Cassava mosaic disease (CMD) is a major viral disease adversely affecting cassava production in Africa and Asia. Genomic regions conferring resistance to the disease have been mapped in African cassava germplasm through biparental quantitative trait loci (QTL) mapping and genome-wide association studies. To facilitate the utilization of these markers in breeding pipelines to support selections, proof-of-concept technical and biological validation research was carried out using independent pre-breeding and breeding populations. Kompetitive Allele-Specific Polymerase Chain Reaction (KASP) assays were designed from three single nucleotide polymorphism (SNP) markers linked to a major resistance locus on chromosome 12 (S12_7926132, S12_7926163) and a minor locus on chromosome 14 (S14_4626854). The designed assays were robust and easy to score with >99% genotype call rate. The overall predictive accuracy (proportion of true positives and true negatives) of the markers (S12_7926132 and S14_4626854) was 0.80 and 0.78 in the pre-breeding and breeding population, respectively. On average, genotypes that carried at least one copy of the resistant allele at the major CMD2 locus had a significantly higher yield advantage. Nevertheless, variation was observed in prediction accuracies for the major locus (S12_7926132) among sub-families from the two populations, suggesting the need for context-specific utilization, for example, by screening for co-segregation of favorable SNP alleles with resistance in the parents being used for crosses. Availability of these validated SNP markers on the uniplex KASP genotyping platform represents an important step in translational genetics toward marker-assisted selection to accelerate introgression of favorable resistant alleles in breeding populations.

中文翻译：

---

在木薯育种计划中选择对木薯花叶病的抗性的Uniplex SNP标记的转换和验证

木薯花叶病（CMD）是一种主要的病毒性疾病，对非洲和亚洲的木薯生产产生不利影响。通过双亲定量性状基因座（QTL）作图和全基因组关联研究，已在非洲木薯种质中绘制了赋予对该病抗性的基因组区域。为了促进这些标记在育种管道中的使用以支持选择，使用独立的预育和育种种群进行了概念验证技术和生物学验证研究。竞争性等位基因特异性聚合酶链反应（KASP）分析方法是通过与12号染色体上的主要抗性基因座（S12_7926132，S12_7926163）和14号染色体上的次要基因座（S14_4626854）连接的三个单核苷酸多态性（SNP）标记设计的。设计的检测方法坚固耐用，易于评分> 基因型检出率99％。在育种前和育种种群中，标记（S12_7926132和S14_4626854）的总体预测准确度（真阳性和真阴性的比例）分别为0.80和0.78。平均而言，在主要C区携带至少一个拷贝的抗性等位基因的基因型MD2基因座具有明显更高的产量优势。然而，在两个人群的亚科中，主要基因座（S12_7926132）的预测准确性存在差异，这表明需要针对具体情况进行利用，例如，通过筛选具有抗药性的有利SNP等位基因的共分离。父母被用来做十字架。这些经过验证的SNP标记在单重KASP基因分型平台上的可用性代表了翻译遗传学朝标记辅助选择迈出的重要一步，从而加速了繁殖种群中有利的抗性等位基因的渗入。