DNA sequence diversity in North American Zizania species

Sheryl Ann Walker, Purdue University

Abstract

Linking naturally occurring variation in complex phenotypic traits to genetic diversity is one of the most important objectives in evolutionary biology. This objective is especially true for evolutionary developmental biology. Developmental genetic studies in model plant species (e.g., Arabidopsis, Petunia, Antirrhinum, Oryza, Zea) have provided an extremely rich understanding of the molecular basis of complex developmental phenotypes and strong evidence for their role in inter-specific variation and even reproductive isolation. These functional genetic studies have identified numerous loci underlying phenotypic traits and many of these traits are linked to phenotypes that affect reproductive viability (i.e., number of flowers produced, number of tillers or inflorescence branches produced). Although a detailed understanding of interspecific variation in development is emerging, we must also develop an understanding of mechanistic evolutionary processes acting within species. Currently, our understanding of the molecular evolutionary mechanisms driving the diversification of developmental pathways underlying naturally occurring intraspecific morphological variation is lacking. My research presents the characterization of the molecular evolution of three North American species of Zizania. Zizania sp. is a small clade of four species of ecologically important aquatic grasses. My research has two specific outcomes: 1) I have characterized the molecular evolution, in North American Zizania sp., of two loci important for regulating grass architectural phenotypes, lateral branching. 2) I have also built a molecular marker database for North American Zizania sp. for ∼ 60 loci involved in three different genetic pathways: 1) developmental genetics, 2) flooding and drought stress responses, and 3) low copy nuclear genes involved in 'housekeeping'. My research represents an important first step for developing Zizania sp. as an evolutionary and ecological system for understanding developmental evolution, molecular ecology, and local adaptation. My research has already proven useful for other ongoing studies of Zizania and will enable future QTL-based studies of morphological adaptations in Zizania species.

Degree

M.S.

Advisors

Zanis, Purdue University.

Subject Area

Botany|Genetics|Evolution and Development

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