The genetics of self-incompatibility in the genus Schlumbergera (Cactaceae)

The genetics of self-incompatibility (SI) was studied in the genus Schlumbergera Lemaire. Nineteen F-1 progeny were intercrossed in a full diallel and reciprocally backcrossed to both parents (Schlumbergera Rocket and Buckleyi, 2n = 2x = 22), Four intra-incompatible but reciprocally compatible classes were obtained in the diallel. All F-1 progeny were reciprocally cross-compatible with both parents, Three F-2 families were generated and 13 to 14 seedlings in each F-2 family were tested for their incompatibility responses. Results of all crosses were consistent with a one-locus, multiallelic SI system under gametophytic control, Schlumbergera has tricellular pollen and dry stigmas with a papillate receptive surface and these features are typically associated with sporophytic SI systems. This is the first report on the inheritance of SI for the Cactaceae, a family of approximate to 1500 species that exhibits SI in at least 28 of its 98 genera (29%).