Abstract

The vessel elements of secondary xylem in branches of columnar and normal apple trees were studied by isolation method and micrograph. The lengths and diameters were measured and the type of side wall (reticulate or pitted) was noted. Most of the perforation plates were simple. Normal apples had more abnormal vessel element cells than columnar apples. The average diameter of the xylem vessel elements of columnar apples was 43.27 µm, which was significantly greater than that of normal apples (32.64 µm). The lengths of the vessel elements did not differ significantly between columnar and normal apples. The results provided a theoretical basis for explaining the early flowering and fruiting of columnar apple trees and their higher fruit yield.

Key words: Columnar apple, isolation method, vessel element.