Vol. 6, Issue 1, Part B (2024)

Urdbean (Vigna mungo L.) is an essential legume crop, but its productivity is severely impacted by pod borer complex (Helicoverpa armigera, Maruca vitrata, and Leucinodes orbonalis), which damages the reproductive structures of the plant. The primary objective of this study was to investigate the metabolomic responses of urdbean germplasm to pod borer infestation and identify potential biomarkers for resistance. A total of 30 diverse urdbean germplasm lines, including both resistant and susceptible varieties, were grown under controlled conditions. The plants were infested with pod borers at the flowering and pod development stages, and their metabolic profiles were analyzed using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Key metabolites such as flavonoids, terpenoids, and amino acids were identified, and their concentrations were compared between control (pre-infestation) and infested plants.
The results revealed a significant upregulation of flavonoids (Quercetin and kaempferol) and terpenoids (Limonene and caryophyllene) in resistant germplasm lines, while a marked reduction in amino acid levels was observed, particularly in resistant lines. Additionally, pod borer infestation was significantly lower in resistant lines, with an average of 3.2 larvae per plant, compared to 8.5 larvae in susceptible lines. Principal component analysis (PCA) and correlation analysis further supported the association between increased secondary metabolites and reduced pest damage. These findings suggest that metabolomic profiling can effectively identify urdbean lines with enhanced resistance to pod borer complex.
In conclusion, this study highlights the potential of using metabolomic profiling as a tool for identifying resistant germplasm and providing valuable insights for breeding pest-resistant varieties. The findings also suggest that integrating metabolomics into breeding programs could accelerate the development of resistant urdbean lines, offering a sustainable approach to pest management and reducing reliance on chemical insecticides.