Data from: The genetic architecture of floral traits in Iris hexagona and Iris fulva

The formation of hybrids among closely related species has been observed in numerous plant taxa. Selection by pollinators on floral traits can act as an early reproductive isolating barrier and may be especially important when there is overlap in distribution and flowering time. In this study, we use Quantitative Trait Locus (QTL) mapping based on 293 codominant SNP markers in an F2 population (n = 328) to assess the size, magnitude, and location of the genetic regions controlling floral traits known to be important for pollinator attraction in 2 species of Lousiana Irises, Iris fulva and Iris hexagona. We also evaluate correlations among F2 traits and identify transgression in the hybrid population. Overall, we observe that differences in most floral traits between I. fulva and I. hexagona are controlled by multiple QTLs and are distributed across several linkage groups. We also find evidence of transgression at several QTL, suggesting that hybridization can contribute to generating phenotypic variation, which may be adaptive in rapidly changing environments.

在众多植物类群中均已观测到近缘物种间杂交体的产生。传粉者对花部性状的选择可作为早期生殖隔离屏障，在物种分布区重叠且花期一致的情况下，该选择作用尤为关键。本研究基于F₂群体（n = 328）中的293个共显性单核苷酸多态性（SNP）标记开展数量性状位点（Quantitative Trait Locus, QTL）定位分析，以解析路易斯安那鸢尾属两个物种——红花鸢尾（Iris fulva）与六棱鸢尾（Iris hexagona）中，已知对传粉者吸引具有重要作用的花部性状的调控遗传区域的大小、效应强度与位置。本研究同时对F₂群体的性状间相关性进行评估，并鉴定杂交群体中的性状超亲分离现象。整体而言，我们发现红花鸢尾与六棱鸢尾间多数花部性状的差异由多个QTL调控，且这些位点分布于多个连锁群上。本研究还在多个QTL处检测到超亲分离的信号，表明杂交可促进表型变异的产生，而这类变异在快速变化的环境中可能具有适应性。