S. Sanchez-campos et al., Displacement of tomato yellow leaf curl virus (TYLCV)-Sr by TYLCV-Is in tomato epidemics in spain, PHYTOPATHOL, 89(11), 1999, pp. 1038-1043
A progressive displacement of tomato yellow leaf curl virus (TYLCV)-Sr by T
YLCV-Is was observed in tomato epidemics in southern Spain based on inciden
ce data of both virus species obtained during surveys conducted between 199
6 and 1998. Ecological factors that might be involved in such a displacemen
t, such as competition of TYLCV-Sr and TYLCV-Is in tomato, transmission by
local biotypes (B and Q) of Bemisia tabaci, and presence in weeds and alter
nate crops, have been analyzed. No selective advantage is observed for TYLC
V-Sr or TYLCV-Is in tomato plants either infected via Agrobacterium tumefac
iens or via B. tabaci. However, TYLCV-Is is more efficiently vectored by lo
cal biotypes of B, tabaci; and common bean, a bridge crop between tomato cr
ops, is a host for TYLCV-Is but not TYLCV-Sr. Therefore, common bean acts a
s a reservoir for TYLCV-Is. These two factors are probably responsible for
the displacement of TYLCV-Sr by TYLCV-Is as the causative agent of epidemic
s in tomato in southern Spain.