Benjamin Blackman
bkblackm@indiana.edu

Indiana University
Department of Biology
Jordan Hall Rm127
1001 East 3rd St.
Bloomington, IN 47405-3700 USA

Advisors:
Loren Rieseberg
Scott Michaels

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Ecology & Evolutionary Biology

Connecting the Sun to Flowering in Sunflower Evolution and Development

The transition from vegetative to floral development is a critical determinant of fitness. Flowering time differences can be elicited as plastic responses to environmental cues such as photoperiod and vernalization; however, differences in flowering time and flowering reaction norms are also be genetically based. The molecular basis of photoperiodic regulation of flowering time has been well studied in Arabidopsis and rice, but these taxa harbor little natural variation in reactions norms. Sunflowers, both wild and domesticated, cover the full range of flowering time responses to photoperiod, including long day, short day, day neutral, and ambiphotoperiodic phenotypes. I aim to use this variation and develop a strong system for examining the relationship between adaptation and speciation, the relationship between intra- and inter-specific variation, and the evolution of genetic networks. Currently, I am sequencing and analyzing expression of homologs of genes involved in photoperiodic regulation of flowering time to verify this pathway's conservation in sunflower. In addition, I am pursuing a combination of candidate gene and forward genetic approaches toward identifying alleles underlying genetic variation in flowering time among domesticated cultivars, along a flowering time cline in H. annuus, and between Helianthus species.

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Publications

Shapiro MD, Marks ME, Peichel CL, Blackman BK, Nereng KS, Jonsson B, Schluter D, and Kingsley DM. Genetic and Developmental Basis of Evolutionary Pelvic Reduction in Threesprine Stickleback.  Nature 428: 717-723  (2004).

Colosimo PF, Peichel CL, Nereng K, Blackman BK, Shapiro MD, Schluter D, and Kingsley DM.  The Genetic Architecture of Parallel Armor Plate Reduction in Threespine Stickleback.  PLOS 2(5): E109  (2004).

McKinnon JS, Mori S, Blackman BK, David L, Kingsley DM, Jamieson L, Chou J, and Schluter D.  Evidence for ecology’s role in speciation.  Nature 429:294-298 (2004).

Blackman BK and Rieseberg LH.  How species arise (Book Review of Speciation by Jerry Coyne and H. Allen Orr).  Science 305: 612  (2004).