Abstract

The leaf anatomy of the Nitraria roborowskii Kom., Nitraria sibirica Pall., and Nitraria tangutorum Bobr. populations from southern Xinjiang, China, were studied. Cross-sections of the leaves were made, and the structural characteristics were determined. Seven major traits of the leaf cross-sections were analyzed by cluster analysis. The leaf morphology and anatomical structure of Nitraria leaves from different populations significantly differed, but the coefficient of variation between different populations was not significant. Leaf palisade and spongy tissues were positively correlated with the mean temperature, average sunshine, and annual precipitation of the habitat. Populations were divided into three main categories: Class I (XBC-2 and XBC-3), which included plants that grew at higher altitudes and were exposed to longer than average sunshine time; Class II (XBC-1, BC-1, and DBC-1), which included plants that grew at lower latitudes and had longer than average sunshine time; and Class III (BC-2, BC-3, DBC-1, and DBC-2), which included plants that grew at intermediate latitudes. Habitat and climate were the main factors associated with phenotype differences among the populations of the three Nitraria species.