Combining ability of recombined F4 papaya lines: a strategy to select hybrid combination

Vettorazzi, Julio Cesar FiorioSanta-Catarina, RenatoPoltronieri, Tathianne Pastana de SousaCortes, Diego Fernando MarmolejoAzevedo, Alinne Oliveira NunesMiranda, Daniel PereiraSantana, Josefa Grasiela SilvaRamos, Helaine Christine CancelaPereira, Messias Gonzaga

The growing demand for quality of papaya by the domestic and international markets requires the development of genotypes that are capable of incorporating traits, such as high yield and fruit quality. This study estimated the genetic parameters and the specific combining ability of F4 papaya lines crossed to the SS-72/12 tester to identify genotypes with higher genetic value for hybrid production. We evaluated 169 treatments consisting of 62 topcross hybrid combinations, 97 F5 lines, and 10 controls in a 13 × 13 lattice design with five replicates and two plants per plot. The following traits were evaluated: plant height (PH), stem diameter (SD), first-fruit insertion height (FFIH), number of marketable fruits (NMF), number of deformed fruits (NDF), number of fruitless nodes (NFN), average fruit weight (FW), and yield (YLD). Differences p < 0.05 were found in most traits evaluated. The specific combining ability estimates indicate that hybrids formed by the cross between SS-72/12 tester and the following lines are promising, considering the multiple traits: UCLA08-088, UCLA08-101, UCLA08-071, UCLA08-014, UCLA08-025, UCLA08-028, UCLA08-122, UCLA08-055, UCLA08-026, and UCLA08-092. These hybrids meet the demands for domestic and international markets and may be available to producers as new papaya cultivars.(AU)

1. Carica papaya L.
2. papaya breeding
3. topcross
4. genetic parameter