Large Seed Watermelon Response in a Landrace to Selection for Seed Size

Understanding the method of inheritance is valuable for breeding watermelon (Citrullus lanatus L.) cultivars with desired seed size. Local open-pollinated landrace were used to investigate inheritance of watermelon seed size. Seed length in 1000 seed was measured. Seed > 20 mm were used. Seed length of 1000 seed of the next generation was measured. Improvement of seed length in response to selection was used to calculate narrow-sense heritability. Mean seed length of landrace was 19.0 mm. Seed used to produce the next generation had a mean length of 20.46 mm. The next generation had a mean seed length of 17.6 mm, a decrease of 14%. Both selection differential and absolute magnitude response to selection was 1.4. Diversity between large seeds is not genetic but likely due to environment. Selection is not recommended for seed size improvement and hybridization may be more suitable for this goal.