Leaf and peel volatile compounds of an interspecific citrus somatic hybrid [Citrus aurantifolia (Christm.) Swing. plus Citrus paradisi Macfayden]

The volatile compounds from leaves and peels of an interspecific citrus somatic hybrid, Citrus aurantifolia (Christm.) Swing. + Citrus paradisi Macfayden, obtained by fusion of protoplasts from lime, Citrus aurantifolia (cv. Mexican Lime) and grapefruit, Citrus paradisi (cv. Star Ruby), were extracted by pentane: ether (1: 1) from liquid nitrogen ball-milled leaves and flavedo and examined by GC-MS in comparison to those of its parents. The hybrid quantitatively retained the ability of the lime parent to synthesize in its leaves the major monoterpene aldehydes (neral, geranial) the monoterpene alcohols (nerol, geraniol), and their acetates, and also the capacity of the grapefruit parent to produce a sesquiterpene aldehyde (beta-sinensal) in its leaves and nootkatone in its peel. Conversely, synthesis of most sesquiterpene hydrocarbons and long chain aliphatic aldehydes, which are present in the lime parent leaves and peel, was strongly inhibited in the hybrid, as in the grapefruit parent. In comparison to its parents, the hybrid overproduced citronellal in its leaves and alpha-sinensal and beta-sinensal in its peel. Based on these results, the future prospects for a better understanding of the inheritance mechanisms with regards to aroma biosynthesis in citrus leaves and peels are discussed. Copyright (C) 2002 John Wiley Sons, Ltd.