Genetic variability and population structure in guava full-sib families via microsatellite markers

Abstract

Abstract: Guava production is a promising activity with great prominence in several regions of Brazil; however, a major obstacle faced by producers is the low number of available cultivars. The present study proposes to estimate and analyze genetic structure and variability, through molecular traits, aiming at the future development of new cultivars. Ninety-four genotypes from 11 full-sib families and the cultivars Paluma, Pedro Sato, and Cortibel 1 were selected for DNA extraction, totaling 97 genotypes. For molecular characterization, 48 pairs of microsatellite primers were used. This information was used to estimate the parameters of genetic diversity, genetic distance, genotype clustering, and the genetic structure of the population. The use of molecular information revealed the existence of genetic variability between the genotypes of the full-sib families and the cultivars. The average number of alleles per locus was 2,542. Expected heterozygosity values ranged from 0.030 to 0.599, averaging 0.401. Observed heterozygosity ranged from 0.010 to 0.577, averaging 0.293. Based on the UPGMA hierarchical clustering method, four groups were formed and crossing is recommended between individuals from groups 1 and 2. Bayesian analysis allowed the distinction of genotypes into only two groups, due to the individuals sharing most of the genomic regions analyzed.

Keywords

• molecular marker
• plant breeding
• Psidium guajava