In a breakthrough that could safeguard pigeonpea crops from devastating losses, researchers from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and the Indian Council of Agricultural Research (ICAR) institutes have identified a gene, Ccsmd04, linked to high resistance against Sterility Mosaic Disease (SMD).
Led by Dr. Manish K. Pandey of ICRISAT, the team collaborated with ICAR–Indian Institute of Pulses Research (Uttar Pradesh), Dr. Rajendra Prasad Central Agricultural University (Bihar), and ICAR–Indian Agricultural Research Institute (Assam). Using advanced genomics, phenomics, and computational analysis, the resistance gene Ccsmd04 was discovered in ‘Asha’ (ICPL 87119), a widely cultivated ICRISAT-bred pigeonpea variety resistant to SMD.
SMD can wipe out up to 90% of pigeonpea yield, posing a serious threat to farmer incomes. The study revealed that Ccsmd04 produces a dormancy/auxin-associated protein, with susceptible plants carrying mutations that impair its function. Researchers also validated four genetic markers that can be used to rapidly screen breeding lines for resistance.
Calling the discovery a “landmark,” ICRISAT Director General Dr. Himanshu Pathak said the identified genetic variants, genes and markers hold immense potential for breeding more resistant pigeonpea varieties.
ICRISAT has been working on host-plant resistance to SMD since 1975. While several resistant varieties have been identified and developed, in-field success has been limited due to the variability in both the virus and its vector, which are mites. This discovery sheds light on the genomic aspects of SMD resistance in pigeonpea.
“We’ve identified a resistance gene and validated four functional InDel markers associated with SMD resistance; these markers can now be used to screen pigeonpea breeding progenies for early generation selection of SMD resistance. This gene information can also be valuable for genetic improvement through gene editing,” said Dr Manish K. Pandey.
The team is set to explore more resistance genes, including those from wild relatives, to ensure stable resistance in farmers' fields. Through strong partnerships and collaboration, they aim to accelerate the varietal development process for SMD resistance in pigeonpea lines with greater precision and speed. This effort will play a key role in advancing India’s goal of self-sufficiency in pulses.