A Comparison of Rind Oil Components of Diploid and Tetraploid Citrus by Gas-Liquid Chromatography

Rind oil components (excluding terpenes) of diploid and tetraploid selections of seven Citrus varieties comprising four species were compared by gas chromatography. The tetraploids were autotetraploid, asexual derivatives of the diploids. Percentages of the oil constituents were markedly similar between diploids and their respective tetraploids. Those significant differences which were found tended to occur at the same peaks among different varieties; the direction of the differences between diploids and tetraploids also tended to be the same for a given peak. 'Royal' grapefruit which may be a natural hybrid, showed several conspicuous differences between its diploid and tetraploid forms, and showed many differences from a more typical grapefruit, the 'Hall'. The diploid and tetraploid forms of 'Lisbon' lemon both had high percentages of oil in the regions of geranyl acetate, geranial, and nerol. The components ocatanal, linalool, nonanol, and a-terpineol were present in substantial quantities in most of the varieties. Each variety could be distinguished from the others by the overall percentages of its various oil components.