Studies On Petal Color Phenotype And Anthocyanin Components Of Rose Germplasms

1.Petal color is one of the most important ornamental characterisitics.The different petal color phenotype were analyzed with the spectrocolorimeter and spectrophotometer on 227 rose germplasms.The results showed that the petal colors of the germplasms were classified into 7 series according to the cluster analysis of the color parameters L*?a*?b*.In the two-dimensional quadrant map of a*and b*,petal colors of germplasms were mainly distributed in the ?????quadrant but none of them in the ? quadrant suggesting the lack of blue color in roses.The distribution of the front petal colors were more concentrated while the distribution of the back petal colors of some orange red and dark red color varieties were dispersed;The L*B was brighter than L*F,but the a*F/b*F/C*F of most series was lower than the a*B/b*B/C*B;Most of the germplasms showed the negative correlations between the lightness(L*)and chroma(C*),which could be clustered into 2 groups.Group 1 contained the germplasms of white and yellow color series.Group 2 included the germplasms of the whole pink,purplish red,orange red color series and part of rose red color series.However,group 3 contained the germplasms of the whole dark red color series and part of rose red color series exhibited the positive correlations between L*and C*,indicating a“blackness”phenomenon in the petal colors.2.The anthocyanins as standards were all detected in the germplasms by HPLC method,which cyanidin-3,5-di-glucoside(Cy3G5G)and pelargonidin-3,5-di-glucoside(Pg3G5G)ranked the most of the contents among six kinds of anthocyanins.Moreover,the contents of anthocyanins in group 3 were much higher than the other two groups.The above results indicated the abundant petal color diversity in rose germplasms.The correlation analysis further indicated that the contents of total anthocyanins(TA)were negatively correlated with L*in all germplasms.TA showed the positive correlations with a*/C*in the germplasms of the first and second groups but the negative correlations in the third group.There were no correlations between the anthocyanins and CIELab parameters in the first group.Two kinds of pelargonidins(Pg)exhibited the positive correlations with a*?b*and C*but no correlations with L in the second group,referring Pg could affect the colors but not the brightness.In the third group,Cy3G5G as the unique anthocyanin presented the negative correlations with L*?a*/C*,indicating Cy3G5G might influence both the colors and the brightness.The significantly higher Cy3G5G contents in the third group might be responsible for the 'blackness' phenomenon in the petal colors.3.Fourteen rose samples were determined using UPLC-DAD-Triple-TOF-MS.An abundance of anthocyanins constituents was identified:Cyanidin 3,5-di-glucoside(Cy3G5G)?Cyanidin 3-glucoside(Cy3G)?Cyanidin 3-p-coumaroylglucoside-5-glucoside(Cy3pC5G)?Cyanidin 3-rutinoside(Cy3Ru)?Cyanidin 3-sambubioside(Cy3Sa)?Pelargonidin 3,5-diglucoside(Pg3G5G)?Pelargonidin 3-glucoside(Pg3G)?Pelargonidin 3-rutinoside(Pg3Ru)?Peonidin 3-(6"-p-coumarylglucoside)(Pn3(6"pC))?Peonidin 3,5-di-glucoside(Pn3G5G)?Peonidin 3-rutinoside(Pn3Ru)?Peonidin 3-p-coumaroylglucoside-5-glucoside(Pn3pC5G),among which Cy3Sa?Pg3Ru?Pn3(6"pC)were first ditected in Rosa.L plants.The content and composition of anthocyanin compounds varied significantly among species and modern roses petals investigated.Distinct differences in the distribution of petal anthocyanins compounds were observed,especially between Rosa species and modern rose cultivars.In general,dark red series were richer in content of anthocyanins,Multivariate statistical analysis clustered the investigated species and cultivars into 4 groups,which were formed according to the content of 12 anthocyanins;white and yellow ones were distant from the dark red?purplish red and orange red ones,which were similar to the pink and rose red cultivars.