基于不同烟碱转化株鉴别标准的白肋烟品种改良效果

在采用不同烟碱转化株鉴别标准对TN86进行改良的基础上，对不同改良种的烟叶经济性状、烟碱转化率和TSNAs含量进行比较分析，以探讨采用不同转化株鉴别标准进行白肋烟品种改良的效果。结果表明，以烟碱转化率低于2.5%作为选择标准得到的改良种1（PNC<2.5）烟碱转化率稳定，上部叶比常规种低37.7%，中部叶低38.3%；总TSNAs含量低，比常规种低17.9%；产量、产值及上中等烟比例也明显优于其他改良种，且后代变异系数最小。改良种2（PNC<3）和改良种3（PNC<5）的烟碱转化性状分离明显，TSNAs含量较高。综合来说，烟株烟碱转化率2.5%作为区别转化株和非转化株的标准较为可靠，选择PNC<2.5的烟株进行留种或制种可以保证后代群体中出现转化株的频率最低，能够更有效地降低降烟碱含量和烟草特有亚硝胺的形成和积累，提高烟叶的香味品质。 

Improvement Effect of Burley Varieties Based on Identification Standard of Different Nicotine Converter

Different improved TN86 varieties developed with different screening standard for identifying nicotine converter and non-converters were compared for economic character, nicotine conversion ratio, and the content of TSNAs. The result showed that nicotine conversion ratio of improved variety 1(PNC<2.5) developed with selecting plants with nicotine conversion ratio of less than 2.5% was more stable, the ratio of upper tobacco was 37.7% lower than conventional breed; which is also 38.3% lower than that of cutters. The total content of TSNAs was 17.9% lower than conventional breed, the yield, output value and the proportion of middle and superior tobacco were better than other improved varieties, and the variable coefficient was lowest. The separations of nicotine conversion characters of improved variety 2(PNC<3) and improved variety 3(PNC<5) were significant, the contents of TSNAs was higher. Generally speaking, there was reliable that difference from between converter and no-converter with nicotine conversion ratio of 2.5%. Choosing the tobacco PNC<2.5 can ensure the lower ratio of appearance of conversed plant, and more effectively reduce the content of nornicotine and the content of TSNAs was formatted and accumulated, then the aroma quality will be improved.