Influence of six dwarfing interstocks on the ‘Fuji’ apple under drought stress

Investigation of growth and physiology of scion on various interstocks to drought stress is a valuable process for apple drought-tolerance stock selection. In this attempt, the ‘Fuji’ apple cultivar grafted on six dwarfing interstocks, including of M series (M26, M9-T337), CG series (CG24) and SH series (SH1, SH6 and SH40) on Malus hupehensis var. Pingyiensis Jiang rootstock were maintained as normal (−10 to-20 Kpa) (control), moderate (−30 to-40 Kpa) and severe drought (−50 to-60 Kpa) stress levels. After 50 days treatment, comprehensive evaluation by subordinate function value (SF) was employed based on trunk growth, net photosynthetic rate, leaf water potential etc., and drought tolerance of ‘Fuji’ apple was ranked as following interstocks: SH6 > SH40 > SH1> M9-T337 > M26 > CG24. Moreover, the determination of ‘Fuji’ apple in responding to drought stress revealed that three antioxidant enzymes (SOD, APX and DHAR) and four genes (DREB2A, ZAT10, SOD1, APX1) constitute the putative key components for drought regulation.