Effects of different rootstocks on mineral contents and fruit qualities of Fuji apple

Rootstock types play important roles in regulating tree growth and fruit quality. In this study, the relationships between the mineral nutrition and the fruit quality were investigated using Fuji apple grafted with different rootstocks. The results showed that stock types influenced the absorption and distribution of mineral nutrients in apple leaf. The contents of P, K, Ca and Cu elements in the leaf of the dwarf stocks were higher than those in the standard stocks, and increased 20.00%，13.50%，9.09% and 32.72% respectively. However, the contents of other elements in the leaf of the dwarf stocks were lower than those in the standard stocks. Moreover, Fuji apple grafted with dwarf stock displayed higher contents of N, P, K, Mg, Fe, Mn and Cu in the fruit excepting for element Ca and B, and increased 39.46%，46.30%，19.13%，9.68%，32.41%，18.96% and 68.31% respectively. Compared with standard stocks, the dwarf stock exhibited higher fruit weight, more accumulation of soluble solids, contents of titratable acidity with increases of 5.53%，5.25% and 6.82%, respectively. The results also indicated that the content of Ca in Fuji apple fruit was only 1.58% of Ca content in leaf, and was the lowest content among all the mineral elements determined in this study. Therefore, this phenomenon probably is the reason that bagged apple fruit leads to occur bitter pit to some extent.