Development of Ogura CMS Fertility-Restored Interspecific Hybrids for Use in Cytoplasm Replacement of Golden-Heart Materials in .

Ogura cytoplasmic male sterility (CMS) is one of the important methods for hybrid seed production in cruciferous crops. The lack of a restorer of fertility gene () in L. restricts the development and utilization of its germplasm resources. In this research, with the gene was used to restore the fertility of Ogura CMS with the golden heart trait. Through the distant cross of two and four , six interspecific hybrid combinations received F1 seeds. The six combinations were different in seed receiving. By morphological observation and molecular marker-assisted selection (MAS), in F1, individuals containing the gene all appeared fertile, while those without it remained male-sterile. The pollen viability of the fertile individuals was measured, and the fertile lines of the six interspecific hybrid combinations were different (40.68-80.49%). Three individuals (containing both and genes) with the highest pollen vitality (≥60%) were backcrossed with fertile cytoplasmic resulting in a total of 800 plants. Based on the MAS, a total of 144 plants with but no were screened (18%). Moreover, through morphological investigation, one individual with normal cytoplasm, stable fertility but without the restoring gene , the gene, and morphological characteristics similar to those of was obtained. These results increased the diversity of germplasm and provided a new method for the utilization of CMS germplasm in crops.