Data from: The genetic architecture of UV floral patterning in sunflower

Background and Aims: The patterning of floral ultraviolet (UV) pigmentation varies both intra- and interspecifically in sunflowers and many other plant species, impacts pollinator attraction, and can be critical to reproductive success and crop yields. However, the genetic basis for variation in UV patterning is largely unknown. This study examines the genetic architecture for proportional and absolute size of the UV bullseye in Helianthus argophyllus, a close relative of the domesticated sunflower. Methods: A camera modified to capture UV light (320–380 nm) was used to phenotype floral UV patterning in an F2 mapping population, then quantitative trait loci (QTL) were identified using genotyping-by-sequencing and linkage mapping. The ability of these QTL to predict the UV patterning of natural population individuals was also assessed. Key Results: Proportional UV pigmentation is additively controlled by six moderate effect QTL that are predictive of this phenotype in natural populations. In contrast, UV bullseye size is controlled by a single large effect QTL that also controls flowerhead size and co-localizes with a major flowering time QTL in Helianthus. Conclusions: The co-localization of the UV bullseye size QTL, flowerhead size QTL and a previously known flowering time QTL may indicate a single highly pleiotropic locus or several closely linked loci, which could inhibit UV bullseye size from responding to selection without change in correlated characters. The genetic architecture of proportional UV pigmentation is relatively simple and different from that of UV bullseye size, and so should be able to respond to natural or artificial selection independently.

背景与研究目的：向日葵及诸多其他植物类群中，花部紫外（ultraviolet, UV）色素图案的种内与种间变异广泛存在，该变异可影响传粉者的吸引效果，且对植物繁殖成功率与作物产量至关重要。然而，紫外图案变异的遗传基础在很大程度上仍未明确。本研究以栽培向日葵的近缘物种银叶向日葵（Helianthus argophyllus）为材料，解析其紫外牛眼斑的比例性与绝对大小的遗传结构。
研究方法：采用改装后可捕捉320–380 nm紫外光的相机，对F2作图群体的花部紫外图案进行表型鉴定；随后通过测序分型（genotyping-by-sequencing）与连锁作图鉴定数量性状位点（quantitative trait loci, QTL），同时评估了这些QTL对自然种群个体紫外图案的预测能力。
主要结果：比例性紫外色素沉积由6个效应中等的加性QTL调控，且可准确预测自然种群中的该表型。与之相对，紫外牛眼斑的大小仅受单个大效应QTL调控，该位点同时控制头状花序大小，且与向日葵属中已报道的一个主要开花时间QTL共定位。
结论：紫外牛眼斑大小QTL、头状花序大小QTL与此前已知的开花时间QTL的共定位现象，可能指向单个具有高度多效性的位点，或是数个紧密连锁的位点；这一现象可能会导致紫外牛眼斑大小无法在不改变相关性状的前提下响应选择。比例性紫外色素沉积的遗传结构相对简单，且与紫外牛眼斑大小的遗传结构存在差异，因此可独立响应自然选择或人工选择。