ABSTRACT
Despite the relevance of the global scenario regarding the papaya (Carica papaya L.) trade, there is still a limited number of papaya cultivars with different fruit patterns. Therefore, it is essential to explore the genetic variability at all levels of the germplasm used in the development of new papaya cultivars to meet its marketing goal. Thus, this study measured and explored the potential of genetic variability based on related to fruit quality traits, of a population of papaya lines in the F5 generation through several statistical analyzes. For this, 97 inbred lines obtained using the Single Seed Descent method, resulting from a cross between the JS-12 and Sekati genotypes, both with Formosa fruit pattern, were evaluated. Results indicated there was genetic variability in the fruit quality. The traits that most contributed to the variability were related to the fruit shape. The diverse population of 97 inbred papaya lines in the F5 generation showed promise for producing commercial-sized fruits in Formosa, Intermediate, and Solo patterns. Additionally, the selection of inbred papaya lines based on fruit shape using morpho-anatomical traits does not compromise physical and chemical parameters related to fruit quality.
Subject(s)
Carica , Fruit , Fruit/genetics , Carica/genetics , Seeds , Cytoplasm , Vegetables , Genetic VariationABSTRACT
Papaya is a tropical and climacteric fruit that is recognized for its nutritional benefits and medicinal applications. Its fruits ripen quickly and show a drastic fruit softening, leading to great post-harvest losses. To overcome this scenario, breeding programs of papaya must invest in exploring the available genetic variation to continue developing superior cultivars with improved fruit quality traits. The objective of this study was to perform a whole-genome genotyping (WGG) of papaya, predict the effects of the identified variants, and develop a list of ripening-related genes (RRGs) with linked variants. The Formosa elite lines of papaya Sekati and JS-12 were submitted to WGG with an Illumina Miseq platform. The effects of variants were predicted using the snpEff program. A total of 28,451 SNPs having Ts/Tv (Transition/Transversion) ratio of 2.45 and 1,982 small insertions/deletions (InDels) were identified. Most variant effects were predicted in non-coding regions, with only 2,104 and 138 effects placed in exons and splice site regions, respectively. A total of 106 RRGs were found to be associated with 460 variants, which may be converted into PCR markers to facilitate genetic mapping and diversity studies and to apply marker-assisted selection (MAS) for specific traits in papaya breeding programs.