Inheritance of fertility restoration of A₅ cytoplasmic-nuclear male sterility system in pearl millet [Pennisetum glaucum (L.) R. Br.]

The A5 cytoplasmic-nuclear male sterility (CMS), the most stable cytoplasm available in pearl millet [Pennisetum glaucum (L). R. Br.] is yet to be utilized on large scale by breeders owing to limited fertility restoration in the available germplasm for this cytoplasm. An understanding of the inheritance of fertility restoration can make significant contributions to restorer breeding efficiency of this CMS system. This study investigated inheritance of fertility restoration of this CMS system in which three diverse isonuclear A-lines (P1) were crossed with two A5 restorer lines (P2) to produce 4 F1s and their respective F2s and two backcrosses. These were evaluated for male sterility (S) and fertility (F) for two seasons at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) Patancheru. The segregation patterns in the F2 (54F: 10S) and BCP1 (3F: 1S) were broadly suggestive of trigenic inheritance of male fertility restoration, where dominant alleles at any two of the three duplicate complimentary loci will lead to fertility restoration.