Detection and characterization of two new CMS systems in faba bean (Vicia faba) *

Abstract Wide crosses were made to identify new cytoplasmic male sterility (CMS) systems in faba beans, based on the interaction of cytoplasm with restorer and maintainer alleles. A total of 330 F1 hybrids were produced in both reciprocal forms. Male sterile segregates were observed in one reciprocal version in the F2 generation of six crosses. Two of these crosses with female parents originating from Afghanistan and Egypt expressed stable male sterility in subsequent backcross generations. Based on the female parents of the two crosses, these two CMS systems were designated CMS 199 and CMS 297. CMS 199 was more stable than CMS 297 during backcross generations and across different environments. Maintainer and restorer lines for both CMS systems were identified. Lower expression of male sterility occurred in CMS 297 in the greenhouse during the winter generations than in isolation cages during the summer generations, which may be utilized to maintain male sterile lines by selfing. Regarding practical applications, the CMS 199 shows great promise for hybrid breeding in faba beans.