Resumo

ZHANG, YG; GUO, SX  e  DAI, HY. Morphological diferences of vessels in the secondary xylem of columnar and standard apple trees. Phyton (B. Aires) [online]. 2012, vol.81, n.2, pp.229-232. ISSN 1851-5657.

The length, dimension and type of the vessel elements in the secondary xylem of columnar and standard apple trees were studied by isolation method and micrograph. Results showed that the shoot xylem vessel cells were reticulate and pitted in columnar and standard apples. Most of the end walls were simple perforation plates. Compared with columnar apple trees, standard apple trees showed more abnormal cells in the xylem vessel cells. Te average diameter of the xylem vessel cells of shoots was signifcantly wider in columnar apple (43.27µm) than in standard apple, (32.64 µm). Length of the xylem vessel cells of shoots didn't have a consistent pattern in columnar and standard apple trees. Results of this study might help to explain why columnar apple trees had higher photosynthetic rates and light energy utilization ratios than standard apple trees. These traits might have contributed to early fowering and fruiting in columnar apple trees.

Palavras-chave : Columnar apple; Isolation method; Vessel Element.

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