An international team coordinated by the French Agricultural Research Centre
for International Development (CIRAD) has released the genome sequence of
sugarcane.

The sugarcane's genome is so complex that conventional sequencing techniques
were proven useless. It comprises between 10 and 12 copies of each
chromosome, when the human genome has just two. This meant that sugarcane
was the last major cultivated plant to have its genome sequenced.

The team used a discovery made in CIRAD 20 years ago: the genome structure
of sorghum, which is very similar to that of the sugarcane. Olivier
Garsmeur, CIRAD researcher and lead author of the study, used the sorghum
genome as a template to assemble and select the sugarcane chromosome
fragments to sequence.

According to the research team, the sugarcane genome is complex for several
reasons:

. *high polyploidy (large number of copies of each chromosome
category)

. *aneuploidy (variable number of copies depending on the chromosome
category)

. *bispecific origin of the chromosomes

. *structural differences and interspecific chromosome recombinants.



[www.cirad.fr]
nome-sequencing