Study On Variation Of Nicotine Conversion And Identification Standards Of Converters For Burley Tobacco

Study on variation of nicotine conversion and identification standards of converters for burley tobacco in sichuan. The result was showed that:1 Relationship between principle alkaloid contents in natural and purified populations of burley tobaccoIn the nature population of burley tobacco, some plants have the ability converting nicotine to nornicotine due to gene mutation, resulting in the abnormal increase of nornicotine content, which has negative effect on tobacco safety and flavor quality. Burley tobacco hybrids Dabai 1 and Eyan 1 were used to investigate the relationship between principle alkaloid contents in bulk and individual samples from natural and purified populations. The results showed that in the purified populations nicotine content accounted for 92%-95% of total alkaloid ; the proportion of anatabine was higher than that of nornicotine, they were 3.2%-5.0% and 1.6%-2.8% respectively; the proportions of anabasine was the lowest. In the natural population contained large amount of converted plants, the nicotine content decreased and the nornicotine content increased, and the nornicotine content was higher than anatabine content. In the purified populations, as the increase of total alkaloids, all the principle individual alkaloids increased linearly, with the order of correlation coefficients with total alkaloids as nicotine > anatabine or anabasine > nornicotine, and with the order of slope for alkaloid increasing as nicotine > nornicotine > anatabine > anabasine. In natural populations, the correlation of total alkaloid with nicotine and nornicotine decreased, and that with anabasine and anatabine did not change. The nicotine and nornicotine were positively correlated in purified populations, but negatively or no correlated in natural populations. Anatabine was significantly and positively correlated with anabasine in both populations.2 The relationship of nicotine conversion rate with individual alkaloid contents and Anat/NnicBurley varieties Dabai 1 and Eyan 1 were used to investigate the relationship of nicotine conversion rate with individual alkaloid contents and the ratio of anatabine to nornicotine in ethylene treated leaves and air-cured leaves. The results indicated that nicotine conversion rate had significantly negative correlations with nicotine content, and significantly positive correlation with nornicotine content. As the increase of nicotine conversion, the contents of anatabine and anabasine remained unchanged. Nicotine conversion rate had significant power function relation with Anat/Nnic. For early conversion induced leaves, when Anat/Nnic was below 0.8, the nicotine conversion rate began to increase significantly, and the corresponding conversion rate was 2.5%; for air-cured leaves, when Anat/Nnic was below 1.1, the nicotine conversion level began to increase markedly, and the corresponding conversion value was from 2.8%-3.0% for Dabai 1 and Eyan 1 respectively.3 Variation of nicotine conversion rate among different leaf positions and leaf areas for burley tobacco of different conversion typeGC method was used to analyze the nicotine conversion rate of burley samples from different leaf positions and leaf areas of plants with different conversion levels. The results showed that for non-converters and high converters, the distribution of nicotine conversion rate among different leaf positions and leaf areas was consistent with small variation; nicotine conversion rate all the samples were below 2% for non-converters and were above 85% for high converters, with no chimera characteristics; so the sampling position had no impacts on identification results. For low converters and medium converters, great variation of nicotine conversion rate existed among different leaf positions and leaf areas, and the chimera characteristics were displayed. The range of nicotine conversion rate for low converters was 2.5%-4.8% for leaf positions, and 2.6%-7.0% for leaf areas. The range of nicotine conversion rate for medium converters was 2.51%-90.6% for leaf positions, and 2.7%-66.9% for leaf area. Since the nicotine conversion rate of certain leaf samples were below the current converter standard, the sampling position would have great impact on converter identification, So lowering the standard was quite necessary for more efficient screening.4. analysis of economic traits and the main chemical components and sensory evaluation quality after air-cured among different varietiesAfter the modulation of different varieties in the upper leaf chemical components of mixed samples and the quality of smoking. The results showed that the alkaloid content of imported varieties K204 was more appropriate and variability of nicotine converters was small and nicotine conversion rate was less than 3%, was almost the purified populations. But The range of nicotine conversion rate was 0.863%-90.464% for domestic varieties TN97, TN90, EY4 and Dabai 1. But other varieties had many nicotine converters of different degrees. Different varieties in sugar, total nitrogen and mineral elements was not very different and the nicotine conversion had significant difference. Smoking results by the known, KT204 of the varieties the aroma character, pure aroma and aroma quantity increased, reduce irritation. But TN97 and TN90 of the two varieties exist nicotine convert plants so quality poor.