Breakdown of resistance in sweet pepper against Pepper yellow mosaic virus in Brazil

plants of capsicum annuum cv. magali r, resistant to pepper yellow mosaic virus (pepymv), which showed severe yellow mosaic, leaf malformation and stunting were observed during the 2003/04 growing season in lins, s？o paulo state, brazil. potyvirus-like particles observed in leaf sap from infected plants under the electron microscope reacted with an antiserum against pepymv in pta-elisa. in addition to c. annuum cv. magali r, this potyvirus also infected systemically the resistant c. annuum cv. rubia r. the nucleotide sequence of part of the cp gene of this potyvirus shared 96-98% identity with that of other pepymv isolates. the partial nucleotide sequence of the 3' ntr showed 94-96% identity with that of pepymv. these data indicate that this potyvirus is a resistance-breaking isolate of pepymv.