Performance of grain sorghum hybrids in soils with low and high aluminum saturation

<div><p>ABSTRACT The presence of aluminum (Al3+) in acidic soils is one of the main causes of low crop yield, since it inhibits the root growth, thus affecting the nutrients and water uptake by plants. An approach to grow crops in areas with high Al3+ saturation is the use of tolerant cultivars. This study aimed to evaluate commercial sorghum hybrids in soils with low and high aluminum saturation, in order to select cultivars with high grain yield, even when exposed to abiotic stress. Twenty hybrids were evaluated for characteristics such as plant flowering, plant height and grain yield. All three traits were significantly affected by Al3+, being grain yield the most affected one. Despite the significant genotypes x environments interaction for grain yield, it was possible to select hybrids with yield above the national average in both environments. The hybrids BRS373, 50A50, AS4639, DKB540, AS4625, A9721R, 1167092, DKB550, 1G282 and AG1040 showed a high yield under low and high Al-saturation conditions.</p></div

Evaluation of grain sorghum hybrids for aluminum tolerance in nutrient solution

<div><p>ABSTRACT. Sorghum (Sorghum bicolor L. Moench) is one of the most important cereal crops in the world. In Brazil, the acreage of grain sorghum during off-season is quite expansive. Most of this area is the Cerrado, a Brazilian biome that is similar to a Savannah and is characterized by high acidity and soluble aluminum at toxic levels for plants. The aluminum acts as a limiting factor in achieving high yields. The purpose of this work was to phenotype sorghum hybrids for aluminum tolerance. Eighteen hybrids were evaluated in a nutrient solution containing {0} or {27} µM Al3+. The work was carried out in a growth chamber at the Embrapa Maize and Sorghum, from April 4 to May 30, 2014. The lines ATF 13B (susceptible) and ATF 14B (tolerant) were used as check cultivars. Based on the Net Root Growth after 120 hours (NRG120), Net Root Growth (NRG168) after 168 hours and Relative Net Root Growth after 168 hours (RNRG168), it was possible to distinguish tolerant hybrids from susceptible ones. The high aluminum saturation reduced root growth by 70%. The hybrids BRS 310 and BRS 373 were tolerant to aluminum stress under nutrient solution. The hybrid BRS 330 was clustered in an intermediate group, with an approximately 50% root growth reduction. The other hybrids were susceptible with significant root reduction.</p></div

Boxplot analysis showing the distribution of agro-industrial traits according to each cluster identified through molecular and phenotypic diversity analysis.

<p>The upper, median, and lower quartiles of gray boxes represent the 75^th, 50^th, and 25^th percentiles of the clusters, respectively. The vertical lines represent the variation of the clusters. Dots represent outliers. CEL: cellulose; EXT: juice extraction; FBY: fresh biomass yield; FLOW: days to flowering; HEM: hemicellulose; LIG: lignin; PH: plant height; POL: sucrose concentration in juice; RSJ: reducing sugars in the juice and TSS: total soluble solids.</p

Principal component analysis using SNP data.

<p>Plotting the first two principal components (PC1 and PC2) using SNP data. The colors of the genotypes correspond to the six subpopulations of sweet sorghum according to the genealogy and the historic background. LIS: Landrace World Collection—ICRISAT sorghum collection; LMN: Landrace Meridian Mississippi—USDA sorghum collection; LSSM: Landrace Sorghum Seed Montpelier—CIRAD sorghum collection; ML: Modern Line; ML—EMBRAPA: Modern Line EMBRAPA; and HL: Historical Line.</p

Neighbor-Joining tree using SNP data.

<p>Genetic distances between the sweet sorghum accessions were calculated using the identity-by-state (IBS) coefficient. The colors of the branches correspond to the six subpopulations defined according to the genealogy and the historic background of the sweet sorghum lines. I-M, II-M, III-M, IV-M, V-M and VI-M correspond to the clusters identified through the Neighbor-Joining method. LIS: Landrace World Collection—ICRISAT sorghum collection; LMN: Landrace Meridian Mississippi—USDA sorghum collection; LSSM: Landrace Sorghum Seed Montpelier—CIRAD sorghum collection; ML: Modern Line; ML—EMBRAPA: Modern Line EMBRAPA; and HL: Historical Line. The scale-bar (0–0.1) represents the coefficient of dissimilarity.</p

Fixed and random effects, heritability, average, minimum and maximum phenotypic values for the agro-industrial traits.

<p>Fixed and random effects, heritability, average, minimum and maximum phenotypic values for the agro-industrial traits.</p