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 ph...在众多植物类群中，近缘物种间杂交种的形成已被广泛观测到。传粉者对花部性状的选择可作为早期生殖隔离屏障，在分布范围与开花期重叠的情况下尤为重要。本研究基于F2群体（n = 328）中的293个共显性单核苷酸多态性（Single Nucleotide Polymorphism，SNP）标记开展数量性状位点（Quantitative Trait Locus，QTL）定位，以评估调控两种路易斯安那鸢尾（Iris fulva与Iris hexagona）中已知对传粉者吸引至关重要的花部性状的遗传区域的大小、效应强度与位置。本研究还评估了F2群体各性状间的相关性，并鉴定了杂交群体中的性状超亲分离现象。总体而言，我们观测到这两个鸢尾物种的多数花部性状差异由多个QTL控制，并分布于多个连锁群中。我们还在多个QTL处发现了超亲分离的证据，表明杂交可助力产生……