Overview

Sugarcane, a herbaceous plant in the family Gramineae, is widely cultivated in temperate and tropical regions. Sugarcane is the main cash crop of tropical sugar producing countries all over the world, especially one of the economic pillars of Southeast Asia Pacific island countries and Oceania islands. In China, sugarcane is the main raw material for sugar production and also an important raw material for light industry, chemical industry and energy.

Geographical Distribution

Sugarcane probably originated in New Guinea or India, and later spread to the South Pacific Islands. It was introduced into southern China around the time of King Xuan of Zhou Dynasty. Around the 10th and the 13th century (which was Song Dynasty), sugarcane was widely planted in provinces south of the Yangtze River.

Sugarcane is produced in more than 100 countries worldwide, the largest producers being Brazil, India and China. Other countries with large cultivation areas include Cuba, Thailand, Mexico, Australia and the United States. Sugarcane production areas in China are mainly located in the southern tropical regions of Guangxi (which produces 60% of the country's sugar cane), Guangdong, Taiwan and Fujian.

Application

• Edible: Sugarcane is rich in sugar and water, and it also contains various vitamins, fats, proteins, organic acids, calcium, iron and other substances beneficial to human metabolism.
• Health care: Sugarcane is sweet in taste and cold in nature. It has the effects of clearing heat and detoxifying the body, relieving thirst and stopping nausea in the stomach.
• Industrial raw materials: Sugarcane stalks are important raw materials for sugar production. The juice in the stalks contains sucrose 12%-15%, reducing sugar, starch, pectin and fat about 4%, and the fibre content of bagasse about 12%.It has high sugar yield in good quality with less fibre or impurity. In addition to a good feed for livestock such as cattle and sheep, the culm tips and leaves can also be used for medicine, making ethanol for alternative energy source, raising yeast, using as building materials and so on.

Genome sequencing

The sugarcane variety AP85-441 was sequenced under the leadership of Fujian Agriculture and Forestry University. The sequencing process involved the utilization of BAC libraries, Hiseq 2500 with PE250 technology, and PacBio RS II. The genome assembly resulted in a genome size of 3.13 Gbp with a Contig N50 of 45 kb. Additionally, using Hi-C physical mapping, the 2.9 Gbp genome sequence was anchored onto 32 chromosomes. Using the MAKER software, a total of 35,525 genes with defined alleles were annotated. The annotated genes exhibited a total of 82,773 alleles, with an average of 2.3 alleles per gene.

S. spontaneum Np-X genome was sequenced under the leadership of Fujian Agriculture and Forestry University. The sequencing process obtained 52 Gb of PacBio CCS long-read data and 417 Gb of Illumina short-read data. Using Canu (v1.9) and Hi-C technologies, the high-quality autopolyploid genome of S. spontaneum Np-X was assembled into 40 pseudochromosomes across 10 homologous groups, resulting in a genome size of 2.76 Gb with a contig N50 of 382 Kb. A total of 122,441 protein-coding genes were annotated. The genome assembly of S. spontaneum Np-X shows significant improvement compared to the previous S. spontaneum AP85-441 genome results.

Reference

1.中国科学院中国植物志委员会. 中国植物志.第10卷[M]. 科学出版社, 1980.

2.Zhang J, Zhang X, Tang H, et al. Allele-defined genome of the autopolyploid sugarcane Saccharum spontaneum L. Nat Genet. 2018;50(11):1565-1573. [OpenLBID: OLB-PM-30297971]

3.Zhang Q, Qi Y, Pan H, et al. Genomic insights into the recent chromosome reduction of autopolyploid sugarcane Saccharum spontaneum. Nat Genet. 2022;54(6):885-896. [OpenLBID: OLB-PM-35654976]