ABSTRACT
The aim of this study were to generate estimates of combining ability in 22 lines of papaya using testers from the 'Solo' and 'Taiwan' group in a top-cross scheme, and identify those hybrids which are superior agronomically. The strains were selected from generations backcrossed for sexual conversion, with the dioecious genotype Cariflora as recurrent parent, and the elite ginoic -andromonoic line, SS 783, as donor. The lines themselves, the top cross hybrids (T1 hybrids and T2 hybrids), and two commercial controls were evaluated in an 8 x 8 lattice design for number of nodes with no fruit (NNSF-un), number of deformed fruit (NFD-un), number of commercial fruit (NFC-un), average fruit weight (PMF-g), fruit length (CF-mm), fruit diameter (DF-mm), average pulp thickness (EP-cm), fruit firmness (FF-N), pulp firmness (PF-N), level of soluble solids (TSS-°brix) and productivity (PROD-t ha-1). Estimates of specific combining capacity were obtained from the difference between the average for each hybrid obtained from the tester and the overall average of crossings with the same tester. The analysis of variance carried out with the adjusted average values revealed genetic variability between treatment groups for all the evaluated characteristics, as well as within each treatment group. Considering the T1 hybrid, the combinations that best reconciled the CEC estimates for the characteristics of production and fruit quality were L3xT1, L8xT1, L10xT1, L11xT1, L16xT1, L17xT1 and L20xT1; for the T2 hybrids the combinations were L12xT2, L13xT2, L17xT2, L21xT2 e L22xT2..
Key words:
Top crosses; Testers; Breeding; Specific combining ability; Carica papaya L.
