‘富士’苹果幼树叶片内源激素与矿质营养年动态变化分析

Annual dynamic analysis of leaf endogenous hormones and mineral nutrition on young ‘Fuji’ apple trees

【目的】探究无土栽培条件下不同砧木类型‘富士’苹果幼树叶片植物激素和矿质元素含量的年动态变化,明确不同砧木类型‘富士’苹果幼树叶片内源激素和养分周年变化特性,为‘富士’苹果砧木矮化性预测和叶片营养诊断提供参考。【方法】以3 a生T337自根砧、T337中间砧和乔砧‘富士’苹果幼树为试材,每小区分别选取长势一致的6株幼树作为1次重复,共3次重复。【结果】3种砧木类型‘富士’苹果幼树生长势强弱为乔砧>T337中间砧>T337自根砧。‘富士’苹果幼树定植后60~90 d,叶片IAA/ABA和(IAA+GA+ZR)/ABA比值均为乔砧>T337中间砧>T337自根砧,叶片ABA含量为T337自根砧>T337中间砧>乔砧,幼树生长势越强,叶片IAA/ABA和(IAA+GA+ZR)/ABA比值越大,叶片ABA含量越少。3种砧木类型‘富士’苹果幼树叶片N和P含量定植后90~150 d变化平稳,K、Ca和Mg含量定植后60~120 d变化较小,表明‘富士’苹果幼树定植后90~120 d叶片矿质元素含量变化较平稳。‘富士’苹果幼树叶片ABA与Ca含量存在极显著正相关关系,(IAA+GA+ZR)/ABA比值和IAA/ABA比值与Ca含量呈极显著负相关关系,相关系数均大于0.8。【结论】年周期内‘富士’苹果叶片内源激素和矿质营养含量呈波动变化趋势,且不同砧木类型间存在一定的差异,取样时间不同,分析结果存在差异。通过激素含量预测‘富士’苹果砧木矮化性的适宜采集叶样时期为定植后60~90 d,而‘富士’苹果叶片营养诊断较合理的采样时期为定植后90~120 d。

【Objective】High density planting with dwarfing rootstocks has been a new growing model for apple production in China. Successful high density planting depends on suitable dwarfing rootstooks for apple scion variety. Field trial for screening suitable dwarfing rootstooks is time-consuming. Therefor, early detecting the potential darfing rootstocks for specific scion variety is of prime importance. Researchers had confirmed that the lower ratios of IAA/ABA and（IAA＋GA＋ZR）/ABA in the leaves of apple trees were associated with drawfing effects of the rootstocks. Fertilization also has an important influence on the vigor of apple trees. Leaf diagnose is a common way for detecting the nutritional status of apple trees. This study aimed at selecting the appropriate stage of sampling of leaves for ensuring the accuracy of the leaf nutrient analysis and the hormone analysis through annual dynamic analysis of leaf endogenous hormones and mineral nutrition on young apple trees of‘Fuji＇.【Methods】The test was conducted from april to November in2015. The young‘Fuji＇apple trees with three kinds of rootstocks were used as test materials. The root-stocks were M9T337, M9T337/M. baccada, and M. baccada respectively. There were six young trees for a plot of each treatment with three repeats. The trees had been cultivated in pearlite in greenhouse since April 1 in 2015. Fertigation was made with nutrient solution based on the modified Hoagland formula, to mix and the solution was replaced every 20 days. The samples of the seventh to ninth leaves in the middle of new shoot were collected every 30 days from June 1. 3 to 4 leaves for one tree were taken for each sampling. The contents of plant hormones and mineral elements were measured after preparation of the samples.【Results】The trees on the rootstock of M. baccada were most vigrous and the trees on M9T337/M. baccada were least vigrous. The contents of plant hormones in the leaves were different in different sampling stages, the ratios of IAA/ABA and（IAA＋GA＋ZR）/ABA in the leaves of the trees varied with the rootstocks from 60 to 90 days after planting, and the order was M. baccada〉T337/M. baccada〉T337, while the leaf ABA content was T337〉T337/M. baccada〉M. baccada. The stronger the growth vigor of the young tree was, the bigger the ratio of leaf IAA/ABA and（IAA＋GA＋ZR）/ABA ratio was, and the lower the leaf ABA content was. Leaf mineral elements contents were also different in different sampling periods. The leaf N and P content of the‘Fuji＇apple trees on three rootstcoks changed smoothly from 90 to 150 days after planting. The leaf K, Ca and Mg content changed a liittle from 60 to 90 days after planting. This indicated that the leaf mineral element contents of young‘Fuji＇apple tree changed more smoothly during the period of 90 to 120 days after planting. The mineral element contents of all kinds of young‘Fuji＇apple trees＇ were not accorded with the apple leaf standard nutritional values made by Li Gangli except for the content of Ca. The correlation of endogenous hormones and some mineral elements content of young‘Fuji＇apple tree was significant. The content of IAA and the content of Ca,GA and P,ABA and P in the leaves was significantly and negatively correlated. The content of IAA andthe content of K or Mg,ZR and Ca,IAA/ABA and P was significantly and positively related. The correlation coefficients were between 0.5 and 0.8. The content of leaf ABA and the content of Ca had a very significantly positive correlation,（IAA＋GA＋ZR）/ABA and IAA/ABA had a very significantly negative correlation with the content of Ca, and both correlation coefficients were over 0.8.【Conclusion】The leaf ratios of IAA/ABA,（IAA＋GA＋ZR）/ABA and the contents of ABA, Ca were correlated with the dwarfing potential of young‘Fuji＇apple trees. The Suitable sampling of the apple leaves of young trees for analysis of endogenous hormones was 60 to 90 days after planting. And the suitable period of leaf nutrition diagnosis was 90 to 120 days after planting.