Flooding is a severe constraint to tomato growth and productivity in many regions. Grafting is a favourable technique to overcome this constraint and a study was conducted to comprehend the histological implications influenced by hormones in the compatible root stock-scion of Solanum species. The scion used for the study was tomato cv. PKM 1 and the different selected flood tolerant Solanumroot stocks, based on the previous studies were Solanum lycopersicum(LE 523, LE 828, LE 102), Solanum torvum, Solanum aculeatissimum and Solanum sysimbriifolium.The compatibility of root stock and scions were evaluated by graft success per cent and microtome studies. Significant differences were observed in graft success per cent among the different tomato grafts. Among the six root stocks and scion combination, Solanum torvum * PKM 1 recorded significantly higher graft success per cent (95%) followed by Solanum sisymbriifolium * PKM 1 (69.40 %), whereas in LE 102* PKM 1 and LE 523* PKM 1grafts, it was 9.34% and 13.3% explicating the graft incompatibility. At the initial stages of observation, control (PKM 1) which is the non-grafted plant manifested better growth than the tomato grafts (30 DAG). The histological studies revealed that the vascular connection was developed earlier in LE 828 * PKM 1 graft compared to Solanum torvum * PKM 1. From this study, it was concluded that LE 828 root stock demonstrated earlier formation of vascular connection and vigorous root growth that enhanced water and nutrient uptake resulting in better growth. Other tomato grafts where the root stocks were Solanum torvum, Solanum aculeatissimum, Solanum sisymbriifolium, though compatible with PKM-1, the vascular connection was delayed. These compatible root stocks might be further studied for its tolerance to survive abiotic and biotic stress in comparison with LE 828 root stock for further validation of superior compatible root stock.