ISOLATION OF CHERRY LEAF ROLL AND BROME MOSAIC-VIRUSES FROM EUROPEAN BEECH AND TRANSMISSION TO BEECH SEEDLINGS

Cherry leaf roll virus (CLRV) and brome mosaic virus (BMV) were transm itted from foliage of European beech to herbaceous plants and then bac k-transmitted to beech seedlings. Beech sampling sites were located in a nature reserve in Northrhine-Westfalia for CLRV and near the villag e of Hilberath, between the borders of the states of Rhineland-Pfalz a nd Northrhine-Westfalia, for BMV. Viruses were identified by bioassay, enzyme-linked immunosorbent assay, and immune electron microscopy. Tr ansmission succeeded when seedlings in the four-leaf stage were inocul ated by stem slashing. Infection rates averaged 24% for BMV and 17% fo r CLRV. Injection of concentrated BMV suspension into stratified beech nuts resulted in 15% infected seedlings 1 yr after infection. Symptoms developed in some inoculated beech seedlings about 4 wk after inocula tion. Electron microscopy of infected tissue showed ultrastructural al terations.