Department of Plant and Soil Sciences and the Delaware Biotechnology Institute, University of Delaware, Newark, DE, USA.
Department of Biomedical Engineering, University of Delaware, Newark, DE, USA.
Ann Bot. 2022 May 12;129(6):657-668. doi: 10.1093/aob/mcac029.
Root lodging is responsible for significant crop losses worldwide. During root lodging, roots fail by breaking, buckling or pulling out of the ground. In maize, above-ground roots, called brace roots, have been shown to reduce susceptibility to root lodging. However, the underlying structural-functional properties of brace roots that prevent root lodging are poorly defined. In this study, we quantified structural mechanical properties, geometry and bending moduli for brace roots from different whorls, genotypes and reproductive stages.
Using 3-point bend tests, we show that brace root mechanics are variable by whorl, genotype and reproductive stage.
Generally, we find that within each genotype and reproductive stage, the brace roots from the first whorl (closest to the ground) had higher structural mechanical properties and a lower bending modulus than brace roots from the second whorl. There was additional variation between genotypes and reproductive stages. Specifically, genotypes with higher structural mechanical properties also had a higher bending modulus, and senesced brace roots had lower structural mechanical properties than hydrated brace roots.
Collectively these results highlight the importance of considering whorl-of-origin, genotype and reproductive stage for the quantification of brace root mechanics, which is important for mitigating crop loss due to root mechanical failure.
根倒伏是导致全球作物减产的主要原因。在根倒伏过程中，根会断裂、弯曲或从土壤中拔出。在玉米中，地上的根，称为支撑根，已被证明可以降低根倒伏的易感性。然而，支撑根防止根倒伏的潜在结构功能特性尚未明确。在这项研究中，我们定量分析了不同轮生、基因型和生殖阶段的支撑根的结构力学特性、几何形状和弯曲模量。
使用三点弯曲试验，我们表明支撑根力学特性因轮生、基因型和生殖阶段而异。
一般来说，我们发现，在每个基因型和生殖阶段内，最靠近地面的第一轮（第一圈）支撑根的结构力学特性比第二轮支撑根更高，弯曲模量更低。基因型和生殖阶段之间还存在额外的差异。具体而言，结构力学特性较高的基因型的弯曲模量也较高，而衰老的支撑根的结构力学特性比水合支撑根的低。
综上所述，这些结果强调了在定量分析支撑根力学特性时，考虑轮生起源、基因型和生殖阶段的重要性，这对于减轻因根力学失效导致的作物损失很重要。
