International Journal of Agriculture Extension and Social Development

author(s)
James Kiden and Nyamal Lok

abstract
Fruit firmness is a vital quality trait in cherry tomatoes (Solanum lycopersicum var. cerasiforme) that significantly impacts consumer preference, post-harvest shelf life, and transportability. Understanding the genetic determinants of fruit firmness can facilitate the breeding of cherry tomatoes with improved qualities. This review paper examines the genetic basis of fruit firmness, emphasizing insights gained from F₂ population studies. The F₂ population, derived from crossing two genetically distinct parents, provides a valuable resource for mapping quantitative trait loci (QTL) and identifying genes associated with fruit firmness. Key studies utilizing F₂ populations have identified several QTLs linked to fruit firmness, highlighting major QTLs on chromosomes 2, 3, and 9. Candidate genes involved in cell wall modification, such as polygalacturonase, pectin methylesterase, and expansins, have been identified and validated through functional analysis. These genes play crucial roles in cell wall degradation and remodeling, influencing fruit firmness. The review also discusses the molecular mechanisms underlying fruit firmness, including the regulation of cell wall composition and structure. Additionally, the interplay between genetic and environmental factors affecting fruit firmness is explored. The insights from F₂ population studies can be applied to breeding programs using marker-assisted selection and genetic engineering to develop cherry tomato varieties with enhanced firmness. Future research should integrate advanced genomic tools and high-throughput phenotyping to further unravel the genetic basis of fruit firmness and develop innovative strategies for improving this important trait.