不同海拔地区烤烟叶片光合特性的日变化特征

Diurnal Variance of Photosynthesis Characteristics of Flue-cured Tobacco at Different Altitudes

以3个遗传背景不同的烤烟品种(‘K326’、‘云烟87’、‘中烟103’)为材料,研究不同海拔(500、900、1 300m)地区烤烟叶片的光合气体交换与叶绿素荧光参数的日变化特征,为烟草种植区划分和区域适宜烤烟品种配置提供理论依据。结果显示:(1)各品种烤烟叶片的净光合速率(Pn)、气孔导度(Gs)和水分利用率(WUE)的日均值与海拔呈正相关关系,而其胞间CO2浓度(Ci)和蒸腾速率(Tr)的日均值与海拔高度呈负相关关系。(2)各品种叶片Pn、Ci、Gs及Tr的日变化在高海拔(1 300m)地区呈"单峰"曲线变化,没有明显的光合"午休"现象;而在较低海拔(500m和900m)地区呈不对称"双峰"曲线变化,在晴天中午时段叶片光合受到明显抑制。(3)3个烤烟品种叶片的PSⅡ原初光能转换效率(Fv/Fm)和PSⅡ潜在活性(Fv/F0)随着海拔的升高而提高。(4)各品种的日光合总量(∑Pn)均呈现随海拔升高而增加的趋势,且‘云烟87’的日光合总量显著高于其他两个品种;各品种的日蒸腾总量(∑Tr)均以海拔900m最高,海拔1 300m最低。研究表明,海拔因素是影响和制约烤烟叶片光合特性及光合生产能力的关键因素,在品种布局时必须考虑其在不同海拔地区的光合特性。

The kinetic parameters of chlorophyll fluorescence and the photosynthetic rate of the different genetic background flue-cured tobacco varieties（＇K326＇,＇Yunyan 87＇,and ＇Zhongyan 103＇） were studied under different altitude conditions,and their influencing factors Gs,Ci,Tr,WUE were investigated.The result showed that：（1）There were positive correlation between the average daily value of Pn,Gs,WUE and altitude and negative correlation between the average daily values of intercellular CO2 concentration（Ci）,transpiration rate（Tr） and altitude.（2）The diurnal variation of Pn,Ci,Gs,and Tr in the leaves presented a one-peak distribution and an unobvious midday depression occurred at altitude of 1300 m,and the diurnal variation of Pn,Ci,Gs,and Tr presented a bimodal pattern and an obvious midday depression occurred in the sunny noon.（3）The primary light energy conversion of PSⅡ（Photo-systemⅡ）（Fv/Fm） and potential activities of PSⅡ（Fv/F0） of the three tobacco varieties increased with increasing altitude.（4）The daily photosynthesis（∑Pn） of the three tobacco varieties increased with increasing altitude,and the daily photosynthesis of ＇Yunyan 87＇ varieties were significantly higher than the other two varieties.At altitude of 900 m,flue-cured tobacco＇s leaves had the highest daily transpiration（∑Tr）,and the lowest in 1 300 m.Obviously,the photosynthetic characteristics and photosynthetic capacity of flue-cured were affected and restricted by altitude factors,and the photosynthetic characteristics of tobacco varieties should be considered during distribution of varieties.