Developing lowland tomatoes (Solanum lycopersicum L.) is a better strategy to resist global warming. Tomato expansion also requires an efficient and organized selection process, including breeding the advanced segregating populations. Using selection indices in combination with biometrical analysis, such as principal component analysis, path analysis, and the Smith-Hazel index, can further improve the effectiveness of the selection concept. Therefore, the presented research aimed to evaluate the lowland F5 tomato lines through various selection indices and select the potential genotypes for further preliminary yield tests. The latest study proceeded in an augmented design, divided into four blocks, with a randomized complete block design as an environmental scheme. For comparison, the five standard tomato cultivars, consisting of Chung, Gustavi, Mawar, Tymoty, and Karina, underwent repeated planting in each block to compare with 45 F5 lines. All the tomato genotypes’ analysis used correlation, path, and principal component analyses, and the Smith-Hazel index. Based on the results, the selection indices with a multivariate approach and genetic analysis proved effective in selecting tomato lines in the F5 populations. The PCA, Smith-Hazel, and path analyses were the best approaches for creating selection indices formed by three characteristics, namely, yield, the number of fruits per bunch, and the number of branches. The selection indices recognized and recommended the 23 tomato F5 strains for further studies in the preliminary yield testing.
Path analysis, PCA, selection criteria, Smith-Hazel index, Solanum lycopersicum
The Smith-Hazel, PCA, and path analysis proved better approaches in forming the selection indices in the presented tomato research. Based on these indices, the selection index formed was 0.22, the yield + 0.1 numbers of fruits per bunch + 0.06 number of branches. The selection indices recognized 23 lowland tomato lines, recommended for inclusion in the preliminary yield tests. However, the five promising tomato strains were MC 74.12.8, KM30.5.2, MC 74.12.5, MC 29.4.6, and MC 29.4.5.