Geographic patterns of genetic variation in three genomes of North American diploid strawberries with special reference to Fragaria vesca subsp. bracteata

Geographic patterns of genetic variation in wild species reflect the interplay of ecological and evolutionary processes. We assessed genetic variation in three genomes across four North American diploid strawberry taxa, with special emphasis on the gynodioecious Fragaria vesca subsp. bracteata (A.Heller) Staudt. Specifically, we sequenced one chloroplast (rpoC2) and two mitochondrial (atp8 and atp8-orf225) genes along with several nuclear microsatellite markers. In addition, we assessed indicators of breeding system (pollen viability and female frequency) for all taxa. The geographic perspective on the distribution of cytoplasmic and nuclear variation revealed the genetic affiliation of the restricted taxa (Fragaria vesca subsp. californica (Cham. & Schltdl.) Staudt and Fragaria mexicana Schltdl.) with the widespread F. vesca subsp. bracteata and identified a hotspot of hybridization within gynodioecious F. vesca subsp. bracteata. Higher pollen viability of hermaphrodites was found ...

野生物种遗传变异的地理格局，反映了生态过程与进化过程之间的动态互作。本研究对北美4个二倍体草莓类群的3套基因组开展了遗传变异评估，重点聚焦于雌全异株（gynodioecious）的腺毛草莓（Fragaria vesca subsp. bracteata (A.Heller) Staudt）。具体而言，我们对1个叶绿体基因（rpoC2）、2个线粒体基因（atp8与atp8-orf225），以及多个核微卫星（nuclear microsatellite）标记进行了测序。此外，我们还测定了所有类群的繁育系统指标，包括花粉活力与雌性个体频率。基于细胞质与核变异的地理分布特征，本研究明确了局限分布类群（Fragaria vesca subsp. californica (Cham. & Schltdl.) Staudt与Fragaria mexicana Schltdl.）与广布的腺毛草莓之间的遗传亲缘关系，并确定了雌全异株腺毛草莓种群内的杂交热点区域。研究发现，两性株（hermaphrodite）的花粉活力更高……