Recurrent selection for high iron and zinc concentrations in black bean grain

Abstract

The iron concentration (FeC) and zinc concentration (ZnC) in common bean grain are quantitative traits, and appropriate breeding techniques are required to achieve genetic gain. The aim of this study was to obtain a recurrent selection population of black bean to increase the FeC and ZnC in the grain and to select the superior progenies for formation of the next cycle and obtain lines. The base population was formed by crosses among ten parents. A total of 351 progenies were obtained, and, after two generations of selection, the 27 best progenies were evaluated in two field trials for FeC, ZnC, 100 seed weight and yield. Analyses of variance were carried out and genetic parameters were estimated. The heritability estimates ranged from 59 to 94% for the four traits. The estimates of expected gain from direct selection for each trait (3 to 21%) and simultaneous selection (1 to 4%) indicate success from selection. The eight progenies, selected based on simultaneous selection, have superior mean values, including to those of 'BRS Supremo' (10% for FeC, 8% for ZnC, 5% for 100 seed weight and 3.8% for yield), the Brazilian black bean cultivar with the highest FeC and ZnC. The recurrent selection population shows high genetic variability and potential for obtaining lines superior to the cultivars currently on the market, allying high agronomic performance and high FeC and ZnC in the grain. Furthermore, this population shows potential for generating a new recurrent selection cycle, from recombination of the eight superior progenies.

Genetic parameters and selection of common bean lines with high nutritional and agronomic quality

“…There was a significant effect of environments for all the traits evaluated (Table 1), indicating that the different locations, years, and crop seasons substantially alter the response of the genotypes. Several studies have reported the effect of environment on the expression of agronomic and nutritional traits in common bean (Dias et al., 2021; Martins et al., 2016; Queiroz et al., 2021). There was also a significant difference among the genotypes for all the traits, except for plant architecture, according to analysis of deviance (Table 1), which shows the genetic variability among the lines and/or cultivars evaluated.…”

“…There was also a significant difference among the genotypes for all the traits, except for plant architecture, according to analysis of deviance (Table 1), which shows the genetic variability among the lines and/or cultivars evaluated. Significant difference among genotypes is essential for there to be progress from selection, and several studies have reported high genetic variability for the nutritional traits (Caproni et al., 2020; Di Prado et al., 2019; Martins et al., 2016; Pereira et al., 2014; Queiroz et al., 2021).…”

“…Consumption of beans from the cultivar Pérola , which has intermediate concentrations and is one of the cultivars most planted in Brazil, provides an average of 24% of iron and 27% of zinc daily requirements, without considering bioavailability, which varies according to diverse factors. These values can be expressively increased through the development of biofortified cultivars that can supply even more of the daily human requirements (Queiroz et al., 2021).…”

“…There is wide genetic variability for iron concentrations (CFe) and zinc concentrations (CZn) in bean grain (Caproni et al., 2020; Pereira et al., 2014; Queiroz et al., 2021), with reported values of up to 94 mg kg −1 for CFe and 51 mg kg −1 for CZn, what would provide an average of 34% of iron and 36% of zinc daily requirements. Nevertheless, combining grain nutritional quality with agronomic quality in a cultivar is the great challenge (Dias et al., 2021).…”

“…Studies have shown that the CFe and CZn in bean grain are traits of a quantitative nature (Izquierdo et al., 2018). However, high magnitude heritability estimates have been reported (Jost et al., 2009; Martins et al., 2016; Queiroz et al., 2021). Furthermore, the genotype × environment interaction has been observed in common bean, both for these traits and for others of agronomic importance (Cichy et al., 2009; Martins et al., 2016), which should be taken into consideration in future recommendations of cultivars.…”