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Somaclonal selection in potato for resistance to common scab provides concurrent resistance to powdery scab
journal contribution
posted on 2023-05-17, 13:25 authored by Robert TeggRobert Tegg, Thangavel, T, Aminian, H, Calum WilsonCalum WilsonVariant somaclones of potato cultivar Russet Burbank, selected for resistance to common scab using in vitro cell selection techniques, were tested for resistance to powdery scab, another important disease of potato caused by Spongospora subterranea. This pathogen also invades roots, producing root galls. Most variants consistently showed increased resistance to powdery scab, both in field and glasshouse challenge, when compared to the parental cultivar, several significantly so. On average, the best variant reduced powdery scab incidence by 51% and severity (tuber surface coverage) by 64%. In contrast, no improvement in the extent of root infection and root galling was seen. These results suggest host interactions during root and tuber infection are distinct. Correlation analyses of disease indices amongst the selected variants showed no association between Sp. subterranea root infection and gall scores, nor between root infection and tuber disease severity. However, a weak positive association was found between root gall score and tuber disease, and a strong correlation between tuber disease incidence and severity scores. Interestingly, positive correlations were also found between the extent of powdery and common scab resistance expressed and both incidence and severity of these diseases within the variants, suggesting a common defence mechanism. The role of thaxtomin A in selecting for concurrent resistance to both diseases is discussed.
History
Publication title
Plant PathologyVolume
62Issue
4Pagination
922-931ISSN
0032-0862Department/School
Tasmanian Institute of Agriculture (TIA)Publisher
Blackwell Publishing LtdPlace of publication
9600 Garsington Rd, Oxford, England, Oxon, Ox4 2DgRights statement
Copyright 2012 The Authors Plant Pathology & BSPPRepository Status
- Restricted