Determination of general combining ability and Heterosis for yield and quality of tomato inbred lines

This study investigates the genetic potential of various lines and testers for breeding purposes, emphasizing the importance of General Combining Ability (GCA) and Specific Combining Ability (SCA) in enhancing crop traits. Lines NBLTM-3, NBLTM-4, and NBLTM-16, along with testers NBLTM-21, NBLTM-24, NBLTM-26, and NBLTM-28, exhibited high GCA, indicating their consistent positive contributions to trait performance. Notably, 68% of the evaluated hybrids displayed high SCA across fourteen traits, highlighting effective combinations and the predominance of non-additive gene action. The analysis revealed that line contributions were more significant than those of testers, with line × tester interactions playing a critical role in hybrid performance. Twelve hybrids demonstrated high overall heterotic status, with NBLTM-4 × NBLTM-29 and NBLTM-3 × NBLTM-28 leading in heterotic responses. Positive heterosis was observed in key traits such as fruit weight and total soluble solids, while negative heterosis was noted in traits like blossom end size. These findings underscore the potential for developing superior hybrids to boost agricultural productivity by focusing on the strengths of both parental lines and hybrid selection.