拉枝角度对中矮1号矮化中间砧库尔勒香梨光合荧光参数的影响

Effects of Branch Angle on the Dwarf Interstock Zhongai 1 Photosynthetic Fluorescence Parameters of Korla Fragrant Pear

【目的】研究不同拉枝角度对中矮1号矮化中间砧库尔勒香梨光合及叶绿素荧光特性的影响,为矮砧密植库尔勒香梨幼树整形栽培最适宜的拉枝角度提供理论依据。【方法】以杜梨为基砧,中矮1号为中间砧木的5年生库尔勒香梨为材料,采用不同拉枝角度(40°、60°、80°、100°)4个处理,测定并分析不同拉枝角度下库尔勒香梨的光合特性和叶绿素荧光特性差异。【结果】不同拉枝角度处理下中矮1号矮化中间砧库尔勒香梨的净光合速率(P_(n))日变化曲线均呈“双峰”型,存在明显的光合午休现象。随着拉枝角度的增大,库尔勒香梨的光合参数也随着增大,但当拉枝角度过大,超过80°时,树体光合作用则会受到抑制。在80°拉枝处理下,库尔勒香梨的光合参数P_(n)、气孔导度(G_(s))、细胞间隙CO_(2)浓度(C_(i))和蒸腾速率(T_(r))日均值均高于其他3个处理,P_(n)日均值最高可达10.04μmol/(m^(2)·s),P_(n)、C_(i)和T_(r)日均值与其他处理存在显著性差异,实际光化学效率(ΦPSⅡ)、光化学淬灭系数(C qp)、非光学淬灭系数(C NPQ)和PSII电子传递速率(R ET)日均值最高。【结论】库尔勒香梨在80°拉枝角度时光合作用最强,受光抑制较弱,80°拉枝角度可作为中矮1号矮化中间砧库尔勒香梨幼树整形栽培的较适宜拉枝角度。

【Objective】To study the effects of different branching angles on the photosynthesis and chlorophyll fluorescence characteristics of Korla fragrant pear on the dwarf interstock of Zhongai 1 in the hope of providing a theoretical basis for establishing the most suitable branching angle for the shaping and cultivation of Korla fragrant pear young trees with dwarf stock and dense planting.【Methods】The 5-year-old Korla fragrant pear with Du pear was used as the base stock and Zhongai 1 as the intermediate rootstock was used as the experimental material.The differences in photosynthetic characteristics and chlorophyll fluorescence characteristics of Korla fragrant pear under different branching angles were determined and analyzed.【Results】The results showed that the diurnal variation curves of P_(n) of Korla fragrant pear treated with different branching angles showed a"double peak"type,and there was an obvious photosynthetic lunch break.With the increase of the branching angle,the photosynthetic parameters of Korla fragrant pear also increased,but when the branching angle was too large,exceeding 80°,the photosynthesis of the tree was inhibited.Under 80°branching treatment,the daily average values of photosynthetic parameters P_(n),G_(s),C_(i),T_(r) and E wu of Korla fragrant pear were higher than those of other three treatments,and the daily mean values of P_(n),C_(i) and T_(r) were significantly different from other treatments.ΦPSII,C qp,C NPQ and R ET had the highest daily average.【Conclusion】Compared with other branch-pulling treatments,the photosynthesis of Korla fragrant pear is the strongest at 80°branch-pulling angle,and the light inhibition is weak.Therefore,80°branch-pulling angle can be used as the dwarf interstock of Korla fragrant pear Zhongai 1.