Abstract

                                The present investigation was carried out with 36 hybrids and they were evaluated for growth, quality, mosaic disease incidence and yield through line x tester method to identify combinations expressing high hybrid vigour in snake gourd. The significant variation in gca, sca and heterosis over the standard variety were noticed for all the traits. The line IC 308557 (L4), IC 284753 (L5), IC 546083 (L6) and the testers Jeyamkondam Local (T2) and Kulithalai Local (T1) were found to be best general combiners for growth, quality, mosaic disease incidence and yield characters. Among the hybrids L2xT3, L7xT2, L2xT4, L5xT1 and L8xT4 were found to be the good specific combiners (gca) for most of the characters viz., growth, ascorbic acid, mosaic disease incidence and yield per vine. Among the 36 hybrids, seven viz., IC333314 x Kumbakonam Local (L2xT3), IC433526 x Kulithalai Local (L3xT1), IC546083 x Kulithalai Local (L6xT1), IC546083 x Kumbakonam Local (L6xT3), IC433526 x Kumbakonam Local (L3xT3), IC284753 x Kulithalai Local (L5xT1) and IC410160 x Jeyamkondam Local (L7xT2) exhibited highly significant positive standard heterosis for growth, quality, mosaic disease incidence and yield. These seven hybrids were found to be suitable for exploiting heterosis.

Key words : Snake gourd, Trichosanthes cucumerina L., Line x Tester, Gene action, Heterosis