Determination Of Anthocyanins And Exploration Of Relationship Between Their Composition And Petal Coloration In Crape Myrtle (Lagerstroemia Hybrid)

Petal coloration and pigment components in 12 American crape myrtle cultivars(Lagerstroemia indica×L. fauriei) and 5 Chinese crape myrtle cultivars (L. indica) werestudied. Color was measured by CIEL~*a~*b~* scale and anthocyanin composition of crapemyrtle was determined using high-performance liquid chromatography coupled to photodiodearray detection and electrospray ionization mass spectrometry (HPLC-DAD/ESI-MS). We usemultiple linear regression analysis (MLR) to explore the relationship between petal color andanthocyanin contents. Results were as follows:Excluding white fowers, there were four anthocyanins in petals of crape myrtle, whichwere delphinidin 3-O-glucoside (Dp3G), cyanidin 3-O-glucoside (Cy3G), petunidin3-O-glucoside (Pt3G) and malvidin 3-O-glucoside (Mv3G). Dp3G; Pt3G and Mv3G werepreviously reported. Cy3G was identified in crape myrtle for the first time. The amounts offlavones and flavonols were also measured. White petals contained high amounts of flavonesand flavonols.The result of multiple linear regression analysis (MLR) indicated that the amount of TF(total flavones and flavonols) and Dp3G affected the bluing of crape myrtle together.Flavones and flavonols contributed to bluing of crape myrtle, so they are importantco-pigments.Based on pigments and co-pigments analysis, fower color breeding towards true-red andblue in crape myrtle were discussed. Cy3G was one of important red-series anthocyanins, soCy3G would play a significant role in true-red crape myrtle breeding. The difficulty in bluecrape myrtle breeding was to find the appropriate proportion between Dp3G and TF, in whichTF could exert a full influence of co-pigmentation effect on Dp3G, and then shift petal colortowards bluer.