Genetic divergence of roundup ready (RR) soybean cultivars estimated by phenotypic characteristics and molecular markers

Abstract

The aim of this study was to estimate the genetic diversity in 74 RR soybean cultivars from different Brazilian breeding programs. Analyzes were based on multivariate statistical techniques from phenotypic characteristics and microsatellite molecular markers (SSR). Ten agronomic traits were used in the analysis of the Euclidean distance, Tocher's clustering, UPGMA clustering and principal component analysis. Eighty-six of 100 SSR primer-pairs studied were selected based on their polymorphism information content, and analyzed using Jaccard Coefficient and UPGMA clustering method. The cultivars were clustered into seven groups according to the UPGMA and Tocher's methods, based on agronomic traits, while molecular analysis identified six groups. The phenotypic distances ranged from 0.46 to 9.79 and the dissimilarity measurements, based on SSR molecular markers, ranged from 0.07 to 0.73. Both results from agronomic traits and molecular markers showed that there is genetic variability among the RR cultivars and that the Monsanto breeding program has the most divergent germplasm. The analyzed agronomic traits and the chosen SSR markers were effective in assessing the genetic diversity among genotypes, besides proving to be useful for characterizing genetic variability of soybean germplasm.

Protein, lipid and isoflavone contents of food-type soybean lines at two sowing dates

“…The groups formed by PCA were concordant with those obtained by the UPGMA method at both sowing dates (Figure 4). The formation of these groups is valuable information for a breeding program because cultivars which are in distant groups are considered more suitable for artificial breeding (VILLELA et al 2014). However, different environmental conditions should be tested for genetic dissimilarity of the chemical components of soybeans due to the great influence of environmental conditions in the expression of these traits.…”

Genetic diversity in soybean genotypes using phenotypic characters and enzymatic markers

“…The fertilization followed the recommendations of Souza and Lobato (2004), performing in-furrow inoculations, and applying 350 kg/ha formulated N-P 2 O 5 -K 2 O (02-30-20). The experimental plot consisted of a single row of 5 m in length, spaced 0.5 m between rows, with a design similar to that used for multiplication and regeneration of germplasm bank accessions without repetitions (Chioratto et al, 2007;Villela et al, 2014).…”

“…Superior and stable genotypes represent a very critical genetic balance, which once reached additional gains, becomes more difficult to be achieved. The consequence of this balance is that most of the cultivars within a region are genetically similar, therefore, with a more limited genetic basis (Hamawaki et al, 2012;Villela et al, 2014).…”

“…In addition to the use of markers, the measurement of agronomic traits is also important because it allows the breeder to identify and select the best genotypes through characters of agronomic relevance, especially those of quantitative nature due to the need to succeed in the correct choice of superior hybrid combinations (Oliveira et al, 2014;Villela et al, 2014).…”

Agronomic performance and genetic diversity among lines and soybean cultivars

“…Regarding to this, parent selection has proven to be the main step of a breeding process (BERTAN et al, 2007;PIMENTEL et al, 2013). In addition, genetic diversity studies based on agronomic traits, in particular quantitative characteristics, have been shown to be good tools for helping breeders choose the best parents (VILLELA et al, 2014).…”