Estimates of genetic parameters, genetic variability, and selection in the S1 generation of peach

Abstract

The growing of peach in mild winter regions is made viable through the use of genotypes that have low need for cold conditions, and this is one of the main aims of breeding for these regions. Thus, the aims of this study were to estimate genetic parameters, evaluate genetic variability, and select families adapted to mild winter regions in the S1 generation of peach through mixed model methodology (REML/BLUP). For that purpose, 22 populations, 84 families, and 2090 individuals were evaluated for the following traits: bud burst rate (BR), node density (ND), plant height (PH), and trunk diameter (TD). Genetic variability was found for all the traits. Individual heritability in the broad sense was of low and medium magnitudes. The PH trait had positive genotypic correlation of high magnitude with TD. The ND trait had moderate negative genotypic correlation with PH and TD. Clustering by the Tocher method resulted in the formation of six mutually exclusive groups. Considering selection intensity of 25%, simultaneous selection for BR, ND, and TD led to predicted gains of 11.3% for BR, 9.7% for ND, -14.2% for PH, and -14.3% for TD, showing the great potential of the germplasm evaluated.

Selection of Theobroma grandiflorum clones adapted to agroforestry systems using an additive index

“…This influence is comparatively greater than that for the other studied characteristics, which are more homogeneous despite being quantitative. The CVg i is a good indicator of the magnitude of variability available in the population for a given characteristic, even allowing inter-population comparison of this parameter (Silva et al, 2020).…”

Clonal selection in S0 and S1 peach trees evaluated in a subtropical environment

“…The peach tree is an autogamous plant, originally adapted to temperate and subtropical zones, which needs a determined accumulation of winter cold to break the period of dormancy and have normal flowering and budding (Silva et al 2020a). The main peach producing regions are situated between latitudes 30º and 45º, north and south.…”