Number of progenies and repetitions for reciprocal full-sib recurrent selection programs in maize

Paula Mikaely Henrique Vieira,Brena Kelly Da Silva Almeida,João Cândido De Souza,Olinda Estefania Ocampos Báez,Matheus Henrique Silveira Mendes

doi:10.1590/1413-7054202145030420

Paula Mikaely Henrique Vieira, Brena Kelly Da Silva Almeida + Show 3 more

Open Access

https://doi.org/10.1590/1413-7054202145030420

Copy DOI

Abstract

ABSTRACT For a reciprocal recurrent selection (RRS) program to succeed, it is essential to maintain genetic variability throughout the selection cycles and to obtain accurate estimates of genetic parameters, which in turn are directly related to the number of progenies and repetitions evaluated. This study evaluates the potential of maize progenies of the sixth cycle of RRS and proposes, using simulation methods, the ideal combination of the number of progenies and repetitions to employ in reciprocal full-sib recurrent selection. A total of 163 full-sib progenies were evaluated in a randomized block design with six repetitions. Based on the yield data, analysis of variance was carried out, and different scenarios were simulated using the Monte Carlo chain method. These scenarios varied in the number of repetitions (two, four, and six) and progenies (30 to 163). The contrast between progenies and controls was significant, revealing the potential of the progenies of the sixth cycle of RRS. The high magnitude of the selective accuracy (0.77) was reflected in high estimates of heritability, which allowed for efficient phenotypic selection, obtaining selection gains of 14.07%. From the estimates of phenotypic and genotypic variance, heritability, accuracy, and standard error, it was found that a repetition number above two results in drastic changes in the estimates of these parameters; however, with the use of 130 progenies, these estimates tend to stabilize, implying that a high number of progenies does not interfere decisively in the quality of most parameters, except for the limits of maximum and minimum variation.

Highlights

Heterosis, or hybrid vigor, is one of the main phenomena responsible for success in the productivity of many crops (Fujimoto et al, 2018; Andorf et al, 2019)
The gains in recurrent selection programs are dependent on the maintenance of genetic variability throughout the selection cycles
There was a significant effect of progeny (p < 0.05) on yield, which indicates the presence of genetic variability between the progenies of the sixth cycle of recurrent selection (RRS) and reveals the existence of differences in the complementarity of the crossings between the two populations (Table 1)

Summary

Introduction

Hybrid vigor, is one of the main phenomena responsible for success in the productivity of many crops (Fujimoto et al, 2018; Andorf et al, 2019). Heterosis can be exploited using reciprocal recurrent selection (RRS), a method in which additive and nonadditive effects are maximized to improve the hybridization between two populations of different heterotic groups (Comstock; Robinson; Harvey, 1949; Hallauer; Carena; Miranda Filho, 2010; Yu et al, 2020). Through RRS, improved populations are used as a source of parental lines for the production of high-performance hybrids (Betran; Hallauer, 1996; Kolawole et al, 2018; Ferreira Júnior et al, 2020). For RRS success to continue over generations, there must be genetic variability in the population. In this case, the use of an ideal number of progenies allows for efficient sampling and coverage of the genetic variability presented in the population, reflecting realistic estimates about its potential. A limited effective number can result in inaccurate representation and lead to the loss of favorable alleles or the fixation of undesirable alleles (Falconer; Mackay, 1996)

Objectives

Methods

Results

Conclusion