Study of inheritance of fertility restoration in pigeonpea lines derived from Cajanus cajanifolius

In this study, single crosses involving four CMS lines and three known fertility restorers were studied to determine the genetics of fertility restoration in pigeonpea (Cajanus cajan L. Millsp.). The F1 plants of all the four hybrids were selfed to produce F2 seed and simultaneously crossed to their corresponding A lines to produce BC1F1 seeds during 2007. The parents, F1, F2 and BC1F1 populations were planted in 2008 rainy season at the Marathwada Krishi Vidyapeeth, Parbhani, India. The interaction of dominant nuclear genes of ICP 2766 with ICPA 2092 produced 100% fertile F1 plant and showed complete dominance for fertility restoration. The restorer ICP 2766 when crossed with ICPA 2092 showed monogenic inheritance (3 : 1), while ICP 2766 crossed with ICPA 2043 revealed digenic inheritance (15 : 1) of fertility restoration. In a cross between ICP 2766 and ICPA 2043, dominant gene of fertility restoration at either of two loci masked the expression of male-sterile recessive alleles at two loci in such a way that it modified normal dihybrid ratio into 15 : 1 ratio and produced duplicate gene interaction.