Hydraulic conductivity and native embolism of Geneva® Series apple rootstocks measured by the XYL’EM-Plus® embolism meter

ABSTRACT Most commercial apple orchards are established on either Marubakaido (Malus prunifolia Borkh.) (high vigor), M-9 (Malus pumila) (low vigor), or a combination of both rootstocks through the intergrafting technique. The Geneva® Series rootstocks were developed as an alternative to orchards modernization. The vigor of rootstocks influences the anatomical xylem formation and, therefore, the canopy cultivar’s hydraulic conductivity. When affected by embolism, hydraulic conductivity harms plant metabolism, reducing crop yield and fruit quality. This study aimed to evaluate four Geneva® Series rootstocks with potential use in southern Brazil, in terms of hydraulic conductivity (K) and percentage loss of conductance (PLC), during the winter period in two different years. The G.213 rootstock presented the best performance for the variables analyzed; however, higher values of xylem functionality loss were observed in G.814.

摘要：目前多数商业苹果园均采用玛鲁巴卡道（Malus prunifolia Borkh.）砧木（高活力型）、M-9（Malus pumila）砧木（低活力型），或通过中间砧嫁接技术组合应用这两类砧木进行建园。日内瓦系列砧木（Geneva® Series rootstocks）的研发旨在作为果园现代化改造的替代方案。砧木活力水平会影响木质部的解剖结构形成，进而作用于树冠接穗品种的导水率（hydraulic conductivity）。当发生木质部栓塞时，导水功能受损会抑制植物代谢，降低作物产量与果实品质。本研究针对四款具备巴西南部应用潜力的日内瓦系列砧木，于两个不同年份的冬季时段，评估其导水率（K）与传导损失率（percentage loss of conductance, PLC）。结果表明，G.213砧木在各项分析指标中表现最优；而G.814砧木的木质部功能损失程度更高。