Genetic Variation and Trait Correlations for Fruit Weight, Firmness and Color Parameters in Wild Accessions of Fragaria chiloensis

Abstract

Fragaria chiloensis is an herbaceous perennial undomesticated species with a high potential for sustainable fruit production in areas where drought and salinity represent a constraint on crop growth and productivity. The present study aimed to examine the genetic variability of fruit weight, firmness and color parameters (L*, a*, b*, Hue angle and Chroma) in wild-collected accessions from south-central Chile. A Bayesian analysis of genetic parameters showed that the traits under study were found to be moderately to highly heritable with estimates from the marginal posterior distributions ranging between 0.26 (firmness) and 0.67 (L*). Interestingly, Hue and Chroma had relatively high values of broad-sense heritability, with the Bayesian credible set: H 2 = 0.53–0.76 and H 2 = 0.42–0.66, respectively. A Bayesian bi-trait analysis showed a positive genetic correlation ( r ^ g = 0.65, probability of the posterior samples <0.05) between fruit weight and Hue, which agreed with the existence of two pleiotropic loci [from simple sequence repeats (SSR) markers FvH4045 and CFACT084 on linkage groups FG3A and FG2A/2B/2C] with probabilities of the posterior estimates of 0.022 and <0.001, respectively. According to the Bayesian credible region, 5 (of 12) correlation estimates were significantly different from zero. Hue and Chroma showed a high and negative genetic correlation ( r ^ g = −0.762), but no significant pleotropic locus. The results are promising and suggest that the genetic variation found among wild populations of F. chiloensis supports the idea of domesticating this crop for sustainable fruit production systems.