杜梨砧木留枝嫁接提高鸭梨耐盐能力的机制

Mechanism of salt tolerance improvement of Pyrus bretschneideri by grafting on researved branches of Pyrus betulaefolia rootstocks

杜梨的耐盐能力较强,是梨的优良砧木,在重盐碱地中保留一定量的杜梨砧木枝可以提高嫁接梨的耐盐能力。本研究以杜梨为砧木,梨接穗为鸭梨,对保留不同数量的杜梨砧木枝的梨树进行研究,分析了保留砧木枝对接穗成活和生长的影响,探讨了砧木枝数量对杜梨叶、功能叶和1 a生枝条叶中Na^+、K^+、Ca^2+、Mg^2+、Cl^-、可溶性糖和脯氨酸含量以及叶片光合生理的影响。结果表明,保留砧木枝可以显著提高接穗的成活率,并提高梨叶片中K^+含量和K^+/Na^+,有利于叶片的气孔开放,促进光合作用。其中保留2个砧木枝既可以提高梨的耐盐能力又能平衡砧木枝与接穗竞争的矛盾,还可显著缓解1 a生枝条叶的受胁迫程度,且叶片有较高的光合速率和水分利用效率,生长量也呈现最大。

Grafting pear trees(Pyrus bretschneideri)on the reserved branches of Pyrus betulaefolia rootstocks can improve its saline resilience,but little was known about the mechanism,thus the research aims to reveal the effect of the reserved branches on the survival rate and growth of the scions and the effect on the salt ion allocation in the grafting individual.Field experiments were conducted to measure the photosynthetic physiology and the contents of salt ions,osmoregulation substances in the different leaves.The result showed that the survival rate of the scions grafted on the branches of reserved P.betulaefolia rootstock was significantly higher than the scions without grafting on the rootstock.The reserved branches raised the K^+,solution sugar and the K^+/Na^+in the salt sensitivity leaves on new current year branches.Rootstock branches with grafting individuals balanced the osmoregulation substances in different leaf types and had a higher photosynthesis rate and water use efficiency.These suggested the reserving branches on the P.betulaefolia rootstocks could change the allocation of salt ions to enhance the salt tolerance,and scions on two branches of reserved rootstocks could grow faster.