The comparative morphology and anatomy of leaves in the serpentine endemic Aster hispidus Thunb. var. leptocladus (Makino) Okuyama and its close relative A. hispidus var. hispidus were examined. Our morphological anal...The comparative morphology and anatomy of leaves in the serpentine endemic Aster hispidus Thunb. var. leptocladus (Makino) Okuyama and its close relative A. hispidus var. hispidus were examined. Our morphological analysis revealed that the leaves of A. hispidus var. leptocladus were significantly smaller and narrower than those of A. hispidus var. hispidus. In particular, our anatomical analysis indicated that a decreased cell number of the horizontal axis of a leaf was involved in A. hispidus var. leptocladus. This was the same process as the changing pattern of the leaves of rheophytic species, and so, similar morphological leaf modifications occurred under different selection pressures of the serpentine soil and flooding frequency of river-stream.展开更多
We compared the leaf morphology and anatomy of the putative rheophytic ecotype of Viola mandshurica W. Becker var. ikedaeana (W. Becker ex Taken.) F. Maek. and its closely related variety, V. mandshurica var. mandshur...We compared the leaf morphology and anatomy of the putative rheophytic ecotype of Viola mandshurica W. Becker var. ikedaeana (W. Becker ex Taken.) F. Maek. and its closely related variety, V. mandshurica var. mandshurica. We showed that the leaf of the rheophytic ecotype of V. mandshurica var. ikedaeana was narrower than that of V. mandshurica var. mandshurica. Moreover, the leaf thickness and guard cell size of the rheophytic ecotype of V. mandshurica var. ikedaeana were significantly larger than those of V. mandshurica var. mandshurica. We further showed that leaves of the rheophytic ecotype of V. mandshurica var. ikedaeana contained fewer cells than did those of V. mandshurica var. mandshurica. Our results suggest that the narrower leaves of V. mandshurica var. ikedaeana are caused by a decrease in the number of cells. A narrower leaf may enable the rheophytic ecotype of V. mandshurica var. ikedaeana to resist the strong flow of water that occurs after heavy rainfall, while a thicker leaf may enhance tolerance to desiccation and high- intensity light.展开更多
文摘The comparative morphology and anatomy of leaves in the serpentine endemic Aster hispidus Thunb. var. leptocladus (Makino) Okuyama and its close relative A. hispidus var. hispidus were examined. Our morphological analysis revealed that the leaves of A. hispidus var. leptocladus were significantly smaller and narrower than those of A. hispidus var. hispidus. In particular, our anatomical analysis indicated that a decreased cell number of the horizontal axis of a leaf was involved in A. hispidus var. leptocladus. This was the same process as the changing pattern of the leaves of rheophytic species, and so, similar morphological leaf modifications occurred under different selection pressures of the serpentine soil and flooding frequency of river-stream.
文摘We compared the leaf morphology and anatomy of the putative rheophytic ecotype of Viola mandshurica W. Becker var. ikedaeana (W. Becker ex Taken.) F. Maek. and its closely related variety, V. mandshurica var. mandshurica. We showed that the leaf of the rheophytic ecotype of V. mandshurica var. ikedaeana was narrower than that of V. mandshurica var. mandshurica. Moreover, the leaf thickness and guard cell size of the rheophytic ecotype of V. mandshurica var. ikedaeana were significantly larger than those of V. mandshurica var. mandshurica. We further showed that leaves of the rheophytic ecotype of V. mandshurica var. ikedaeana contained fewer cells than did those of V. mandshurica var. mandshurica. Our results suggest that the narrower leaves of V. mandshurica var. ikedaeana are caused by a decrease in the number of cells. A narrower leaf may enable the rheophytic ecotype of V. mandshurica var. ikedaeana to resist the strong flow of water that occurs after heavy rainfall, while a thicker leaf may enhance tolerance to desiccation and high- intensity light.
