Exine Sculpture in Pariana Pollen (Gramineae) |
| |
| Authors: | Maria Lea Salgado-Labouriau Siwert Nilsson Milagro Rinaldi |
| |
| Institution: | 1. Instituto de Geosciencias UnB , 70910, DF, Brasilia, Brazil;2. Swedish Museum of Natural History , Palynological Laboratory , Box 50007, S-104 05, Stockholm, Sweden;3. Centro de Ecologia , IVIC, Apartado 21827, 1020A, Caracas, Venezuela |
| |
| Abstract: | Pollen grains of eieven species of Pariana, a small genus of herbaceous bamboos, were studied using LM, SEM and TEM. Ten of them have the Pariana stenolemma-type of pollen characterized by areolate exine due to relatively high and well separated denticulate processes on a slightly undulated tectum, vestigial columellae and no distinct annulus. At the pore edge the foot layer is thickened and folded. P. campetris (P. campestris-type) shows this exine feature only at magnifications higher than x 2000, whereas the denticulate processes are clearly visible at x 400 magnification in the other ten species. The pores are bordered by a distinct annulus. The high relief of the Pariana pollen forming a relatively rough surface would offer more friction in wind transport than the smooth surface of other grass pollen grains. Insects visiting the flowers have been observed which support the idea of possible insect pollination. If this would be the case, the parianas would be an example of correlation between pollen form and function in the evolution of the Gramineae. |
| |
| Keywords: | |
|
|
