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Table 2 Severity of apple scab at two timepoints in 2019 on a scab differential host set in the research orchard at Geneva, New York

From: Field apple scab susceptibility of a diverse Malus germplasm collection identifies potential sources of resistance for apple breeding

Differential hosta

Host name

PI number

R gene

Severity (1–9, July)

Severity (1–9, August)

h0

Gala

392303

–

5

6

h1

Golden Delicious

590184

Rvi1

7

7

h2

TSR34t15 (syn. PRI 384-1)

589780

Rvi2

4

4

h3

Malus × 'Geneva'

589079

Rvi3.1, Rvi3.2, Rvi3.3

3

4

h4

TSR33t239

N/Ab

Rvi4

5

5

h5

OR45T132 (syn. PRI 333-9)

589829

Rvi5

4

4

h6

Priscilla

589965

Rvi6

1

1

h7

Malus floribunda sel. 821

589827

Rvi6, Rvi7

4c

4c

h9

Malus × 'Dolgo'

588870

Rvi9, unknown

4

4

h11

Malus baccata 'jackii'

594110

Rvi11, unknown

1

1

h12

Malus baccata 'Hansens baccata #2'

589838

Rvi12

1

1

  1. The scab severity within the tree canopy was visually assessed in four replicate trees of each accession using a 9 point scale described by Lateur and Populer (1994) and adapted by Patocchi et al. (2009), taking the most severely infected tree of each accession as the representative sample. These differential host accessions have known apple scab resistance genes (Bus et al. 2011) corresponding to specific races of V. inaequalis. Plant Introduction (PI) number of each accession is provided according to the USDA Germplasm Resources Information Network (GRIN)
  2. aDifferential apple hosts carrying specific Rvi scab resistance genes as described in Patocchi et al. (2020)
  3. bNot available in the USDA-PGRU GRIN database
  4. cScab severity reported by Papp et al. (2019)