翻译：在品质方面两年的可滴定酸含量较对照分别降低2917、3478可溶性糖含量较对照分别提高1540、3041且与对照间差异显著；PG-9菌株处理的苹果根际土壤速效磷含量高于对照872而全磷含量低于对照1138；

Translation: In terms of quality, the titratable acid content of the apples treated with the PG-9 strain decreased by 29.17% and 34.78% respectively compared to the control group, while the soluble sugar content increased by 15.40% and 30.41% respectively, and the differences were significant. The available phosphorus content in the apple rhizosphere soil treated with the PG-9 strain was 8.72% higher than the control, while the total phosphorus content was 11.38% lower than the control.