栽培穿龙薯蓣田间持水量与光合作用关系的研究

目的]研究栽培穿龙薯蓣田间持水量与光合作用的关系,为穿龙薯蓣栽培的水分管理提供理论依据。方法]采用盆栽试验,用CI-340超轻型便携式光合测定仪测定光合参数。结果]70%的田间持水量是穿龙薯蓣光合能力最强的土壤含水量,此时蒸腾速率和水分利用效率较高。在50%田间持水量条件下,净光合速率日变化均呈明显的双峰曲线;70%田间持水量的峰值出现在中午12时和下午16时,分别为7.3、6.5μmol/(m2·s),有轻微的光合"午休"现象。结论]栽培穿龙薯蓣以控制土壤水分含量为田间持水量的70%最佳。

Study on the Relationship between Field Water Capacity and Photosynthesis of Cultivated Dioscorea nipponica Makino

Objective] To study the relationship between field water capacity and photosynthesis of cultivated Dioscorea nipponica Makino,so as to supply a theory reference in the herbs’ water management.Method] The pot experiment was used and the relative photosynthesis parameters were measured with portable photosynthesis instrument CI-340.Result] The three photosynthesis parameters of the net photosynthetic rate(Pn),transpiration rate(Tr) and water use efficiency(WUE) all reached a higher value when the field water capacity was 70%.The diurnal variation of Pn tended to a double-peak curve when the field water capacity was beyond 50%.The peak value presented at 12 o’clock and 16 O’clock,they were 7.3 and 6.5 μmol/(m2·s),respectively,showing a slight "noon break" phenomena.Conclusion] The 70% field water capacity would be the optimum value in the Dioscorea nipponica Makino cultivation.