Variabilité naturelle des souches du virus Y de la pomme de terre dans les cultures de piment du sud-est de la France. Caractérisation et classification en pathotypes

Abstract

RÉSUMÉ

Genetic analysis of broad spectrum resistance to potyviruses using doubled haploid lines of pepper (Capsicum annuum L.)

“…Based on the phenotypic response of a differential pepper host range, strains of PVY have been grouped according to virulence and three pathotypes have been defined (Gebre Selassie et al ., 1985) : P(0), the common pathotype is virulent on Yolo Wonder ; the P(1) pathotype is virulent on Yolo Y ; the P(1,2) pathotype is virulent on Yolo Y and Florida VR2 . These different strains are very closely related serologically (Gebre Selassie et al ., 1985) .…”

“…These different strains are very closely related serologically (Gebre Selassie et al ., 1985) . PVY isolates collected from pepper plants and weeds in France, Italy, and Spain mostly belonged to the P(0) pathotype and incited severe necrotic symptoms on the cultivar, Bastidon (Marte et al ., 1991 ;Arteaga & Ortega, 1986) .…”

Potato virus Y group C isolates are a homogeneous pathotype but two different genetic strains.

“…PVY N and PVY O isolates from potato do not infect pepper mechanically (Gebre Selassie et al, 1985) but this assay has not previously been reported for PVY C isolates. Results obtained in the host range assay are presented in Table 1 : PVY C isolates 26, 28 and 29 infected pepper as efficiently as did PVY-P21.…”

“…Thus, the ability or inability to infect pepper turned out to be a PVY C strain-specific property. Interestingly, the PVY C isolates of the PVY NP cluster (PVY C" ) were able to infect pepper while other potato isolates are not (Gebre Selassie et al, 1985). This could imply some type of coevolution within PVY and its plant hosts, as suggested for the Potyviridae in general (Ward et al, 1995).…”

“…There are other resistance genes against PVY that define pathotypes. For example, pepper PVYs are classified in pathotypes (Gebre Selassie et al, 1985). In this case, genetic distances estimated from their restrictotypes show that isolates from different pathotypes fall into the same genetic strain (F. Ponz, unpublished results).…”