1. College of Horticulture, South China Agricultural University, Guangzhou 510642, P. R. China
2. Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510642, P. R. China
3. Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong, Maoming 525100, P. R. China