Allele frequency and selection efficiency in cross populations of Andean x Mesoamerican common beans (Phaseolus vulgaris L. Fabales, Fabaceae)

Abstract

Strategies were investigated for improving efficiency in the use of segregating common bean (Phaseolus vulgaris) populations using crosses between the Andean cultivar BRS-Radiante and the Mesoamerican parent cultivar Carioca-MG by developing populations with 12.5%, 25%, 50%, 75% and 87.5% of the allele frequency of one of the parents. For each of the five populations we evaluated for two traits, the number of days to the beginning of flowering and grain yield (g plot -1 ), in the F 2:3 (sown in February 2006) and F 2:4 (sown in July 2006) generation progenies using 15 x 15 lattice design experiments, with 44 progenies (n = 220 plants) plus the two parents and three controls being evaluated for each generation. In terms of variability release, the populations with different parental allele frequencies presented no consistent tendency of alteration. In general, genetic variance was stated among progenies in all populations, indicating success with selection. For grain yield, the lowest mean was observed in the populations with 50% of the alleles of both parents. If, for instance, the objective is to develop earlier flowering lines, the best strategy is to perform two, or at least one, backcross with the earliest parent. The most suitable allele frequency is to be determined according to the desired grain type.

Alternatives for selection of carioca common bean lines that combine upright plants and slow grain darkening

“…However, for GD, this likely did not occur. A similar result was found by Baldoni et al (2008) when they evaluated common bean progenies from populations with different allele frequencies for grain yield and number of days to flowering traits.…”

“…The results showed that when the trait has low h 2 , as was the case for PA, backcrossing with the parent with the best phenotypic manifestation of the trait did not provide an expressive advantage. This was also observed by Baldoni et al (2008), in which the highest proportion of alleles in the population that generated the progenies was only more advantageous when the trait had a high h 2 . There are other reports in the literature, especially with the soybean crop, in which the highest allele proportion of the population was "required" when the cross involved a non-adapted line (Vello et al, 1984).…”

“…An alternative that has not yet been evaluated is obtaining segregating populations with different allele frequencies from parents differing in plant architecture and in speed of grain darkening. This strategy has already been used in soybean (Vello, Fehr, & Bahrenfus, 1984) in crosses involving commercial lines with non-adapted introduced lines, as well as in crosses between common bean lines from the Mesoamerican and Andean gene pools (Baldoni, Ramalho, & Abreu, 2008).…”

Research Article Genetic control of traits related to grain filling in the common bean

“…In such a condition for this trait, it can be inferred that there is heterosis, but in the sense of reducing the expression of the trait. In the literature, there are reports that the allelic interaction of dominance is less important than the additive one (Moreto et al, 2007;Baldoni et al, 2008;Martins et al, 2017). Nevertheless, there are reports that dominance may have a marked effect on grain yield (Chung and Stevenson, 1973;Foolad and Bassiri, 1983;Pereira et al, 2007;.…”