Rootstock mediated enhancement of abiotic and biotic stress tolerance in acid lime (Citrus aurantiifolia)

The study aimed to evaluate the performance of different rootstocks for acid lime (Citrus aurantiifolia) under salinity and nematode stress, focusing on their impact on plant growth and biochemical parameters. Grafted combinations involving acid lime (PKM 1) scions with rangpur lime and wood apple rootstocks were tested for salinity tolerance and resistance to Tylenchulus semipenetrans. The study, conducted from 2023 to 2024 at Tamil Nadu Agricultural University, HC & RI, Coimbatore, Tamil Nadu, utilized varying sodium chloride (NaCl) concentrations to simulate salinity stress and nematode inoculation for biotic stress evaluation. Results indicated that the R5 combination (acid lime PKM 1 scion grafted onto rangpur lime) exhibited the highest salinity tolerance, evidenced by better chlorophyll retention, membrane stability, and enhanced activity of antioxidant enzymes such as catalase and superoxide dismutase. Similarly, T3 (acid lime PKM 1 scion grafted onto wood apple) plants demonstrated improved nematode resistance, marked by higher leaf phenol content and peroxidase activity, as well as a reduced nematode population. These findings suggest that grafting onto rangpur lime and wood apple rootstocks strengthens the physiological and biochemical mechanisms in acid lime, enabling better adaptation to environmental stresses. This study provides suitable rootstock options for enhancing acid lime productivity in areas impacted by nematode and salinity problems.