The availability of stable cytoplasmic male sterile(CMS or A) lines coupled with a robust restoration system(R lines) is an essential prerequisite for efficient hybrid breeding.CMS-enabled hybrid technology holds immense potential to enhance the long-stagnant productivity of pigeonpea. In the present investigation, cytoplasmic substitutions were made in the nuclear backgrounds of early-maturing pigeonpea varieties or lines. Three new CMS lines(ICPL 88039 A, Pusa 992 A, and DPP 3-2A) resulted from genetic crosses involving cytoplasmic donors from A2(GT 288A) and A4(ICPA 2089) categories. In addition to visual inspection of anthers, pollen-staining techniques and scanning electron microscopy(SEM)analysis were used to confirm pollen sterility. Further, given the relevance of the plant mitochondrial genome to CMS manifestation, 25 mitochondrion-specific DNA markers were assayed on these newly developed A lines and isogenic maintainer(B) lines. DNA polymorphism between Pusa 992 A and Pusa 992 B as revealed by the nad7a_del marker confirmed the successful combination of sterilizing cytoplasm(A4) and nonrestoring nuclear background(Pusa 992). Such cytoplasm-specific DNA markers are required for A2-CMS as well. Further, to assess restoration ability, potential restorers were crossed with these CMS lines, and as a consequence, promising A × R combinations exhibiting 100%pollen fertility could be identified. In parallel, we also analyzed the inheritance patterns underlying fertility restoration using ICPL 88039A-derived F2 and BC1F1populations,and established a monogenic dominant model to explain the phenomenon of A2-CMS restoration. In summary, we report the successful development of new CMS lines and describe their effective deployment in hybrid breeding of pigeonpea. The availability of stable cytoplasmic male sterile (CMS or A) lines coupled with a robust restoration system (R lines) is an essential prerequisite for efficient hybrid breeding. CMS-enabled hybrid technology holds immense potential to enhance the long-stagnant productivity of pigeonpea. Three new CMS lines (ICPL 88039 A, Pusa 992 A, and DPP 3-2A) resulted from genetic crosses involving cytoplasmic donors from A2 In addition to visual inspection of anthers, pollen-staining techniques and scanning electron microscopy (SEM) were used to confirm pollen sterility. Further, given the relevance of the plant mitochondrial genome to CMS manifestation, 25 mitochondrion-specific DNA markers were assayed on these newly developed A lines and isogenic maintainer (B) lines. DNA polymorphism between Pusa 992 A and Pusa 9 92 B as revealed by the nad7a_del marker confirmed the successful combination of sterilizing cytoplasm (A4) and nonrestoring nuclear background (Pusa 992). Such cytoplasm-specific DNA markers are required for A2-CMS as well. Further, to assess restoration ability, potential restorers were crossed with these CMS lines, and as a consequence, promising A × R combinations exhibiting 100% pollen fertility could be identified. In parallel, we also analyze the inheritance patterns underlying fertility restoration using ICPL 88039A-derived F2 and BC1F1populations, and established In summary, we report the successful development of new CMS lines and describe their effective deployment in hybrid breeding of pigeonpea.