PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Meloidogyne incognita constrains tomato production and can increase reliance on chemical nematicides. This study evaluated graft compatibility and the performance of susceptible tomato cultivars grafted onto selected resistant Solanum rootstocks under nematode-infested field conditions in Assam. The susceptible cultivars Arka Samrat and Dona-55 were grafted onto S. torvum or S. lycopersicum cv. Hisar Lalit using the cleft-grafting technique. A randomised block design with six treatments and four replications was used in 2023. Graft success, plant height, days to flowering and fruiting, fruit yield and nematode-related parameters were assessed. The highest graft success was recorded for Arka Samrat grafted onto S. torvum (67.90%), followed by Dona-55 grafted onto S. torvum (66.66%). Arka Samrat grafted onto S. torvum also produced the greatest number of fruits per plant (20.50), the highest average fruit weight (118.38 g) and the highest total fruit yield (628.00 q/ha). This combination had the fewest galls (7.00) and egg masses (2.75) per root system, the lowest final soil nematode population (120.00 per 200 cc) and the lowest reproduction rate (0.49). Grafted plants generally flowered and fruited later than non-grafted plants but showed improved yield and reduced nematode multiplication. Under the conditions studied, S. torvum was the more promising rootstock for the evaluated tomato cultivars.