The present investigation reports reciprocal hybrids between Citrus sunki, belonging to the "True Citrus" taxonomic group, and Severinia buxifolia of the "Primitive Citrus" group. This represents the first case of sexual hybridization between genera of distinct taxonomic groups of the subtribe Citrinae, which have several complementary agronomic and phytosanitary attributes. Thus, there exists considerable interest in determining the potential of such hybrids as rootstocks, as well as a possible genetic bridge to combine, by breeding at diploid level, nuclear and cytoplasmic genes of Severinia with Citrus and other citrus intergeneric hybrids.
