Limits...
QTL and candidate gene mapping for polyphenolic composition in apple fruit.

Chagné D, Krieger C, Rassam M, Sullivan M, Fraser J, André C, Pindo M, Troggio M, Gardiner SE, Henry RA, Allan AC, McGhie TK, Laing WA - BMC Plant Biol. (2012)

Bottom Line: This co-location was confirmed by genetic mapping of markers derived from the gene sequences.Leucoanthocyanidin reductase (LAR1) co-located with a QTL cluster for the fruit flavanols catechin, epicatechin, procyanidin dimer and five unknown procyanidin oligomers identified near the top of linkage group (LG) 16, while hydroxy cinnamate/quinate transferase (HCT/HQT) co-located with a QTL for chlorogenic acid concentration mapping near the bottom of LG 17.We conclude that LAR1 and HCT/HQT are likely to influence the concentration of these compounds in apple fruit and provide useful allele-specific markers for marker assisted selection of trees bearing fruit with healthy attributes.

View Article: PubMed Central - HTML - PubMed

Affiliation: The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Palmerston North Research Centre, Palmerston North 4442, New Zealand. David.Chagne@plantandfood.co.nz

ABSTRACT

Background: The polyphenolic products of the phenylpropanoid pathway, including proanthocyanidins, anthocyanins and flavonols, possess antioxidant properties that may provide health benefits. To investigate the genetic architecture of control of their biosynthesis in apple fruit, various polyphenolic compounds were quantified in progeny from a 'Royal Gala' × 'Braeburn' apple population segregating for antioxidant content, using ultra high performance liquid chromatography of extracts derived from fruit cortex and skin.

Results: Construction of genetic maps for 'Royal Gala' and 'Braeburn' enabled detection of 79 quantitative trait loci (QTL) for content of 17 fruit polyphenolic compounds. Seven QTL clusters were stable across two years of harvest and included QTLs for content of flavanols, flavonols, anthocyanins and hydroxycinnamic acids. Alignment of the parental genetic maps with the apple whole genome sequence in silico enabled screening for co-segregation with the QTLs of a range of candidate genes coding for enzymes in the polyphenolic biosynthetic pathway. This co-location was confirmed by genetic mapping of markers derived from the gene sequences. Leucoanthocyanidin reductase (LAR1) co-located with a QTL cluster for the fruit flavanols catechin, epicatechin, procyanidin dimer and five unknown procyanidin oligomers identified near the top of linkage group (LG) 16, while hydroxy cinnamate/quinate transferase (HCT/HQT) co-located with a QTL for chlorogenic acid concentration mapping near the bottom of LG 17.

Conclusion: We conclude that LAR1 and HCT/HQT are likely to influence the concentration of these compounds in apple fruit and provide useful allele-specific markers for marker assisted selection of trees bearing fruit with healthy attributes.

Show MeSH

Related in: MedlinePlus

Phenotypic distribution of four flavanol compounds measured in 2010 in the 'Royal Gala' × 'Braeburn' segregating population based on the LAR1 genetic marker genotypes. A: catechin, B: procyanidin-B2, C: epicatechin and D: procyanidin oligomers. The concentrations are expressed as μg/g of fresh weight.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3285079&req=5

Figure 3: Phenotypic distribution of four flavanol compounds measured in 2010 in the 'Royal Gala' × 'Braeburn' segregating population based on the LAR1 genetic marker genotypes. A: catechin, B: procyanidin-B2, C: epicatechin and D: procyanidin oligomers. The concentrations are expressed as μg/g of fresh weight.

Mentions: The HRM-based genetic marker for LAR1 that mapped at the top of LG 16 was fully informative, segregating ef x eg, and it could be employed for QTL detection in both parental maps. The PCR primers for this polymorphic marker were positioned in the fourth intron of LAR1. This marker had the highest LOD score for all eight flavanol compounds in both parental maps (Table 2a). MQM analysis with LAR1 as a cofactor revealed no other QTL within the LG 16 region or anywhere else in the genome. The f and g alleles for 'Royal Gala' and 'Braeburn', respectively, were associated with higher concentration of flavanols. The individuals carrying the homozygous ee genotype exhibited significantly lower concentrations of flavanol compounds in the fruit skin and no flavanol was detected in the fruit cortex (Figure 3).


QTL and candidate gene mapping for polyphenolic composition in apple fruit.

Chagné D, Krieger C, Rassam M, Sullivan M, Fraser J, André C, Pindo M, Troggio M, Gardiner SE, Henry RA, Allan AC, McGhie TK, Laing WA - BMC Plant Biol. (2012)

Phenotypic distribution of four flavanol compounds measured in 2010 in the 'Royal Gala' × 'Braeburn' segregating population based on the LAR1 genetic marker genotypes. A: catechin, B: procyanidin-B2, C: epicatechin and D: procyanidin oligomers. The concentrations are expressed as μg/g of fresh weight.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3285079&req=5

Figure 3: Phenotypic distribution of four flavanol compounds measured in 2010 in the 'Royal Gala' × 'Braeburn' segregating population based on the LAR1 genetic marker genotypes. A: catechin, B: procyanidin-B2, C: epicatechin and D: procyanidin oligomers. The concentrations are expressed as μg/g of fresh weight.
Mentions: The HRM-based genetic marker for LAR1 that mapped at the top of LG 16 was fully informative, segregating ef x eg, and it could be employed for QTL detection in both parental maps. The PCR primers for this polymorphic marker were positioned in the fourth intron of LAR1. This marker had the highest LOD score for all eight flavanol compounds in both parental maps (Table 2a). MQM analysis with LAR1 as a cofactor revealed no other QTL within the LG 16 region or anywhere else in the genome. The f and g alleles for 'Royal Gala' and 'Braeburn', respectively, were associated with higher concentration of flavanols. The individuals carrying the homozygous ee genotype exhibited significantly lower concentrations of flavanol compounds in the fruit skin and no flavanol was detected in the fruit cortex (Figure 3).

Bottom Line: This co-location was confirmed by genetic mapping of markers derived from the gene sequences.Leucoanthocyanidin reductase (LAR1) co-located with a QTL cluster for the fruit flavanols catechin, epicatechin, procyanidin dimer and five unknown procyanidin oligomers identified near the top of linkage group (LG) 16, while hydroxy cinnamate/quinate transferase (HCT/HQT) co-located with a QTL for chlorogenic acid concentration mapping near the bottom of LG 17.We conclude that LAR1 and HCT/HQT are likely to influence the concentration of these compounds in apple fruit and provide useful allele-specific markers for marker assisted selection of trees bearing fruit with healthy attributes.

View Article: PubMed Central - HTML - PubMed

Affiliation: The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Palmerston North Research Centre, Palmerston North 4442, New Zealand. David.Chagne@plantandfood.co.nz

ABSTRACT

Background: The polyphenolic products of the phenylpropanoid pathway, including proanthocyanidins, anthocyanins and flavonols, possess antioxidant properties that may provide health benefits. To investigate the genetic architecture of control of their biosynthesis in apple fruit, various polyphenolic compounds were quantified in progeny from a 'Royal Gala' × 'Braeburn' apple population segregating for antioxidant content, using ultra high performance liquid chromatography of extracts derived from fruit cortex and skin.

Results: Construction of genetic maps for 'Royal Gala' and 'Braeburn' enabled detection of 79 quantitative trait loci (QTL) for content of 17 fruit polyphenolic compounds. Seven QTL clusters were stable across two years of harvest and included QTLs for content of flavanols, flavonols, anthocyanins and hydroxycinnamic acids. Alignment of the parental genetic maps with the apple whole genome sequence in silico enabled screening for co-segregation with the QTLs of a range of candidate genes coding for enzymes in the polyphenolic biosynthetic pathway. This co-location was confirmed by genetic mapping of markers derived from the gene sequences. Leucoanthocyanidin reductase (LAR1) co-located with a QTL cluster for the fruit flavanols catechin, epicatechin, procyanidin dimer and five unknown procyanidin oligomers identified near the top of linkage group (LG) 16, while hydroxy cinnamate/quinate transferase (HCT/HQT) co-located with a QTL for chlorogenic acid concentration mapping near the bottom of LG 17.

Conclusion: We conclude that LAR1 and HCT/HQT are likely to influence the concentration of these compounds in apple fruit and provide useful allele-specific markers for marker assisted selection of trees bearing fruit with healthy attributes.

Show MeSH
Related in: MedlinePlus