Production of embryo rescued hybrids between the landrace “Friariello” ( Capsicum annuum var. annuum ) and C. baccatum var. pendulum : phenotypic and cytological characterization

Capsicum baccatum var. pendulum is a valuable source of disease resistance and fruit quality traits that could play an important role in the genetic improvement and safeguard of local varieties of common peppers. However, its use for C. annuum var. annuum breeding has been scarce due to postzygotic incompatibilities. In this work, we obtained seven interspecific hybrids between the Italian landrace ‘Friariello’ of C. annuum var. annuum and C. baccatum var. pendulum through embryo rescue. The F1 hybrids were verified by SSR markers and by in situ hybridization, which confirmed their hybrid status and provided evidence for differences in the repetitive content between the parental genomes. These hybrids were vigorous and, for several morphological traits, were intermediate between their parents. However, they were male sterile. The cytological analysis revealed several abnormalities occurring at various stages of the male meiosis. A number of these anomalies were likely the result of structural differences (e.g. a reciprocal translocation, a paracentric inversion) between the two genomes. Due to hybrid pollen sterility, backcross progenies (BC1) were obtained when hybrids were used as female parents. A partial restoration of the fertility in BC1 makes promising the exploitation of this material in breeding programs.