Species composition and genetic structure of Fusarium graminearum species complex populations affecting the main barley growing regions of South America

CASTAÑARES E., DINOLFO M.I., DEL PONTE E., PAN D. & STENGLEIN S.A.

PLANT PATHOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 p. 930 - 939

0032-0862

Members of the Fusarium graminearum species complex (FGSC), such as F. graminearum and F. asiaticum are the main cause of Fusarium Head Blight (FHB) ofwheat and barley worldwide. In this study, 117 FGSC isolates obtained fromcommercial barley grain produced in Argentina (n=43 isolates), Brazil (n=35),and Uruguay (n=39) were identified to species and trichothecene genotypes usingamplified fragment length polymorphism (AFLP) and sequence related amplifiedpolymorphism (SRAP) markers. In addition, sequencing of reductase (RED) and trichothecene3-0-acetyltransferase (Tri101) wasused for a subset of 24 isolates. The majority of the isolates (n=103) wereidentified as F. graminearum, whichwas the only species found in Argentina. In Uruguay, only one F. cortaderiae isolate was found among F. graminearum isolates. In Brazil, F. graminearum also dominated thecollection (22/35), followed by F.meridionale (8/35), F. asiaticum (2/35),F. cortaderiae (2/35), and F. austroamericanum (1/35). The specieswere structured by trichothecene genotype: all F. graminearum were of the 15-acetyldeoxynivalenol (ADON), F. meridionale, F. asiaticum and F. cortaderiaewere of the nivalenol (NIV), and F. austroamericanumwas of the 3-ADON genotype. Both AFLP and SRAP data showed high levels ofgenetic variability, which was higher within than among countries. The isolateswere not structured by country of origin. SRAP analysis grouped F. graminearum in a separate clusterfrom the other species within the complex. AFLP analysis, however, failed toresolve the species into distinct clades with partial clustering of F. meridionale, F. austroamericanum, F.asiaticum and F. graminearumisolates.