Selection strategies in agronomic characters in progenies F3:4 of transgenic soy RR

Abstract

The selection indexes aggregate information to multiple characters and, with this, they are able to carry out the selection of a set of variables simultaneously. The objective was to verify the genetic potential of agronomic traits and to select soybean F3:4 progenies based on different selection strategies. 123 progenies and the parents were sown in randomized blocks with two replications. The gains of direct selection by the indexes, the sum of “ranks” and the genotype-ideotype were lower for all characters when compared to the gains of direct and indirect selection. The rank sum index stood out for achieving the highest total gain with 37.11%. The index of the genotype-ideotype obtained a lower gain (-0.48%) for the character number of days for flowering compared to the sum index of “ranks” (-0.54%) and reached a negative gain for the attribute insertion height of the first pod with -1.82%. The genetic potential of the F3:4 population is high and allows different selection strategies to be applied to reach superior genotypes. The progenies UFU 72, UFU 116, UFU 86, UFU 45, UFU 117, UFU 56, UFU 5, UFU 106, UFU 6, UFU 4, UFU 73, UFU 101, UFU 96, UFU 90, UFU 123, UFU 116, UFU 88, UFU 65, UFU 70, UFU 3, UFU 69 and UFU 37 were selected by both selection indexes. The UFU 72, UFU 90, UFU 88 and UFU 69 progenies are agronomically superior both in direct and indirect selection, as in Mulamba and Mock (1978) sum of “ranks” selections and genotype-ideotype.

Genetic parameters and selection strategies for soybean progenies aiming at precocity and grain productivity

“…The application of direct selection in 145 F 2:3 progenies (UFUS 7415 × TMG 7161 RR) in Uberlândia-MG gave the lowest SG of NDF (-5.34) and NDM (-4.22%), while the highest SG were obtained for PROD (16.19%), PHF (12.21%) and PHM (16.45%), a result close to the present study (Silva et al, 2021). In 123 F 3:4 progenies of soybean (BRS 256 RR × TMG 1179 RR) direct SG of -2.32% for NDF, 7.22% for PHF, 12.93% for HIP, 18.06% for NNM were observed and 9.12% for PROD (Carneiro et al, 2021).…”

“…In 386 F 5 progenies from seven segregating populations sown in Jaboticabal-SP, a total of 36.04% SG was obtained for the sum of ranks index by Mulamba and Mock (1978) while for the genotype-ideotype distance index it was obtained 29.85% of total SG (Bizari et al, 2017). In turn, similar total SG were obtained for 123 F 3:4 soybean progenies (BRS 256 RR × TMG 1179 RR), in which total SG of 37.11% was obtained for the sum index of "ranks" of Mulamba and Mock (1978), while for the genotypeideotype distance index a total of 36.95% SG was obtained, with the PROD in the latter being 4.42% and for the sum of "ranks" 3.55% (Carneiro et al, 2021). Fifteen superior RCF 3:4 progenies were selected from 4 segregating soybean populations that showed greater selection gains through the applied selection indices.…”

“…The occurrence of pleiotropism, a property in which a gene simultaneously affects two or more traits, may be the main factor that contributes to the achievement of high magnitude of genetic correlations. In soybean, correlation studies have focused on the evaluations of the characters collected from flowering to maturation, with emphasis on productivity and its components (Carneiro et al, 2021;Silva et al, 2021;Smiderle et al, 2019;Zuffo et al, 2018).…”

“…The success of genetic improvement depends on the existence of genetic variability, which allows the selection of superior soybean genotypes in relation to cultivars (Carneiro et al, 2021). These new genotypes must simultaneously present favorable characters that provide a significant increase in grain yield (Vianna et al, 2019).…”

Genetic stability of melon (Cucumis melo L. cv. Meloni) based on inter-simple sequence repeat and phenotypic characteristics

“…The stability of the new cultivars was demonstrated by the minimum coefficient of variation (CV) of single plant yields and controlled spatial heterogeneity (Fasoula et al 2020). Parental selection increases the probability of forming superior cultivars because of the genetic diversity that makes it possible to select superior genotypes (Carneiro et al 2021). The method of cultivar assembly by hybridization cannot be separated from Mendelian's Law I regarding the segregation of allele pairs during gamete formation and Mendelian II regarding alleles inherited by parents who will pair independently at fertilization (Van Dijk 2018).…”