Combining ability for fruit yield and quality in papaya recombinant inbred lines from the sexual conversion backcrossing

In Brazil there is a limitation in the choice of commercial papaya hybrids for cropping. This factor is responsible for the crop vulnerability to the pests and diseases attack, being of great importance the investigations that aim at the availability of new genotypes. In papaya breeding programs to developed new hybrids, the lines should be evaluated by their combining ability. This step is important to select the superior parents for superior hybrid production. The objective of this research was to evaluate the combining ability of recombinant inbred lines by using elite testers in order to select papaya hybrid combinations with productive capacity and fruit quality, to supply the new cultivars demand, mainly from the Solo group. 34 genotypes were evaluated in a randomized complete block design with six replicates and three plants per plot. The specific combining ability (SCA) was estimated based on 12 traits related to fruit quality and yield. The hybrid combinations SS-72/12 × UCLCF01-01, SS-72/12 × UCLCF01-02, SS-72/12 × UCLCF01-09, Sekati × UCLCF01-04, Sekati × UCLCF01-10 and JS-12 × UCLCF01-17 were superior for presenting positive estimates of the SCA effects for the number of commercial fruits, fruit weight, pulp and fruit firmness and soluble solids that are the most important traits for the crop. These Solo and Formosa hybrid combinations have great potential to supply the consumer market demand, especially the small fruit hybrids, constituting national and international novelty as the first Solo hybrids.