Abstract:

In order to identify the correlation of rust infection and disease level to the leaf age and the leaf anatomic structure in Zizyphus jujuba Mill. cv. ‘Dongzao’, rust inoculation experiment was conducted with three different-aged leaves, and the anatomic properties of the leaves were observed. The results showed that rust was more easily infected as the leaves were young, i.e., the degree of infection took on the descending order of young leaves, fully-grown leaves, and mature leaves. In other words, mature leaves had the strongest resistance to rust. Anatomical study revealed structure differences with the leaf age, including the thickness of the cutin layer, the thickness of the upper epidermis and lower epidermis, the thickness of the leaf blade, the thickness of the palisade tissue, the thickness of the spongy tissue, the ratio of palisade tissue to spongy tissue, the tightness of leaf tissue structure, the porosity of leaf tissue structure, the stoma density, and the stoma size. However, the stoma elongation was not significantly different. The leaf morphological structure was correlated with jujube rust occurrence, and can be used as indicators for the control of jujube rust and for selecting rust-resistant plus trees in jujube ‘Dongzao’.