Assessment of Genetic Variability, Heritability and Genetic Advance for Vegetative, Yield and Yield Component Traits in Tomato (Solanum lycopersicum L.) in Burkina Faso

Abstract

In Burkina Faso, tomatoes have a significant portion in vegetable production and play a major socio-economic impact within rural populations. To meet the increased demand for fresh tomatoes, the development of improved tomato varieties is one of the important strategies for which studies on variability and association studies are essential to carry out selection within the population to improve different traits. To understand the genetic variability, heritability, and genetic advance in tomato, a study was conducted at Farako-Bâ research station from April 2023 to March 2024. Thirty (30) hybrids and their six (06) parents, were evaluated in a completely randomized design with one plant as experimental unit repeated 10 times. Plant height (PH, cm), principal stem diameter (PSD, mm), number of primary ramification (RAM), days to first flowering (DFLO) and fruit maturity (DMAT), total number of fruits per plant (TNFP), fruit yield per plant (YIELD, g), as well as equatorial fruit diameter (EFD, mm) and individual fruit weight (IFW, g) were recorded. The results showed that for all traits, PCV was slightly higher than GCV, indicating that variations are slightly influenced by the environment. TNFP and IFW recorded high PCV and GCV, with high genetic gain as per mean (GAM), indicating the presence of significant variability and the effect of additive genes action. Simple selection based on the observation of the phenotype allows for the improvement of these traits. Vegetative and cycles parameters showed moderate to low PCV and GCV with moderate to low GAM. Improving these parameters requires to enhance the genetic base of the population, following by recurrent selection. Heritability was high for all traits and coupled with high GAM for fruit yield and its components; moderate / low for vegetative and cycle parameters. Thus, yield and its components are less influenced by the environment, hence the effectiveness of direct selection, while vegetative and cycle parameters are under non-additive genes action. Exploiting heterosis, dominance and epistasis effects, and single plant selected would be a necessity to improve these parameters. PSD and TNFP would be the major component of yield given their strong positive correlation, while earliness would be in detriment of yield. These results would be of great helpful for the selection of high-performing genotypes in this population derived from the diallel.