不同矮化中间砧嘎啦苹果幼树形态与不同径级根系养分累积分布特征

为了明确不同中间砧嘎啦苹果幼树的树体形态和不同径级根系养分分布特征,揭示树体矮化与根系矿质营养分布和积累之间的关系,选取GM256、辽砧2号、SH1、SH6、SH38和SH40矮化中间砧和乔砧的3年嘎啦苹果盆栽幼树为试材,测定树体的形态指标和根系结构特征,将根系分不同径级解析后,测定矿质营养含量和养分累积量。结果表明,与乔砧嘎啦苹果相比,不同中间砧嘎啦苹果的树体高度和干截面积明显减小,致矮程度由强到弱依次为:SH38、SH1、SH6、GM256、SH40和辽砧2号。不同矮化中间砧、不同径级根系矿质营养的含量存在明显的差异,矮化中间砧嘎啦苹果0.5 mm根系中矿质营养含量最高,随着根系直径的增加,矿质营养含量呈递减趋势,SH38中间砧嘎啦苹果根系对K和Mg的吸收能力较强,SH1中间砧嘎啦苹果根系对Cu、Fe和Zn的吸收能力强。GM256中间砧嘎啦苹果各径级根系中P、Ca、Fe累积量以及直径3 mm粗根中的K、Mg、Zn累积量最高,辽砧2号直径3 mm细根中的K、Mg和Zn累积量高于乔砧和其他中间砧。生长势较弱的SH38、SH1和SH6嘎啦苹果根系养分的累积量较低,可作为冷凉气候苹果产区嘎啦苹果适宜的矮化中间砧。实际应用中应当充分考虑果园的立地条件、土壤供肥能力以及不同砧穗组合的营养需求特性,以实现苹果的优质高效生产。

Tree Morphology,Accumulation and Distribution Characteristics of Mineral Nutrient in Root System of Gala Apple Young Tree with Different Dwarfing Interstocks

In this study,we aimed to identify the differences of tree morphology,accumulation and distribution characteristics of mineral nutrient in root system of Gala apple young tree with different dwarfing interstocks.The re-sults were expected to reveal the relations between the tree dwarfing ability and accumulation,distribution of mineral nutrient in root system.Gala apple saplings (in pots)grafted onto dwarfing interstocks (GM256,Liaozhen No.2, SH1 ,SH6,SH38,and SH40)with uniform growth vigour were used as the experimental material.After spring shoot growth stopped,plant height and cross-sectional area were measured.The root morphology indexes were analyzed by WINRhizo analysis software.For the measurement of mineral nutrient contents,healthy plants at the same growth stage were removed from the pots,and were dissected and separated into different diameter root system.The contents and accumulations of mineral nutrient were determined.The results showed that plant height and cross-sectional area of Gala apple trees grafted onto dwarfing interstocks were obviously lower than that of the control.The degree of dwarfing of the interstocks followed the order of SH38 >SH1 >SH6 >GM256 >SH40 >Liaozhen No.2.Differences in mineral nutrient contents in different diameter root system of Gala apple young tree among different dwarfing in-terstocks were obviously different.The mineral nutrient contents in <0.5 mm diameter root system were highest,and the mineral nutrient contents decreased with the increase of root system diameter.The contents of K and Mg of Gala apple root system for SH38 were highest.Root system for SH1 interstocks had the highest Cu,Fe and Zn contents. The accumulations of P,Ca,Fe in all parts of GM256 interstocks root system and that of K,Mg and Zn in >3 mm diameter root system were higher than control and other treatments.The accumulations of K,Mg and Zn in <3 mm diameter root system for Liaozhen No.2 were highest.The mineral nutrient accumulations of SH38,SH1 and SH6 with weak growth vigour were lower than that of Liaozhen No.2,GM256 and CK with strong growth vigour.The opti-mal interstocks for Gala apple with better dwarfing effect were SH38,SH1 and SH6.In practical application,site condition,soil supplying nutrient capability and nutrient requirement characteristics of different stock-scion combi-nations should be fully considered,which for realizing the high quality and high efficiency production of apple.