Physical Mutagenesis of Arabica Coffee Seeds and Seedlings

Abstract

Coffee, a perennial tropical crop, can be grown from seed or from cloned plants in the form of cuttings, grafts or tissue cultured plants. Arabica coffee is most commonly grown from seeds while Canephora is mostly grown vegetatively from cuttings and other propagules. Improving Arabica coffee through conventional breeding is seriously limited by the lack of genetic variation within the cultivated and wild species. Mutation breeding provides great potential to induce the novel genetic variation needed for Arabica coffee improvement. Here we present protocols for mutation induction of coffee seed and seedlings using the FAO/IAEA in-house gamma (60Cobalt) and X-ray (RS2400 irradiator) sources. Methods for mutation induction using gamma- and X-ray mutagenesis techniques are described. Methods for the preparation, seed quality control and post-radiation treatment of materials are also provided along with example data for radio-sensitivity testing of Coffea arabica seed under laboratory conditions.