Genome-wide association study reveals the genetic basis of brace root angle and diameter in maize

Abstract

Brace roots are the main organ to support the above-ground part of maize plant. It involves in plant growth and development by water absorption and lodging resistance. The bracing root angle (BRA) and diameter (BRD) are important components of brace root traits. Illuminating the genetic basis of BRA and BRD will contribute the improvement for mechanized harvest and increasing production. A GWAS of BRA and BRD was conducted using an associated panel composed of 508 inbred lines of maize. The broad-sense heritability of BRA and BRD was estimated to be respectively 71% ± 0.19 and 52% ± 0.14. The phenotypic variation of BRA and BRD in the non-stiff stalk subgroup (NSS) and the stiff stalk subgroup (SS) subgroups are significantly higher than that in the tropical/subtropical subgroup (TST) subgroups. In addition, BRA and BRD are significantly positive with plant height (PH), ear length (EL), and kernel number per row (KNPR). GWAS revealed 27 candidate genes within the threshold of p < 1.84 × 10−6 by both MLM and BLINK models. Among them, three genes, GRMZM2G174736, GRMZM2G445169 and GRMZM2G479243 were involved in cell wall function, and GRMZM2G038073 encoded the NAC transcription factor family proteins. These results provide theoretical support for clarifying the genetic basis of brace roots traits.

Breeding maize of ideal plant architecture for high‐density planting tolerance through modulating shade avoidance response and beyond

“…Vertical root‐pulling resistance has been used as an estimation of root strength and architecture, and a number of QTLs have been identified in previous studies; however, none have yet been cloned (Landi et al, 2002; Landi et al, 2007; Farkhari et al, 2013). Recently, a GWAS study of brace root angle and brace root diameter using 508 maize inbred lines identified 27 candidate genes, yet none of these has been functionally validated (Sun et al, 2022). In another study, Zhang et al (2018b) analyzed a large teosinte‐maize population and identified 133 QTLs for nodal root number.…”

Genome-Wide Association Study Identified Novel SNPs Associated with Chlorophyll Content in Maize

“…Wang et al [27] carried out a study on drought tolerance in maize seedlings that found ZmVPP1, and transgenic maize with enhanced ZmVPP1 expression exhibited improved drought tolerance. Sun et al [28] identified candidate genes that affect bracing root angle and diameter. Li et al [29] used GWAS to reveal the candidate gene of maize seed germination traits and found 58 genetic variation sites and 36 candidate genes, which provided important implications for the molecular breeding of maize seed germination.…”

Genome-Wide Meta-Analysis of QTLs Associated with Root Traits and Implications for Maize Breeding

“…The following supporting information can be downloaded at: . References [ 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 , 132 , 133 , 134 , 135 , 136 , 137 , 138 , 139 , 140 , 141 ] are cited in the supplementary materials.…”