Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College of Yangzhou University, Yangzhou 225009, China.
Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
Genes (Basel). 2022 Mar 24;13(4):579. doi: 10.3390/genes13040579.
Stalk lodging presents a major constraint on maize ( L.) quantity and quality and hampers mechanized grain harvesting. Stalk diameter (SD) and rind penetrometer resistance (RPR) are crucial indicators of stalk lodging. To dissect the genetic architecture of these indicators, we constructed a recombinant inbred line (RIL) population derived from a cross between maize inbred lines LDC-1 and YS501 to identify quantitative trait loci (QTLs) controlling SD and RPR. Corresponding phenotypes of basal second, third, and fourth internodes in four environments were determined. By integrating QTL mapping results based on individual environments and best linear unbiased prediction (BLUP) values, we identified 12, 12, and 13 QTLs associated with SD and 17, 14, and 17 associated with RPR. Each QTL accounted for 3.83-21.72% of phenotypic variation. For SD-related QTLs, 30 of 37 were enriched in 12 QTL clusters; similarly, RPR-related QTLs had 38 of 48 enriched in 12 QTL clusters. The stable QTL for SD on chromosome 9 was validated and delimited within a physical region of 9.97 Mb. Confidence intervals of RPR-related QTLs contained 169 genes involved in lignin and polysaccharide biosynthesis, with 12 of these less than 500 kb from the peak of the corresponding QTL. Our results deepen our understanding of the genetic mechanism of maize stalk strength and provide a basis for breeding lodging resistance.
茎秆倒伏严重限制了玉米（L.）的产量和品质，也阻碍了机械化谷物收获。茎直径（SD）和果皮硬度计阻力（RPR）是衡量茎秆倒伏的重要指标。为了剖析这些指标的遗传结构，我们构建了一个来自玉米自交系 LDC-1 和 YS501 的重组自交系（RIL）群体，以鉴定控制 SD 和 RPR 的数量性状基因座（QTL）。在四个环境中，确定了基部第二、第三和第四节间的相应表型。通过整合基于个体环境的 QTL 作图结果和最佳线性无偏预测（BLUP）值，我们鉴定出 12、12 和 13 个与 SD 相关的 QTL 和 17、14 和 17 个与 RPR 相关的 QTL。每个 QTL 解释了 3.83-21.72%的表型变异。对于与 SD 相关的 QTL，37 个中有 30 个在 12 个 QTL 簇中富集；同样，与 RPR 相关的 QTL 中有 38 个在 12 个 QTL 簇中富集。在第 9 号染色体上与 SD 相关的稳定 QTL 得到验证，并在 9.97Mb 的物理区域内进行了定位。与 RPR 相关的 QTL 的置信区间包含 169 个参与木质素和多糖生物合成的基因，其中 12 个基因距离相应 QTL 的峰值不到 500kb。我们的研究结果加深了我们对玉米茎秆强度遗传机制的理解，为培育抗倒伏性提供了基础。
