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Variation in Fusarium graminearum isolates from Nepal associated with their host of origin

Carter, J.P., Rezanoor, H.N., Desjardins, A.E., Nicholson, P.
Plant pathology 2000 v.49 no.4 pp. 452
Gibberella zeae, Zea mays, Oryza sativa, Triticum aestivum, genetic variation, geographical variation, fungal anatomy, genetic markers, restriction fragment length polymorphism, polymerase chain reaction, genetic polymorphism, ribosomal DNA, host plants, plant diseases and disorders, random amplified polymorphic DNA technique, intergenic DNA, Nepal
A collection of group II Fusarium graminearum [Gibberella zeae] isolates obtained from maize, wheat and rice from different locations in Nepal in 1993 and 1997 were identified using a combination of morphological and molecular criteria. The variation within this collection was analyzed using RAPD markers, intergenic spacer (IGS) RFLP and PCR polymorphisms. The isolates were divided into 2 groups, A and B, by RAPD analysis. Isolates in group A yielded 4 different PCR polymorphic markers, but all the isolates in group B yielded a single polymorphic marker. The IGS RFLP analysis was consistent with division of the isolates into two groups. Isolates from wheat and rice were more frequently placed in group A, while isolates from maize were more evenly distributed between the groups. Results indicate that host preference might be a factor in the division of isolates, although the year of isolation may also have had an influence. No geographical factors or agricultural practices could be identified to account for the observed variation.