Molecular Evidence of Sugarcane Evolution and Domestication http://www.botgard.ucla.edu/html/MEMBGNewsletter/images/volume4/Saccharu mvariegated.jpg Rachel Jabaily and Maggie Koopman http://www.travellerspoint.com/photos/41787/suga r%20cane ,%20yum!.jpg Poaceae: Andropogoneae: Saccarum officinarum x S.spontaneum users.chello .be 11. Hawaiian sugar cane varieties http://www.travelwithachallenge.co m/Images/Travel_Article_Library/Hawaii/ Gay-andRobinson/Hawaii- Sugar-Cane-Varieties.jpg http://calib an.mpiz-koeln.mpg.de/~stueber/koehler/ZUCKER.jpg History of Sugar www.plantcultures.org • Arabic “sukkar” and Sanskrit “sharkara” • Originally cultivated in New Guinea (6000 BC), but crop mainly developed in India • Traditionally used in Indian in religious ceremonies and to treat leprosy/gallstones. Referred to in Sanskrit texts from 600 BC. • Chewed initially, then boiled for sweet water. • Arab traders moved to Egypt and the Mediterranean. Major trading ports in Italy. • Planted in the New World 15 years after Columbus Sugar today • Brazil, India, China, Thailand, Pakistan, Mexico, Australia top producers • 70% cane, 30% beet (but really, mostly HFCS) Historical theories • Role of S. barberi, S. sinense in cultivation • Crossing between Saccharum and other genera? (Erianthus, Miscanthus, Sclerostacha, Narenga) • Interspecific hybrid origin of S. officinarum S. sinense . S. sinense http://digitalis .mobot.org S. barberi S. spontaneum x Modern cultivars S. barberi http:// ecocrop.fao.org/ECPix/000009/9432.jpg S. robustum S. edule S. officinarum Nobelization S. officinarum (female) S. spontaneum (male) F1 High sugar cultivar -occurred in the 19th century in Java and India from just a few initial clones QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. S. robustum, S. officinarum x8 S. spontaneum x10 (highly variable chromosome number) “Sweet” questions • How does the mode of crop reproduction (ie. Clonal vs. seed setting) contribute to the genetics of domestication? • Does high ploidy number correspond to high sweetness? • There seems to be a lack of data on “wild” populations of some of these species/cultivars. Does information on localities/amount confuse or help clarify the picture? • How were researchers initially misled by morphology/flavenoid data and what other problems can high ploidy number create when trying to study the origin of crops? • Do we know anything about the selection of S. Recent work • Genome mapping with AFLP markers (Hoarau et al 2001) • QTL analysis of cultivars (Hoarau et al 2002)