3)Types of mutagens a)Physical rays β-rays(β- particles) ° Gamma-rays Neutrons · Ultraviolet rays Particles from accelerators b)Chemical Base analogues and related compounds Alkylating agents · Aides Nitrous acid Hydroxylamines · Antibiotics
3) Types of mutagens a) Physical • X-rays • Gamma-rays • Ultraviolet rays • -rays (-particles) • Neutrons • Particles from accelerators b) Chemical • Base analogues and related compounds • Alkylating agents • Azides • Nitrous acid • Hydroxylamines • Antibiotics
2. The characteristics of Mutation Breeding a) High frequency and wide spectrum of mutation b) Minor modification of varieties Improvement of oligo-traits in plants c) Breaking linkage of genes /inducing segment translocation 3. Achievements of Mutation Breeding a Worldwide(1990): 1030 varieties b In China(1989): 325 (Rice, wheat, cotton,.)
2. The characteristics of Mutation Breeding 3. Achievements of Mutation Breeding a. Worldwide(1990): 1030 varieties b. In China(1989): 325 (Rice, wheat, cotton, …) a) High frequency and wide spectrum of mutation b) Minor modification of varieties Improvement of oligo-traits in plants c) Breaking linkage of genes / inducing segment translocation