Citrus hybrids

Figure 4.5. The NP composition of a typical plant extract (in this case, a citrus hybrid) as revealed by gas chromatographic analysis. The peaks on the upper trace represent the different chemicals detected by the instrument, with the peak area being a measure of the amount of any substance. Note that there are a few major NP peaks but even more very minor ones. The spikes pointing down on the lower trace are the odours detected by a human sniffer with their perceived odour name. Note the human detection of odour does not always correspond to the emergence of a major chemical peak. For example near the start of the analysis, the green or burning smell detected by the human does not correspond to any instrument detection so those chemicals are below the level of detection of the instrument. (Modified from the data of Morton M, Smoot JM, Mahattanatawee K, Grosser] and Rouseff RL, Citrus Research and Education Center, University of Florida.)...

Exposure of citrus fruits to ethylene has been shown to increase the incidence of stem-end rot caused primarily by D natalensis (113, 124, 125, 126, 127). Higher than recommended ethylene concentrations (75, 106, 116, 128, 129) and temperature (116) and an increase in degreening duration (116, 125) caused significant increases in stem-end rot. Anthracnose, caused by . gloeosporioides, is a serious disease of specialty citrus hybrids such as Robinson, Lee, Nova, and Page (130, 131), when fruit are exposed to ethylene. Incidence was related directly to length of degreening (130), ethylene concentration (132,... 

In addition to the above, there is another group of limonoids present in a citrus hybrid, calamondin (Citrus reticulata cv. 

ScoRA, R. W., J. W. Cameron, and J. A. Berg, Rind and leaf oils of tetraploid interspecific Citrus hybrids and their diploid and tetraploid parents. Taxon, 19, 752-761 (1970). 

Jourdan PS, McIntosh CA, Mansell RL (1985b) Naringin levels in citrus tissues. II. Quantitative distribution of naringin in Citrus paradisi Macfad. Plant Physiol 77 903-908 Kamiya S, Esaki S, Konishi F (1979) Flavonoids in citrus hybrids. Agric Biol Chem 43 1529-1536 Kefford JF, Chandler BV (1970) The chemical constituents of Citrus fruits. Academic Press, New York... 

Pummeline 1,6-diOH, 3-OMe, 10-Me Citrus hybrids [27], C. hybrid Yalaha (C. paradisi x C. tangerina) [30]... 

Berhow, M.A., Omura, M., Ohta, H., Ozaki, Y., and Hasegawa, S. 1994. Limonoids in seeds of three citrus hybrids related to citrus ichangensis. Phytochemistry, 36, (4), 923-925. Schwager, J., Mohajeri, M.H., Fowler, A., and Weber, P. 2008. Challenges in discovering bioactives for the food industry. Current Opinion in Biotechnology, 19, (2), 66—72. 

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