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Phenotypic and fine genetic characterization of the D locus controlling fruit acidity in peach.

Boudehri K, Bendahmane A, Cardinet G, Troadec C, Moing A, Dirlewanger E - BMC Plant Biol. (2009)

Bottom Line: We also constructed a peach BAC library of 52,000 clones with a mean insert size of 90 kb.The screening of the BAC library with markers tightly linked to D locus indicated that 1 cM corresponds to 250 kb at the vicinity of the D locus.We also constructed a peach BAC library of approximately 15x genome equivalent.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institut National de la Recherche Agronomique/UR0419, Unité de Recherches sur les Espèces Fruitières, Centre de Bordeaux, Villenave d'Ornon, France. kboudehr@bordeaux.inra.fr

ABSTRACT

Background: Acidity is an essential component of the organoleptic quality of fleshy fruits. However, in these fruits, the physiological and molecular mechanisms that control fruit acidity remain unclear. In peach the D locus controls fruit acidity; low-acidity is determined by the dominant allele. Using a peach progeny of 208 F2 trees, the D locus was mapped to the proximal end of linkage group 5 and co-localized with major QTLs involved in the control of fruit pH, titratable acidity and organic acid concentration and small QTLs for sugar concentration. To investigate the molecular basis of fruit acidity in peach we initiated the map-based cloning of the D locus.

Results: In order to generate a high-resolution linkage map in the vicinity of the D locus, 1,024 AFLP primer combinations were screened using DNA of bulked acid and low-acid segregants. We also screened a segregating population of 1,718 individuals for chromosomal recombination events linked to the D locus and identified 308 individuals with recombination events close to D. Using these recombinant individuals we delimited the D locus to a genetic interval of 0.4 cM. We also constructed a peach BAC library of 52,000 clones with a mean insert size of 90 kb. The screening of the BAC library with markers tightly linked to D locus indicated that 1 cM corresponds to 250 kb at the vicinity of the D locus.

Conclusion: In the present work we presented the first high-resolution genetic map of D locus in peach. We also constructed a peach BAC library of approximately 15x genome equivalent. This fine genetic and physical characterization of the D locus is the first step towards the isolation of the gene(s) underlying fruit acidity in peach.

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Related in: MedlinePlus

AFLP markers detecting polymorphisms between low-acid bulks and normally-acid bulks revealed on polyacrylamide gel. AFLP markers showing a band in low-acid bulks (BD1 and BD2) but not in normally-acid (Bd1 and Bd2) bulks are surrounded with a continuous line. AFLP markers showing a faint band in Bd1 and Bd2 bulks, not selected for genetic mapping, are surrounded with a dotted line.
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Figure 2: AFLP markers detecting polymorphisms between low-acid bulks and normally-acid bulks revealed on polyacrylamide gel. AFLP markers showing a band in low-acid bulks (BD1 and BD2) but not in normally-acid (Bd1 and Bd2) bulks are surrounded with a continuous line. AFLP markers showing a faint band in Bd1 and Bd2 bulks, not selected for genetic mapping, are surrounded with a dotted line.

Mentions: Among the 1,024 primer combinations tested, 960 provided readable amplification products. Thirty to 90 bands were observed on AFLP gels per primer combination with a size range from 60 to 1,000 bp, but only 6.5% of the bands were polymorphic between the 'Ferjalou Jalousia®' and 'Fantasia' parents. Markers whose bands were present in BD1 and BD2 bulks and absent from Bd1 and Bd2 bulks were potentially linked to the D locus (Fig. 2). A total of 34 markers were identified as putatively linked to the D locus (Table 1). Nineteen primer combinations each revealed only one D-linked marker, six primer combinations produced two D-linked markers (pGC-AGG, pCA-GCG, pTC-CAC, pCA-ACC, pCA-TCC and pAA-ACA) and one primer combination revealed three D-linked markers (pGC-TCT). As expected, all 34 AFLP markers were mapped on linkage group 5. AFLP markers close to the D locus (within 22 cM) were clearly polymorphic between bulks. AFLP markers mapped further away (beyond 27 cM) were polymorphic markers between bulks but with a very faint band for "d" bulks. Fourteen AFLP markers were located within the first 10 cM containing the D locus.


Phenotypic and fine genetic characterization of the D locus controlling fruit acidity in peach.

Boudehri K, Bendahmane A, Cardinet G, Troadec C, Moing A, Dirlewanger E - BMC Plant Biol. (2009)

AFLP markers detecting polymorphisms between low-acid bulks and normally-acid bulks revealed on polyacrylamide gel. AFLP markers showing a band in low-acid bulks (BD1 and BD2) but not in normally-acid (Bd1 and Bd2) bulks are surrounded with a continuous line. AFLP markers showing a faint band in Bd1 and Bd2 bulks, not selected for genetic mapping, are surrounded with a dotted line.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698847&req=5

Figure 2: AFLP markers detecting polymorphisms between low-acid bulks and normally-acid bulks revealed on polyacrylamide gel. AFLP markers showing a band in low-acid bulks (BD1 and BD2) but not in normally-acid (Bd1 and Bd2) bulks are surrounded with a continuous line. AFLP markers showing a faint band in Bd1 and Bd2 bulks, not selected for genetic mapping, are surrounded with a dotted line.
Mentions: Among the 1,024 primer combinations tested, 960 provided readable amplification products. Thirty to 90 bands were observed on AFLP gels per primer combination with a size range from 60 to 1,000 bp, but only 6.5% of the bands were polymorphic between the 'Ferjalou Jalousia®' and 'Fantasia' parents. Markers whose bands were present in BD1 and BD2 bulks and absent from Bd1 and Bd2 bulks were potentially linked to the D locus (Fig. 2). A total of 34 markers were identified as putatively linked to the D locus (Table 1). Nineteen primer combinations each revealed only one D-linked marker, six primer combinations produced two D-linked markers (pGC-AGG, pCA-GCG, pTC-CAC, pCA-ACC, pCA-TCC and pAA-ACA) and one primer combination revealed three D-linked markers (pGC-TCT). As expected, all 34 AFLP markers were mapped on linkage group 5. AFLP markers close to the D locus (within 22 cM) were clearly polymorphic between bulks. AFLP markers mapped further away (beyond 27 cM) were polymorphic markers between bulks but with a very faint band for "d" bulks. Fourteen AFLP markers were located within the first 10 cM containing the D locus.

Bottom Line: We also constructed a peach BAC library of 52,000 clones with a mean insert size of 90 kb.The screening of the BAC library with markers tightly linked to D locus indicated that 1 cM corresponds to 250 kb at the vicinity of the D locus.We also constructed a peach BAC library of approximately 15x genome equivalent.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institut National de la Recherche Agronomique/UR0419, Unité de Recherches sur les Espèces Fruitières, Centre de Bordeaux, Villenave d'Ornon, France. kboudehr@bordeaux.inra.fr

ABSTRACT

Background: Acidity is an essential component of the organoleptic quality of fleshy fruits. However, in these fruits, the physiological and molecular mechanisms that control fruit acidity remain unclear. In peach the D locus controls fruit acidity; low-acidity is determined by the dominant allele. Using a peach progeny of 208 F2 trees, the D locus was mapped to the proximal end of linkage group 5 and co-localized with major QTLs involved in the control of fruit pH, titratable acidity and organic acid concentration and small QTLs for sugar concentration. To investigate the molecular basis of fruit acidity in peach we initiated the map-based cloning of the D locus.

Results: In order to generate a high-resolution linkage map in the vicinity of the D locus, 1,024 AFLP primer combinations were screened using DNA of bulked acid and low-acid segregants. We also screened a segregating population of 1,718 individuals for chromosomal recombination events linked to the D locus and identified 308 individuals with recombination events close to D. Using these recombinant individuals we delimited the D locus to a genetic interval of 0.4 cM. We also constructed a peach BAC library of 52,000 clones with a mean insert size of 90 kb. The screening of the BAC library with markers tightly linked to D locus indicated that 1 cM corresponds to 250 kb at the vicinity of the D locus.

Conclusion: In the present work we presented the first high-resolution genetic map of D locus in peach. We also constructed a peach BAC library of approximately 15x genome equivalent. This fine genetic and physical characterization of the D locus is the first step towards the isolation of the gene(s) underlying fruit acidity in peach.

Show MeSH
Related in: MedlinePlus