论文部分内容阅读
本文研究了在不同土壤水分条件下对2年生油松苗光合作用和生长的影响.并探讨了短期的土壤干旱处理对提高苗木抗旱的可能性.处理Ⅰ、Ⅱ、Ⅲ、Ⅳ的土壤含水量分别为14.5%、18.8%、27.1%和34.2%.处理Ⅰ的光饱和速率只占处理Ⅱ的88%,而处理Ⅰ的单株干重只有处理Ⅱ的60%,单株叶面积为45%.光饱和速率与单株干重的相关系数为0.87,而叶面积乘光合速率与单株干重之间的相关系数为0.97.土壤干旱严重地影响了单株总叶面积.所用中偏重壤土上,最佳土壤含水量为20%左右.在土壤干旱过程中,处理Ⅰ的净光合比处理Ⅱ、Ⅲ、Ⅳ下降慢.在土壤含水量为10%左右时,各处理的净光合速率为零,而暗呼吸仍有正常值的50%.浇水后1天,各处理的净光合作用速率均能恢复到对照的50%以上,以处理Ⅰ的恢复程度最大,为70%.浇水后3天,各处理均能恢复到对照的水平.处理Ⅰ、Ⅱ的暗呼吸也迅速恢复.在第二次土壤干旱过程中,各处理的净光合比第一次干旱时下降慢.
This paper studied the effects of different soil moisture conditions on the photosynthesis and growth of two-year-old Pinus tabulaeformis seedlings and discussed the possibility of short-term soil drought treatment to improve seedling drought resistance.The soil moisture content of treatments Ⅰ, Ⅱ, Ⅲ and Ⅳ 14.5%, 18.8%, 27.1% and 34.2%, respectively.The light saturation rate of treatment Ⅰ was only 88% of that of treatment Ⅱ, while that of treatment Ⅰ was only 60% of that of treatment Ⅱ, and the leaf area per plant was 45%. The correlation coefficient between light saturation rate and dry weight per plant was 0.87, while the correlation coefficient between leaf photosynthesis rate and single plant dry weight was 0.97. Soil drought seriously affected the total leaf area per plant. , And the best soil water content is about 20% .In the process of soil drought, the net photosynthetic rate of treatmentsⅠ, Ⅱ, Ⅲ, Ⅳdecreased slowly.When the soil moisture was10%, the net photosynthetic rate of each treatment was0 , While the dark respiration still had 50% of the normal value.While one day after watering, the net photosynthesis rate of all the treatments could recover more than 50% of the control, and the recovery of treatment Ⅰ was the largest, which was 70% 3 days, each treatment can be restored to the control level.Inductive treatment of Ⅰ, Ⅱ dark breathing quickly Complex. In the second soil during drought, the net photosynthetic process each fall slower than the first time drought.