Sarah S. Kreunen
Project Topic / Abstract:
"Pollen and Anther Development in the American Lotus (Nelumbo lutea)"
Nelumbonaceae is a small family of aquatic flowering plants
comprised of two species, Nelumbo nucifera and Nelumbo lutea.
Nelumbo nucifera, the Indian or sacred lotus is found
throughout Asia and Australia; while N. lutea, the American
lotus or water chinquapin, occurs in eastern and southern
North America. Traditionally, the lotus plays a symbolic
role in Hinduism and Buddhism and is used in some Asian
cultures as a source of food and medication. In addition to
these factors of more colloquial interest, Nelumbo and
members of closely related waterlily families are believed
to occupy a phylogenetically important position at the base
of angiosperms. Characters of evolutionary significance in
phylogenetic studies are the ontogeny of pollen and anthers.
Prior to this investigation, little was known about these
events in Nelumbo. The focus of this presentation will be
these events which have now been morphologically documented
utilizing scanning electron microscopy, transmission
electron microscopy, and light microscopy. Several stages
have been documented in the development of pollen. These
include sporogenous tissue, microspore mother cells,
tetrads, free spores, and mature pollen grains. The
deposition of the layers in the pollen wall and the
morphology of mature pollen grains have also been evaluated.
Further, the morphology and developmental changes in the
anther have been documented. These include number of cell
layers composing the anther wall; tapetum type and pattern
of its maturation and degradation; and endothecial
thickenings, including type and location. The present
investigation is the first to employ electron microscopy in
the study of anther and pollen development in N. lutea.
Moreover, only three studies have ultrastructurally examined
pollen development in related waterlilies.
1999 American Journal of Botany 86: 1662-1676, and color cover of Dec
journal issue. Cover | Article | Abstract
1997 National Conference on Undergraduate
Research (Austin, TX)
1997 Truman Undergraduate Research
Symposium (Kirksville, MO)
1997 Sigma Xi Student Research Symposium
1998 Pollen and Spores: Morphology and
Biology - Conference (London & Kew, UK)
1998 Missouri Academy of Science (St.
1998 Truman Undergraduate Research
Symposium (Kirksville, MO)
1998 Sigma Xi Student Research Symposium
1998 Tri-Beta Biological Honor Society
Regional Meeting (Steelville, MO)
1998 Undergraduate Research Poster Day at
the State Capital (Jefferson City, MO)
1998 Expanding Horizons. Undergraduate Research at Truman State
Truman Review Summer 1998, Vol. 3, No.