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A major locus for chloride accumulation on chromosome 5A in bread wheat.

Genc Y, Taylor J, Rongala J, Oldach K - PLoS ONE (2014)

Bottom Line: Chloride (Cl-) is an essential micronutrient for plant growth, but can be toxic at high concentrations resulting in reduced growth and yield.A major Cl- concentration QTL (5A; barc56/gwm186) was identified in three field environments, and accounted for 27-32% of the total genetic variance.Alignment between the 5A QTL interval and its corresponding physical genome regions in wheat and other grasses has enabled the search for candidate genes involved in Cl- transport, which is discussed.

View Article: PubMed Central - PubMed

Affiliation: School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, South Australia, Australia; South Australian Research and Development Institute, Plant Genomics Centre, Waite Campus, Glen Osmond, South Australia, Australia.

ABSTRACT
Chloride (Cl-) is an essential micronutrient for plant growth, but can be toxic at high concentrations resulting in reduced growth and yield. Although saline soils are generally dominated by both sodium (Na+) and Cl- ions, compared to Na+ toxicity, very little is known about physiological and genetic control mechanisms of tolerance to Cl- toxicity. In hydroponics and field studies, a bread wheat mapping population was tested to examine the relationships between physiological traits [Na+, potassium (K+) and Cl- concentration] involved in salinity tolerance (ST) and seedling growth or grain yield, and to elucidate the genetic control mechanism of plant Cl- accumulation using a quantitative trait loci (QTL) analysis approach. Plant Na+ or Cl- concentration were moderately correlated (genetically) with seedling biomass in hydroponics, but showed no correlations with grain yield in the field, indicating little value in selecting for ion concentration to improve ST. In accordance with phenotypic responses, QTL controlling Cl- accumulation differed entirely between hydroponics and field locations, and few were detected in two or more environments, demonstrating substantial QTL-by-environment interactions. The presence of several QTL for Cl- concentration indicated that uptake and accumulation was a polygenic trait. A major Cl- concentration QTL (5A; barc56/gwm186) was identified in three field environments, and accounted for 27-32% of the total genetic variance. Alignment between the 5A QTL interval and its corresponding physical genome regions in wheat and other grasses has enabled the search for candidate genes involved in Cl- transport, which is discussed.

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Related in: MedlinePlus

Location of Cl− concentration QTL (barc56/gwm186) on chromosome 5A detected in field trials (Balaklava, Georgetown and Roseworthy) with varying salinity levels.The outlier statistics represent LOD scores (Table 4).
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pone-0098845-g001: Location of Cl− concentration QTL (barc56/gwm186) on chromosome 5A detected in field trials (Balaklava, Georgetown and Roseworthy) with varying salinity levels.The outlier statistics represent LOD scores (Table 4).

Mentions: In the initial analysis in which differences in phenology were not included, there were few Cl− concentration QTL co-locating with QTL for maturity on 5A and 5D (data not shown). Similar to Bonneau et al. [36], after the known differences in the genetic component of the phenology were addressed by fixing the maturity genes in the analyses, 14 QTL were identified (Table 4). However, most QTL were specific to single environments, and only three QTL were detected in two or more environments (3A, 5A, 7D) indicating some genotype by environment interaction. Interestingly, there were no co-located QTL controlling trait variation from hydroponics and field trials. The most significant QTL in hydroponics on chromosome 2A explained 20% of the total genetic variance and the Krichauff allele was responsible for increased Cl− concentration. QTL on chromosome 3A and 7D were detected from multi-location trials and explained 4–11% of the total genetic variance, while QTL on 5A accounted for 27-32% of the total genetic variance (Table 4). Either the Berkut (3A, 5A) or the Krichauff (7D) allele was associated with increased Cl− concentration at these loci. As the two QTL on 5A appear in tandem, these loci were further investigated to determine whether there may just be one rather than two separate QTL. The plot of outlier statistics (Figure 1) shows that there is in fact just one QTL on 5A expressed at all field locations. The QTL detected at one location only accounted for a small proportion of the total genetic variance, varying from 3.6 to 9.9% with either the Berkut or Krichauff allele being associated with increased Cl− concentration (Table 4).


A major locus for chloride accumulation on chromosome 5A in bread wheat.

Genc Y, Taylor J, Rongala J, Oldach K - PLoS ONE (2014)

Location of Cl− concentration QTL (barc56/gwm186) on chromosome 5A detected in field trials (Balaklava, Georgetown and Roseworthy) with varying salinity levels.The outlier statistics represent LOD scores (Table 4).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4043771&req=5

pone-0098845-g001: Location of Cl− concentration QTL (barc56/gwm186) on chromosome 5A detected in field trials (Balaklava, Georgetown and Roseworthy) with varying salinity levels.The outlier statistics represent LOD scores (Table 4).
Mentions: In the initial analysis in which differences in phenology were not included, there were few Cl− concentration QTL co-locating with QTL for maturity on 5A and 5D (data not shown). Similar to Bonneau et al. [36], after the known differences in the genetic component of the phenology were addressed by fixing the maturity genes in the analyses, 14 QTL were identified (Table 4). However, most QTL were specific to single environments, and only three QTL were detected in two or more environments (3A, 5A, 7D) indicating some genotype by environment interaction. Interestingly, there were no co-located QTL controlling trait variation from hydroponics and field trials. The most significant QTL in hydroponics on chromosome 2A explained 20% of the total genetic variance and the Krichauff allele was responsible for increased Cl− concentration. QTL on chromosome 3A and 7D were detected from multi-location trials and explained 4–11% of the total genetic variance, while QTL on 5A accounted for 27-32% of the total genetic variance (Table 4). Either the Berkut (3A, 5A) or the Krichauff (7D) allele was associated with increased Cl− concentration at these loci. As the two QTL on 5A appear in tandem, these loci were further investigated to determine whether there may just be one rather than two separate QTL. The plot of outlier statistics (Figure 1) shows that there is in fact just one QTL on 5A expressed at all field locations. The QTL detected at one location only accounted for a small proportion of the total genetic variance, varying from 3.6 to 9.9% with either the Berkut or Krichauff allele being associated with increased Cl− concentration (Table 4).

Bottom Line: Chloride (Cl-) is an essential micronutrient for plant growth, but can be toxic at high concentrations resulting in reduced growth and yield.A major Cl- concentration QTL (5A; barc56/gwm186) was identified in three field environments, and accounted for 27-32% of the total genetic variance.Alignment between the 5A QTL interval and its corresponding physical genome regions in wheat and other grasses has enabled the search for candidate genes involved in Cl- transport, which is discussed.

View Article: PubMed Central - PubMed

Affiliation: School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, South Australia, Australia; South Australian Research and Development Institute, Plant Genomics Centre, Waite Campus, Glen Osmond, South Australia, Australia.

ABSTRACT
Chloride (Cl-) is an essential micronutrient for plant growth, but can be toxic at high concentrations resulting in reduced growth and yield. Although saline soils are generally dominated by both sodium (Na+) and Cl- ions, compared to Na+ toxicity, very little is known about physiological and genetic control mechanisms of tolerance to Cl- toxicity. In hydroponics and field studies, a bread wheat mapping population was tested to examine the relationships between physiological traits [Na+, potassium (K+) and Cl- concentration] involved in salinity tolerance (ST) and seedling growth or grain yield, and to elucidate the genetic control mechanism of plant Cl- accumulation using a quantitative trait loci (QTL) analysis approach. Plant Na+ or Cl- concentration were moderately correlated (genetically) with seedling biomass in hydroponics, but showed no correlations with grain yield in the field, indicating little value in selecting for ion concentration to improve ST. In accordance with phenotypic responses, QTL controlling Cl- accumulation differed entirely between hydroponics and field locations, and few were detected in two or more environments, demonstrating substantial QTL-by-environment interactions. The presence of several QTL for Cl- concentration indicated that uptake and accumulation was a polygenic trait. A major Cl- concentration QTL (5A; barc56/gwm186) was identified in three field environments, and accounted for 27-32% of the total genetic variance. Alignment between the 5A QTL interval and its corresponding physical genome regions in wheat and other grasses has enabled the search for candidate genes involved in Cl- transport, which is discussed.

Show MeSH
Related in: MedlinePlus