Pollen exine substructure In Fagus (Fagaceae): role of tufts in exine expansion
- 1 October 1990
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Botany
- Vol. 68 (10), 2195-2200
- https://doi.org/10.1139/b90-286
Abstract
We compare results obtained from mature pollen of Fagus sylvatica L. using high-resolution scanning electron microscopy with fransmission electron microscopy images from several stages, from the early free microspore through to mature pollen grains. Exine processes (tufts) on young and mature grains are rodlike, with cross striations 10–15 nm wide. The total diameter of the tufts is 70–100 nm on exines of young microspores and up to 200–250 nm on mature exines. Tufts about 70 nm wide on the young microspores contain about five stacks of loops about 30 nm in diameter, whereas larger tufts on more mature exines have many stacks of the 30 nm wide loops. At maturity there is a mixture of large (200–250 nm wide) and small (70–100 nm wide) tufts and some tapering down from over 200 nm in width to less than 100 nm. There is continuity and a similar range of widths between the tufts as they occur as bacules and components of the tectum. We conclude that either new large-sized tufts are inserted during growth or some of the small (original sized) tufts increase in diameter from their bases toward the outer tip, or that both of these processes occur.Keywords
This publication has 2 references indexed in Scilit:
- Ontogenetic Development of Spinous Exine in Hibiscus syriacus (Malvaceae)American Journal of Botany, 1988
- Substructure in exines of Artemisia vulgaris (Asteraceae)Review of Palaeobotany and Palynology, 1981