THE POSSIBLE EPIDEMIOLOGICAL SIGNIFICANCE OF POLLEN AND SEED TRANSMISSION IN THE CHERRY LEAF ROLL VIRUS/BETULA SPP. COMPLEX
Three isolates of CLRV from B. verrucosa Ehrh. growing in widely separated parts of the United Kingdom possessed few, if any, antigenic determinants not held in common. Significantly, the virus was transmitted in pollen to four of 114 birch seedlings and was present in two of 73 progeny produced by a naturally infected mother tree which received virus-free pollen. Up to 22% of seed collected from open pollinated and naturally infected birch trees carried virus.