The sugarcane grown today is a hybrid from two species, Saccharum
officinarum ? the original sugarcane domesticated in India 3,000 years ago ?
and S. spontaneum. The genome of sugarcane which was completed a few months
ago contains 10 billion base pairs in 100-130 chromosomes, three times the
size of the human genome.
According to Marcelo Falsarella Carazzolle, bioinformatics coordinator in
the Genomics and Bioenergy Laboratory at the University of Campinas's
Biology Institute (IB-UNICAMP) in S?o Paulo, Brazil, the sugarcane genome
has grown to be a giant, and working on it with current genomic methods is
difficult. Carazzolle and his team developed a different strategy which is
much less costly and time consuming, designed to map specific portions of
the genomes of polyploid plants.
The research team developed Polyploid Gene Assembler (PGA), a software that
will help reconstruct complex genomes such as the sugarcane's. PGA focused
on small portions of the genome, corresponding to about 1%-2%, exactly where
the genes of interest are located. Carazzolle's team identified a total of
39,234 genes, 60.4% of which were clustered into known grass gene families.
"Our findings for the genome of S. spontaneum highlighted for the first time
the molecular basis of certain significant characteristics, such as high
productivity and resistance to biotic and abiotic stress. These results can
be used in future functional and genetic studies. They will also support the
development of new sugarcane varieties."