Estimation of yield and yield-related genetic parameters in citron watermelon ( <i>Citrullus lanatus</i> var. <i>citroides</i> )

This study aims to improve citron watermelon, an underutilized African crop. Despite its climate resilience and economic importance, the estimation of yield-related genetic parameters remain unexplored. Ten high-yielding accessions were crossed in a bi-parental mating design to develop five hybrids that were evaluated together with their parents in a randomized complete block design, replicated thrice. Traits such as fruit yield, length and weight displayed the greatest potential to respond to selection owing to high heritability (61.64, 73.80% and 59.00%, respectively) and genetic advance (4585.09, 77.32 and 73.27%, respectively). Fruit weight, rind thickness and yield showed significant positive heterosis (p < .05) in hybrids 7 × 8 and 1 × 2, indicating their potential for heterotic improvement. Hybrids 1 × 2 and 3 × 4 were the best cross combinations for elevated Vitamin C levels and rind thickness for both forms of heterosis. Gene number estimates revealed a range from minor to oligogenic control, with fruit weight controlled by 5.81 genes using Wright’s estimator. Total soluble solutes had the lowest number of genes in all hybrid combinations coupled with a low genetic advance of 0.44, displaying a low response to selection using this population. This study highlights several traits that have the potential to improve citron watermelon productivity.