甜柿开心形冠层结构特征及光合作用特性的研究

Studies on Structural Features and Photosynthetic Characteristics of Open-heart-shaped Canopy of Non-astringent Persimmon

研究了阳丰甜柿开心形冠层的结构特征以及冠层不同部位叶片的光合作用差异,建立了叶面积与叶片长、叶片宽间关系的线性回归方程。结果表明:冠层不同空间的相对光照强度表现出从上层到下层、从外围到内膛逐渐降低的趋势,且不同层次间差异显著;冠层上部结果枝叶片的净光合速率、蒸腾速率和水分利用效率均显著高于下部结果枝叶片的;结果枝叶片的净光合速率比徒长枝叶片高出35.92%,差异达极显著水平;叶龄为45 d的叶片的净光合速率极显著高于叶龄为60 d、15 d的叶片的。

We studied the structural features and photosynthetic characteristics of open-heart-shaped canopy of non-astringent persimmon （Diospyros kaki Thunb） variety ＂Youhou＂, and established the linear regression equations describing the relationships among leaf length, leaf width and leaf area of ＂Youhou＂. The results indicated that the relative sunlight intensity （RSI） decreased gradually from the upper layer to the lower layer, and from the periphery to the inner of the open-heart-shaped canopy, and the RSI in various layers was significantly different （P〈0.05）. The net photosynthetic rate, transpiration rate and water use efficiency of the middle leaves on upper bearing branches in the canopy were significantly higher than those of the middle leaves on lower bearing branches. In addition, the net photosynthetic rate of the leaves on bearing branches was 35.92% higher than that of the leaves on spindling branches, and their difference reached a very significant level. The 45-d-old leaves had very significantly higher net photosynthetic rate than 60-d-old and 15-d-old leaves.