Callus induction and embryo regeneration in Coffea arabica L. anthers by silver nitrate and ethylene

The genetic breeding of coffee by conventional methods to obtain new cultivars is time-consuming. Anther culture can yield homozygous lines quickly from bi-haploids. This study used anther cultures of Coffea arabica L. cv. Catuaí Vermelho 99, and tested the effect of silver nitrate (AgNO3) and ethylene in callus-formation induction and bi-haploid seedling regeneration. The anthers were inoculated in MS to which 2 mg L-1 2,4-D had been added with AgNO3 (5 mg L-1) together with ethylene being introduced or not, for different periods (the control, 2, 4, 6, and 8 days). At the end of 12 days, the anthers were transferred to the regeneration medium, to which 0.108 mg L-1 kinetin had been added. Greater oxidation and intumescence were observed in the first days after exposure to ethylene; the cultivar Catuaí Vermelho 99 responded to callus formation and also direct embryogenesis in the presence of ethylene.