Table_2_Identification of Quantitative Trait Loci Hotspots Affecting Agronomic Traits and High-Throughput Vegetation Indices in Rainfed Wheat.XLSX

Understanding the genetic basis of agronomic traits is essential for wheat breeding programs to develop new cultivars with enhanced grain yield under climate change conditions. The use of high-throughput phenotyping (HTP) technologies for the assessment of agronomic performance through drought-adaptive traits opens new possibilities in plant breeding. HTP together with a genome-wide association study (GWAS) mapping approach can be a useful method to dissect the genetic control of complex traits in wheat to enhance grain yield under drought stress. This study aimed to identify molecular markers associated with agronomic and remotely sensed vegetation index (VI)-related traits under rainfed conditions in bread wheat and to use an in silico candidate gene (CG) approach to search for upregulated CGs under abiotic stress. The plant material consisted of 170 landraces and 184 modern cultivars from the Mediterranean basin. The collection was phenotyped for agronomic and VI traits derived from multispectral images over 3 and 2 years, respectively. The GWAS identified 2,579 marker-trait associations (MTAs). The quantitative trait loci (QTL) overview index statistic detected 11 QTL hotspots involving more than one trait in at least 2 years. A CG analysis detected 12 CGs upregulated under abiotic stress in six QTL hotspots and 46 downregulated CGs in 10 QTL hotspots. The current study highlights the utility of VI to identify chromosome regions that contribute to yield and drought tolerance under rainfed Mediterranean conditions.

深入理解农艺性状的遗传基础，对于在气候变化条件下培育高产新品种的冬小麦育种计划至关重要。利用高通量表型技术（HTP）通过干旱适应性性状来评估农艺性能，为植物育种开辟了新的可能性。HTP与全基因组关联研究（GWAS）定位方法相结合，可以成为解析小麦复杂性状遗传控制的有用手段，以提升其在干旱胁迫下的产量。本研究旨在鉴定与雨养条件下冬小麦农艺性状和遥感植被指数（VI）相关联的分子标记，并采用虚拟筛选候选基因（CG）的方法，寻找在非生物胁迫下上调的CGs。植物材料包括来自地中海盆地的170个地方品种和184个现代栽培种。该集合在3年和2年内分别对农艺性状和来自多光谱图像的VI性状进行了表型分析。GWAS识别出2,579个标记-性状关联（MTAs）。定量性状位点（QTL）概述指数统计检测到11个涉及至少2年多个性状的QTL热点。候选基因分析在6个QTL热点中检测到12个在非生物胁迫下上调的CGs，在10个QTL热点中检测到46个下调的CGs。当前研究突出了VI在识别对雨养地中海条件下产量和耐旱性有贡献的染色体区域中的效用。