Phytophthora and Pythium species associated with root rot of young apple trees and their control

Incidencia y agentes causales de enfermedades de raíz y sus antagonistas en manzanos de Chihuahua, México

“…Aunque los portainjertos G.30 y MM.111 fueron altamente susceptibles (más de 50-75%), son ampliamente These rootstocks showed symptoms of infection with five Oomycete isolates, with P. cactorum C1 and Pythium ultimum isolates being the most pathogenic. These rootstocks along with MM.106 have been reported as the most susceptible to these pathogens (Roiger and Jeffers, 1991;Uthkede and Smith, 1991;Latorre et al, 2001). Similar results were found by Latorre et al (2001) after inoculation of Phytophthora isolates, with P. cactorum resulting the most virulent and pathogenic to M.9, M.25, MM.106 and MM.111 apple rootstocks.…”

“…Estos portainjertos mostraron síntomas de infección a cinco aislados de Oomicetos, siendo P. cactoum C1 y Pythium ultimum los aislados más patogénicos. Estos portainjertos junto con MM.106 han sido reportados como los más susceptibles a estos patógenos (Roiger y Jeffers, 1991; Uthkede y Smith, 1991;Latorre et al, 2001). Resultados similares fueron encontrados por Latorre et al (2001) después de la inoculación de aislados de Phytophthora, siendo P. cactorum el más virulento y patogénico a los portainjertos M.9, M.25, MM.106 and MM.111.…”

“…In the present study, P. cactorum, P. ultimum, F. sacchari and F. oxysporum were the most pathogenic species. These species have previously been reported in other studies as causal agents of root rot diseases in apple trees of major importance worldwide (Uthkede and Smith, 1991;Latorre et al, 2001).…”

“…vs Oomycetes) using a dual culture technique in Petri dishes (90 mm) containing Potato-DextroseAgar (PDA). A paper filter disc (6 mm) containing the mycelium and conidia unquantified of the pathogen was placed on one side of the dish and another filter paper disc containing the mycelium and conidia unquantified of the antagonist was Smith, 1991;Latorre et al, 2001). Durante este tiempo, se monitorearon semanalmente los síntomas característicos resultado de las infecciones de hongos y Oomicetos.…”

“…The inoculum was 3 d old and grown in vegetable broth V8 [V8 juice (Campbell´s ™) and calcium carbonate (CaCO 3; Sigma Aldrich)] at 28 °C under orbital shaking at 140 rpm (Orbit 1900, Labnet International Inc.). The inoculated rootstocks were maintained for another two months under greenhouse conditions (Uthkede and Smith, 1991;Latorre et al, 2001). During this time, the characteristic symptoms resulting from the fungal and Oomycete infections were monitored weekly.…”