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.

研究背景与研究目的：向日葵及诸多其他植物类群中，花紫外（ultraviolet, UV）色素图案在种内与种间均存在变异，该变异可影响传粉者的吸引行为，对植物繁殖成功率与作物产量至关重要。然而，目前学界对紫外图案变异的遗传基础仍知之甚少。本研究以栽培向日葵的近缘物种银叶向日葵（Helianthus argophyllus）为材料，解析其紫外靶斑的比例与绝对大小的遗传结构。

研究方法：使用经改装、可捕捉320~380nm紫外光的相机，对F2作图群体的花紫外图案进行表型测定；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），并评估这些QTL对自然群体个体紫外图案的预测能力。

主要研究结果：比例型紫外色素沉着由6个效应中等的QTL以加性方式调控，这些QTL可有效预测自然群体中的该表型。与之相反，紫外靶斑大小仅受单个大效应QTL调控，该QTL同时控制花盘大小，且与向日葵属中已报道的主效开花时间QTL共定位。

研究结论：紫外靶斑大小QTL、花盘大小QTL与已知的开花时间QTL三者共定位，提示其可能为单个多效性位点或多个紧密连锁的位点；该遗传结构可能导致紫外靶斑大小无法在不改变相关性状的前提下响应选择。比例型紫外色素沉着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，因此其可独立响应自然选择或人工选择。