Potato virus M in tomato crops in Southern Italy [Apulia - Lycopersicon esculentum].

A strain of potato M carlavirus (PVM-To) was isolated in Apulia (Southern Italy)from tomato plants, in which it was always found in mixed infections with cucumber mosaic cucumovirus (CMV) or potato Y potyvirus (PVY). PVM-To alone induced no symptoms in tomato but aggravated the symptoms induced by PVY. The sequence of the 3' end of PVM-To RNA showed the presence of two putative ORFs sharing 97 and 91% aminoacid sequence identity, respectively, with the 34K (coat) and 12K (putative nucleotide-binding) proteins of PVM. This appears to be the first record of natural infections of PVM in tomato