打顶对烤烟上部叶质体色素和磷素含量动态变化的影响

Effects of Topping on Dynamic Changes of Chromoplast Pigment and Phosphorus Content in Upper Leaves of Flue-cured Tobacco

以湘烟3号为试验材料,研究了烤烟打顶后上部烟叶中质体色素、磷含量的动态变化及其相关关系,结果表明:烤烟在打顶后的生育期间,烟叶的磷、叶绿素、类胡萝卜素含量的变化趋势较为一致,打顶当天的含量最高,随后则不同程度地下降;叶绿素和类胡萝卜素的分解前期较少,主要在打顶后的30～45 d之间;影响烟叶中磷含量的主要因素是叶绿素a、类胡萝卜素,均与磷含量呈极显著正相关;其次是叶绿素,表现为显著正相关关系;而叶绿素a/b值、类胡萝卜素/叶绿素值与磷含量表现为正相关关系,但未达到显著水平。

The flue -cured tobacco variety Xiangyan No. 3 was used as the experimental material, and the dynamic changes of chromoplast pigments and phosphorus content in the upper tobacco leaves after topping and their relationships were studied. The results demonstrated that： during the growth season after topping, the contents of phosphorus, chlorophyll and carotenoid in tobacco leaves showed the similar variation tendency： it was the highest on the day of topping, and then decreased to a certain extent. The degradation of both chlorophyll and carotenoid occurred mainly from the 30th to the 45th day after topping, and it happened little in the earlier period. The factors influencing the phosphorus content in tobacco leaves were mainly chlorophyll a content and carotenoid content, and they both had very significant and positive correlation with the phosphorus content （ P 〈 0.01 ）. The chlorophyll content also had signif- icant and positive correlation with the phosphorus content （ P 〈 0.05 ）. The chlorophyll a/b and the ratio of carotenoid content to chlorophyll content had weak positive influence on the phosphorus content （ P 〉 0.05 ）.