A Chinese research team from Guangxi University has successfully decoded the genome of the modern cultivated sugarcane variety Xintaitang No. 22 (XTT22), shedding light on the highly complex allopolyploid genome of sugarcane and its evolutionary mechanisms.

Sugarcane plays a vital role in the production of sugar, alcohol, and bioenergy, offering substantial economic and agricultural value. XTT22 was once the leading sugarcane variety in terms of planting area in China for 15 consecutive years. More than 90 percent of the country's fourth and fifth-generation sugarcane varieties were developed using it as a parent.

According to Liu Yaoguang, an academician of the Chinese Academy of Sciences (CAS), the genome of XTT22 decoded in this study is the most complete and highest-quality genome assembly of modern cultivated sugarcane to date.

Another CAS academician, Han Bin noted that since the launch of the Sugarcane Expressed Sequence Tag (SUCEST) project in the 1990s, countries such as Brazil, France, China, Australia, and the United States have been jointly working to advance sugarcane genomics.

However, earlier genome drafts of sugarcane faced significant issues, including incomplete chromosomes and highly fragmented sequences. As a result, obtaining a complete and accurate genome of modern cultivated sugarcane has remained elusive.

"This study is like drawing a detailed 'map' of the sugarcane genome. In the past, the 'map' was so vague that we could only roughly navigate it," said Zhang Jisen, research team leader from the Guangxi University.

"Now, however, every 'street' and even every 'room' on the 'map' is clearly marked," Zhang added.

Sugarcane breeding primarily relied on traditional hybridization methods, where parent plants were selected based on experience to observe the performance of their offspring. However, this approach proved to be both time-consuming and inefficient.

Leveraging advancements in genomics, scientists can now use the "genomic map" to precisely pinpoint genes closely associated with sugarcane yield and sugar content, enabling more targeted improvements and optimization.

"With the widespread application of genomics in sugarcane breeding, the yield, sugar content, and disease resistance of sugarcane are expected to see further improvements," said Zhang.

The research was recently published in the journal Nature Genetics.