Sequencing of Sugarcane Genome

Why in news?

A global team of researchers recently announced the sequencing of sugarcane genome.

Why is it so significant?

• Sugarcane produces 80% of the world’s sugar.
• It has also emerged as the primary crop for biofuel production.
• The sugarcane genome is nearly 20 times bigger than that of rice.
• Its complex genetic makeup has so far posed challenges to classical sequencing approaches.
• So significantly, sugarcane is one of the last crop plants to be genome-mapped.
• In comparison, the rice genome was cracked nearly 14 years ago.

How was it done?

• 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.
• An earlier discovery that the genomic structures of sugarcane and sorghum being very similar helped here.
• Sugarcane and sorghum share large fragments with numerous genes in the same order.
• So scientists used the sorghum genome (which was sequenced years ago) as a template.
• The template was used to assemble and select the sugarcane chromosome fragments to sequence.

What are the benefits?

• Until now, breeding programmes were restricted to hybridisation and was followed by cumbersome field assessments.
• With the recent finding, sugarcane breeding will be able to enter the age of molecular biology.
• The finding will help scientists create a reference genome of sugarcane.
• The reference sequence can help in effectively analysing and comparing variations between various sugarcane varieties.
• It can also help develop new molecular screening techniques to supplement conventional breeding methods.
• Characteristics that contribute to improving a variety rely on the combination of several genes inherited.
• The traits may include yield, drought resistance and ability to withstand pest attacks.
• So if scientists can identify genes associated with these agronomic traits, they can easily be transferred to commercial varieties.
• This in turn could shorten the time required for getting a new variety to the field.
• Varieties - Theoretically, the maximum sucrose content that sugarcane can have is around 25%.
• This could be breached with the knowledge of molecular mechanisms involved in sucrose storage in the plant.
• Very significantly, sugarcane is a known water-consuming crop.
• Genetic sequences linked to enduring water stress can help develop varieties that require lesser water.

What lies ahead for India?

• The cracking of the sugarcane genome can transform the sector.
• But India needs to clarify its stance on GM foods as India does not currently allow GM food crops.
• This is essential to reap the benefit of the advances in sugar genome sequencing.
• Notably, Brazil (with largest area in the world under sugarcane) recently allowed commercial cultivation of the world’s first GM sugarcane.

Source: BusinessLine