|Baldwin, Elizabeth - Liz|
Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Proceedings
Publication Acceptance Date: 8/1/2013
Publication Date: 4/11/2014
Citation: Deterre, S., Mccollum, T.G., Leclair, C., Bai, J., Manthey, J.A., Salvatore, J.J., Raithore, S., Baldwin, E.A., Plotto, A. 2014. Secondary metabolite composition in Citrus x Poncirus trifoliata hybrids. Proceedings of Florida State Horticultural Society. 126:206-215. Interpretive Summary: The hybrids of citrus x Poncirus trifoliata are receiving a renewed interest because they show less symptoms of the citrus greening disease due to Candidatus liberibacter asiaticus. Fruit of P. trifolata are inedible, but after several generations of crosses with citrus, some hybrids may produce fruit with potential commercial interest. One family of such hybrids was analyzed for fruit composition of secondary metabolites. This is the beginning of a systematic research that will evaluate quality of citrus x poncirus hybrids.
Technical Abstract: Poncirus trifoliata L.Raf is used as a parent in citrus rootstock breeding because it confers desirable characteristics, such as disease resistance and cold hardiness. However, fruit of P. trifoliata hybrids typically have unpleasant flavor. The objective of this study was to determine the chemical composition of juice from P. trifoliata hybrids for comparison with the fruit of P. trifoliata. Six hybrids were studied: the female parent (5-14-96, 1/4 P. trifoliata), the male parent (1-11-7, no P. trifoliata), and four siblings (6-49-96, 6-49-116, 6-49-148 and 6-49-163, all 1/8 P. trifoliata). Juice from these hybrids was analyzed for volatiles, flavonoids, limonoids, sugars and acids. Juice of P. trifoliata was also analyzed. The volatile profile of juice from the female parent showed the most similarity to P. trifoliata, with many sesquiterpene hydrocarbons and esters. The hybrid 6-49-163 presented a similar pattern regarding volatile composition. However, another hybrid, 6-49-116, also presented the high content of limonoids and flavonoids measured in the female parent and in P. trifoliata. For these preliminary results, we observed differences among siblings with the same parents based on their secondary metabolite composition. Complex differences in volatiles, limonoid and flavonoid compounds among P. trifoliata hybrids were revealed in this study. When eventually correlated with sensory data, our results could be used to evaluate the chemical basis of juice quality and thus select P. trifoliata hybrids for consumption.