Citrus somatic hybrid leaf essential oil

The essential oil from the leaves of a Citrus interspecific somatic hybrid obtained by symmetric protoplast fusion between 'Milam' lemon [purported se xual hybrid of C. Jambhiri 'Lush (x) C, sinensis] and 'Femminello' lemon (C . limon L. Burm f.) has been characterized by steam distillation CC-MS anal ysis and its composition compared with that of the corresponding oils obtai ned from the parent plants. The amount (%) of the different classes of substances present in the oils s how, in the new hybrid, an overall lowering of the hydrocarbon fraction and an increase of the oxygenated components. The somatic hybrid shows a close similarity in the amounts of terpenes, sesquiterpenes and alcohols with th e 'Milam' parent and in the amount of aldehydes with the other parent. Rema ining oxygenated components appear lower in the hybrid with respect to both parents. Because of their genetic origins, the hybrid cells possess the nuclear geno me of both parents and should potentially maintain all their genetic traits . However, the closer similarities found in the composition of the essentia l oils in the leaves of the somatic hybrid and the 'Milam' parent could be interpreted as the dominance, in the nucleus, of the genetic information fr om this parent, although possible interactions between the nucleus and the mitochondrial genome cannot be at present accounted for since the origin of the latter is uncertain. Copyright (C) 2000 John Wiley & Sons, Ltd.