不同土壤水分条件对中国沙棘和俄罗斯沙棘的光合和蒸腾作用的影响

通过野外不同生境和田间不同干旱条件下对中国沙棘(H ipp ophaerham noid es L inn ssp.s inens is R ous i)和俄罗斯沙棘(H ipp ophae rham noid es L innssp.turkestan ica R ous i×H ipp ophae rham noid es L inn ssp.m ong olica cv.R ous i)的光合和蒸腾作用的日进程进行研究后发现:随着土壤水分含量的增加,沙棘的光合速率和蒸腾速率随之升高.在不同的土壤水分条件下,光合作用和蒸腾作用的日进程表现为双峰或单峰曲线,峰值的出现时间也随土壤水分条件的变化而变化.中国沙棘光合速率的日平均值表现为雌株高于雄株,而俄罗斯沙棘表现为水分条件适宜时雄株略高于雌株,受到干旱胁迫后雌株大于雄株,且俄罗斯沙棘的光合能力优于中国沙棘.俄罗斯沙棘的蒸腾速率的日均值为雌株高于雄株,中国沙棘雌雄株蒸腾速率的差异规律不一致.光合速率和蒸腾速率与土壤含水量的回归分析表明,二者呈显著的正相关,回归方程为一元二次方程,复相关系数接近1.

Effects on Photosynthetic Rate and Transpiration Rate of Chinese Seabuckthorn and Russion Seabuckthorn under Different Soil Water Condition

Photosynthetic rate and transpiration rate of Chinese seabuckthorn and Russion seabuckthorn were studied in different soil water condition.It was found that photosynthetic rate and transpiration rate increased with the increase of the soil water content.The day course of photosynthetic rate and transpiration rate were single summit or double summit in different soil water condition,and the time of the summit became changed with the soil water content.In the suitable water content,the mean photosynthetic rate of the male of Russion seabuckthorn was higher than that of the female one,but under the drought stress,the result was reversed.The mean photosynthetic rate of the female of Chinese seabuckthorn was higher than that of the male one.The photosynthetic capacity of Russion seabuckthorn was higher than that of Chinese one.The mean transpiration rate of the female of Russion seabuckthorn was higher than that of the male one.The mean transpiration rate of the male and female Chinese seabuckthorn had no difference.The regression analysis showed that the equations of the photosynthetic rates or transpiration rates and water content in soil can be expressed by y=a bx cx~2.