Diallel cross analysis for fruit traits in watermelon

Abstract

Current demands of consumers and thus producers are important when targeting watermelon breeding programs, especially in programs aimed at improvement of fruit traits. A complete diallel set has been investigated for breeding values of six watermelon lines, via general and specific combining ability, relationships between general and specific combining ability, heritability and heterosis for fruit size, rind thickness, soluble solids and fruit shape. The lines P2 and P4 were good general combiners for fruit size. These lines also had high values of specific combining ability in direct and reciprocal crosses. The lines with negative general combining ability for fruit size (P1 and P5) can be used in breeding for small fruits (4-6 kg), good taste (high sugar content), desired rind thickness, desired fruit form and high fruit ratio. Relationships between general and specific combining ability indicated that the additive effect played an important role in the expression of fruit weight, rind thickness and sugar content, while fruit shape was inherited incompletely dominantly.