Range-wide population genetics and variation in morph ratio in style-dimorphic Narcissus papyraceus (Amaryllidaceae)

Premise of the study: Theoretical models state that natural selection and mating patterns account for floral morph ratio in style- polymorphic plants. However, the demographic history of populations can also influence variation in morph ratios. If so, we hypothesize an association between the morph ratios and the genetic structure across populations. Methods: We used nuclear microsatellites to assess genetic variation and structure in populations of Narcissus papyraceus, a style-dimorphic plant whose floral morph ratios (L-morph to S-morph) gradually vary throughout its distribution range in the southwestern SW Mediterranean Basin. We implemented analyses to relate the genetic features of populations with their morph ratios. Key results: We found greater frequencies of the S-morph in central populations and declining frequencies toward the periphery. This geographic pattern was not associated with the genetic structure of populations. Instead, we found two distinct genetic groups, mainl...