ABSTRACT
Mutagenesis is an event capable of causing mutations, an important driving force for biological evolution, and also responsible for providing genetic variation. A mutation, indicating a change in the DNA sequence
1National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China. ae-mail: jmeng@mail.hzau.edu.cn 2Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China. *Corresponding author
of the genetic material, can be caused by spontaneous mutagenesis or induced mutagenesis. However, spontaneous mutations in nature occur at very low rates and are diffi cult to be selected for crop breeding. Induced mutagenesis by physical, chemical and biological mutagens show much higher mutation rates, which have provided abundant useful variations for crop breeding and improvement, and shortened the breeding process compared with traditional breeding programs (Konzak et al. 1976; Waugh et al. 2006; Parry et al. 2009).
