Regulations under consideration by the U.S. Food and Drug Administration and the World Health Organization propose that nicotine concentration in tobacco (Nicotiana tabacum L.) should be lowered to non‐addictive levels (0.3 to 0.5 mg g⁻¹). The proposed standards are 90 to 95% lower than the nicotine concentration typically documented in commercially available cultivars. Research was conducted in six environments to evaluate two cultivars with normal alkaloid levels (K326 and NC95) and four genotypes with low alkaloid levels (DH16A, DH22A, DH32, and LAFC53). Each cultivar and genotype was paired with three N application rates: 70, 85, and 100% of the recommended rate. As N application declined, so too did cured leaf yield and nicotine, anabasine, and anatabine concentration in K326 and NC95. These factors were generally not affected by N application in the low alkaloid genotypes. In contrast, LAFC53 consistently produced the lowest cured leaf quality, value, and reducing sugar concentration when compared to all other cultivars. This observation demonstrates that K326 isolines are agronomically superior to LAFC53. Despite reductions in nicotine, the lowest documented concentration was still 10‐fold greater than the proposed minimum (LAFC53). Nitrogen did not influence the measured parameters as much as genetics; therefore, additional research that involves other agronomic practices is warranted. In addition, further genetic manipulation will be required to meet the standards proposed by regulatory groups.

中文翻译：

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遗传因素对烤烟收获后测量的影响大于施氮量

美国食品药品监督管理局和世界卫生组织正在考虑的法规建议将烟草（尼古拉烟草）中的尼古丁浓度降低至非成瘾水平（0.3至0.5 mg g ^-1）。提议的标准比市售品种中通常记录的尼古丁浓度低90％至95％。在六个环境中进行了研究，以评估两个生物碱水平正常的品种（K326和NC95）和四个生物碱水平较低的基因型（DH16A，DH22A，DH32和LAFC53）。每个品种和基因型都与三种氮素施用量配对：建议施用量的70％，85％和100％。随着氮肥施用量的减少，治愈的叶片产量以及K326和NC95中烟碱，烟碱和阿那他滨的浓度也下降了。在低生物碱基因型中，这些因素通常不受氮施用的影响。相反，与所有其他品种相比，LAFC53始终产生最低的腌制叶片质量，价值和降低的糖浓度。该观察结果表明，K326等位基因在农学上优于LAFC53。尽管尼古丁减少，但记录的最低浓度仍比建议的最低浓度（LAFC53）高10倍。氮对遗传参数的影响不如遗传学那么大。因此，需要进行涉及其他农艺实践的附加研究。此外，将需要进一步的基因操作来满足监管机构提出的标准。