) and natural variation in lg1 associates with more upright leaves in maize breeding lines (Dzievit et al 2019;Tian et al 2011). A significant negative correlation was identified between middle leaf angle and resistance to NLB (AUDPC) in the 282-line maize diversity panel (Flint-Garcia et al 2005; p < 0.001; R 2 = 0.175; Figure S6), however, population structure or kinship was not accounted for.…”

Abscisic Acid Represses Rice Lamina Joint Inclination by Antagonizing Brassinosteroid Biosynthesis and Signaling

“…For example, the grain yields of the brassinosteroid (BR)-deficient rice mutant Osdwarf4-1 , which has erect leaves, is greater in densely planted populations [7]. Therefore, an increasing number of recent studies have focused on identifying the responsible genes/quantitative trait loci (QTLs) that control leaf angles in major crop plants, including rice [8,9,10], maize [11,12,13], and wheat [14,15]. Most recently, two novel QTLs, upright plant architecture1 ( UPA1 ) and UPA2 , have been identified to regulate leaf angle in maize, thus providing the potential to enhance maize yields by increasing planting densities [16].…”