不同模式下整形方式对骏枣养分运转分配过程中光合特性的影响

【目的】研究骏枣不同整形方式在不同栽培密度下的光合特性,获得具有较好光合效能的栽培模式;对比较骏枣不同生育时期间净光合速率,分析枣树在营养生长阶段向生殖生长阶段转变过程中的养分运转分配规律。【方法】在2019年5~7月,利用LI-6400XT光合分析仪和SPAD-502 Plus型便携式叶绿素仪,分别测定在不同栽培密度下不同整形方式的成龄骏枣树的光合特性与叶绿素含量。【结果】I和II在7月末花期的P_n、G_s、C_i、T_r以及SPAD值显著高于5月初花期,而WUE和L_s则相反;II在5月初花期和7月末花期的P_n、G_s、T_r、L_s以及SPAD值均显著高于I,而C_i和WUE值则相反;相关分析中,P_n与G_s、T_r、WUE、SPAD,G_s与T_r、SPAD,WUE与SPAD呈极显著正相关(P<0.01),C_i与L_s、WUE呈极显著负相关(P<0.01),WUE与T_r、L_s呈显著正相关(P<0.05);主成分分析中,当保留3个公因子时,累积贡献率大于90%,第一主成分(光合因子)中,T_r的贡献最大,其次是G_s和P_n,第二主成分(气孔因子)中C_i、L_s的贡献较大,第三主成分(水分因子)中贡献最大的是SPAD值,其次是WUE,对I、II在不同时期的光合效率综合得分排序为:II(7月末花期)>I(7月末花期)>II(5月初花期)>I(5月初花期)。【结论】处于生殖生长阶段的7月末花期叶片的光合效能与处于营养生长阶段的5月初花期相比更强,叶片由原来累积、消耗养分的库转变为制造、输出养分的源,生殖器官花和果成为新的养分储存的库。将单轴主干形的株行距设定为(1.5×4.0)m与疏散分层形的株行距设定为(1×2.25)m相比,是当地更具有高光合效能的骏枣栽培模式。

Effects of Shaping Methods in Different Modes on Photosynthetic Characteristics of Ziziphus Jujuba cv. junzao during Nutrient Transport and Distribution

【Objective】 To study the photosynthetic characteristics of Ziziphus jujuba cv. Junzao with different shaping methods and under cultivation densities in the hope of obtaining the cultivation mode with better photosynthetic efficiency. Meanwhile, the net photosynthetic rate of Junzao jujube in different physiological periods was compared to understand the distribution of nutrients in jujube tree during the transition from vegetative growth stage to reproductive growth stage. 【Method】 From Mayto July in 2019, LI-6400XT photosynthetic analyzer and SPAD-502 Plus portable chlorophyll analyzer were used, the photosynthetic characteristics and chlorophyll content of jujube trees with different shaping methods under different planting densities were measured. 【Result】 The P_n, G_s, C_i, T_r and SPAD values of I and II at the end of July were significantly higher than those at the beginning of May, WUE and Ls were just the opposite. The values of P_n, G_s, T_r, L_s and SPAD in early May and late July were significantly higher than those in I,Ci and WUE values were the opposite. In correlation analysis, Pn was positively correlated with G_s, T_r, WUE, SPAD, G_{s w}ith _Tr, SPAD, WUE with SPAD (P < 0.01), Ci was negatively correlated with Ls and WUE (P < 0.01), WUE was positively correlated with T_r and Ls (P < 0.05); In principal component analysis, when three common factors were retained, the cumulative contribution rate was more than 90%. Among the first principal components (photosynthetic factors), T_r contributed the most, followed by G_s and P_n. C_i and L_s contributed more to the second principal component (stomatal factor). The third principal component (water factor) contributed the most to SPAD, followed by WUE. The comprehensive scores of photosynthetic efficiency of I and II in different periods were arranged as follows: II (flowering at the end of July) >I (flowering at the end of July)>II (flowering at the beginning of May)>I (flowering at the beginning of May).【Conclusion】 The photosynthetic efficiency of leaves at the end of July in reproductive growth stage was stronger than that at the beginning of May in vegetative growth stage. Leaf transforms from a nutrient pool that accumulated and consumed nutrients to a nutrient source that manufactured and exported nutrients, Flowers and fruits of reproductive organs become new storehouses of nutrients.The uniaxial trunk shape at 1.5 m×4.0 m row spacing was compared with the evacuation stratification with 1 m×2.25 m row spacing, which was a more suitable cultivation mode for local Ziziphus jujuba cv. Junzao production.