白肋烟烟碱转化性状的主基因+多基因遗传分析

为了掌握白肋烟烟碱转化性状的遗传规律，利用高和低烟碱转化的白肋烟品种Va1050(P1)、Va1053(P2)配制了F1代和F2群体，基于4个世代采用植物数量性状主基因+多基因混合遗传模型分析法对烟碱转化性状进行了遗传分析，并估算了遗传参数。结果表明：白肋烟烟碱转化的遗传符合2对等加性-等显性主基因+加性-显性多基因遗传模型(E-5)，主基因遗传率为58.18%，多基因遗传率为11.72%。因此，白肋烟烟碱转化性状由2对主基因控制，同时还存在多基因的修饰作用和环境因素的影响。在育种实践中，烟碱转化性状的高遗传率对目标亲本的有效选择可利于优质低烟碱转化品种的选育，另外，也需要在烟叶调制和陈化过程加强温湿度的控制。

Genetic Analysis of Nicotine Conversion of Burley Tobacco Using Mixed Model of Major Gene and Polygene

In order to understand the genetic control of nicotine conversion in burley tobacco the joint genetic analysis of nicotine conversion was carried out based on four generations P1 (Va1050 with high nicotine conversion), P2 (Va1053 with low nicotine conversion) and their F1 and F2 using mixed model of major gene and polygene. Genetic parameters were also estimated. The results showed that the genetic model of two pairs of major genes with equal additive and equal dominant effect and polygenes with additive and dominant effect (E-5) was selected for nicotine conversion of burley tobacco materials used in this study. The heritability of major genes and polygenes was 58.18% and 11.72%, respectively. As a consequence, nicotine conversion of burley tobacco mainly was controlled by two pairs of major genes and modified by polygenes and environmental factors such as temperature and humidity. In practical breeding, it will be effective that selecting parents with low conversion for breeding target varieties because of high heritability of this trait. Additionally, temperature and humidity control are also very important for reducing nicotine conversion during tobacco leaves curing and aging.