TY - EJOU AU - M, Kiehr AU - Delhey, R AU - Lusto, J TI - Wilt and vascular root rot (Pythium tracheiphilum) of lettuce in Bahía Blanca, Argentina T2 - Phyton-International Journal of Experimental Botany PY - 2015 VL - 84 IS - 2 SN - 1851-5657 AB - A new disease of lettuce has been observed in the surroundings of Bahía Blanca, Argentina. The symptoms include dwarfing, general chlorosis, wilting, root rot, and leaf blight, sometimes followed by plant death. Pythium tracheiphilum Matta was found to be consistently associated with those symptoms. The morphological and morphometric characteristics of this oomycete are described. Isolates obtained from field-infected lettuce plants were inoculated to lettuce and caused similar symptoms as those found in natural infections. Seedling emergence was also severely affected following experimental inoculation. Koch’s Postulates were fulfilled by recovering the fungus from inoculated plants. The new disease shows a high destructive potential but currently has a limited prevalence and incidence. KW - Pythium tracheiphilum KW - Lettuce KW - Lactuca sativa KW - Argentina DO - 10.32604/phyton.2015.84.423