干旱条件下断根对苹果幼树生长和光合特性的影响

Effect of Root Pruning on the Growth and Photosynthesis of Young Apple Tree in Drought Area

控制地上部营养生长是果树生产中的一项重要工作。现以2年生盆栽苹果幼树为研究对象,分析了干旱条件下断根对苹果幼树生长发育和光合作用的影响。结果表明:干旱胁迫导致苹果叶片的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci)下降,提高了叶片的水分利用效率(WUE),而断根对这些指标没有显著影响。断根能够刺激苹果幼树产生大量新根,干旱条件下,断根处理后苹果根系再生能力显著下降。苹果春梢和叶片生物量,春梢长度和粗度,叶片长度、宽度和叶面积等营养生长特性都表现为T0>T1>T2>T3的变化趋势。在干旱条件下进行断根处理,苹果叶片的光合能力和根系再生能力大大降低,春梢和叶片生长发育受到严重抑制。

Controlling vegetative growth of the acrial part is an important work in fruit production,both root pruning and water stress are all effective measures in suppressing the vegetative growth of fruit trees.The present study was established to determine the effect of root pruning and water stress on the growth and photosynthesis of 2-year-old apple trees.The results showed that drought reduced the foliar photosynthetic rate（Pn）,transpiration rate（Tr）,stomatal conductance（Gs）and intercellular CO2concetration（Ci）,and increased the water use efficiency,but root pruning had no effect on these parameters.Root pruning stimulated many new roots,but the root recovery capability decreased under drought condition.The variation of spring shoot and leaf biomass,spring shoot length,foliar length,width and area,et al.They were all in a same trend T0〉T1〉T2〉T3.In total,the apple leaf photosynthesis and root recovery capability were greatly reduced,and the growth of spring shoot and leaf were greatly inhibited.