不同种植密度烤烟净光合速率日变化与生理生态因子的关系

摘要

以"吉烟九号"成熟期烟叶为试材,探讨不同种植密度下烤烟净光合速率日变化与生理生态因子的关系.结果表明,3个种植密度的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、叶片温度(TL)和大气温度(Ta)的日变化均为单峰曲线,峰值多出现在11:00或13:00,没有"午休"现象;种植密度过高或过低都会不同程度降低光合作用,以15100株/hm2群体结构较为合理,Pn最大,光合能力较强;在3个种植密度下,影响烤烟Pn的主要生理因子是Gs,主要生态因子是PAR.%Relationship between diurnal changes of net photosynthetic rates (Pn) and physio-ecological factors in leaves of “Jiyan NO.9” plum were studied in different planting densities.Results showed that the diurnal changes of Pn, stomatal conductance (Gs), transpiration rates (Tr), leaf temperature (TL), and air temperature (Ta) of three densities appeared as single peak curves, and the majority of peaks presented to 11:00 or 13:00 without midday depression.Higher or lower planting densities decreased photosynthesis.The reasonable planting density was 15,100 plants per square ha with the highest Pn as well as strong photosynthetic capacity.Under the three densities, the major physiological factors affecting Pn was Gs and the major ecological factors was PAR.