Combined selection in new papaya hybrids

The advancement of technology, substantial investments and strategic partnerships have significantly boosted the development of new hybrids within the scope of papaya genetic breeding programs. Through hybridization, it became possible to obtain fruits of exceptional quality, standing out for their attractive appearance, better flavor and greater durability. In this context, the objective of this work was to carry out the combined selection of new papaya hybrids, with the aim of identifying hybrids with the potential to become competitive cultivars on the market. 46 papaya hybrids from the UENF/CALIMAN genetic breeding program were evaluated. Furthermore, the commercial cultivars 'Golden THB', 'Vitória' and 'Candy' were included in the experiment. The experiment was conducted in a 7 x 7 lattice design, with 5 replications and 4 plants per plot. A total of fifteen morphoagronomic and quality characteristics of the fruits were evaluated, as follows: First fruit insertion height (FFIH); Plant height (PH); Stem diameter (SD); Number of commercial fruits (NCF); Number of deformed fruits (NDF); Number of nodes without fruits (NNWF); Average fruit weight (AFW); Fruit firmness (FF); Pulp firmness (PF); Fruit length (FL); Fruit diameter (FD); Hoopoe thickness (HT); Percentage of pulp volume (%PV); Soluble solids content (SSC); Fruit production (FP). The selection of hybrids was carried out through combined selection, with selection pressure of 21%. The selective accuracy values found in this experiment ranged from 0.74 for FF to 0.98 for CF, values considered high. Accuracy values are linked to selection precision and refer to the correlation between the true genetic values of individuals and their predicted genetic values. Furthermore, the relative lattice efficiency was greater than 100% for 9 of the 15 characteristics evaluated. The efficiency of the lattice is associated with its ability to discriminate the averages of the treatments evaluated. When this value is less than 100, it is recommended to abandon the lattice and use complete randomized blocks. As the lattice efficiency was greater than 100 for most characteristics, and the others presented values close to 100, it was decided to analyze the data in a lattice design. Through combined selection, 10 superior genotypes were identified. Among them, the hybrids UC30, UC39 and UC67 stand out, which have the Formosa standard, and the hybrids UC31, UC72, UC59, UC57, UC60, UC71 and UC65, which have an intermediate standard. The results obtained in this study demonstrated the superiority of the selected hybrids in relation to the commercial cultivars Candy and Vitória, both in terms of morpho-agronomic characteristics and fruit quality. These advantages are evident through the selection gain obtained through combined selection in several parameters evaluated such as SD (1.57), NCF (15.72), SSC (0.97), NDF (-5.24), NNWF (-6.47), FL (1.30), HT (1.80), %PV (1.53) and FP (16.59). The development of these new genotypes can guarantee greater competitiveness and sustainability of the papaya crop in the market and increase the availability of varieties with higher productivity and better quality, in addition to providing farmers with new cultivars with attractive commercial characteristics for the national and international market.