Natural resistance to Potato virus Y in Solanum tuberosum Group Phureja

Abstract

Key Message Novel major gene resistance against Potato virus Y in diploid populations of Solanum tuberosum Groups Phureja and Tuberosum was biologically and genetically characterised. Named Ry(o)phu, it mapped to chromosome 9. Abstract A new source of genetic resistance derived from Solanum tuberosum Group Phureja against Potato virus Y (PVY) was identified and genetically characterised in three diploid biparental potato populations. Segregation data for two populations (05H1 and 08H1) suggested the presence of a single dominant gene for resistance to PVY which, following DaRT analysis of the 08H1 cross, was mapped to chromosome 9. More detailed genetic analysis of resistance utilised a well-characterised SNP-linkage map for the 06H1 population, together with newly generated marker data. In these plants, which have both S. tuberosum Group Phureja and S. tuberosum Group Tuberosum in their pedigree, the resistance was shown to map to chromosome 9 at a locus not previously associated with PVY resistance, although there is evidence for at least one other genetic factor controlling PVY infection. The resistance factor location on chromosome 9 (named as Ry(o)phu) suggests a potential role of NB-LRR genes in this resistance. Phenotypic analysis using a GUS-tagged virus revealed that a small amount of PVY replication occurred in occasional groups of epidermal cells in inoculated leaves of resistant plants, without inducing any visible hypersensitive response. However, the virus did not enter the vascular system and systemic spread was completely prevented.

Plant Molecular Responses to Potato Virus Y: A Continuum of Outcomes from Sensitivity and Tolerance to Resistance

“…In genotypes carrying Ry(o) phu and Ry sto genes amplification of PVY N605 (infectious clones carrying GUS) could be detected in limited areas, while in cv. Tacna (carrying Ry adg -gene) no amplification of the virus was detected [80].…”

“…Recently, a dominant resistant gene Ry(o) phu was identified in S. tuberosum ssp. Phureja, conferring resistance to PVY o , PVY NTN , and PVY N-Wi strains [80]. The introduction of R genes into cultivated potato has shown to confer durable resistance against several PVY strains [40,81]; however, the number of potato cultivars carrying Ry-genes is relatively low (see review [40]).…”

“…However, in some cases of resistance (e.g., cv. Tacna carrying Ry adg [80]) viral multiplication is not detected, indicating that different mechanisms blocking viral infection might be in place in different pathosystems. It is clear that the mechanistic basis of resistance signaling differs depending on the R-protein involved (e.g., SA-dependent or SA independent).…”

“…Another question remaining is whether, in plant, PVY is perceived by multiple receptors. This was indicated in resistant interaction governed by Ry(o) phu [80], where extensive analysis of several biparental cross-populations was performed. Perception of PVY was also confirmed to occur in susceptible interactions [14,109].…”

Potato virus Y and Potato leafroll virus management under climate change in sub-Saharan Africa

“…28,57 Furthermore, mature plant resistance has often been overcome by recombinant strains. 58 Breeders have introduced genes for hypersensitive resistance and extreme resistance to PVY. 20,57 Hypersensitive resistance is mostly PVYstrain specific and the death of virus-infected cells leads to localised necrotic lesions.…”