Moyers Brook T, Owens Gregory L, Baute Gregory J, Rieseberg Loren H
Department of Botany and Biodiversity Research Centre, University of British Columbia, Room 3529-6270 University Blvd, Vancouver, BC V6T 1Z4, Canada.
Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA.
Ann Bot. 2017 Jul 1;120(1):39-50. doi: 10.1093/aob/mcx038.
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.
A camera modified to capture UV light (320-380 nm) was used to phenotype floral UV patterning in an F 2 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.
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 .
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.
在向日葵及许多其他植物物种中，花朵紫外线（UV）色素沉着的模式在种内和种间均存在差异，影响传粉者的吸引力，并且对繁殖成功率和作物产量可能至关重要。然而，紫外线模式变化的遗传基础在很大程度上尚不清楚。本研究调查了驯化向日葵的近缘种——银叶向日葵中紫外线靶心的比例和绝对大小的遗传结构。
使用一台经过改装以捕捉紫外线（320 - 380纳米）的相机，对一个F2作图群体中的花朵紫外线模式进行表型分析，然后通过简化基因组测序和连锁作图来鉴定数量性状基因座（QTL）。还评估了这些QTL预测自然群体个体紫外线模式的能力。
紫外线色素沉着比例由六个中等效应的QTL以加性方式控制，这些QTL可预测自然群体中的这种表型。相比之下，紫外线靶心大小由一个单一的大效应QTL控制，该QTL还控制花盘大小，并且与向日葵中的一个主要开花时间QTL共定位。
紫外线靶心大小QTL、花盘大小QTL和一个先前已知的开花时间QTL的共定位可能表明存在一个单一的高度多效性基因座或几个紧密连锁的基因座，这可能会抑制紫外线靶心大小在相关性状不变的情况下对选择作出响应。紫外线色素沉着比例的遗传结构相对简单，与紫外线靶心大小的遗传结构不同，因此应该能够独立地对自然选择或人工选择作出响应。
