Presence of the protruding oncus is affected by developmental stage and acetolysis technique.

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Bruce K. Kirchoff, Emeritus Professor (Creator)
The University of North Carolina at Greensboro (UNCG )
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Abstract: A protruding oncus is a projection of the intine in the aperture region. The ubiquitous use of acetolysis in palynological research has led to the presence of a protruding oncus being underreported. Controlled experiments with pollen samples collected from undehisced and dehisced anthers demonstrate that the presence of a protruding oncus is affected by the state of the anther at maturity: dehisced or undehisced and by the preparation technique. In investigating the occurrence of onci, particular attention should be paid both to the dehiscence state of the anthers and the effect of the preparation technique on the intine. Although it has been suggested that protruding onci and pollen buds can be distinguished based on three criteria (size, presence of a large vacuole, separation of the protrusion from the grain), most of these distinctions break down when information is included from more recent studies. Additional study of protruding intinous structures may help clarifing the difference between pollen buds and protruding onci.

Additional Information

Language: English
Date: 2012
pollen grain, intine, acetolysis, anther, oncus, pollen bud, Rubiaceae, biology, botany, plant evolution

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