Is there a possibility to improve a developed hybrid? A current demand on papaya (Carica papaya L.)

The development of hybrid cultivars is one of the most important contributions of a breeding program. A high allelic fixation of the parent lines is essential to guarantee the uniformity of developed hybrids. In this sense, papaya segregation has been observed in the parent lines, impacting the pattern of the hybrids obtained and, consequently, their commercialization. Thus, this study aimed to evaluate the JS-12, Sekati, and SS-72/12 genotypes, which are parents of important papaya hybrids, to identify possible segregations and proceed with the generation progress through self-fertilization of selected genotypes for agronomic traits of interest. A mass selection was carried out, selecting 400 plants based on the phenotype, being: 100 plants from the Sekati parent, 100 from the SS-72/12 parent, and 200 plants from the JS-12 parent, of which 100 plants with smaller fruits (JS12-P) and 100 plants with larger fruits (JS12-G). These plants were agronomically evaluated for 15 traits in three evaluation periods. Descriptive statistics of the observations, diversity analysis, as well as the combined selection index and direct selection were performed. Through the descriptive and phenotypic variability analysis, it was possible to verify the existence of variability in the parents, enabling the selection of 80 genotypes, 72 of which were selected via combined selection and eight by direct selection. Given the existence of parents' segregation, the extreme importance of selecting lines with different patterns to be explored in the papaya breeding program is emphasized to purify the parents and adjust the hybrids to meet the consumer market's demand.

Automated summary

This study aimed to evaluate the parent lines of important papaya hybrids and progress the genetics through self-fertilization. Through selection and analysis, 80 promising genotypes were identified, emphasizing the importance of selecting parent lines with different patterns.