Nitrogen Application Modifies the Seed and Oil Yields and Fatty Acid Composition of Nicotiana tabacum

Abstract

Tobacco is traditionally an industrial crop that is used for manufacturing cigarettes. However, due to health concerns and global tobacco control movements, alternative uses of tobacco are urgently needed to support tobacco farmers and vendors. Tobacco is also an oilseed crop with an oil yield ranging from 30% to 40 of its dry weight. However, there is still no information on the effects of nitrogen application on tobacco seed yield and seed oil production. The objective of this study was to evaluate the effects of N fertilization (90, 120, 150, and 180 kg·ha−1 N) on the seed yield, oil content, fatty acid composition, and seed germination characteristics of tobacco plants at two locations. The results showed that applying increasing amounts of N to tobacco plants significantly increased their total seed yields and oil content. Nitrogen application also modified the fatty acid composition of the seed oil, as more unsaturated fatty acids were produced under the increasing N application rate treatments than under the control. Moreover, increasing the N application rate generally significantly increased the yields of individual fatty acids as well. Nevertheless, the increased seed oil content and altered fatty acid composition did not affect seed germination traits, as the seed germination potential and rate showed no obvious change among treatments or the control. The height and size of the tobacco plants also increased with the increasing N application rate, which would be beneficial for increasing biomass production for bioenergy. This study shows for the first time the feasibility of increasing the seed and oil yields and modifying the fatty acid composition of tobacco plants by increasing N addition.