The invention relates to an apple 
dwarfing self-rooted 
rootstock SH38 or SH40 large-scale breeding method. The method is suitable for cultivating SH38 or SH40, and specifically comprises the steps oftaking an SH38 or SH40 grafted 
seedling which is grafted close to the root part and taking 
malus robusta as a 
rootstock or a self-rooted 
seedling as a 
seed tree, carrying out 
annual growth branch budnotching, 
horizontal branch pressing, fixing and soil burying, performing twisting on the new 
shoot base newly grown from the horizontally pressed 
branch, carrying out 
hormone treatment, matrix land-filling, 
humidity and fertilization management, 
seedling lifting, and seedling separation to obtain SH38 or SH40 
dwarfing self-rooted 
rootstock. According to the breeding method, the SH38 or SH40 current year-growth semi-lignified 
shoot does not leave from the 
parent body to root, and has the advantages that the propagation conditions are mild, the production process is simple, the technical 
operability and achievability are high, the seedling rate is high, the seedling quality is good, and the like. By adoption of the method of the invention, the apple 
dwarfing self-rooted rootstock SH38, SH40can realize large-scale and low-cost propagation, thereby obtaining the apple dwarfing self-rooted rootstock SH38 or SH40 with stable traits, neat and consistent tree growth, early flowering and early fruit, 
fertilizer saving, 
water saving, land saving and high uniformity of the fruit 
shape index.