Limits...
First steps to understand heat tolerance of temperate maize at adult stage: identification of QTL across multiple environments with connected segregating populations.

Frey FP, Presterl T, Lecoq P, Orlik A, Stich B - Theor. Appl. Genet. (2016)

Bottom Line: High temperatures have the potential to cause severe damages to maize production.Furthermore, we identified six heat-tolerance and 112 heat-responsive candidate genes colocating with the previously mentioned QTL.To investigate their contribution to the response to heat stress and heat tolerance, differential expression and sequence variation of the identified candidate genes should be subjected to further research.

View Article: PubMed Central - PubMed

Affiliation: Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany.

ABSTRACT

Key message: Dents were more heat tolerant than Flints. QTL for heat tolerance with respect to grain yield at field conditions were identified considering multiple populations and environments. High temperatures have the potential to cause severe damages to maize production. This study aims to elucidate the genetic mechanisms of heat tolerance under field conditions in maize and the genome regions contributing to natural variation. In our study, heat tolerance was assessed on a multi-environment level under non-controlled field conditions for a set of connected intra- and interpool Dent and Flint populations. Our findings indicate that Dent are more heat tolerant during adult stage than Flint genotypes. We identified 11 quantitative trait loci (QTL) including 2 loci for heat tolerance with respect to grain yield. Furthermore, we identified six heat-tolerance and 112 heat-responsive candidate genes colocating with the previously mentioned QTL. To investigate their contribution to the response to heat stress and heat tolerance, differential expression and sequence variation of the identified candidate genes should be subjected to further research.

No MeSH data available.


Related in: MedlinePlus

Genetic positions of heat-tolerance (black) and heat-responsive (orange) candidate genes in the quantitative trait loci (QTL) confidence intervals and flanking markers (black) of the QTL hot spot regions in the first track. Tracks 2–7 show logarithmic odds ratio (LOD) scores (circumferential black), detected QTL positions (radial black) and confidence intervals (red) of the QTL analyses for which QTL have been detected: principal component 1 (PC1) and the heat susceptibility indexes (HSI) of the traits dry yield (DY), adjusted dry yield (DYA), the time to female (FF) and male flowering (MF) and the leaf scorching (LS). QTL hot spots are denoted in transparent red. Genetic positions of SNP markers are shown in the most inner circle
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Fig6: Genetic positions of heat-tolerance (black) and heat-responsive (orange) candidate genes in the quantitative trait loci (QTL) confidence intervals and flanking markers (black) of the QTL hot spot regions in the first track. Tracks 2–7 show logarithmic odds ratio (LOD) scores (circumferential black), detected QTL positions (radial black) and confidence intervals (red) of the QTL analyses for which QTL have been detected: principal component 1 (PC1) and the heat susceptibility indexes (HSI) of the traits dry yield (DY), adjusted dry yield (DYA), the time to female (FF) and male flowering (MF) and the leaf scorching (LS). QTL hot spots are denoted in transparent red. Genetic positions of SNP markers are shown in the most inner circle

Mentions: We identified a total of 11 QTL (Table 4), each explaining between 7 and 13 % of the variance (R2) of the respective HSI or PC. With simultaneous fits across all QTL detected for each HSI or PC with several QTL, 19, 17, 19 and 18 % of the variance could be explained for HSIDY, HSIDYA, HSIMF and PC1, respectively. The highest additive effects on QTL for HSIDY and HSIDYA (QHSI:DYa and QHSI:DYb as well as QHSI:DYAa and QHSI:DYAb) were observed for the parental alleles of inbreds P040 and S067, which were the parental inbred lines of population 1. At the genomic position of QHSI:DYa and QHSI:DYAa, the S067 allele had a negative additive effect, whereas at position of QHSI:DYb and QHSI:DYAb, the P040 allele showed a negative additive effect. We observed further a highly significant dominance effect in population 1 for the previously mentioned four QTL, which was negative at QHSI:DYa and QHSI:DYAa and positive at QHSI:DYb and QHSI:DYAb. A total of 6 heat-tolerance genes and 112 heat-responsive genes, identified by Frey et al. (2015), were found in the 11 QTL confidence intervals (Table 5 and Supplementary material—Table 2). Overlapping the QTL confidence intervals resulted in 5 QTL hot spots (Fig. 6), where two were located on chromosome 2 and one on chromosomes 3, 5 and 9.Table 5


First steps to understand heat tolerance of temperate maize at adult stage: identification of QTL across multiple environments with connected segregating populations.

Frey FP, Presterl T, Lecoq P, Orlik A, Stich B - Theor. Appl. Genet. (2016)

Genetic positions of heat-tolerance (black) and heat-responsive (orange) candidate genes in the quantitative trait loci (QTL) confidence intervals and flanking markers (black) of the QTL hot spot regions in the first track. Tracks 2–7 show logarithmic odds ratio (LOD) scores (circumferential black), detected QTL positions (radial black) and confidence intervals (red) of the QTL analyses for which QTL have been detected: principal component 1 (PC1) and the heat susceptibility indexes (HSI) of the traits dry yield (DY), adjusted dry yield (DYA), the time to female (FF) and male flowering (MF) and the leaf scorching (LS). QTL hot spots are denoted in transparent red. Genetic positions of SNP markers are shown in the most inner circle
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835532&req=5

Fig6: Genetic positions of heat-tolerance (black) and heat-responsive (orange) candidate genes in the quantitative trait loci (QTL) confidence intervals and flanking markers (black) of the QTL hot spot regions in the first track. Tracks 2–7 show logarithmic odds ratio (LOD) scores (circumferential black), detected QTL positions (radial black) and confidence intervals (red) of the QTL analyses for which QTL have been detected: principal component 1 (PC1) and the heat susceptibility indexes (HSI) of the traits dry yield (DY), adjusted dry yield (DYA), the time to female (FF) and male flowering (MF) and the leaf scorching (LS). QTL hot spots are denoted in transparent red. Genetic positions of SNP markers are shown in the most inner circle
Mentions: We identified a total of 11 QTL (Table 4), each explaining between 7 and 13 % of the variance (R2) of the respective HSI or PC. With simultaneous fits across all QTL detected for each HSI or PC with several QTL, 19, 17, 19 and 18 % of the variance could be explained for HSIDY, HSIDYA, HSIMF and PC1, respectively. The highest additive effects on QTL for HSIDY and HSIDYA (QHSI:DYa and QHSI:DYb as well as QHSI:DYAa and QHSI:DYAb) were observed for the parental alleles of inbreds P040 and S067, which were the parental inbred lines of population 1. At the genomic position of QHSI:DYa and QHSI:DYAa, the S067 allele had a negative additive effect, whereas at position of QHSI:DYb and QHSI:DYAb, the P040 allele showed a negative additive effect. We observed further a highly significant dominance effect in population 1 for the previously mentioned four QTL, which was negative at QHSI:DYa and QHSI:DYAa and positive at QHSI:DYb and QHSI:DYAb. A total of 6 heat-tolerance genes and 112 heat-responsive genes, identified by Frey et al. (2015), were found in the 11 QTL confidence intervals (Table 5 and Supplementary material—Table 2). Overlapping the QTL confidence intervals resulted in 5 QTL hot spots (Fig. 6), where two were located on chromosome 2 and one on chromosomes 3, 5 and 9.Table 5

Bottom Line: High temperatures have the potential to cause severe damages to maize production.Furthermore, we identified six heat-tolerance and 112 heat-responsive candidate genes colocating with the previously mentioned QTL.To investigate their contribution to the response to heat stress and heat tolerance, differential expression and sequence variation of the identified candidate genes should be subjected to further research.

View Article: PubMed Central - PubMed

Affiliation: Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany.

ABSTRACT

Key message: Dents were more heat tolerant than Flints. QTL for heat tolerance with respect to grain yield at field conditions were identified considering multiple populations and environments. High temperatures have the potential to cause severe damages to maize production. This study aims to elucidate the genetic mechanisms of heat tolerance under field conditions in maize and the genome regions contributing to natural variation. In our study, heat tolerance was assessed on a multi-environment level under non-controlled field conditions for a set of connected intra- and interpool Dent and Flint populations. Our findings indicate that Dent are more heat tolerant during adult stage than Flint genotypes. We identified 11 quantitative trait loci (QTL) including 2 loci for heat tolerance with respect to grain yield. Furthermore, we identified six heat-tolerance and 112 heat-responsive candidate genes colocating with the previously mentioned QTL. To investigate their contribution to the response to heat stress and heat tolerance, differential expression and sequence variation of the identified candidate genes should be subjected to further research.

No MeSH data available.


Related in: MedlinePlus