TY - JOUR
T1 - Sudden death of Theobroma cacao L. caused by Verticillium dahliae Kleb. in Peru and its in vitro biocontrol
AU - Leon-Ttacca, Betsabe
AU - Arévalo-Gardini, Enrique
AU - -Bouchon, Anne Sophie
N1 - The Authors wish to thank the The Agricultural Research Service of the United States Department of Agriculture (usda-ars), for their technical support. Moreover, also to the United States Embassy in Lima, Peru, for their support while carrying out this work. Further, to Instituto de Cultivos Tropicales (ict) for allowing us to work
in their facilities and laboratories, and to all the cocoa producing organizations of Peru for enabling carrying out the sampling in their areas.
PY - 2019/1/14
Y1 - 2019/1/14
N2 - In the Atusparia sector, Tocache, of the San Martín region in Peru, two-year-old plants of Theobroma cacao L. (Malvaceae) of the CCN-51 clone showed for the first time in January 2010, symptoms of leaf yellowing, wilt and dieback, with an internal obstruction of the vascular system of the plant. To isolate the fungus, diseased tissues were cultured in Petri dishes containing potato dextrose agar oxytetracycline, and the identification was based on morphological and microscopic analyses and by the Sanger sequencing. Pathogenicity tests were carried out on three-months-old T. cacao ICS-1 clone plants and were inoculated with a conidia suspension of 1x107 cfu/mL employing two inoculation methods (Drench to the soil and stem puncture). Likewise, the antagonistic capacity (mycoparasitism and antibiosis) was established in vitro with endophytic Trichoderma isolates on the pathogen. With both inoculation methods symptoms of wilt of different degrees of severity were observed and the causal agent of sudden death in T. cacao was confirmed to be the fungus Verticillium dahliae Kleb. blast sequence analysis revealed that the isolate showed 100 % homology with V. dahliae sequences in GenBank. Trichoderma TE-91 was identified as the most aggressive mycoparasite because its metabolites inhibited completely the mycelial growth of the pathogen
AB - In the Atusparia sector, Tocache, of the San Martín region in Peru, two-year-old plants of Theobroma cacao L. (Malvaceae) of the CCN-51 clone showed for the first time in January 2010, symptoms of leaf yellowing, wilt and dieback, with an internal obstruction of the vascular system of the plant. To isolate the fungus, diseased tissues were cultured in Petri dishes containing potato dextrose agar oxytetracycline, and the identification was based on morphological and microscopic analyses and by the Sanger sequencing. Pathogenicity tests were carried out on three-months-old T. cacao ICS-1 clone plants and were inoculated with a conidia suspension of 1x107 cfu/mL employing two inoculation methods (Drench to the soil and stem puncture). Likewise, the antagonistic capacity (mycoparasitism and antibiosis) was established in vitro with endophytic Trichoderma isolates on the pathogen. With both inoculation methods symptoms of wilt of different degrees of severity were observed and the causal agent of sudden death in T. cacao was confirmed to be the fungus Verticillium dahliae Kleb. blast sequence analysis revealed that the isolate showed 100 % homology with V. dahliae sequences in GenBank. Trichoderma TE-91 was identified as the most aggressive mycoparasite because its metabolites inhibited completely the mycelial growth of the pathogen
KW - biological control
KW - endophyte, wilt
KW - Trichoderma
U2 - 10.21930/rcta.vol20_num1_art:1251
DO - 10.21930/rcta.vol20_num1_art:1251
M3 - Article
VL - 20
SP - 133
EP - 148
JO - Ciencia y Tecnología Agropecuaria
JF - Ciencia y Tecnología Agropecuaria
IS - 1
M1 - 1251
ER -