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中，花的紫外（UV）色素斑纹模式存在种内与种间变异。该变异可影响传粉者的访花行为，对植物繁殖成功率与作物产量至关重要，但目前学界对紫外花纹变异的遗传基础仍缺乏系统认知。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）的相对面积与绝对大小的遗传架构。
研究方法：使用经改装、可捕获320–380 nm紫外光的相机，对F2作图群体的花部紫外花纹进行表型分型；随后通过测序分型（genotyping-by-sequencing）与连锁作图技术，定位数量性状位点（quantitative trait locus，QTL）。此外，本研究还评估了上述QTL对自然种群个体紫外花纹表型的预测能力。
主要结果：花紫外色素相对面积受6个效应中等的QTL加性调控，且该组QTL可有效预测自然种群中的该表型。与之相对，紫外靶斑的绝对大小仅受1个大效应QTL控制，该QTL同时调控头状花序大小，并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与既往报道的开花时间QTL三者共定位，提示其可能为单个具有高度多效性的基因位点，或是数个紧密连锁的基因位点；该现象意味着，若不改变相关联性状，则无法通过选择作用调控紫外靶斑的大小。而花紫外色素相对面积的遗传架构相对简洁，且与紫外靶斑大小的遗传机制存在显著差异，因此其可独立响应自然选择或人工选择。