夜温对不同品种烟苗顶芽主要内源激素含量的影响

在人工气候箱中以烤烟品种云烟87、K326、中烟100和红大为材料，采用人工模拟设置不同夜间温度，研究不同品种烤烟苗期（五叶一心-栽后25d）顶芽赤霉素（GA3）、生长素（IAA）和细胞分裂素（CTK）含量变化对夜温变化的响应。结果表明：（1）从连续夜间处理25d平均含量来看，随着夜间处理温度的升高以及处理时间的延长，4个烤烟品种烟苗顶芽内源激素对夜温响应存在一个转折温度点，其中CTK响应转折点为夜温11℃或15℃，GA3响应转折点为夜温11℃，各激素含量最大值主要集中在夜温处理后的5～20d。（2）从各品种响应来看，夜温升高更有利于烤烟苗期顶芽CTK、IAA的合成积累，其中云烟87在夜温11℃处理第20天时CTK含量达到最高值51.23mol·L-1，第5天时IAA含量最高（29.27mol·L-1）；中烟100在夜温11℃处理第10天时CTK含量最高（51.03mol·L-1），第5天时IAA含量最高（32.72mol·L-1）；K326在夜温15℃处理第10天时CTK含量最高（44.65mol·L-1），在夜温19℃处理第20天时IAA含量最高（35.47mol·L-1）；红大在夜温19℃处理第15天时CTK含量最高（50.61mol·L-1），第20天时IAA含量最高（29.57mol·L-1）。

Impacts of Night Temperature on Main Endogenous Hormones Content in Seeding Top of Flue-cured Tobacco

Taking tobacco cultivars of ‘Yunyan 87’, ‘K326’, ‘Zhongyan100’ and ‘Hongda’ as materials to analyze the effect of night temperature on the contents of GA3 (crown gibberellin), IAA (crown auxin) and CTK (crown cytokinins) in flue-cured tobacco, by using man-made climate chambers. The results showed that, under continuous treatment with increasing night temperature for 25 days, there was a temperature turning point between night temperature and the tobacco seedling crown endogenous hormone in all of flue-cured tobacco, the temperature turning point of CTK was 11℃ or 15℃, while that of GA3 was 11℃. The peak value of hormone contents was at 5 to 20 days after their seedling. The increasing night temperature was benefit to the accumulation of CTK and IAA in top seeding of flue-cured tobacco, the content of CTK of ‘Yunyan 87’ reached to the peak value with 51.23mol·L-1, after 20 days under 11℃ treatment, while its content of IAA reached to the peak value with 29.27mol·L-1 after 5 days. The content of CTK of ‘Zhongyan 100’ reached to the peak value with 51.03mol·L-1, after 10 days in 11℃ treatment, while its content of IAA reached to the peak value with 32.72mol·L-1 after 5 days. The content of CTK of ‘K326’ reached to the peak value with 44.65mol·L-1 after 10 days in 15℃ treatment, while its content of IAA reached to the peak value with 35.47mol·L-1 after 20 days in 19℃ treatment. The content of CTK of ‘Hongda’ reached to the peak value with 50.61mol·L-1 after 15 days in 19℃ treatment, while its content of IAA reached to the peak value with 29.57mol·L-1 after 20 days.