Breeding by Interspecific Crosses and Its Bulb Production in Lilium Spp.

In this study, we surveyed the cross-compatibility between lily varieties and the growth, development, and flowering characteristics of the hybrid lily progenies, to collect foundational data for the breeding of interspecific hybrids of Lilium. Further, we aimed to select effective growth media conditions for embryo and ovule cultivation in order to develop hybrid progenies in the interspecific hybrid lilies. Lilium × fomolongi RaizanNo.2 variety was used as the seed parent. Oriental lily (O) variety Sorbonne; Asiatic lily (A) variety Brunello; and a Longiflorum-Asiatic (LA) hybrid lily, Royal Fantasy, were used as pollen parents. For each cross-combination, 30 plants were interspecifically crossed. The number of recovered progeny was highest for the FA hybrid, at 23, and 18 FLA hybrids and 11 FO hybrids were recovered. Seed production for the F × A cross was 76.6% and for the F × O cross was 46.6%, indicating a difference between the crosses. We performed the following experiment to increase the development of shoots in the in vitro culture of hybrid progeny. A MS medium was used as the base medium; cytokinins BA at a concentration of 2.0, 3.0, or 5.0 mg/L and TDZ at a concentration of 0.2, 0.3, or 0.5 mg/L were added to the in vitro cultures. For the FO progeny, the shoot development rate was highest with 2.0 mg/L BA, at 18%, and 3.0 mg/L and 5.0 mg/L BA resulted in a lower rate of 12%. The TDZ addition tended to yield identical or similar results to that of the control media. For the FA progeny, the addition of TDZ tended to lead to a higher shoot development rate and was superior with 0.3 mg/L treatment. However, the addition of BA to the media resulted in a shoot development rate between 14.3% and 15.7%, similar to that of the control.