COMPARISON OF RESISTANCE TO POTYVIRUSES WITHIN SOLANACEAE - INFECTIONOF POTATOES WITH TOBACCO ETCH POTYVIRUS AND PEPPERS WITH POTATO A-POTYVIRUSE AND Y-POTYVIRUSE

The reaction of several cultivated potato varieties (Solanum tuberosum L.) to three strains of tobacco etch potyvirus (TEV-F, TEV-Mex21 and TEV-ATCC) and the reaction of several pepper lines (Capsicum annuum L. and C. chinense L.) to two strains of potato Y potyvirus (PVYO and PV YN) and one strain of potato A potyvirus (PVA-M) was tested. The potat o varieties included in this study carried resistance genes against PV Y, PVA and potato V potyvirus, but all were susceptible to TEV and dev eloped mottle and mosaic symptoms. TEV was readily transmitted by mech anical inoculation from tobacco and potato to potato, whereas transmis sion from pepper to potato occurred infrequently. TEV was transmitted through potato tubers, and from pepper to potato plants by aphids. Lac k of detectable systemic infection following graft-inoculation indicat ed extreme resistance to PVYO and PVA in several pepper lines. No pepp er line was systemically infected with PVYN following mechanical inocu lation (graft-inoculation was not carried out with PVYN). The developm ent of necrotic lesions following mechanical and graft-inoculation ind icated hypersensitive response to PVYO in several pepper lines which r esembled the resistance responses to these potyvirus strains in potato . Results of this study together with previous work indicate that C. a nnuum cv. Avelar is resistant to four potyviruses [PVY, PVA, pepper mo ttle potyvirus (PepMoV) and some isolates of TEV]; C. annuum cv. Criol lo de Morelos and C. chinense PI 152225 and PI 159236 are resistant to three potyviruses (PVY, PepMoV and PVA; and PVY, PepMoV and TEV, resp ectively); C. annuum 9093-1 and 92016-1 are resistant to PVY and PepMo V; and C. annuum cv. Jupiter and C. annuum cv. RNaky are resistant to PVYN and PVA.