Genetic diversity and heterotic grouping of sorghum lines using SNP markers

Sorghum breeding programs are based predominantly on developing homozygous lines to produce single cross hybrids, frequently with relatively narrow genetic bases. The adoption of complementary strategies, such as genetic diversity study, enables a broader vision of the genetic structure of the breeding germplasm. The purpose of this study was to evaluate the genetic diversity of sorghum breeding lines using structure analysis, principal components (PC) and clustering analyses. A total of 160 sorghum lines were genotyped with 29,649 SNP markers generated by genotyping-by-sequencing (GBS). The PC and clustering analyses consistently divided the R (restorer) and B (maintainer) lines based on their pedigree, generating four groups. Thirty-two B and 21 R lines were used to generate 121 single-cross hybrids, whose performances were compared based on the diversity clustering of each parental line. The genetic divergence of B and R lines indicated a potential for increasing heterotic response in the development of hybrids. The genetic distance was correlated to heterosis, allowing for the use of markers to create heterotic groups in sorghum.

Genetic diversity and heterotic grouping of sorghum lines using SNP markers

Sorghum breeding programs are based predominantly on developing homozygous lines to produce single cross hybrids, frequently with relatively narrow genetic bases. The adoption of complementary strategies, such as genetic diversity study, enables a broader vision of the genetic structure of the breeding germplasm. The purpose of this study was to evaluate the genetic diversity of sorghum breeding lines using structure analysis, principal components (PC) and clustering analyses. A total of 160 sorghum lines were genotyped with 29,649 SNP markers generated by genotyping-by-sequencing (GBS). The PC and clustering analyses consistently divided the R (restorer) and B (maintainer) lines based on their pedigree, generating four groups. Thirty-two B and 21 R lines were used to generate 121 single-cross hybrids, whose performances were compared based on the diversity clustering of each parental line. The genetic divergence of B and R lines indicated a potential for increasing heterotic response in the development of hybrids. The genetic distance was correlated to heterosis, allowing for the use of markers to create heterotic groups in sorghum.(AU)

Performance agronômica de híbridos de sorgo granífero estimada pelo método GGE biplot / Agronomic performance of granifero sorghum hybrids estimated by GGE Biplot method

Uma grande vantagem do sorgo é sua característica xerófita, o que lhe atribui um potencial, como sucessão às culturas de verão, na produção de grãos, sendo fundamental a utilização de híbridos adaptados aos diferentes ambientes de cultivo. Assim, o objetivo deste trabalho foi gerar parâmetros a respeito da capacidade adaptativa de híbridos de sorgo granífero pelo método GGE biplot. Os ensaios foram conduzidos, na safrinha de 2017, em sistema de plantio direto, em quatro ambientes, Rio Verde, Sete Lagoas, Teresina e Sinop. Todos os ensaios foram conduzidos, no delineamento em blocos casualizados, com três repetições e trinta e seis híbridos. Foram avaliadas as características: florescimento, altura de plantas e produtividade de grãos. Os dados foram submetidos às análises de variância individuais e conjunta, aplicado posteriormente o critério de agrupamento de Scott-Knott e estimados os parâmetros de adaptabilidade e estabilidade. Os híbridos promissores quanto às características avaliadas e em função dos parâmetros de adaptabilidade e estabilidade foram 1610001, 1610006, 1610051 e o 1G100.

A great advantage of sorghum it its xerophytic characteristics, which gives the potential, as a succession to summer crops in grain production. Therefore, it is fundamental to choose cultivars adapted and productive to different growing conditions. The objective of this study was to provide information about adaptive capacity of sorghum hybrids by the GGE biplot method. The trials were conducted, in 2017 as a second crop, no-tillage system, in four environments: Rio Verde, Sete Lagoas, Teresina and Sinop. All trials were conducted in a randomized complete block design with three replicates and thirty-six hybrids. The characteristics of flowering, plant height and grain yield were evaluated. It was realized individual and joint analyses of variance, after applied Scott-Knott grouping criterion and estimated the parameters of adaptability and stability. Promising hybrids for the characteristics evaluated and according to the adaptability and stability parameters were 1610001, 1610006, 1610051 and 1G100.

Performance agronômica de híbridos de sorgo granífero estimada pelo método GGE biplot / Agronomic performance of granifero sorghum hybrids estimated by GGE Biplot method

Uma grande vantagem do sorgo é sua característica xerófita, o que lhe atribui um potencial, como sucessão às culturas de verão, na produção de grãos, sendo fundamental a utilização de híbridos adaptados aos diferentes ambientes de cultivo. Assim, o objetivo deste trabalho foi gerar parâmetros a respeito da capacidade adaptativa de híbridos de sorgo granífero pelo método GGE biplot. Os ensaios foram conduzidos, na safrinha de 2017, em sistema de plantio direto, em quatro ambientes, Rio Verde, Sete Lagoas, Teresina e Sinop. Todos os ensaios foram conduzidos, no delineamento em blocos casualizados, com três repetições e trinta e seis híbridos. Foram avaliadas as características: florescimento, altura de plantas e produtividade de grãos. Os dados foram submetidos às análises de variância individuais e conjunta, aplicado posteriormente o critério de agrupamento de Scott-Knott e estimados os parâmetros de adaptabilidade e estabilidade. Os híbridos promissores quanto às características avaliadas e em função dos parâmetros de adaptabilidade e estabilidade foram 1610001, 1610006, 1610051 e o 1G100.(AU)

A great advantage of sorghum it its xerophytic characteristics, which gives the potential, as a succession to summer crops in grain production. Therefore, it is fundamental to choose cultivars adapted and productive to different growing conditions. The objective of this study was to provide information about adaptive capacity of sorghum hybrids by the GGE biplot method. The trials were conducted, in 2017 as a second crop, no-tillage system, in four environments: Rio Verde, Sete Lagoas, Teresina and Sinop. All trials were conducted in a randomized complete block design with three replicates and thirty-six hybrids. The characteristics of flowering, plant height and grain yield were evaluated. It was realized individual and joint analyses of variance, after applied Scott-Knott grouping criterion and estimated the parameters of adaptability and stability. Promising hybrids for the characteristics evaluated and according to the adaptability and stability parameters were 1610001, 1610006, 1610051 and 1G100.(AU)

Sorghum flour fractions: correlations among polysaccharides, phenolic compounds, antioxidant activity and glycemic index.

Nutrients composition, phenolic compounds, antioxidant activity and estimated glycemic index (EGI) were evaluated in sorghum bran (SB) and decorticated sorghum flour (DSF), obtained by a rice-polisher, as well as whole sorghum flour (WSF). Correlation between EGI and the studied parameters were determined. SB presented the highest protein, lipid, ash, ß-glucan, total and insoluble dietary fiber contents; and the lowest non-resistant and total starch contents. The highest carbohydrate and resistant starch contents were in DSF and WSF, respectively. Phenolic compounds and antioxidant activities were concentrated in SB. The EGI values were: DSF 84.5 ± 0.41; WSF 77.2 ± 0.33; and SB 60.3 ± 0.78. Phenolic compounds, specific flavonoids and antioxidant activities, as well as total, insoluble and soluble dietary fiber and ß-glucans of sorghum flour samples were all negatively correlated to EGI. RS content was not correlated to EGI.

Genetic evaluation of grain sorghum hybrids in Brazilian environments using the REML/BLUP procedure

When it comes to recommending sorghum (Sorghum bicolor) cultivars, it is essential to carry out a genetic evaluation of the agronomic traits of promising genotypes from several common environments where the crop is cultivated. This study consisted of a genetic evaluation of 52 experimental grain sorghum hybrids and eight commercial cultivars. Hybrids were evaluated in 19 experiments representing the most varied cultivation conditions in Brazil. Traits of agronomic interest such as grain yield, flowering and plant height were analysed. Genotypic evaluation was performed following the REML/BLUP (Restricted Maximum Likelihood/Best Linear Unbiased Predictor) procedure; the MHPRVG (Harmonic Mean of Relative Performance of Genotypic Values) method was also employed to study stability and adaptability. Hybrids which stood out in terms of highest grain yield based on genotypic values, stability and adaptability were 0306037, 1G150, DKB 599, 0306039, 1G282 and 0307671. Of these, only 1G282 showed restrictions as to plant height. For flowering, experimental hybrids showed shorter cycles than commercial cultivars, confirming the efficiency of genetic improvement for this trait. With the analysis of grain yield considering days to flowering and plant height as covariates, it was observed that most of the hybrids of greater performance, showed grain yield to be positively influenced by plant height and days to flowering.

Genetic evaluation of grain sorghum hybrids in Brazilian environments using the REML/BLUP procedure

When it comes to recommending sorghum (Sorghum bicolor) cultivars, it is essential to carry out a genetic evaluation of the agronomic traits of promising genotypes from several common environments where the crop is cultivated. This study consisted of a genetic evaluation of 52 experimental grain sorghum hybrids and eight commercial cultivars. Hybrids were evaluated in 19 experiments representing the most varied cultivation conditions in Brazil. Traits of agronomic interest such as grain yield, flowering and plant height were analysed. Genotypic evaluation was performed following the REML/BLUP (Restricted Maximum Likelihood/Best Linear Unbiased Predictor) procedure; the MHPRVG (Harmonic Mean of Relative Performance of Genotypic Values) method was also employed to study stability and adaptability. Hybrids which stood out in terms of highest grain yield based on genotypic values, stability and adaptability were 0306037, 1G150, DKB 599, 0306039, 1G282 and 0307671. Of these, only 1G282 showed restrictions as to plant height. For flowering, experimental hybrids showed shorter cycles than commercial cultivars, confirming the efficiency of genetic improvement for this trait. With the analysis of grain yield considering days to flowering and plant height as covariates, it was observed that most of the hybrids of greater performance, showed grain yield to be positively influenced by plant height and days to flowering.(AU)