Abstract/Details

<i>ramosa1</i> in the development and evolution of inflorescence architecture in grasses


2010 2010

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Abstract (summary)

Branching architecture of the flower-bearing structures in grasses, known as inflorescences, is a morphological trait that is subject to natural and artificial selection since it affects both reproduction and grain yield. Genes underlying this trait are sought to explain the molecular basis underlying the phenotypic diversity of these structures. The ramosa1 (ra1) gene encodes a transcription factor that controls branching architecture in maize inflorescences (tassel and ear). Reduced ra1 activity in maize produces ears with crooked rows of kernels due to the generation of extra spikelets, a phenotype that may have been selected on during the derivation of modern maize. Patterns of nucleotide diversity coupled with statistical tests and phylogenetics suggest a regulatory element at the ra1 locus was a target of artificial selection during maize’s domestication from its wild progenitor teosinte. We also narrowed the timeframe for the probable origin of ra1 during the evolution of grasses and found sequence variations in some species correlate with their respective inflorescence architectures. These results suggest this gene was important in the evolution of inflorescence architecture in other grasses, most notably in sorghum where statistical tests show ra1 may have been a target of artificial selection during its evolution, most likely to increase grain yield. Since this gene may have been important during the domestication and cultivation of two crops, maize and sorghum, this research may lead to future breeding projects to increase grain yield in these and other cereal grasses.

Indexing (details)


Subject
Genetics;
Evolution and Development
Classification
0369: Genetics
0412: Evolution and Development
Identifier / keyword
Biological sciences; Andropogoneae; Domestication; Epf; Grasses; Inflorescence; Maize; Ramosa1
Title
<i>ramosa1</i> in the development and evolution of inflorescence architecture in grasses
Author
Sigmon, Brandi Adell
Number of pages
161
Publication year
2010
Degree date
2010
School code
0097
Source
DAI-B 72/03, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
9781124431543
Advisor
Vollbrecht, Erik
Committee member
Becraft, Philip; Brendel, Volker; Clark, Lynn; Serb, Jeanne
University/institution
Iowa State University
Department
Genetics, Development and Cell Biology
University location
United States -- Iowa
Degree
Ph.D.
Source type
Dissertations & Theses
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
3438812
ProQuest document ID
849718637
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
http://search.proquest.com/docview/849718637
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