Abstract：
Yellow dwarf viruses (YDVs) spread by aphids are some of the most economically important barley (Hordeum vulgare) virus-vector complexes worldwide. Detection and control of these viruses are critical components in the production of barley, wheat, and numerous other grasses of agricultural importance. Genetic control of plant diseases is often preferable to chemical control to reduce the environmental and economic cost of foliar insecticides. Accordingly, the objectives of this work were to (i) screen a barley population for resistance to YDVs under natural infection using phenotypic assessment of disease symptoms, (ii) implement drone imagery to further assess resistance and test its utility as a disease screening tool, (iii) identify the prevailing virus and vector types in the experimental environment, and (iv) perform a genome-wide association study to identify genomic regions associated with measured traits. Significant genetic differences were found in a population of 192 barley inbred lines regarding their YDV symptom severity, and symptoms were moderately to highly correlated with grain yield. The YDV severity measured with aerial imaging was highly correlated with on-the-ground estimates (r = 0.65). Three aphid species vectoring three YDV species were identified with no apparent genotypic influence on their distribution. A quantitative trait locus impacting YDV resistance was detected on chromosome 2H, albeit undetected using aerial imaging. However, quantitative trait loci for canopy cover and mean normalized difference vegetation index were successfully mapped using the drone. This work provides a framework for utilizing drone imagery in future resistance breeding efforts for YDVs in cereals and grasses, as well as in other virus-vector disease complexes.
摘要：
由蚜虫传播的黄矮病毒（YDV）是全球经济上最重要的大麦（HordeumvulgareL.）病毒载体复合物。这些病毒的检测和控制是大麦生产的关键组成部分，小麦,以及许多其他具有农业重要性的草。植物病害的基因控制通常比化学控制更可取，以减少流行病学。环境,和叶面杀虫剂的经济成本。因此，这项工作的目的是I）使用疾病症状的表型评估，筛选大麦种群对自然感染下的YDV抗性，II）实施无人机图像以进一步评估耐药性并测试其作为疾病筛查工具的效用，III）确定实验环境中流行的病毒和载体类型，和IV）进行全基因组关联研究，以鉴定与测量性状相关的基因组区域。在192个大麦自交系的群体中，发现其YDV症状严重程度存在显着遗传差异，并且症状与谷物产量中度至高度相关。航空成像测量的YDV严重程度与地面估计值高度相关（r=0.65）。鉴定出3种蚜虫物种对3种YDV物种的媒介，对其分布没有明显的基因型影响。在染色体2H上检测到影响YDV抗性的QTL，尽管使用航空成像未被发现。然而,使用无人机成功绘制了冠层覆盖和平均NDVI的QTL。这项工作为将来在谷物和草类中YDV的抗性育种工作中利用无人机图像提供了一个框架，和其他病毒载体疾病复合体。
