BOX38, a DNA Marker for Selection of Essential Oil Yield of Rosa × rugosa

Rosa rugosa L. was a famous aromatic plant whose cultivars (Rosa × rugosa) have been widely used in the perfume industry in Asia. The perfume market looks for rose cultivars bearing higher essential oil, while the oil yields of most R. × rugosa have not been evaluated due to limiting conditions, such as insufficient cultivation areas. Here, we tested the yield and the aroma components of essential oil of 19 R. × rugosa. The results indicated that the yields of nerol, citronellol, and geraniol could represent an alternative index of the total yield of essential oil. Sequence syntenic analysis indicated that the Rosa genus specific cis-element Box38 was highly polymorphic. The Box38 region isolation of Rosa × rugosa by flanked primers proved that Box38 repeat number was significantly positively correlated with the essential oil yield of the corresponding cultivar. In the breeding of Rosa × rugosa, six-Box38-repeat could be a robust threshold for selection of high-essential-oil roses. Together, we found that Box38 was a DNA marker for essential oil yield and that it would be helpful in the early selection and breeding of essential oil roses.