Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA.
Department of Plant & Wildlife Science, Brigham Young University, Provo, UT, USA.
Commun Biol. 2023 Mar 27;6(1):326. doi: 10.1038/s42003-023-04620-9.
Bromus tectorum L. is arguably the most successful invasive weed in the world. It has fundamentally altered arid ecosystems of the western United States, where it now found on an excess of 20 million hectares. Invasion success is related to avoidance of abiotic stress and human management. Early flowering is a heritable trait utilized by B. tectorum, enabling the species to temporally monopolize limited resources and outcompete the native plant community. Thus, understanding the genetic underpinning of flowering time is critical for the design of integrated management strategies. To study flowering time traits in B. tectorum, we assembled a chromosome scale reference genome for B. tectorum. To assess the utility of the assembled genome, 121 diverse B. tectorum accessions are phenotyped and subjected to a genome wide association study (GWAS). Candidate genes, representing homologs of genes that have been previously associated with plant height or flowering phenology traits in related species are located near QTLs we identified. This study uses a high-resolution GWAS to identify reproductive phenology genes in a weedy species and represents a considerable step forward in understanding the mechanisms underlying genetic plasticity in one of the most successful invasive weed species.
雀麦（Bromus tectorum L.）可以说是世界上最成功的入侵杂草。它从根本上改变了美国西部的干旱生态系统，现在在超过 2000 万公顷的土地上都能发现它的踪迹。入侵的成功与避免非生物胁迫和人类管理有关。早期开花是雀麦利用的一种可遗传特征，使该物种能够暂时垄断有限的资源，并与本地植物群落竞争。因此，了解开花时间的遗传基础对于综合管理策略的设计至关重要。为了研究雀麦的开花时间性状，我们为雀麦组装了一个染色体尺度的参考基因组。为了评估组装基因组的效用，对 121 个不同的雀麦品系进行了表型分析，并进行了全基因组关联研究（GWAS）。我们鉴定的 QTL 附近定位了候选基因，这些基因代表了先前与相关物种的株高或开花物候性状相关的基因的同源物。本研究利用高分辨率 GWAS 在一种杂草物种中鉴定了生殖物候学基因，这代表了在最成功的入侵杂草物种之一中理解遗传可塑性机制的重要一步。
