八棱海棠与M9T337砧木的木质部水力结构特征

Characteristics of Xylem Hydraulic Structure of Malus Robusta and M9T337 Rootstock

以八棱海棠和M9T337砧木为试验材料,通过测量其根和茎的导管直径和导管密度,计算其根和茎的比导水率和脆弱性指数,比较2种砧木水力学特征的差别。结果表明,八棱海棠的导管直径和比导水率大于M9T337砧木,具有更强的导水能力。M9T337砧木的导管密度大于八棱海棠,抗栓塞能力显著高于八棱海棠。因此,2种砧木乔化或矮化机制受其水分输导能力的影响,M9T337砧木的水分输导能力低可能是其实现矮化效果的重要原因。

Using Malus robusta and M9T337 rootstock as experimental materials,the specific water conductivity and vulnerability index of roots and stems were calculated by measuring the vessel diameter and vessel density of their roots and stems to compare the differences in hydraulics characteristics between the 2 rootstocks.The results showed that the vessel diameter and specific hydraulic conductivity of the Malus robusta were greater than those of the M9T337 rootstock which indicating a greater hydraulic conductivity capability.The vessel density of the M9T337 rootstock was higher than that of the Malus robusta,and its anti-embolism ability was significantly higher than that of the Malus robusta.Therefore,the mechanism of arbor or dwarfing of the 2 rootstocks was influenced by their water transport capacity,and the low water transport capacity of M9T337 rootstock could be an important reason for achieving dwarfing effect.