Transcript Molecular Evidence of Sugarcane Evolution and Domestication

Molecular
Evidence of
Sugarcane
Evolution and
Domestication
http://www.botgard.ucla.edu/html/MEMBGNewsletter/images/volume4/Saccharu
mvariegated.jp g
Rachel Jabaily and
Maggie Koopman
http://www. travellerspoint.com/photo s/41787 /suga r%20cane ,%20yu m!.jpg
Poaceae: Andropogoneae: Saccarum
officinarum x S.spontaneum
users.chello.be
11. Hawaiian sugarcane varieties
http://www.travelwithachallenge.com/Images/Travel_Article_Library/Hawaii/Gay-andRobinson/Hawaii-Sugar-Cane-Varieties.jpg
http://caliban.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)