西伯利亚杏不同树冠光合特性及产量差异

Photosynthetic Characteristics and Yield Components of Different Tree Crowns of Armeniaca sibirica

为揭示西伯利亚杏不同树冠内光合特性及产量的空间变化规律,筛选西伯利亚杏高产树冠类型,以西伯利亚杏为试验材料,按主枝基角进行概率分级并划分树形,对6—9月西伯利亚杏不同树形、不同冠层部位的光照强度、净光合速率、蒸腾速率、气孔导度以及产量进行测定,分析其光合日变化及产量差异。结果表明:西伯利亚杏依据主枝基角划分为紧密形(α<30°)、均匀形(30°≤α≤39°)、开阔形(α>39°)。不同树形、冠层部位及生长时期的净光合速率、蒸腾速率、气孔导度总体表现为外部>中部>内部,6月大于7、9月,开阔形>均匀形>紧密形。开阔形各冠层在不同时期的净光合速率日变化基本呈单峰曲线,均匀形各冠层在6、9月呈单峰曲线,在7月呈双峰曲线,紧密形各冠层在6月呈单峰曲线,在7、9月呈双峰曲线。在不同冠层间,除7月紧密形外部最大净光合速率与内部无显著性差异和9月均匀形外部显著高于内部外,其余各树形冠层外部各时期的最大净光合速率均极显著高于自身内部;在不同树形间,开阔形各冠层最大净光合速率在6月极显著或显著高于其他树形,在7月均高于其他树形,且在中部、外部达到显著水平,而9月各树形总体差异不显著。除开阔形各冠层蒸腾速率日变化在6月和紧密形各冠层在9月为双峰曲线外,其余均呈单峰曲线。不同树形的气孔导度各冠层日变化在6月均为单峰曲线,在7、9月均呈双峰曲线。各冠层中外部冠层单株产量最高,达1006.88 g,占比53.61%,且极显著高于中部、内部冠层;各树形中开阔形单株产量最高,达1303.00 g,极显著高于均匀形、紧密形。

In order to reveal the spatial variation of photosynthetic characteristics and yield of different crown of Armeniaca sibirica,and to filter the types of high yield crown of A.sibirica,this paper used A.sibirica as experimental materials based on the probability classification of branch angle and dividing tree shapes,measured the photosynthetically active radiation(PAR),net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs)and yield of different tree shapes,canopies of A.sibirica and analyzed the diurnal changes of photosynthesis and yield differences.The results showed that A.sibirica was divided into compact shape(α<30°),uniform shape(30°≤α≤39°),and open shape(α>39°)based on the branch angle.The Pn,Tr,and Gs of different tree shapes,canopies and growth periods mainly displayed June>July,September,outer>middle>inner,open shape>uniform shape>compact shape.The diurnal variation of Pn of open shape showed unimodal curve in each month.The Pn of each canopy of uniform shape showed unimodal curve in June and September and bimodal curve in July.The Pn of each canopy of compact shape showed unimodal curve in June and bimodal curve in July and September.Among different canopies,the max of Pn of the outer canopy of different tree shapes was extremely significantly higher than the inner canopy,except that the max of Pn of compact shape outer was not significantly different with its inner in July,and the max of Pn of uniform shape outer was significantly higher than that in the inner in September.Among different tree shapes,the max of Pn of open shape was extremely significantly or significantly higher than other tree shapes in June.In July,the max of Pn of open shape was higher than other tree shapes,and there were significant differences in the middle and outer.However,in September,there was no significant difference in max of Pn between the different tree shapes.For Tr,except that different canopies of open shape in June and different canopies of compact shape in September were bimodal curve,different canopies of other tree shapes showed unimodal curve.For Gs,the canopies with different tree shapes showed unimodal curve in June and bimodal curve in July and September.The highest yield of 1006.88 g/plant was found in the outer canopy,accounting for 53.61%,which was extremely significantly higher than in the middle canopy or inner canopy.The yield of open shape(1303.00 g/plant)was extremely significantly higher than the uniform shape and compact shape.