不同小麦种光合作用对光、温、CO_2及水分胁迫的反应

Responses of Photosynthesis to Light, Temperature, CO_2,and Water Stress in Different Wheat Species

本文以三个典型的小麦种为材料,对其部分生理生态特性进行了研究。结果表明野生一粒小麦及节节麦的光饱和点都在1050μEm^(-2)s^(-1)左右,而普通小麦中国春的光饱和点为850μEm^(-2)s^(-1)左右。饱和光强下野生一粒小麦和节节麦的光合速率分别比中国春高36.3％和27.2％。光合作用最适温度野生一粒小麦和节节麦均在35℃左右,较普通小麦中国春高（中国春为30℃左右）。在100至300ppm CO_2浓度下,野生一粒小麦光合速率上升最快,节节麦次之,中国春最低;说明野生一粒小麦和节节麦更能适于较低的CO_2浓度。在水分胁迫下（不同渗透势甘露醇溶液处理半小时）,野生一粒小麦和节节麦光合放氧速率下降明显比中国春缓慢。所以,野生一粒小麦和节节麦较普通小麦中国春更能适应高温,高光,对水分胁迫的耐性较强,它们的光合机构有何差别,值得进一步研究。

The ecological and physiological traits of wheat (Triticum) were studied in three different wheat species. The results revealed that the saturated light intensity was about 1050 μEm-2 s-1 for T. boeoticum and Ae. squarrosa, and about 850 μEm-2 s-1 for T. aestivum cv. Chinese Spring. The photosynthetic rate of T. boeoticum and Ae. squarrosa were respectively 36.3% and 27.2% higher than that of Chinese Spring under saturated light intensity. The optimum temperature of photosynthesis of T. boeoticum and Ae. squarrosa was about 35℃, and was higher than that of Chinese Spring (about 30℃). Under CO2 concentrations of 100-300 ppm, the increasement of photosynthetic rate of T. boeoticum was the fastest, Ae. squarrosa the second, and Chinese Spring the slowest. Under water stress conditions (treated with mannitol solution for half an hour), the photosynthetic oxygen evolution rate of T. boeoticum and Ae. Squarrosa declined more slowly than that of Chinese Spring. Therefore, compared with Chinese Spring, T. boeoticum and Ae. squarrosa can adapt to higher temperature, higher light intensity, slower CO2 concentration and are more tolerant to water stress. Yet, their differences in photosynthetic apparatus should be studied further.