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.

研究背景与目的：向日葵及诸多其他植物类群的花紫外（ultraviolet, UV）色素斑模式存在种内与种间变异，该变异可影响传粉者的吸引行为，对植物的繁殖成功与作物产量至关重要。然而，紫外斑型变异的遗传基础在很大程度上仍未被阐明。本研究以栽培向日葵的近缘物种银叶向日葵（Helianthus argophyllus）为材料，解析其紫外靶斑（UV bullseye）的比例大小与绝对尺寸的遗传结构。
研究方法：本研究使用可捕捉320–380nm紫外光的改装相机，对F2作图群体的花紫外斑型进行表型分型；随后通过测序分型（genotyping-by-sequencing）与连锁作图（linkage mapping）鉴定数量性状位点（quantitative trait loci, QTL）；同时评估了这些QTL对自然群体个体紫外斑型的预测能力。
主要结果：比例性紫外色素沉着受6个中效QTL的加性调控，且这些QTL可在自然群体中预测该表型。与之相对，紫外靶斑大小仅受单个大效应QTL调控，该位点同时调控头状花序大小，且与向日葵属中已报道的主要开花时间QTL共定位。
研究结论：紫外靶斑大小QTL、头状花序大小QTL与此前已报道的开花时间QTL的共定位现象，可能指向单个高度多效性位点或是数个紧密连锁的位点；这或许会导致紫外靶斑大小无法在不改变相关性状的前提下对选择做出响应。紫外色素占比的遗传结构相对简单，且与紫外靶斑大小的遗传机制存在差异，因此其能够独立响应自然选择或人工选择。