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, and structural differences and interspecific chromosome recombinants.
Source: Crop Biotech Update, International Service for Acquisition of Agri-Biotech Applications.