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On Some Experiments in Raising a Nicotine-free Tobacco Plant

1937; Botanical Society of Japan; Volume: 51; Issue: 605 Linguagem: Inglês

10.15281/jplantres1887.51.306

2185-3835

HIROSI HASEGAWA,

Plant Virus Research Studies

1. Recently, owing to hygienic reasons, manufacturers endeavour to make cigars and cigarettes which are free from nicotine or very low in its content, yet retaining the good flavour of tobacco. Several such products have hitherto been offered to market, but none of them being actually nicotine-free.2. KÖNIG (1933) and SENGBUSCH (1935) were successful in breeding a new strain of tobacco plant with a very low nicotine content, though not yet entirely devoid of it.3. The present author made some experiments on mutual graftings between the tobacco- and the tomato-plant, and has succeeded in producing, on one hand, nicotine-free tobacco leaves and, on the other, tomato leaves containing nicotine.4. The experiments on grafting between the tobacco and other solanaceous plants, with respect to its effect upon the nicotine content, were already conducted by GRAFE and LINSBAUER (1906), MEYER and SCHMIDT (1910) and SILBERSCHMIDT (1933), but all these investigators have undertaken their observations only a short time after grafting, while the author's own experiments have been extended over a period as long as seven months.5. A. WENUSCH'S method for the determination of minute quantities of nicotine was solely used in the present investigation.(a) In the cases of experiments: tobacco plant (graft) other solanaceous plants (stock)' after 44 days of grafting, nicotine has completely disappeared from the grafted tobacco plant even while vigorously growing, and in the reverse cases nicotine became clearly demonstrable in the leaves of non-tobacco grafts.(b) In the case of experiment: tomato (graft)/tobacco (stock), nicotine not only made its appearance in tomato plant shortly after grafting, but was gradually increased in its quantity, until a considerably high content of about 2% has been attained (viz. 0.19% after 100 days and 1.91% after 210 days). These results are very noteworthy and far more conspicuous than those of previous authors.6. The tobacco leaves prepared for smoking from the grafting: tobacco/tomato proved to be very mild and sweet, as they contain no trace of nicotine. On the contrary, the nicotine-containing tomato leaves from the reciprocal grafting were highly stimulative with a perceptible odour of nicotine.7. In regard to the physiological processes leading to the disappearance resp. formation of nicotine in grafted plants, further metabolic investigations are needed.