Подсолнечник

Helianthus annuus L.

http://www.uapress.arizona.edu/onlinebks/weeds/sunflowr.htm

http://www.artchive.com/artchive/g/gauguin/vangogh.jpg

http://www.artquotes.net/masters/vangogh/vangogh_sunflowers1888.jpg

http://www.1st-art-gallery.com/artists/vincent_van_gogh/van_goghs1.jpg

http://www.art.com/asp/sp-asp/_/pd--10106228/sp--A/Sunflowers.htm

http://www.larose.com/Cups_and_Mugs/images/Sunflowers_Van_Gogh.JPG

http://www.abundantlifeseeds.com/stores/1/Russian_Mammoth_P163C106.cfm?UserID=5542&jsessionid=8c30a4fadecd$FE$DB$7

http://static.flickr.com/23/37469881_9ac0e3d549_m.jpg

Domestication? Competing Theories

Mexican Hypothesis (Lentz et al 2001)

• Archaeological evidence– San Andrés, Tabasco,

Mexico– Dated to 4130 ± 40

B.P. (seed) and 4085 ± 50 B.P. (achene)

– Size well within range of domesticated sunflower seeds

Eastern North American Hypothesis (Crites 1993)

• Archaeological evidence– 6 completely carbonized sunflower seeds– 4265 ± 60 years B.P.– Hayes site, Tennessee, U.S.A.– Size (length increased by 30%, width by 45%)

• 5.7 mm x 2.2 mm• 7.3 mm x 3.3 mm• 6.7 mm x 2.9 mm• 6.9 mm x 2.9 mm • 7.3 mm x 2.9 mm• 7.4 mm x 3.8 mm

cutoff for domestication is between 5 and 7 mm

Problems with Mexican Hypothesis (Smith 2006)

From Smith 2006

Problems with Mexican Hypothesis (Smith 2006)

• No documentation that San Andrés seed is Helianthus annuus.

• San Andrés achene lacks striations indicative of H. annuus.

• San Andrés is outside of current wild range

From Smith 2006

Genetic Data (Harter et al 2004)

• Defined two population clusters (groups with distinct allelle frequencies—18 microsatellite loci– Mexico + Arizona– Central US

• 10 runs of algorithm assigned domesticates to US

• After subdividing US cluster, all domesticates assigned to easternmost populations

from Harter et al 2004

from Harter et al 2004

from Harter et al 2004

Questions

• Algorithm?

• Site 20 (Oklahoma)

More genetic data

• Wills and Burke (2006)– chloroplast DNA suggests (?) single origin of

domesticated sunflower in U.S.

• Liu and Burke (2006)– nucleotide diversity confirms “single” origin of

domesticated sunflower– cannot determine location of event

Liu and Burke (2006) cont.

Something I wish had been addressed

from Harter et al 2004

• Liu and Burke (2006) only published a phylogeny including Native American land races.

• Gene flow is easy (Snow et al 1998 and cited refs.) and it affects the behavior of wild plants (Snow et al 2003)

• How should one deal with gene flow between crops and wild relatives?

• At what point will gene flow obscure any phylogenetic signal?

Literature Cited• Crites, G.D. 1993. Domesticated sunflower in fifth millennium B.P. Temporal Context: New

evidence from Middle Tennessee. American Antiquity, 58: 146-148.• Harter, A.V., K.A. Gardner, D. Falush, D.L. Lentz, R.A. Bye, L.H. Rieseberg. 2004. Origin of

extant domesticated sunflowers in eastern North America. Nature, 430: 201-205.• Lentz, D.L. M.E.D. Pohl, K.O. Pope, A.R. Wyatt. (2001). Prehistoric Sunflower (Helianthus

annuus L.) Domestication in Mexico. Economic Botany, 55: 370-376.• Rieseberg, L.H., A.V. Harter. (2006). Molecular evidence and the evolutionary history of the

domesticated sunflower. In Motley, T. N. Zerega, H. Cross (eds.) Darwin’s Harvest: New Approaches to the Origins, Evolution, and Conservation of Crops. Columbia University Press.

• Smith, B.D. 2006. Eastern North America as an independent center of plant domestication. Proceedings of the National Academy of Sciences, U.S.A. 103: 12223-12228.

• Snow, A.A., P. Moran-Palma, L.H. Rieseberg, A. Wszelaki, G.J. Seiler. 1998. Fecundity, phenology, and seed dormancy of F1 Wild-Crop Hybrids in Sunflower (Helianthus annuus, Asteraceae). American Journal of Botany, 85: 794-801.

• Snow, A.A., D. Pilson, L.H. Rieseberg, M.J. Paulsen, N. Pleskac, M.R. Reagon, D.E. Wolf, S.M. Selbo. 2003. A Bt transgene reduced herbivory and enhances fecundity in wild sunflowers. Ecological Applications, 13: 279-286.

• Wills, D.M., J.M. Burke. 2006. Chloroplast DNA variation confirms a single origin of domesticated sunflower (Helianthus annuus L.). Journal of Heredity, 97: 403-408.