J14D1 



HR 



Fig. 1. Leaves from Turkish tobacco infected with different strains of tobacco mosaic 

 virus. Top: TMV — tobacco mosaic; YA — yellow aucuba; GA — green aucuba; M — masked; 

 J14D1 — Jensens derivative 1 from strain 14; HR — Holmes' ribgrass (Knight, 1947). 

 Bottom: TMV and two serial groups of strains isolated by Drs. F. O. Holmes and M. 

 Baylor, and F. L. Black (Black and Knight, 1953). 



