Introgression of self-compatibility from Coffea heterocalyx to the cultivated species Coffea canephora.

Self-compatibility segregation was assessed in two successive backcross progenies originating from an interspecific cross between Coffea canephora (self-incompatible) and Coffea heterocalyx (self-compatible). After self- and cross-pollination, pollen tube behaviour in styles was observed under ultraviolet fluorescence microscopy and fruit-set was determined at harvesting time. Segregation ratios in the two progenies were consistent with monofactorial control of self-compatibility. Self-compatible plants exhibited higher fruit-set than self-incompatible ones in open-pollination conditions. Segregation of AFLP markers was scored in the first backcross progeny. By molecular linkage analysis, the S locus could be mapped to a short linkage group.