Source: Chinese Academy of Tropical Agricultural Sciences

January 16—After one year of hard work led by Wang Wequan, Research Fellow of the Chinese Academy of Tropical Agricultural Sciences (CATAS) has completed the genome sequencing of three varieties of cassava. Meanwhile, thanks to several UHT sequencing technologies, the Academy has obtained the comparatively detailed genome map of cassava.

According to Peng Ming, Director of Tropical Biological Institute of CATAS, cassava as “the king of starch” is one of the three major tuber crops and the world’s sixth major crop for staple food. It provides food to 600 million people in the world. In China, cassava enjoys huge potential as a source of new energy, industrial raw material and food. It is one of the most important economic crops in tropical regions of China, with a plantation area of 500,000 hectares, over 10 million tons of production every year, worth 14 billion yuan. It is estimated that cassava can be grown in 1.5 million hectares of land in China, with annual output worth 50 billion yuan.

In 2006, CATAS established the team for genome sequencing of cassava. After one year of hard work, the team completed the sequencing of three varieties: Ku50, W14 and CAS36, using the mixing stragety of Solexa, 454 and BAC to finish the assembly of the genomic data.

China has led the world in the research in cassava, especially finishing the comparatively detailed genome map of three varieties. These data will provide information on the features of the genome structure of cassava, and necessary instrument for global innovative research in the crop and its application. They will also lay a foundation for decoding how cassava can transform solar energy for starch accumulation so effectively and its molecular regulation mechanism to with stand drought and soil leanness. Therefore, the completeness of the genome sequencing work is significant for global food security and bio-energy development.

China has already established a germplasm base for cassava with 450 specimens, 85% of the core germplasm. A whole system of germplasm evaluation, breeding, demonstration and extension has also been set up to have cultivated 15 varieties of Huanan series, covering 11 million hectares of land for extension, worth over 11 billion yuan of value added. Scale industrial development has also been enhanced to replace small-scale production. The annual output has reached two million tons for starch, and one million tons for fuel ethanol. The imported volume of dry cassava every year is three million tons. The whole industry has employed one million labors from the rural areas. In 2009, key technologies on selection and breeding, and industrialized production for cassava won the second-class national prize. The basic research in cassava improvement has also gained the state sponsoring to establish the technological platform for transgenic breeding of cassava in China.

（Date: 09:03 18 Jan. 2010）