遗传改良降低白肋烟杂交种烟碱转化率研究

【目的和方法】本研究针对中国白肋烟主栽杂交种鄂烟1号烟碱转化株比例和烟碱转化率高的问题，采用转化株早期诱导鉴定和选择技术对其亲本进行了改良，配置出改良杂交种LC-1和LC-2，并探讨了其增质减害效果。【结果】经过3代定向选择后亲本材料B21的转化株比例由70.7%降低到0.0%～0.5%；B37由10.9%降低到0.0%～0.5%。两个改良鄂烟1号（2005年）的总转化株比例分别为5.0%和11.6%，分别比对照常规鄂烟1号的45.0%降低约 9倍和4倍；混合样品的烟碱转化率分别为2.14%和3.13%，比对照的10.65%分别降低4倍和2.4倍；总TSNA含量分别比常规种降低86.7% 和102.6%，其NNN 含量分别降低186.9%和155.5%。改良杂交种香味品质明显改善，表现为烟叶风格程度增加，香气质、香气量提高，杂气减少。【结论】改良杂交种生物碱组成得到优化，增质减害效果明显，具有很大的推广利用价值。

Study on Decreasing Nicotine Conversion in Chinese Burley Hybrid Through Genetic Improvement

Objective and method] The study was conducted, through early identification and selection, to investigate the effect of selecting parents of Eyanl for nicotine conversion and to compare the effects on reducing converters, decreasing tobacco specific nitrosamine and increasing flavor quality in improved hybrids, LC-1 and LC-2, with the regular hybrid, which had high proportion of converters in the population. Result ] Through 3 generation systemic selections, the proportion of converters in the population of B21 reduced to 0.0% to 0.5% from 70.7% in the original population, and for B37, reduced also to the same proportion from 10.9%. The proportions of total converters in the two improved hybrids were 5.0% and i i .6%, respectively, 9 and 4 times lower than the regular hybrid which had the proportion of 45.0%. The percent nicotine conversions of the two improved hybrids in the bulk samples were 2.14% and 3.13%, respectively, 4 and 2.4 times lower than the contract which had the number of 10.65%. The total TSNA contents in the two improved hybrids decreased 86.7% and 102.6% compared with regular hybrid, and the difference was mainly caused by NNN reduction, the percent decreases were 186.9% and 155.5%, respectively. Improved hybrids had better tobacco flavor quality than the regular hybrid, with increased burley style, enhanced aroma quality and quantity, and decreased offensive odor Conclusion ] The improved hybrids had better alkaloid composition, higher flavor quality and lower harm, therefore had high value of utilization in burley tobacco production.