Changes of Alkaloid Composition During Curing in Three lsogenic Burley Tobaccos and Their F1 Hybrids

Abstract Quantitative changes of nicotine, nornicotine, anabasine (including anatabine), and total alkaloids in the juvenile leaves and roots of Nicotiana tabacum cv. Burley 21 (HN) and its isogenic lines selected for nicotine conversion (C), and low total alkaloids (LN) were studied during air-curing simulation. In the leaf, the C line contained less total alkaloids but more nornicotine than the HN line, suggesting that some may have been converted to nornicotine during leaf growth. The conversion phenomenon was not observed in the root. The root tissues of the LN line showed a high rate of nicotine decomposition at the inception of curing. On the basis of F1 results, both total alkaloids and nicotine conversion are governed by dominant factors. An intermediate nornicotine / nicotine ratio for the cured leaves of the LN and C hybrids indicated the presence of converter modifiers in the LN line. In the C line and its hybrids the decrease of nicotine content mainly occurred at the beginning of curing, whereas the nornicotine increase appeared after the eighth day of curing. The amount of anabasine was increased in the leaf but was decreased in the roots by curing