Disease incidence of charcoal rot ( Macrophomina phaseolina ) on soybean in north-western Argentina and genetic characteristics of the pathogen

REZNIKOV, SEBASTIAN; VELLICCE, GABRIEL RICARDO; MENGISTU, ALEMU; ARIAS, RENEE SILVIA; GONZALEZ, VICTORIA; LISI, VICENTE DE; MARÍA GABRIELA, GARCÍA; CARLA MARÍA LOURDES, ROCHA; PARDO, ESTEBAN MARIANO; CASTAGNARO, ATILIO PEDRO; PLOPER, LEONARDO DANIEL

CANADIAN JOURNAL OF PLANT PATHOLOGY-REVUE CANADIENNE DE PHYTOPATHOLOGIE

CANADIAN PHYTOPATHOLOGICAL SOC

Año: 2018 p. 1 - 11

0706-0661

Charcoal rot of soybean (Glycine max (L.) Merr.), caused by Macrophomina phaseolina (Tassi) Goid., is an economically importantdisease worldwide. In recent years, charcoal rot has become a concern for farmers in north-western Argentina. The present work aimed to (1)evaluate disease incidence of charcoal rot; (2) assess morphological and genetic characteristics of M. phaseolina isolates from soybean andother hosts collected in north-western Argentina; and (3) compare genetic diversity between soybean isolates of M. phaseolina from Argentinaand the USA. Incidence of charcoal rot evaluated in 11 locations during five growing seasons (2008?2012) was 1%, 1%, 1%, 5?10% and 90%,respectively, indicating a gradual increase over the cropping seasons. Cluster analysis by AFLP of Argentinean isolates exhibited one maingroup, with isolate Mp56 separated at a genetic distance of 0.70. Four main groups were identified using SSR markers at the same geneticdistance, with Mp56 and Mp53 separated from them. There was no clear association between AFLP, SSR profiles, morphological characteristicsor host of origin within isolates from Argentina. However, using principal coordinate analysis of SSRs, 22 isolates of M. phaseolina fromsoybean from north-western Argentina were clearly distinguished from 11 isolates previously collected from two states in the USA. Our resultsconfirmed the increasing importance of charcoal rot in north-western Argentina and identified characteristics of isolates that may be useful forbreeding for disease resistance and developing integrated management programmes for charcoal rot in Argentina in the future.