Yellow starthistle is an outcrossing, diploid annual native to the Mediterranean region (http://en.wikipedia.org/wiki/Centaurea_solstitialis), where it is restricted to disturbed sites. Recent classifications place it in subfamily Carduoideae, tribe Cardueae, and subtribe Centaureinae. The species was introduced to South America in the mid-1600s and then to North America (via Chile) in the mid-1800s. In addition to persistently disturbed habitats, starthistle has successfully invaded annual and perennial grasslands, pastures, shrub steppe, open woodlands in western North America and temperate South America. In North America, the species has been reported from 41 states and five provinces, with the largest infestations occurring in California (15 million acres) and the Pacific Northwest (3.3 million acres). Starthistle infestations degrade rangelands by reducing forage quality, altering wildlife habitat, depleting soil moisture, displacing native plants, and decreasing native plant and animal diversity. The species is considered to be diploid, with a gametic chromosome number of 8 (http://www.tropicos.org/Project/IPCN) and a genome size of circa 853 Mbp (http://data.kew.org/cvalues/).

• Nucleotide sequences (19 total) on GenBank as of 12/2012: available here
• ESTs (40,407 Sanger reads) on GenBank as of 12/2012: available here
• EST library for invasive genotype from Argentine based on 454 sequencing (274 Mbp): available online.
• 4-plex NimbleGen microarray (34,343 unigenes; 68,686 features). Note that the NimbleGen array includes 24,545 unigenes from yellow starthistle and 9,798 from spotted knapeed)

We generated the Sanger EST library described above, which we have employed to study the distribution of whole genome duplications in the Compositae. We also developed the 454 EST library and NimbleGen microarray in collaboration with an NSERC-SRO project on the evolutionary genomics of Compositae weeds. We are collaborating with the latter project on a population genomics study based on 454 EST data, as well as on the development of a dense genetic map based on RAD sequencing. Lastly, we are collaborating with an Indiana METACyte (Lilly Foundation)-funded project to search for expression differences between native and invasive populations of the species

Barker MS, NC Kane, A Kozik, RW Michelmore, M Matvienko, SJ Knapp, and LH Rieseberg. 2008. Multiple paleopolyploidizations during the evolution of the Asteraceae reveal parallel patterns of duplicate gene retention after millions of years. Molecular Biology and Evolution 25:2445-2455.

Lai Z, NC Kane, A Kozik, KA Hodgins, KM Dlugosch, MS. Barker, M Matvienko, Q Yu, KG Turner, SA Pearl, GDM Bell, Y Zou, C Grassa, A Guggisberg, KL Adams, JV Anderson, DP Horvath, RV Kesseli, JM Burke, RW Michelmore, and LH Rieseberg. 2012. Genomics of Compositae weeds: EST libraries, microarrays, and evidence of introgression. American Journal of Botany, In review.