环割和摘心对薄壳山核桃枝条生长和叶片碳氮代谢物积累的影响

【目的】探索薄壳山核桃(Carya illinoensis)合理高效的修剪措施,提高薄壳山核桃结果枝的比例,为建立丰产优质的修剪技术体系提供理论依据。【方法】以5年生薄壳山核桃品种‘波尼'(‘Pawnee')的幼树新梢为试验材料,研究环割和摘心处理对不同规格(以枝条长度进行划分)生长期枝条的生长和叶片中碳氮代谢物积累的影响。【结果】规格A(20～25 cm)、规格B(30～35 cm)和规格C(40～45 cm)枝条经环割处理后长度均低于对照,粗度和叶片碳氮代谢物含量均高于对照; 其中规格A枝条长度低于对照22.09%,规格C枝条的粗度与对照的差异最大; 可溶性糖含量一直呈上升趋势,而淀粉和可溶性蛋白含量均呈先上升后下降的趋势。规格A、B和C枝条摘心处理后长度均低于对照,粗度和叶片碳氮代谢物含量均高于对照; 其中规格A枝条长度低于对照15.05%,规格B和C粗度与对照差异显著; 叶片碳氮代谢物含量出现不同的变化趋势,其中规格B枝条碳氮代谢物含量与对照存在显著差异; 规格C枝条平均萌发两条新枝,最大长度达26.75 cm,最大粗度达8.86 mm。【结论】环割和摘心处理均能抑制‘波尼'枝条长度生长并促进粗度生长,但在不同规格间的效果有差异; 摘心对规格C枝条萌发新枝的促进效果最好。

Effects of ringing and cutting off growing-tip on shoot growth and carbon-nitrogen metabolite accumulation in leaves of pecan

[Objective]The present study investigated reasonable and efficient pruning methods in pecan (Carya illi-noinensis), in order to provide a theoretical basis for cultivating a high-yield. [ Method] Different-size branches of'Pawnee', a 5-year-old pecan cultivar, were used as experimental materials to study the effects of ringing and cutting off the growing-tips on the growth of branches and the accumulation of carbon-nitrogen metabolites in leaves. [Results]The lengths of branches in group A (20-25 cm in length), B (30-35 cm in length) and C (40-45 cm in length) were lower than the control, while the diameters of A, B and C branches were higher than the control, after ringing treat-ments. The length of A branches was lower than the control by 22.09%, and the difference in diameter between the C branches and the control was the largest. The content of soluble sugar in leaves exhibited an increasing trend, while starch and soluble protein contents showed an up-down pattern. The content of carbon-nitrogen metabolites in the leaves of A, B and C branches was higher than that in the leaves of the control. The content of soluble sugars constantly in-creased, and other indices showed an increasing trend initially and then a decreasing trend. The length of the A, B and C branches was lower than the control, while the diameter and carbon-nitrogen metabolite content in all groups were higher than those in the control after cutting off the growing-tips. However, the carbon-nitrogen metabolite contents showed different trends among the groups. The average number of new developmental branches in group C was two, with a maximum length of 26. 75 cm and a maximum diameter of 8.86 mm. The content of carbon-nitrogen metabolites in group B was significantly different compared to that in the control. [Conclusion] The cutting off growing-tip treatment in-hibited the growth of branches in length, and promoted the growth of branches in diameter. Branches in group C sprouted buds, and showed the best response to treatments.