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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 long-term resistance experiment highlighting year-by-year disease pressure variation for four cultivars, one resistant (‘Redgauntlet’), two of differing degrees of intermediate resistance (‘Cambridge Favourite’, ‘Elsanta’) and one susceptible, (‘Hapil’).
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fig1: A long-term resistance experiment highlighting year-by-year disease pressure variation for four cultivars, one resistant (‘Redgauntlet’), two of differing degrees of intermediate resistance (‘Cambridge Favourite’, ‘Elsanta’) and one susceptible, (‘Hapil’).

Mentions: Disease manifestation in the field varies depending upon the season and the climatic variables such as night temperature26 as well as genotype. Cultivars with varying degrees of resistance (one highly resistant, one intermediate, two susceptible) were monitored for seven years in an artificially inoculated plot in order to determine if their disease resistance was consistent over multiple years. Each year ten replicates of each plant were planted in a randomized block design. The results show that there are clear seasonal differences in levels of disease development (Figure 1). For example, in 2006 the disease pressure was sufficiently low that the susceptible cultivar ‘Elsanta’ displayed overall wilt scores that were at similar levels to ‘Redgauntlet’ in the following year. Despite the large seasonal variation in 5/7 years ‘Hapil’ was the most susceptible and ‘Redgauntlet’ was the most resistant cultivar. Variance estimates within progeny replicates reveal that variance is not equally distributed among progeny members, with the greatest variance observed in progeny replicates with intermediate wilt scores, indicating either a difficulty in classifying genotypes of intermediate resistance (for example, due to the fact that other developmental traits may be influencing the timing of disease development which are not adequately captured in the phenotyping approach) or a strong genotype by environment interaction when resistance is partial (for example, due to patchy distribution of pathogens with differing virulence across the field) (Supplementary Figure S1).


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 long-term resistance experiment highlighting year-by-year disease pressure variation for four cultivars, one resistant (‘Redgauntlet’), two of differing degrees of intermediate resistance (‘Cambridge Favourite’, ‘Elsanta’) and one susceptible, (‘Hapil’).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig1: A long-term resistance experiment highlighting year-by-year disease pressure variation for four cultivars, one resistant (‘Redgauntlet’), two of differing degrees of intermediate resistance (‘Cambridge Favourite’, ‘Elsanta’) and one susceptible, (‘Hapil’).
Mentions: Disease manifestation in the field varies depending upon the season and the climatic variables such as night temperature26 as well as genotype. Cultivars with varying degrees of resistance (one highly resistant, one intermediate, two susceptible) were monitored for seven years in an artificially inoculated plot in order to determine if their disease resistance was consistent over multiple years. Each year ten replicates of each plant were planted in a randomized block design. The results show that there are clear seasonal differences in levels of disease development (Figure 1). For example, in 2006 the disease pressure was sufficiently low that the susceptible cultivar ‘Elsanta’ displayed overall wilt scores that were at similar levels to ‘Redgauntlet’ in the following year. Despite the large seasonal variation in 5/7 years ‘Hapil’ was the most susceptible and ‘Redgauntlet’ was the most resistant cultivar. Variance estimates within progeny replicates reveal that variance is not equally distributed among progeny members, with the greatest variance observed in progeny replicates with intermediate wilt scores, indicating either a difficulty in classifying genotypes of intermediate resistance (for example, due to the fact that other developmental traits may be influencing the timing of disease development which are not adequately captured in the phenotyping approach) or a strong genotype by environment interaction when resistance is partial (for example, due to patchy distribution of pathogens with differing virulence across the field) (Supplementary Figure S1).

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.