What is the importance of mapping Sugarc

Sugarcane was the last major cultivated plant to have its genome sequenced. This was because of its huge complexity: the genome comprises between 10 and 12 copies of each chromosome, when the human genome has just two. It was an international team coordinated by CIRAD that achieved this milestone. CIRAD is a French Agricultural Research Centre for International Development and is working for the sustainable development of tropical and Mediterranean regions. It will now be possible to modernize the methods used to breed sugarcane varieties. This will be a real boon to the sugar and biomass industry.
Sugarcane produces 80 per cent of the world’s sugar and emerged as the primary crop for biofuel production. A global team of researchers mapped the sugarcane genome using a variety grown in the Réunion Islands.
It will help scientists create a reference genome of sugarcane, which can be used to develop molecular tools to supplement conventional breeding methods. This reference sequence is also an essential resource to analyse the variations between the sugarcane varieties.
Until now, sugarcane cultivar breeding programmes were restricted to hybridisation, followed by cumbersome field assessments. As with all cultivated plants before it, sugarcane breeding will now be able to enter the age of molecular biology. The genome is so complex that classical sequencing approaches proved useless.
The sugarcane genome is nearly 20 times bigger than that of rice. While the rice genome could be sequenced about 15 years ago, the sugarcane genome proved a tough nut .
Each of the 10 basic sugarcane chromosomes is duplicated in 8-10 copies with a total of more than 100 chromosomes. In comparison, the human genome has just 23 pairs of chromosomes.
The genomic structures of sugarcane and sorghum are very similar. The scientists were thus able to use the sorghum genome as a template to assemble and select the sugarcane chromosome fragments to sequence.
The newly acquired genomic information will help sugarcane breeders develop varieties as per their requirements. For example, they can breed varieties that can withstand droughts, those requiring lesser water or cultivars containing higher sucrose levels. Theoretically, the maximum sucrose content that sugarcane can have is around 25 per cent.
This, in principle, could be breached if we know the molecular mechanisms involved in sucrose storage in the plant.
While many major institutes working on sugarcane research in Australia, South Africa and elsewhere were involved in the research, India was not part of it. However, a private institute in Maharashtra — Vasantdada Sugar Institute — was part of a larger consortium put together by CIRAD. All countries can “use the data produced in the study even if they are not part of the consortium.