Structure and ultrastructure of the stigma and style of Luehea divaricata (Malvaceae-Grewioideae)

LATTAR, ELSA; GOTELLI, MARINA; GALATI, BEATRIZ

PLANTA

SPRINGER

Lugar: Germany; Año: 2023 vol. 257 p. 1 - 7

0032-0935

LueheaMilld. is a Neotropical genus with 18 species. This paper reports the study of the structure and the ultra-structure of the stigma and the style of Luehea divaricataMilld. using bright-feld microscope and transmission electron microscope. Multiseriate papillae are observed in the stigma. The papillae cells are large with a content that stains intensively and the sub-stigmatic tissue resembles the style’s transmitting tissue. L. divaricatahas a closed style with an epidermis that presents raised stomata and multicellular trichomes. Numerous organelles and a large nucleus are present in the dense cytoplasm of the transmitting tissue cells. A relevant feature is that the cells of this tissue in the species studied present a very thick middle lamella with two zones of diferent electron density in the angle of contact between cells, and convex lens-shaped thickenings of the cell wall are prominent mainly also in these angles of contact. The growth of the pollen tube is initiated on the stigmatic papillae surface and continues growing in the middle lamella of the sub-stigmatic tissue and the transmitting tissue, mainly at the contact angle between cells. The present work is the frst contribution to the knowledge of structure and ultrastructure of the stigma and style in the genus Luehea, as well as to the subfamily Grewioideae (Malvaceae)