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Identification of genomic regions involved in tolerance to drought stress and drought stress induced leaf senescence in juvenile barley.

Wehner GG, Balko CC, Enders MM, Humbeck KK, Ordon FF - BMC Plant Biol. (2015)

Bottom Line: BlastX search for associated marker sequences revealed that respective SNPs are in some cases located in proteins related to drought stress or leaf senescence, e.g. nucleotide pyrophosphatase (AVP1) or serine/ threonin protein kinase (SAPK9).GWAS resulted in the identification of many QTLs involved in drought stress and leaf senescence of which two major QTLs for drought stress and leaf senescence were located on chromosome 5H and 2H.Results may be the basis to incorporate breeding for tolerance to drought stress or leaf senescence in barley breeding via marker based selection procedures.

View Article: PubMed Central - PubMed

Affiliation: Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Resistance Research and Stress Tolerance, Rudolf-Schick-Platz 3, Sanitz, 18190, Germany. gwendolin.wehner@jki.bund.de.

ABSTRACT

Background: Premature leaf senescence induced by external stress conditions, e.g. drought stress, is a main factor for yield losses in barley. Research in drought stress tolerance has become more important as due to climate change the number of drought periods will increase and tolerance to drought stress has become a goal of high interest in barley breeding. Therefore, the aim is to identify quantitative trait loci (QTL) involved in drought stress induced leaf senescence and drought stress tolerance in early developmental stages of barley (Hordeum vulgare L.) by applying genome wide association studies (GWAS) on a set of 156 winter barley genotypes.

Results: After a four weeks stress period (BBCH 33) leaf colour as an indicator of leaf senescence, electron transport rate at photosystem II, content of free proline, content of soluble sugars, osmolality and the aboveground biomass indicative for drought stress response were determined in the control and stress variant in greenhouse pot experiments. Significant phenotypic variation was observed for all traits analysed. Heritabilities ranged between 0.27 for osmolality and 0.61 for leaf colour in stress treatment and significant effects of genotype, treatment and genotype x treatment were estimated for most traits analysed. Based on these phenotypic data and 3,212 polymorphic single nucleotide polymorphisms (SNP) with a minor allele frequency >5% derived from the Illumina 9 k iSelect SNP Chip, 181 QTL were detected for all traits analysed. Major QTLs for drought stress and leaf senescence were located on chromosome 5H and 2H. BlastX search for associated marker sequences revealed that respective SNPs are in some cases located in proteins related to drought stress or leaf senescence, e.g. nucleotide pyrophosphatase (AVP1) or serine/ threonin protein kinase (SAPK9).

Conclusions: GWAS resulted in the identification of many QTLs involved in drought stress and leaf senescence of which two major QTLs for drought stress and leaf senescence were located on chromosome 5H and 2H. Results may be the basis to incorporate breeding for tolerance to drought stress or leaf senescence in barley breeding via marker based selection procedures.

No MeSH data available.


Related in: MedlinePlus

Genetic map. Shows QTL including the significant associated SNP marker positions for significant blasted proteins (BlastX) linked to drought stress or leaf senescence, related traits for drought stress treatment and percentage of phenotypic variance (explained R2 in %) of the SNPs for all linkage groups (barley chromosomes)
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Fig3: Genetic map. Shows QTL including the significant associated SNP marker positions for significant blasted proteins (BlastX) linked to drought stress or leaf senescence, related traits for drought stress treatment and percentage of phenotypic variance (explained R2 in %) of the SNPs for all linkage groups (barley chromosomes)

Mentions: From the 353 significantly associated SNPs detected in the control treatment, stress treatment and across treatments (DSI), 127 proteins were identified by an NCBI Blast of the marker sequences. Out of these 19 proteins turned out to be related to drought stress, 10 proteins related to leaf senescence and 98 proteins turned out to be not related to drought stress or leaf senescence. Out of the 29 proteins for drought stress and leaf senescence (Table 5), 16 revealed associations under drought stress conditions. These were in a next step assigned to the barley chromosomes by the known genetic localization of respective SNPs (Fig. 3). Most of these were located at barley chromosome 2H and 5H, none were mapped on chromosome 6H.Fig. 3


Identification of genomic regions involved in tolerance to drought stress and drought stress induced leaf senescence in juvenile barley.

Wehner GG, Balko CC, Enders MM, Humbeck KK, Ordon FF - BMC Plant Biol. (2015)

Genetic map. Shows QTL including the significant associated SNP marker positions for significant blasted proteins (BlastX) linked to drought stress or leaf senescence, related traits for drought stress treatment and percentage of phenotypic variance (explained R2 in %) of the SNPs for all linkage groups (barley chromosomes)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4440603&req=5

Fig3: Genetic map. Shows QTL including the significant associated SNP marker positions for significant blasted proteins (BlastX) linked to drought stress or leaf senescence, related traits for drought stress treatment and percentage of phenotypic variance (explained R2 in %) of the SNPs for all linkage groups (barley chromosomes)
Mentions: From the 353 significantly associated SNPs detected in the control treatment, stress treatment and across treatments (DSI), 127 proteins were identified by an NCBI Blast of the marker sequences. Out of these 19 proteins turned out to be related to drought stress, 10 proteins related to leaf senescence and 98 proteins turned out to be not related to drought stress or leaf senescence. Out of the 29 proteins for drought stress and leaf senescence (Table 5), 16 revealed associations under drought stress conditions. These were in a next step assigned to the barley chromosomes by the known genetic localization of respective SNPs (Fig. 3). Most of these were located at barley chromosome 2H and 5H, none were mapped on chromosome 6H.Fig. 3

Bottom Line: BlastX search for associated marker sequences revealed that respective SNPs are in some cases located in proteins related to drought stress or leaf senescence, e.g. nucleotide pyrophosphatase (AVP1) or serine/ threonin protein kinase (SAPK9).GWAS resulted in the identification of many QTLs involved in drought stress and leaf senescence of which two major QTLs for drought stress and leaf senescence were located on chromosome 5H and 2H.Results may be the basis to incorporate breeding for tolerance to drought stress or leaf senescence in barley breeding via marker based selection procedures.

View Article: PubMed Central - PubMed

Affiliation: Julius Kühn-Institut (JKI), Federal Research Centre for Cultivated Plants, Institute for Resistance Research and Stress Tolerance, Rudolf-Schick-Platz 3, Sanitz, 18190, Germany. gwendolin.wehner@jki.bund.de.

ABSTRACT

Background: Premature leaf senescence induced by external stress conditions, e.g. drought stress, is a main factor for yield losses in barley. Research in drought stress tolerance has become more important as due to climate change the number of drought periods will increase and tolerance to drought stress has become a goal of high interest in barley breeding. Therefore, the aim is to identify quantitative trait loci (QTL) involved in drought stress induced leaf senescence and drought stress tolerance in early developmental stages of barley (Hordeum vulgare L.) by applying genome wide association studies (GWAS) on a set of 156 winter barley genotypes.

Results: After a four weeks stress period (BBCH 33) leaf colour as an indicator of leaf senescence, electron transport rate at photosystem II, content of free proline, content of soluble sugars, osmolality and the aboveground biomass indicative for drought stress response were determined in the control and stress variant in greenhouse pot experiments. Significant phenotypic variation was observed for all traits analysed. Heritabilities ranged between 0.27 for osmolality and 0.61 for leaf colour in stress treatment and significant effects of genotype, treatment and genotype x treatment were estimated for most traits analysed. Based on these phenotypic data and 3,212 polymorphic single nucleotide polymorphisms (SNP) with a minor allele frequency >5% derived from the Illumina 9 k iSelect SNP Chip, 181 QTL were detected for all traits analysed. Major QTLs for drought stress and leaf senescence were located on chromosome 5H and 2H. BlastX search for associated marker sequences revealed that respective SNPs are in some cases located in proteins related to drought stress or leaf senescence, e.g. nucleotide pyrophosphatase (AVP1) or serine/ threonin protein kinase (SAPK9).

Conclusions: GWAS resulted in the identification of many QTLs involved in drought stress and leaf senescence of which two major QTLs for drought stress and leaf senescence were located on chromosome 5H and 2H. Results may be the basis to incorporate breeding for tolerance to drought stress or leaf senescence in barley breeding via marker based selection procedures.

No MeSH data available.


Related in: MedlinePlus