Clevenger Josh, Chu Ye, Chavarro Carolina, Botton Stephanie, Culbreath Albert, Isleib Thomas G, Holbrook C C, Ozias-Akins Peggy
Center for Applied Genetic Technologies, Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, United States.
Department of Horticulture, Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Tifton, GA, United States.
Front Plant Sci. 2018 Feb 5;9:83. doi: 10.3389/fpls.2018.00083. eCollection 2018.
Late leaf spot (LLS; ) is a major fungal disease of cultivated peanut (). A recombinant inbred line population segregating for quantitative field resistance was used to identify quantitative trait loci (QTL) using QTL-seq. High rates of false positive SNP calls using established methods in this allotetraploid crop obscured significant QTLs. To resolve this problem, robust parental SNPs were first identified using polyploid-specific SNP identification pipelines, leading to discovery of significant QTLs for LLS resistance. These QTLs were confirmed over 4 years of field data. Selection with markers linked to these QTLs resulted in a significant increase in resistance, showing that these markers can be immediately applied in breeding programs. This study demonstrates that QTL-seq can be used to rapidly identify QTLs controlling highly quantitative traits in polyploid crops with complex genomes. Markers identified can then be deployed in breeding programs, increasing the efficiency of selection using molecular tools. Field resistance to late leaf spot is a quantitative trait controlled by many QTLs. Using polyploid-specific methods, QTL-seq is faster and more cost effective than QTL mapping.
晚叶斑病（LLS）是栽培花生的一种主要真菌病害。利用一个对田间数量抗性进行分离的重组自交系群体，通过QTL-seq技术来鉴定数量性状位点（QTL）。在这种异源四倍体作物中，使用既定方法会产生较高比例的假阳性单核苷酸多态性（SNP）位点，从而掩盖了显著的QTL。为了解决这个问题，首先使用多倍体特异性SNP鉴定流程来鉴定可靠的亲本SNP，进而发现了与LLS抗性相关的显著QTL。这些QTL通过4年的田间数据得到了验证。使用与这些QTL连锁的标记进行选择，显著提高了抗性，这表明这些标记可立即应用于育种计划。本研究表明，QTL-seq可用于快速鉴定控制复杂基因组多倍体作物中高度数量性状的QTL。然后，所鉴定的标记可应用于育种计划，提高利用分子工具进行选择的效率。对晚叶斑病的田间抗性是一个由许多QTL控制的数量性状。使用多倍体特异性方法，QTL-seq比QTL定位更快且更具成本效益。
