Department of Plant Sciences, North Dakota State University, Fargo, ND 58108, USA.
USDA-Agricultural Research Service, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Blvd. N., Fargo, ND 58102-2765, USA.
Int J Mol Sci. 2020 Feb 22;21(4):1497. doi: 10.3390/ijms21041497.
Phomopsis stem canker (PSC) caused by is increasingly becoming a global threat for sunflower production. In this study, the genetic basis of PSC resistance was investigated in a recombinant inbred line (RIL) population developed from a cross between HA 89 (susceptible) and HA-R3 (resistant). The RIL population was evaluated for PSC disease incidence (DI) in seven screening trials at multiple locations during 2016-2018. The distribution of PSC DI in the RIL population was continuous, confirming a polygenic inheritance of the trait. A moderately high broad-sense heritability (, 0.76) was estimated for the trait across environments. In the combined analysis, both the genotype and the genotype × environment interactions were highly significant. A linkage map spanning 1505.33 cM was constructed using genotyping-by-sequencing derived markers. Marker-trait association analysis identified a total of 15 quantitative trait loci (QTL) associated with PSC resistance on 11 sunflower chromosomes, each explaining between 5.24 and 17.39% of the phenotypic variation. PSC resistance QTL were detected in two genomic regions each on chromosomes 3, 5, 13, and 17, while one QTL each was detected in the remaining seven chromosomes. Tightly linked single nucleotide polymorphism (SNP) markers flanking the PSC resistance QTL will facilitate marker-assisted selection in PSC resistance sunflower breeding.
黄萎病（Phomopsis stem canker）由 Phomopsis longicolla 引起，对向日葵生产构成全球性威胁。本研究以 HA 89（感病）和 HA-R3（抗病）杂交衍生的重组自交系（RIL）群体为材料，研究黄萎病抗性的遗传基础。在 2016-2018 年期间，在多个地点的 7 次筛选试验中，对 RIL 群体的黄萎病发病率（DI）进行了评估。RIL 群体的黄萎病 DI 分布呈连续型，表明该性状受多基因控制。在不同环境下，该性状的广义遗传力（, 0.76）被评估为中等偏高。综合分析结果表明，基因型和基因型×环境互作均高度显著。利用基于测序的基因型数据构建了一张包含 1505.33 cM 的连锁图谱。标记-性状关联分析共鉴定到 11 个向日葵染色体上与黄萎病抗性相关的 15 个数量性状位点（QTL），每个 QTL 解释了 5.24%至 17.39%的表型变异。在染色体 3、5、13 和 17 上，每个染色体上各检测到两个与黄萎病抗性相关的基因组区域，而在其余七个染色体上，每个染色体上仅检测到一个 QTL。与黄萎病抗性 QTL 紧密连锁的单核苷酸多态性（SNP）标记将有助于黄萎病抗性向日葵的分子辅助选择。
