Genetic structure of Paeonia rockii is positively related to the environmental factors such as latitude,
longitude, elevation, mid-day temperature in January and August, mean annual suntime, mean annual precipitation, mean
annual evaporation, soil type based on the results from the correlation analysis between the genetic distance and geographic
and environmental distance. For populations of P. rockii, the closer in geographical distance, the less environmental
difference between them. It is suggested that the current genetic structure of P. rockii is highly impacted by ecological or
natural selection in this study. Key words: temperature; light; tree peony; speciation |