Grass Diversity
Evolution
and Diversification of Inflorescences in Millet Grasses
This
project attempts to understand the evolution of the thirty or
so genera in the millet grass clade through species level
phylogenies and comparative inflorescence development. The
group has as its morphological synapomorphy the presence of
sterile branchlets (bristles) in the inflorescence, giving
the inflorescences a bristly or feathery appearance.
Important genera include Setaria
(including
foxtail millet), Pennisetum
(pearl
millet) and Cenchrus
(various
sand burs). Broad-scale chloroplast phylogenies and
comparative inflorescence developmental studies have been
published, and we have supplemented these findings with new
data from a novel nuclear marker, knotted1.
The comparison of chloroplast and nuclear data, together with
southern analysis, had shown that there are a number of
allopolyploid genera and species. Two masters projects have
examined variation within individual genera, one of which is
unique in that it lacks any sign of bristles in the
inflorescence at maturity or during development. The on-going
phylogenetic and developmental studies are clarifying our
understanding of the systematics of this group as well as
providing vital data for exploring the genetic basis of
inflorescence diversity.
Collaborators:
Liliana Giussani, Sandra Aliscioni, Institutio de Botánica
Darwinion, Buenes Aires, Argentina; Emilie Bess, University
of Illinois, Champagne-Urbana; Anya Penly, Elizabeth Kellogg,
University of Missouri-St Louis.
