Limits...
Two in one sweep: aluminum tolerance and grain yield in P-limited soils are associated to the same genomic region in West African sorghum.

Leiser WL, Rattunde HF, Weltzien E, Cisse N, Abdou M, Diallo A, Tourè AO, Magalhaes JV, Haussmann BI - BMC Plant Biol. (2014)

Bottom Line: Significant genotype-by-phosphorus interaction was detected but with small magnitude compared to the genotype variance component.Using genome wide association mapping based on 220 934 SNPs we identified one genomic region on chromosome 3 that was highly associated to grain yield production.The identified SNPs can help accelerate breeding for increased sorghum productivity under unfavorable soil conditions and contribute to assuring food security in WA.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Sorghum (Sorghum bicolor L. Moench) productivity is severely impeded by low phosphorus (P) and aluminum (Al) toxic soils in sub-Saharan Africa and especially West Africa (WA). Improving productivity of this staple crop under these harsh conditions is crucial to improve food security and farmer's incomes in WA.

Results: This is the first study to examine the genetics underlying sorghum adaptation to phosphorus limitation in a wide range of WA growing conditions. A set of 187 diverse sorghum genotypes were grown in 29 -P and + P field experiments from 2006-2012 in three WA countries. Sorghum grain yield performance under -P and + P conditions was highly correlated (r = 0.85***). Significant genotype-by-phosphorus interaction was detected but with small magnitude compared to the genotype variance component. We observed high genetic diversity within our panel, with rapid linkage disequilibrium decay, confirming recent sequence based studies in sorghum. Using genome wide association mapping based on 220 934 SNPs we identified one genomic region on chromosome 3 that was highly associated to grain yield production. A major Al-tolerance gene in sorghum, SbMATE, was collocated in this region and SbMATE specific SNPs showed very high associations to grain yield production, especially under -P conditions, explaining up to 16% of the genotypic variance.

Conclusion: The results suggest that SbMATE has a possible pleiotropic role in providing tolerance to two of the most serious abiotic stresses for sorghum in WA, Al toxicity and P deficiency. The identified SNPs can help accelerate breeding for increased sorghum productivity under unfavorable soil conditions and contribute to assuring food security in WA.

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Scatter plot between grain yield performance (BLUPs) of 187 sorghum genotypes estimated across sites in Mali, Niger and Senegal in 15 –P environments versus 14 + P environments, with genotype dots color-coded for their morphological race-classification.
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Fig1: Scatter plot between grain yield performance (BLUPs) of 187 sorghum genotypes estimated across sites in Mali, Niger and Senegal in 15 –P environments versus 14 + P environments, with genotype dots color-coded for their morphological race-classification.

Mentions: Significant grain yield (52%) and plant height (22%) reduction and delayed heading (29%) occurred under –P relative to the + P conditions. The individual –P sites had generally lower repeatabilities for grain yield than the + P sites (Additional file 1: Table S1) but broad sense heritability (h2) computed across the 15 –P sites was slightly higher than for the 14 + P sites (Table 1), due to proportionally smaller genotype-by-environment interactions (GxE) among –P environments. Most of the variation for grain yield in –P as well as in + P conditions could be attributed to genotypic effects, with variance component ratios (G:GxE) being greater than one. The genotype-by-P (GxP) interaction variance component estimated across all 29 sites was significant but small. No distinct mega-environments could be delineated in a GGE-biplot analysis (only the 8 common checks were used, see Additional file 2) and the correlation between –P and + P grain yield performance (Figure 1) was high (r = 0.85***), indicating strong correspondence of genotypic performance for grain yield between –P and + P conditions. Therefore best linear unbiased predictions (BLUPs) for grain yield across all environments for each genotype could be used for further analyses. Additionally to the grain yield BLUPs across all environments, we also used grain yield BLUPs estimated only across –P or + P conditions in order to assess genomic regions associated specifically to grain yield under either –P or + P conditions (Table 2). Although genotypes from different sorghum races showed wide variation for grain yield performance in both fertility conditions (Figure 1), the Caudatum accessions showed somewhat more specific adaptation to + P conditions whereas the Durra and Durra inter-racials accessions were generally better adapted to –P conditions (Figure 1, Additional file 3).Table 1


Two in one sweep: aluminum tolerance and grain yield in P-limited soils are associated to the same genomic region in West African sorghum.

Leiser WL, Rattunde HF, Weltzien E, Cisse N, Abdou M, Diallo A, Tourè AO, Magalhaes JV, Haussmann BI - BMC Plant Biol. (2014)

Scatter plot between grain yield performance (BLUPs) of 187 sorghum genotypes estimated across sites in Mali, Niger and Senegal in 15 –P environments versus 14 + P environments, with genotype dots color-coded for their morphological race-classification.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4256928&req=5

Fig1: Scatter plot between grain yield performance (BLUPs) of 187 sorghum genotypes estimated across sites in Mali, Niger and Senegal in 15 –P environments versus 14 + P environments, with genotype dots color-coded for their morphological race-classification.
Mentions: Significant grain yield (52%) and plant height (22%) reduction and delayed heading (29%) occurred under –P relative to the + P conditions. The individual –P sites had generally lower repeatabilities for grain yield than the + P sites (Additional file 1: Table S1) but broad sense heritability (h2) computed across the 15 –P sites was slightly higher than for the 14 + P sites (Table 1), due to proportionally smaller genotype-by-environment interactions (GxE) among –P environments. Most of the variation for grain yield in –P as well as in + P conditions could be attributed to genotypic effects, with variance component ratios (G:GxE) being greater than one. The genotype-by-P (GxP) interaction variance component estimated across all 29 sites was significant but small. No distinct mega-environments could be delineated in a GGE-biplot analysis (only the 8 common checks were used, see Additional file 2) and the correlation between –P and + P grain yield performance (Figure 1) was high (r = 0.85***), indicating strong correspondence of genotypic performance for grain yield between –P and + P conditions. Therefore best linear unbiased predictions (BLUPs) for grain yield across all environments for each genotype could be used for further analyses. Additionally to the grain yield BLUPs across all environments, we also used grain yield BLUPs estimated only across –P or + P conditions in order to assess genomic regions associated specifically to grain yield under either –P or + P conditions (Table 2). Although genotypes from different sorghum races showed wide variation for grain yield performance in both fertility conditions (Figure 1), the Caudatum accessions showed somewhat more specific adaptation to + P conditions whereas the Durra and Durra inter-racials accessions were generally better adapted to –P conditions (Figure 1, Additional file 3).Table 1

Bottom Line: Significant genotype-by-phosphorus interaction was detected but with small magnitude compared to the genotype variance component.Using genome wide association mapping based on 220 934 SNPs we identified one genomic region on chromosome 3 that was highly associated to grain yield production.The identified SNPs can help accelerate breeding for increased sorghum productivity under unfavorable soil conditions and contribute to assuring food security in WA.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Sorghum (Sorghum bicolor L. Moench) productivity is severely impeded by low phosphorus (P) and aluminum (Al) toxic soils in sub-Saharan Africa and especially West Africa (WA). Improving productivity of this staple crop under these harsh conditions is crucial to improve food security and farmer's incomes in WA.

Results: This is the first study to examine the genetics underlying sorghum adaptation to phosphorus limitation in a wide range of WA growing conditions. A set of 187 diverse sorghum genotypes were grown in 29 -P and + P field experiments from 2006-2012 in three WA countries. Sorghum grain yield performance under -P and + P conditions was highly correlated (r = 0.85***). Significant genotype-by-phosphorus interaction was detected but with small magnitude compared to the genotype variance component. We observed high genetic diversity within our panel, with rapid linkage disequilibrium decay, confirming recent sequence based studies in sorghum. Using genome wide association mapping based on 220 934 SNPs we identified one genomic region on chromosome 3 that was highly associated to grain yield production. A major Al-tolerance gene in sorghum, SbMATE, was collocated in this region and SbMATE specific SNPs showed very high associations to grain yield production, especially under -P conditions, explaining up to 16% of the genotypic variance.

Conclusion: The results suggest that SbMATE has a possible pleiotropic role in providing tolerance to two of the most serious abiotic stresses for sorghum in WA, Al toxicity and P deficiency. The identified SNPs can help accelerate breeding for increased sorghum productivity under unfavorable soil conditions and contribute to assuring food security in WA.

Show MeSH
Related in: MedlinePlus