不同树形对灰枣叶片光合及叶绿素荧光特性的影响

[目的]研究灰枣树形改造后的篱壁形、主干形、Y形与原树形小冠疏层形的光合特性、叶绿素荧光特性,获得具有高光效能的枣树树形,为简约标准化的枣树形栽培模式提供技术参考.[方法]利用LI-6400XT光合分析仪和超便携式调制叶绿素荧光仪MINI-PAM-Ⅱ,分别测定4种不同树形的4～5a生灰枣树的光合与叶绿素荧光参数,分析光...

Effects of Different Tree Shapes on Photosynthetic and Chlorophyll Fluorescence Characteristics of Ziziphus Jujuba cv. Huizao Leaves

【Objective】 Taking Ziziphus Jujuba cv. Huizao as the test material, through the comparison of photosynthetic characteristics and chlorophyll fluorescence characteristics of hedgerow wall shape, trunk shape, Y shape (test group) and original small crown sparse layer shape (control CK), as well as the correlation analysis of photosynthetic and chlorophyll fluorescence parameters to obtain the jujube tree shape with high light efficiency and to determine the simplified standardized jujube tree shape cultivation mode and provide technical reference and theoretical basis. 【Methods】 Using li-6400xt photosynthetic analyzer and mini-pam-II, the photosynthetic and chlorophyll fluorescence characteristics of 4-5-year-old grey jujube trees with different tree shapes were measured. 【Results】 In photosynthetic characteristics, Pn, Gs, Ci and Tr of different tree shapes were different. It could be seen from the light response curve that the PN of each tree increased with the increase of PAR. When PAR was about 0-500 μmol/(m²·s), the Pn value of Y-shape was the highest and the growth rate was the fastest, followed by hedge shape, trunk shape and control (CK); when par was above 500 μmol/(m²·s), the Pn value of hedge shape was the highest, followed by main stem shape, Y-shape and control (CK). Compared with CK, Gs and Tr of hedgerow, trunk and Y-shape were higher, while Ci was lower. Gs and Tr of hedgerow were the highest, Ci was the lowest, which were 0.202, 6.563 mmol/(m²·s) and 196.79 μmol/mol, followed by the main trunk and Y-shape. Gs and Tr of CK are the lowest, Ci was the highest, which were 0.171, 4.828 mmol/(m²·s) and 246.25 μmol/mol, respectively. Among the chlorophyll fluorescence parameters, Fv/Fm, ΦPSII, qP, NPQ and ETR of different tree shapes were different, among which Fv/Fm, ΦPSII, qP and ETR of hedgerow were higher than that of trunk >Y> CK, while NPQ was the opposite, and Fv/Fm, ΦPSII, qP and ETR of hedgerow were the highest, NPQ was the lowest, 0.81, 0.55, 0.763, 53.52 and 2.88, respectively; CK was 0.73, 0.45, 0.693, 38.53 and 3.51, respectively. It could be seen that the light conversion efficiency of hedgerow was higher than that of the trunk, Y and CK, and it could be seen from the correlation between Pn and chlorophyll fluorescence parameters that Pn had a very significant positive correlation with Fv/Fm, ФPSII, qP, and a very significant negative correlation with NPQ, and the correlation between Pn and qP, Fv/Fm was closer than that between ФPSII and NPQ. 【Conclusion】 Among the three tree shapes transformed under the row spacing of (1×4.5) m, the hedge wall shape is the tree shape with better high light efficiency, followed by the trunk shape and the Y shape.