Portage Des Sioux, Missouri, USAUndergraduate Research Assistant
Biology Major and Chemistry Minor
Rottboelliinae Grasses of Tanzania
With their characteristic sunken spiklet, the Rottboelliinae grasses of Tanzania are a morphologically interesting group. These grasses are a part of the economically important grass family Poaceae, which includes such grasses as maize. Preliminary data suggests that the grasses are closely related to maize.
To study their phylogenetic relationship, DNA will be extracted from these plants to analyze the phytochrome B and ndhf genes. Phytochrome B is a nuclear gene coding for a photoreceptor that helps with light absorption in photosynthesis. Ndhf is a chloroplast gene that is thought to code for NADH, which facilitates in electron transport.
Presently all samples have been extracted, amplified and will be finished being sequenced by the end of May. Phytochrome B sequencing will follow, as well as phylogenetic analysis of the sequenced data.
Once completed, these analyses will help answer such questions as, "How closely are these grasses related to maize?" "Are these taxa monophyletic?" and "If these taxa are not monophyletic, how many times has this morphology evolved?".
"Bristle Clade" Grasses of Australia
In addition, I am participating in another molecular project to help clarify some questions about the Panicoid "bristle clade", a group of grasses that includes foxtail and pearl millet. Past morphological analysis has suggested that all grasses with bristles in the inflorescence form a monophyletic group. Until now, molecular evidence has been obtained for only a small fraction of these grasses.
Some unusual taxa that are potentially in the "bristle clade", because they possess inflorescence bristles, were collected in Australia for use in molecular analysis. Molecular evidence from the phytochrome B and ndhf genes will help to determine the evolutionary relationship of these grasses.
All of these samples have been extracted, amplified, and will be sequenced for ndhf by the end of May. Phytochrome B sequencing and phylogenetic analysis will follow.
After the molecular work is completed, the data should help answer whether these grasses really belong to the "bristle clade" as the morphological data suggests. It may also give a better understanding of the relationships between other genera within the "bristle clade".