1. School of Computer Science, South China Normal University, Guangzhou, P. R. China
2. The Key Laboratory of Intelligent Education Technology and Application of Zhejiang Province, Zhejiang Normal University, Jinhua, P. R. China
3. Agro-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, P. R. China
4. Guangdong Key Laboratory for Crop Germplasm, Resources Preservation and Utilization, Guangzhou, P. R. China
5. Computing and Mathematics Manchester Metropolitan University, Metropolitan University, Manchester, UK