Limits...
Two quantitative trait loci, Dw1 and Dw2, are primarily responsible for rootstock-induced dwarfing in apple.

Foster TM, Celton JM, Chagné D, Tustin DS, Gardiner SE - Hortic Res (2015)

Bottom Line: The apple dwarfing rootstock 'Malling9' ('M9') has been used worldwide both to reduce scion vigour and as a genetic source for breeding new rootstocks.A smaller-effect QTL affecting dwarfing (Dw2) was identified on LG11, and four minor-effect QTLs were found on LG6, LG9, LG10 and LG12.Phenotypic analysis indicates that the combination of Dw1 and Dw2 has the strongest influence on rootstock-induced dwarfing, and that Dw1 has a stronger effect than Dw2.

View Article: PubMed Central - PubMed

Affiliation: The New Zealand Institute for Plant & Food Research Ltd , Palmerston North Private Bag 11600, Palmerston North 4474, New Zealand.

ABSTRACT
The apple dwarfing rootstock 'Malling9' ('M9') has been used worldwide both to reduce scion vigour and as a genetic source for breeding new rootstocks. Progeny of 'M9' segregate for rootstock-induced dwarfing of the scion, indicating that this trait is controlled by one or more genetic factors. A quantitative trait locus (QTL) analysis of a rootstock population derived from the cross between 'M9' × 'Robusta5' (non-dwarfing) and grafted with 'Braeburn' scions identified a major QTL (Dw1) on linkage group (LG) 5, which exhibits a significant influence on dwarfing of the scion. A smaller-effect QTL affecting dwarfing (Dw2) was identified on LG11, and four minor-effect QTLs were found on LG6, LG9, LG10 and LG12. Phenotypic analysis indicates that the combination of Dw1 and Dw2 has the strongest influence on rootstock-induced dwarfing, and that Dw1 has a stronger effect than Dw2. Genetic markers linked to Dw1 and Dw2 were screened over 41 rootstock accessions that confer a range of effects on scion growth. The majority of the dwarfing and semi-dwarfing rootstock accessions screened carried marker alleles linked to Dw1 and Dw2. This suggests that most apple dwarfing rootstocks have been derived from the same genetic source.

No MeSH data available.


Related in: MedlinePlus

Composition of each phenotypic class by Dw1 and Dw2 genotype. Trees from both populations (449 trees in total) were visually assessed after 7 years of growth and placed into one of five phenotypic classes, D=dwarf, SD=semi-dwarf, I=intermediate, V=vigorous and VV=very vigorous.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4595989&req=5

fig5: Composition of each phenotypic class by Dw1 and Dw2 genotype. Trees from both populations (449 trees in total) were visually assessed after 7 years of growth and placed into one of five phenotypic classes, D=dwarf, SD=semi-dwarf, I=intermediate, V=vigorous and VV=very vigorous.

Mentions: As rootstock-induced dwarfing becomes more pronounced over successive growth cycles, an expert visual assessment of the whole tree phenotype after 7 years provided an overall measure of scion vigour. When 449 grafted trees from both populations were compared, a clear trend relating rootstock genotype to phenotypic class was observed. All the dwarfed and semi-dwarfed trees were grafted onto rootstocks with Dw1 and Dw2 or Dw1 alone, whereas the vigorous and very vigorous trees had rootstocks carrying Dw2 alone, Dw1 alone, or neither locus (Figure 5). Nearly 40% of the vigorous trees were on rootstocks carrying Dw2, indicating that this locus alone is not sufficient to dwarf the scion.


Two quantitative trait loci, Dw1 and Dw2, are primarily responsible for rootstock-induced dwarfing in apple.

Foster TM, Celton JM, Chagné D, Tustin DS, Gardiner SE - Hortic Res (2015)

Composition of each phenotypic class by Dw1 and Dw2 genotype. Trees from both populations (449 trees in total) were visually assessed after 7 years of growth and placed into one of five phenotypic classes, D=dwarf, SD=semi-dwarf, I=intermediate, V=vigorous and VV=very vigorous.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595989&req=5

fig5: Composition of each phenotypic class by Dw1 and Dw2 genotype. Trees from both populations (449 trees in total) were visually assessed after 7 years of growth and placed into one of five phenotypic classes, D=dwarf, SD=semi-dwarf, I=intermediate, V=vigorous and VV=very vigorous.
Mentions: As rootstock-induced dwarfing becomes more pronounced over successive growth cycles, an expert visual assessment of the whole tree phenotype after 7 years provided an overall measure of scion vigour. When 449 grafted trees from both populations were compared, a clear trend relating rootstock genotype to phenotypic class was observed. All the dwarfed and semi-dwarfed trees were grafted onto rootstocks with Dw1 and Dw2 or Dw1 alone, whereas the vigorous and very vigorous trees had rootstocks carrying Dw2 alone, Dw1 alone, or neither locus (Figure 5). Nearly 40% of the vigorous trees were on rootstocks carrying Dw2, indicating that this locus alone is not sufficient to dwarf the scion.

Bottom Line: The apple dwarfing rootstock 'Malling9' ('M9') has been used worldwide both to reduce scion vigour and as a genetic source for breeding new rootstocks.A smaller-effect QTL affecting dwarfing (Dw2) was identified on LG11, and four minor-effect QTLs were found on LG6, LG9, LG10 and LG12.Phenotypic analysis indicates that the combination of Dw1 and Dw2 has the strongest influence on rootstock-induced dwarfing, and that Dw1 has a stronger effect than Dw2.

View Article: PubMed Central - PubMed

Affiliation: The New Zealand Institute for Plant & Food Research Ltd , Palmerston North Private Bag 11600, Palmerston North 4474, New Zealand.

ABSTRACT
The apple dwarfing rootstock 'Malling9' ('M9') has been used worldwide both to reduce scion vigour and as a genetic source for breeding new rootstocks. Progeny of 'M9' segregate for rootstock-induced dwarfing of the scion, indicating that this trait is controlled by one or more genetic factors. A quantitative trait locus (QTL) analysis of a rootstock population derived from the cross between 'M9' × 'Robusta5' (non-dwarfing) and grafted with 'Braeburn' scions identified a major QTL (Dw1) on linkage group (LG) 5, which exhibits a significant influence on dwarfing of the scion. A smaller-effect QTL affecting dwarfing (Dw2) was identified on LG11, and four minor-effect QTLs were found on LG6, LG9, LG10 and LG12. Phenotypic analysis indicates that the combination of Dw1 and Dw2 has the strongest influence on rootstock-induced dwarfing, and that Dw1 has a stronger effect than Dw2. Genetic markers linked to Dw1 and Dw2 were screened over 41 rootstock accessions that confer a range of effects on scion growth. The majority of the dwarfing and semi-dwarfing rootstock accessions screened carried marker alleles linked to Dw1 and Dw2. This suggests that most apple dwarfing rootstocks have been derived from the same genetic source.

No MeSH data available.


Related in: MedlinePlus