Early leaf development of Typha domingensis Pers. (Typhaceae)

Abstract

ABSTRACT Typha domingensis Pers. (cattail) is a globally widespread aquatic plant that causes significant impacts as an invasive species; this ability is dependent on its photosynthetic capacity that is related to leaves. Thus, understanding leaf development is essential for interpreting shoot growth and the formation of its photosynthetic area. This study investigates leaf ontogeny in T. domingensis from early stages until complete development of primary tissues. Plants were collected from natural wetlands and cultivated in a greenhouse. Rhizomes were then selected, and leaves were removed to enable the emergence of new shoots. Rhizome fragments containing leaves were collected at 1-day intervals until day 7 and were subjected to routine procedures in plant microtechnique. New leaves emerged from lateral buds located along the rhizome. The anatomy of scale leaves differs from that of photosynthetic leaves since they contain solid inclusions without palisade parenchyma. Leaf primordia arose laterally from the shoot apical meristem, which was organized as a tunica-corpus. Final leaf shape was influenced by different meristematic zones: the leaf apical meristem, the marginal meristem, the rib meristem, and intercalary meristems. Most leaf tissues developed basipetally, except for xylem and phloem. Within seven days following leaf initiation, all primary tissues were developed and morphologically functional. Leaf formation of Typha domingensis is similar to that of other monocot species. Leaves of T. domingensis develop very early, providing fully functional photosynthetic tissues, which may have implications for its invasive capacity.