Limits...
Mapping QTL associated with Verticillium dahliae resistance in the cultivated strawberry (Fragaria × ananassa).

Antanaviciute L, Šurbanovski N, Harrison N, McLeary KJ, Simpson DW, Wilson F, Sargent DJ, Harrison RJ - Hortic Res (2015)

Bottom Line: Average wilt scores were significantly associated with multiple QTL, which were mostly significant across all years.A clear and statistically significant relationship was observed between resistant, tolerant and susceptible material and the total number of markers present in the different resistance classes.These markers are abundant in the cultivated strawberry germplasm indicating that, despite the large number of markers, clear genetic gain is possible through marker-assisted breeding.

View Article: PubMed Central - PubMed

Affiliation: East Malling Research, New Road, East Malling , Kent ME19 6BJ, UK.

ABSTRACT
A biparental cross of octoploid strawberry segregating for resistance to Verticillium dahliae, the causative agent of Verticillium wilt, was screened under field conditions for three seasons. Average wilt scores were significantly associated with multiple QTL, which were mostly significant across all years. Markers significantly associated with the traits were used to screen material with known wilt resistance and susceptibility phenotypes. A clear and statistically significant relationship was observed between resistant, tolerant and susceptible material and the total number of markers present in the different resistance classes. In field situations resistance QTL appear to behave in an additive manner. These markers are abundant in the cultivated strawberry germplasm indicating that, despite the large number of markers, clear genetic gain is possible through marker-assisted breeding.

No MeSH data available.


(a) Three-dimensional scatter-plot of mean phenotypic scores from three years of field phenotyping (time points selected for QTL analysis) for 173 individuals of the ‘Redgauntlet’ × ‘Hapil’ mapping population. The red colouring indicates increasing resistance. (b) As a, but highlighting the mean phenotypic scores for the parental lines ‘Redgauntlet’ and ‘Hapil’. Transgressive segregation can be clearly observed across all years.
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fig4: (a) Three-dimensional scatter-plot of mean phenotypic scores from three years of field phenotyping (time points selected for QTL analysis) for 173 individuals of the ‘Redgauntlet’ × ‘Hapil’ mapping population. The red colouring indicates increasing resistance. (b) As a, but highlighting the mean phenotypic scores for the parental lines ‘Redgauntlet’ and ‘Hapil’. Transgressive segregation can be clearly observed across all years.

Mentions: As observed for the long-term experiment, the disease pressure varied over the three years, with the lowest overall disease pressure observed in 2010. However, the correlation between years was moderately high and always statistically significant (Table 1 and Figure 4a). Again, the variance of the progeny across years varied most for phenotypes with intermediate resistance (see Supplemenary Figure S1 for within year variation). The segregation of resistance in the population is transgressive, with individuals displaying more extreme phenotypes than the parents of the mapping population (Figure 4b; see also Figure 3). Trait segregation was declared transgressive when at least one progeny had a value that was higher or lower than that of the highest or lowest parent, by at least twice the standard deviation of the parents.27 The number of transgressive segregant varied between year to year, however two highly resistant individuals and three highly susceptible individuals were significant across all years.


Mapping QTL associated with Verticillium dahliae resistance in the cultivated strawberry (Fragaria × ananassa).

Antanaviciute L, Šurbanovski N, Harrison N, McLeary KJ, Simpson DW, Wilson F, Sargent DJ, Harrison RJ - Hortic Res (2015)

(a) Three-dimensional scatter-plot of mean phenotypic scores from three years of field phenotyping (time points selected for QTL analysis) for 173 individuals of the ‘Redgauntlet’ × ‘Hapil’ mapping population. The red colouring indicates increasing resistance. (b) As a, but highlighting the mean phenotypic scores for the parental lines ‘Redgauntlet’ and ‘Hapil’. Transgressive segregation can be clearly observed across all years.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595976&req=5

fig4: (a) Three-dimensional scatter-plot of mean phenotypic scores from three years of field phenotyping (time points selected for QTL analysis) for 173 individuals of the ‘Redgauntlet’ × ‘Hapil’ mapping population. The red colouring indicates increasing resistance. (b) As a, but highlighting the mean phenotypic scores for the parental lines ‘Redgauntlet’ and ‘Hapil’. Transgressive segregation can be clearly observed across all years.
Mentions: As observed for the long-term experiment, the disease pressure varied over the three years, with the lowest overall disease pressure observed in 2010. However, the correlation between years was moderately high and always statistically significant (Table 1 and Figure 4a). Again, the variance of the progeny across years varied most for phenotypes with intermediate resistance (see Supplemenary Figure S1 for within year variation). The segregation of resistance in the population is transgressive, with individuals displaying more extreme phenotypes than the parents of the mapping population (Figure 4b; see also Figure 3). Trait segregation was declared transgressive when at least one progeny had a value that was higher or lower than that of the highest or lowest parent, by at least twice the standard deviation of the parents.27 The number of transgressive segregant varied between year to year, however two highly resistant individuals and three highly susceptible individuals were significant across all years.

Bottom Line: Average wilt scores were significantly associated with multiple QTL, which were mostly significant across all years.A clear and statistically significant relationship was observed between resistant, tolerant and susceptible material and the total number of markers present in the different resistance classes.These markers are abundant in the cultivated strawberry germplasm indicating that, despite the large number of markers, clear genetic gain is possible through marker-assisted breeding.

View Article: PubMed Central - PubMed

Affiliation: East Malling Research, New Road, East Malling , Kent ME19 6BJ, UK.

ABSTRACT
A biparental cross of octoploid strawberry segregating for resistance to Verticillium dahliae, the causative agent of Verticillium wilt, was screened under field conditions for three seasons. Average wilt scores were significantly associated with multiple QTL, which were mostly significant across all years. Markers significantly associated with the traits were used to screen material with known wilt resistance and susceptibility phenotypes. A clear and statistically significant relationship was observed between resistant, tolerant and susceptible material and the total number of markers present in the different resistance classes. In field situations resistance QTL appear to behave in an additive manner. These markers are abundant in the cultivated strawberry germplasm indicating that, despite the large number of markers, clear genetic gain is possible through marker-assisted breeding.

No MeSH data available.