Evaluation of pollen production in Bromus catharticus Vahl and Guadua trinii (Nees) Nees ex Rupr. (Poaceae) for interpretation of fossil data

We evaluated pollen production per anther, per lower, and per spikelet of the grassland species Bromus catharticus and the forest taxon Guadua trinii (Poaceae), which have divergent pollination syndrome. We collected ten anthers of each taxon to determine differences in pollen production based on po...

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Bibliographic Details
Main Authors: Jefferson Nunes Radaeski, Soraia Girardi Bauermann
Format: Article
Language:English
Published: Universidade Federal de Santa Catarina 2016-12-01
Series:Biotemas
Subjects:
Online Access:https://periodicos.ufsc.br/index.php/biotemas/article/view/44277
Description
Summary:We evaluated pollen production per anther, per lower, and per spikelet of the grassland species Bromus catharticus and the forest taxon Guadua trinii (Poaceae), which have divergent pollination syndrome. We collected ten anthers of each taxon to determine differences in pollen production based on pollination system. Anthers were macerated and pollen grains were counted in a Neubauer chamber. Pollen morphology was observed using optical and scanning electron microscopy to establish relationships between pollen grain production and morphology. The anemophilous species Bromus catharticus (2,556,000 pollen grains/spikelet) has twice the pollen production per anther and per spikelet compared to Guadua trinii (1,716,000 pollen grains/spikelet), a species that requires biotic assistance for pollination. Pollen grain size is inversely proportional to production. Microechinate ornamentation, which is not expected to occur in anemophilous species, was observed on pollen of both taxa. Our results indicate that the frequency of forest Poaceae in the quaternary records may be underestimated while frequency of grassland taxa may be overestimated, leading to misrepresentation of the respective flora in this period.
ISSN:0103-1643
2175-7925