Genetic-molecular characterization in guava full-sib progeny

Abstract

Brazil is one of the world's largest producers of guava (Psidium guajava L.), a very promising fruit in the northern region of the state of Rio de Janeiro. Despite this, no guava cultivar has been developed for the region. Thus, this study proposed to examine a population of guava full sibs using microsatellite markers and to identify which genotypes are the most divergent for future crosses, to select cultivars better adapted to the soil and climatic conditions of northern Rio Janeiro. Ninety-six superior genotypes were selected according to their agronomic traits, which were characterized using 45 microsatellite markers. The genetic distance between the analyzed genotypes, their clustering pattern and the genetic structure of the population were estimated. Hierarchical cluster analysis by the neighbor joining method indicated the formation of three distinct groups. The use of molecular information revealed the existence of moderate genetic variability between the genotypes of the full-sib families. Bayesian analysis separated the genotypes into only two groups, as the individuals shared most of the analyzed genomic regions. The most genetically divergent guava genotypes, that is, those allocated to different groups, such as genotypes 5 and 85, should be recommended for future crosses to obtain segregating populations, thus giving continuity to the guava breeding program.

Molecular characterization of guava Psidium guajava in Cereté, Córdoba, Colombia

“…In the studied populations, the utilized markers showed an average of 4 alleles per locus, which were lower than those reported by De Oliveira et al (2022), Chiveu (2018), Mehmood et al (2016) and higher than those reported by Kumar et al (2023), Oliveira et al (2022), Kumar et al (2020), Kherwar et al (2018), and similar to that reported by Chaithanya et al, 2014. The total number of guava alleles found was 39, a result similar to that obtained by Kumar et al (2023), which could be attributed to Wahlund effect (Martín, 2017), the self-pollinating behavior of the species due to possessing perfect flowers, which aids in self-fertilization (Kumari et al, 2018), and to the extent of the populations used in each of the studies (Díaz et al, 2022).…”

“…The average number of effective alleles (Ne) was 3.2, which was lower than that obtained by Mehmood et al (2016), higher than that reported by Kumar et al (2023), Oliveira et al (2022) and similar to that obtained by Sitther et al (2014).…”