Quantitative trait locus (QTL) identification in perennial fruit crops is impeded largely by their lengthy generation time, resulting in costly and labor-intensive maintenance of breeding programs. In a grapevine (genus Vitis) breeding program, although experimental families are typically unreplicated, the genetic backgrounds may contain similar progenitors previously selected due to their contribution of favorable alleles. In this study, we investigated the utility of joint QTL identification provided by analyzing half-sib families. The genetic control of powdery mildew was studied using two half-sib F1 families, namely GE0711/1009 (MN1264 × MN1214; N = 147) and GE1025 (MN1264 × MN1246; N = 125) with multiple species in their ancestry. Maternal genetic maps consisting of 1077 and 1641 single nucleotide polymorphism (SNP) markers, respectively, were constructed using a pseudo-testcross strategy. Ratings of field resistance to powdery mildew were obtained based on whole-plant evaluation of disease severity. This 2-year analysis uncovered two QTLs that were validated on a consensus map in these half-sib families with improved precision relative to the parental maps. Examination of haplotype combinations based on the two QTL regions identified strong association of haplotypes inherited from 'Seyval blanc', through MN1264, with powdery mildew resistance. This investigation also encompassed the use of microsatellite markers to establish a correlation between 206-bp (UDV-015b) and 357-bp (VViv67) fragment sizes with resistance-carrying haplotypes. Our work is one of the first reports in grapevine demonstrating the use of SNP-based maps and haplotypes for QTL identification and tagging of powdery mildew resistance in half-sib families.

中文翻译：

---

使用基于SNP的图谱对种间半同胞葡萄家族的白粉病抗性进行遗传解剖。

多年生水果作物的数量性状基因座（QTL）鉴定在很大程度上因其较长的生成时间而受到阻碍，从而导致育种计划的成本高昂且劳动强度大。在葡萄（葡萄属）繁殖计划中，尽管通常不复制实验科，但由于其有利的等位基因的贡献，遗传背景可能包含先前选择的相似祖细胞。在这项研究中，我们调查了通过分析半同胞家庭提供的联合QTL识别的效用。使用两个同胞半同胞F1家族（GE0711 / 1009（MN1264×MN1214; N = 147）和GE1025（MN1264×MN1246; N = 125））研究了白粉病的遗传控制。产妇遗传图谱分别由1077和1641单核苷酸多态性（SNP）标记组成，使用伪测试交叉策略构建。基于对病害严重程度的全厂评估，获得了对白粉病的田间抗性等级。这项为期2年的分析揭示了两个QTL，这些QTL在这些半同胞家庭的共识图上得到了验证，相对于父母图而言，其准确性有所提高。基于两个QTL区域的单倍型组合的检查确定了从'Seyval blanc'到MN1264继承的单倍型与白粉病的抗性密切相关。这项研究还包括使用微卫星标记建立带有抗性单倍型的206-bp（UDV-015b）和357-bp（VViv67）片段大小之间的相关性。