【作者】 张满让；

【导师】 束怀瑞；

【作者基本信息】 西北农林科技大学 ， 果树学， 2013， 博士

【摘要】 富士苹果因其品质好，耐贮运，深受中国消费者的偏爱，但富士苹果在黄土高原产区难以成花，即使使用矮化性能较好的M26中间砧，其产量通常较低。拉枝是解决富士苹果较难成花的有效措施之一，本研究以嫁接在M26中间砧的5年生红富士树体为试验材料，研究拉枝角度在70°、90°和110°下，其短枝、中长枝顶端的碳氮和激素变化规律及成花结果状况，利用碳氮示踪技术探索在不同拉枝角度下碳氮的运输分配规律，探讨拉枝角度对苹果生理特性的影响，为生产上解决富士苹果在黄土高原地区成花难的问题提供依据；同时在理论上探索富士苹果难以成花的生理特征，为研究解决富士苹果难以成花的问题提供研究方法和思路。本研究主要包括以下研究内容：（1）拉枝角度对苹果枝组构成的影响；（2）拉枝角度对苹果光合作用的影响；（3）拉枝角度对苹果枝条顶梢尖碳、氮含量及变化的影响；（4）拉枝角度对苹果碳氮再分配的影响研究；（5）拉枝角度对苹果枝条顶梢尖激素平衡及动态变化的影响；（6）拉枝角度对苹果成花结果的影响；（7）拉枝角度对苹果果实品质的影响。试验结果如下：1、随着拉枝角度的加大，增加了富士和嘎拉苹果的短枝比例，降低了中长枝的比例；拉枝角度加大在富士苹果上增加短枝数量比嘎拉苹果较为明显。富士苹果较小的拉枝角度所抽生的枝条位于顶端的居多，较大的拉枝角度所抽生的枝条位于基部的居多，而且短枝数量逐渐增加。富士苹果随着拉枝角度的增大，短枝顶芽的成花率显著增加，长枝顶芽成花率较低；嘎拉苹果短枝和长枝顶芽90°与110°拉枝成花率差异不显著；嘎拉苹果在不同拉枝角度下无论短枝还是长枝的成花率普遍高于红富士，这说明嘎拉苹果的生长极性较弱。加大拉枝角度不仅能够提高富士和嘎拉苹果单个叶片的光合作用效率，而且能够提高整个苹果枝条的光合作用效率。2、苹果枝条随着拉枝角度的加大新生枝条的顶梢尖总糖含量和C/N比值增加，而顶梢尖的总氮含量降低，短枝和中长枝都是如此；短枝顶梢尖的总糖含量和C/N高于中长枝，而总氮含量较低，相对于中长枝而言拉枝能够刺激短枝顶端的碳的积累，有利于短枝形成花芽；同时嘎拉苹果枝条的顶端总糖含量整体比富士要高，说明嘎拉比富士生长极性较弱，不需过大的拉枝角度就能达到成花所需要的碳的积累。3、随着拉枝角度的加大，增加了富士和嘎拉苹果短枝和中长枝顶端的ABA和ZR含量，降低了IAA和GA含量；短枝中的ABA和ZR含量高于中长枝，而IAA和GA却低于中长枝；且处理间差异显著，这说明加大拉枝角度能够抑制富士苹果旺长，使得短枝尽早停长，更容易促进花芽的形成；而嘎拉苹果在110°与90°情况下都能及时停长，有利于花芽形成的物质贮备及形成花芽的激素平衡环境；嘎啦苹果90°为适宜的拉枝角度，富士苹果110°为适宜的拉枝角度。4、加大拉枝角度能够使富士苹果的短枝顶芽和中长枝顶芽中的13C素积累急剧增加；光合产物在被拉枝的枝条上的积累也在增加，向外运输减少；在树体的地上部分光合作用产物向上运输在减少，向下运输在增加，在水平方向运输变化不大，对根系的运输也在减少。光合作用产物主要积累在叶片和枝条本身；其次才主要分配给主枝木质部和韧皮部、一年生枝条和上部枝条上，其余器官积累较少。加大拉枝角度有利于短枝芽中碳素的积累，且这种积累增加显著，这对花芽形成有利。较小的拉枝角度光合产物主要向上运输，有利于树体的生长；加大拉枝角度，光合产物向下运输增加显著，抑制树体营养生长，创造形成花芽的有利条件。5、拉枝角度的加大，富士苹果整株树体对氮肥的吸收利用率在下降；根系对氮肥的吸收能力也在下降，特别是细根的下降最为明显，拉枝能够降低树体吸收肥料的能力，加大拉枝角度树体的极性减弱，对氮肥的吸收和运输能力降低，致使富士苹果树体的15N利用率显著下降，一年生枝条、短枝顶端、中长枝顶端、叶片、主根、粗根和细根的氮的利用率下降；短枝顶端的利用率下降的更为明显，从而抑制富士苹果旺长，增加短枝顶芽中的C/N，有利于成花结果。随着拉枝角度的加大，主干韧皮部，主枝韧皮部、主枝木质部、一年生枝、中长枝顶端和细根的15N分配率在降低，而短枝顶端、苹果叶片的15N分配率在增加。根系吸收的15N主要存在在叶片中，叶片中的15N含量最大，其次为主根、粗根和细根，一年生枝条中的15N含量较低，短枝和中长枝顶端的15N含量最低。6、富士苹果果实中的糖以果糖和蔗糖为主，葡萄糖和山梨醇含量较低；有机酸含量以苹果酸为主，其余酸类物质含量较低；酚类物质以绿原酸和紫丁香酸类物质含量为主，其余酚类物质含量较低。随着拉枝角度的加大，糖类物质和酚类物质在增加，而酸类物质在降低，加大拉枝角度，能够提高富士苹果果实的品质。更多还原

【Abstract】 ‘Fuji’ is the most widely grown apple cultivar in China because of its good quality, longstorage and easy transportation，but has a severe biennial fruiting habit in the Loess PlateauRegion of China even if the interstock ‘M26’ was used. Bending branch has been used toinduce floral buds in ‘Fuji’ apple for a decade in China. The effect of branch bending angle onphysiological characteristics of ‘Fuji and Gala’ apple were studied in order to provide a basisfor the apple industry and for the theoretical research. The main research includes:(1)Proportion of spur (<5cm), medium (5-15cm), long (>15cm) shoots in response to threebending levels of ‘Fuji’ and ‘Gala’ apples;(2) The photosynthetic rate of single leaf in theshoot and whole shoot in response to three bending levels of ‘Fuji’ and ‘Gala’ apples;(3)Nutrient accumulation in the shoot terminals of ‘Fuji’ and ‘Gala’ apples in response tothree different levels of branch bending;(4) Distribution rates of ‘13C’ and ‘15N’ in every partof apple tree through ‘13C’ and ‘15N’ tracking in apple tree in response to three levels ofbranch bending of ‘Fuji’ apples;(5) Dynamic course of Endogenous Hormones of Shootsterminal in Fuji and Gala Apple tree influenced by three different levels of branch bending;(6)Proportion of flower buds of the terminal buds in the shoots in response to three bendinglevels of ‘Fuji’ and ‘Gala’ apples;(7)Average content of sugars, organic acids and phenoliccompounds in ‘Fuji’ apples in response to three levels of branch bending.Number and proportion of the spurs was increased and number of the long and themedium shoots was decreased with increasing bending angles, suggesting that bending with alarger angle can inhibit more vegetative growth of the branches; this is more obvious in ‘Fuji’apple.‘Fuji’ apple was more sensitive to bending levels than ‘Gala’ apple, and a higherproportion of spurs were found on the branches when they were bent at a larger angle in ‘Fuji’apple. There were more acrotony shoots under the lower branch bending level, more basitonyshoots, spurs and spur flower buds with increasing bending levels, and a small number ofterminal flower buds in medium-long shoots in ‘Fuji’ apple. In ‘Gala’ apple, proportion ofterminal flower buds in both spurs and long-medium shoots had no significant variation (P <0.05) between90°and110°. Proportion of terminal flower buds in ‘Gala’ apple was higherthan ‘Fuji’ apple; it showed that ‘Gala’ apple is easier to form terminal flower buds. Thephotosynthetic rate of the single leaf and whole branch were increased with increasing level of branch bending.Total sugar and ratio of C/N in the shoot terminals were increased while total nitrogenconcentration in the shoot terminals decreased with the increasing of bending angles. Totalsugar concentration, total nitrogen concentration and ratio of C/N in the shoot terminalspresented significant variation among three bending levels in both ‘Fuji’ and ‘Gala’ apples.Average of total sugar concentrations in spur apexes was significantly higher than inlong-medium shoot terminals. Thus, branch bending stimulated more carbon accumulation inthe spurs than in the long-medium shoots. Total sugar concentrations and ratio of C/N showedsignificant variation among four sampling dates; and total nitrogen showed significantvariation in most sampling dates in both cultivars.Increase of branches bent angle caused a rise in endogenous ABA and ZR production,and a decrease in the concentration of IAA and GA in shoot terminals. Average of ABA andZR concentrations in spur apexs was significantly higher than in long-medium shoot terminals,but the average of IAA and GA concentrations in spur apexs was lower than in long-mediumshoot terminals. ABA, ZR, IAA and GA concentration in spur apexes showed significantdifference with the increasing of bending angles.‘Fuji’ was more sensitive to bending levelsthan ‘Gala’, and the vegetative growth was reduced in ‘Fuji’ apple with a larger angle branchbending. Thus, a larger angle branch bending can stop spur growth as so as early in ‘Fuji’apple, and might cause it to form a floral-bud. But the spurs in ‘Gala’ apple can be stoppedgrowth and might form floral-buds by branch bending under the90°angle. During the wholegrowing season, the ABA concentration in Gala shoots terminals always were higher thanthose in ‘Fuji’, But the IAA was lower than ‘Fuji’.The ‘13C’ content in the shoot terminals and the carbohydrates in the bent branch wereincreased with the increasing of branch bending angles in ‘Fuji’ apple, so in the whole thetransportion of carbohydrates from the labelled branch to other part of the tree was decreased;the transportion was different, deceased to parts up the labelled branch and roots, increased toparts down the labelled branch above ground, and not change to the same horizontal laterals.Carbohydrates were mainly distribute to the leaves, labelled branches, and then to xylem andphloem of labelled branch, shoots, branches up labelled branch, at last to other organs.Average of the carbohydrates in the spur apex were increased with the increasing of branchbending angles in ‘Fuji’ apple, and showed significant variation, this was in favor of formingflower buds. Carbohydrates were mainly transported to up parts under the small branchbending angles, on the contrary, were mainly transported to down parts under large branchbending angle.The content of15N-urea of the whole tree was decreased with the increasing of branch bending angles in ‘Fuji’ apple; the capacity of the root absorption of15N-urea was being weakat the same time, especially for fine-roots. Branch bending could reduce the absorption andtransport of nitrogen fertilizer capacity of the ‘Fuji’ apple tree, caused the polarity weakens oftree, resulted in decrease in utilization of15N-urea of the tree. The utilization of15N-urea ofnew shoots, spur apexs, long-medium shoots terminals, leaves, main roots, thick roots andfine roots were decreased with the increasing of branch bending angles, this is more obviousfor spur apexs, suggesting that bending with a larger angle can inhibit more vegetative growthof the branches, increase C/N in spur apexs, and was in favor of floral-bud formation.Distribution of15N-urea in xylem and phloem of the trunk, new shoots, long-medium shootsterminals and fine roots were decreased with increasing bending levels, while Distribution of15N-urea in spur apexs and leaves were increased with increasing bending levels.15N-ureaabsorbed by roots were mainly distribute to the leaves, and then to main roots, fine roots andthick roots, next to new shoots, at last to spurs and long-medium shoots.Fructose was the most abundant compound of all those quantified sugars in ‘Fuji’ applefruits, followed by sucrose. Glucose and sorbitol content showed a similar range. Amongorganic acids, malic acid especially is the most abundant compound in ‘Fuji’ apple fruits,followed by Citric acid. Fumaric acid concentration was the lowest among the quantifiedorganic acids; nonetheless, the taste effect of fumaric acid on the flavour of fruits is, despiteits scarcity, stronger than the effect of citric acid. Chlorogenic acid was the major phenoliccompound found in ‘Fuji’ fruits. Syringic acid showed nearly one third the concentration ofchlorogenic acid content in this study. Catechin and Sinapic acid content showed a similarrange. Total sugar, content of simple sugar, total phenolic compounds and average content ofevery kind of phenolic compound in ‘Fuji’ fruits were increased, while total organic acidsconcentration and average content of every kind of organic acid in ‘Fuji’ fruits were decreasedwith the increasing of bending angles, and the quality of apple fruits was improved.更多还原