Diallel analysis of hybrid combinations of watermelon grown in an agroecological production system

Abstract

ABSTRACT Watermelon is an important crop in the Northeast region of Brazil; therefore, the development of lines and cultivars adapted to the edaphoclimatic conditions of this region and to agroecological production systems is essential for farmers and the environment. This study estimated general combining ability (GCA) and specific combining ability (SCA), as well as their reciprocal effects, for earliness and for yield and fruit traits in watermelon genotypes. The experiments were conducted at the Universidade Federal do Vale do São Francisco (UNIVASF), in Petrolina, PE, Brazil, during two evaluation cycles. A randomized block design was used, with 19 treatments, three replications, and plots containing five plants. The data were subjected to analysis of variance and diallel analysis. Non-additive gene effects predominated for 58.8% of the variables. The GCA analysis showed that the parents BGH-UNIVASF 177 and BGH-UNIVASF 67 were the most promising for obtaining hybrids with higher marketable fruit yield and greater fruit weight. The parent 'Sugar Baby' was identified as a good combiner for earliness, fruit diameter, and soluble solids content. The parent BGH-UNIVASF 189 was identified as a good combiner for total fruit yield and soluble solids content. Hybrid 3×4 was the most promising for the greatest number of agronomically important traits. Hybrids 1×2, 1×4, and 2×4 were promising for earliness, soluble solids content, fruit yield, good vegetative development, and lower fruit weight. No reciprocal effects were found for the traits evaluated.