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1. Resistance to diseases and pests: Upside-down pearl rootstock has strong resistance to diseases and pests, can provide apple trees with better disease and insect resistance genes, and helps to improve the disease resistance of apple trees.

2. Strong stress tolerance: Upside-down pearl rootstock has strong stress tolerance and can adapt to different soil conditions and environmental changes, providing a better growth environment for apple trees.

3. Improve yield and quality: Upside-down pearl rootstock has a positive impact on the growth and development of apple trees and fruit quality, and can increase apple yield and quality.

4. Good tree shape control: After grafting an apple tree with upside-down pearl rootstock, it can effectively control the growth momentum of the apple tree, making the tree shape more elegant and easier to manage.