Mutation induction and evaluation for resistance to leaf mottling in citrus

A series of experiments were conducted to develop a protocol for in vitro culture of nuclear embryos and mutation induction in citrus. It was found that the optimum medium for support of in vitro growth and plantlet regeneration consisted of the basic Murashige and Skoog's medium supplemented with myo-inositol (100 mg/l), pyridoxine-HCl (1 mg/l), nicotinic acid (1 mg/l), thiamine (0.2 mg/l), Fe-EDTA (25 mg/l), sugar (20g/l), agar-agar (7 g/l) and benzyladenine (1 mg/l) with a pH of 5.7. LD50 for gamma irradiation was 100 - 150 Gy. For ethyl methanesulfonate, concentrations up to 24.6 ml/l were tolerable. Screening for resistance to leaf mottling organism among the resulting seedlings gave promising results. A few plants had been recovered exhibiting a certain degree of resistance to this pathogen. (author). 1 ref., 10 tabs