Senior Curator, MBG
• Systematics and Phylogeny of the Mustard Family Brassicaceae (Cruciferae)
• Brassicaceae of the Himalayas, Central Asia, and the New World
• Evolution of Arabidopsis and Related Genera
Web Page: MBG
Morphology and Relationships of the Brassicaceae Genera Nasturtium, Warea, and Paysonia. Ihsan Al-Shehbaz is the world's leading expert on the systematics and phylogeny of the mustard family Brassicaceae (Cruciferae). His studies incorporate intensive fieldwork, herbarium study, and molecular methods. There are a number of small genera in Brassicaceae in which generic and species relationships are unclear, either because of insufficient collection or study. Students could work on clarifying the relationships within these small genera so that a stable taxonomic treatment can be published. The genus containing water cress, Nasturtium, is represented by 5-6 species, of which two are endemic to North America, one North African, one Eurasian, one European, and possibly one in Spain. The genus containing pineland cress, Warea, has four species all in the southeastern United States (mostly Florida). The eight species of Paysonia are found primarily in Tennessee, with some in Texas and northern Mexico. Students undertaking these projects can work with some or all of the following activities, depending on their background and interests: fieldwork; organization of MBG herbarium collections and specimens borrowed from other institutions; review of pertinent literature; examination and measurement of morphological structures, recording data; assisting with the preparation of keys and species descriptions, extracting DNA from silica-dried leaf material, amplifying ITS, chloroplast DNA spacers, or other regions; analyzing sequence data, and generating phylogenetic tree hypotheses of relationships between species; and assisting with manuscript preparation. Students can participate as co-authors in the preparation of manuscripts for publication based on this research.
• Franzke, A., M. A. Lysak, I. A. Al-Shehbaz, M. A. Koch, and K. Mummenhoff. 2010. Cabbage family affairs: The evolutionary history of Brassicaceae. Trends in Plant Sciences 16: 108-116.
• Warwick, S. I., K. Mummenhoff, C. A. Sauder, M. A. Koch, and I. A. Al-Shehbaz. 2010. Closing the gaps: Phylogenetic relationships in the Brassicaceae based on DNA sequence data of nuclear ribosomal ITS. Pl. Syst. Evol. 285: 209-232.
• Al-Shehbaz, I. A. and co-workers. 2010. Brassicaceae. Pp. 224-746 in Flora of North America Editorial Committee (eds.). Oxford University Press, New York.
• Couvreur, T. L. P., A. Franzke, I. A. Al-Shehbaz, F. Bakker, M. A. Koch, and K. Mummenhoff. 2010. Molecular phylogenetics, temporal diversification and principles of evolution in the mustard family (Brassicaceae). Mol. Biol. Evol. 27: 55-71.
• Beilstein, M. A., I. A. Al-Shehbaz, S. Mathews, and E. A. Kellogg. 2008. Brassicaceae phylogeny inferred from phytochrome A and ndhF sequence data: Tribes and trichomes revisited. Amer. J. Bot. 95: 1307-1327.