Abstract: The diurnal variation of photosynthetic indexes of Cymbidium lowianum cultivated in 5 kinds of cultivation medium was determined adopting LI-6400 photosynthetic performance. The results showed that the diurnal variation of photosynthetic indexes such as net photosynthetic rate, transpiration rate, intercellular CO₂ concentration, stomatal conductance, were of the same trend, presented a double-peak curve. The change value of net photosynthetic rate, intercellular CO₂ concentration and stomatal conductance of Cymbidium lowianum cultivated in medium Ⅳ were relatively large, next came medium Ⅲ, and there were significant differences between mediumⅣ, Ⅲ  and medium Ⅴ (CK) (p<0.05). In general, the medium Ⅳwas the optimum culture medium for the growth of Cymbidium lowianum.

Key words: Cymbidium lowianum, cultivation medium, photosynthetic physiology

摘要： 探讨5种不同栽培基质对碧玉兰光合指标日变化的影响。结果表明：5种基质栽培的碧玉兰，其净光合速率、蒸腾速率、胞间CO₂浓度及气孔导度的日变化趋势基本呈“双峰”曲线。在基质Ⅳ（1/4树皮+1/4泥炭+1/4水苔+1/4陶粒）中栽培的碧玉兰净光合速率、胞间CO₂浓度及气孔导度变化值相对较大，其次是基质Ⅲ（1/2树皮+1/4泥炭+1/4水苔），两者与对照差异显著（p<0.05）。综合来看，基质Ⅳ最适宜碧玉兰的生长。

关键词: 碧玉兰, 栽培基质, 光合生理