RED STELE RESISTANT STRAWBERRIES AND THEIR ROLE IN EPIDEMIOLOGY OF PHYTOPHTHORA FRAGARIAE

S. Khanizadeh, D. Buzard
Evaluation of strawberry genotypes for susceptibility to Phytophthora fragariae has been based almost exclusively on visual assessment, i.e. reddening of stele in the root due to its simplicity. Resistant cultivars are not immune from infection and relatively high numbers of oospores may be observed in the symptomless root tissues of inoculated resistant types within 6 weeks. Therefore, while reddening of red stele in field-grown plants may be used as a preliminary diagnostic feature, visual symptoms alone should not be used as a criterion to assess susceptibility. Genotypes in which the pathogen sporulates to a limited extent in the root may be classified as resistant in genetic studies but this does not imply that they are not infected. Attention should be paid to the term ‘resistant’ which is used widely in horticulture and pathology, i.e. a cultivar resistant to P. fragariae may not show any symptoms of red stele even though it is infected by the fungus. (Published: 1992, HortScience 27:870.)
Khanizadeh, S. and Buzard, D. (1993). RED STELE RESISTANT STRAWBERRIES AND THEIR ROLE IN EPIDEMIOLOGY OF PHYTOPHTHORA FRAGARIAE. Acta Hortic. 348, 517-517
DOI: 10.17660/ActaHortic.1993.348.109
https://doi.org/10.17660/ActaHortic.1993.348.109

Acta Horticulturae