Genetic Diversity of Cercospora kikuchii Isolates From Soybean Cultured in Argentina as Revealed by Molecular Markers and Cercosporin Production

Abstract

Leaf blight and purple seed, caused by the fungal pathogen Cercospora kikuchii (Matsumoto & Tomoyasu) M. W. Gardner are very important diseases of soybean (Glycine max L. Merr.) in Argentina. The aims of this work were: (a) to confirm and to assess the genetic variability among C. kikuchii isolates collected from different soybean growing areas in Santa Fe province using inter simple sequence repeats (ISSR) markers and sequence information from the internal transcribed spacer (ITS) region of rDNA and (b) to analyze the cercosporin production of the regional C. kikuchi isolates in order to assess whether there was any relationship between the molecular profiles and the toxin production. Isolates from different regions in Santa Fe province were studied. The sequence of the ITS regions showed high similarity (99-100%) to the GenBank sequences of C. kikuchii BRCK179 (accession number AY633838). The ISSR markers clustered all the isolates into many groups and cercosporin content was highly variable among isolates. No relationship was observed between ITS region, ISSR groups and origin or cercosporin content. The high degree of genetic variability and cercosporin production among isolates compared in this study characterizes a diverse population of C. kikuchii in the region.

More Cercospora Species Infect Soybeans across the Americas than Meets the Eye

“…Several lines of evidence suggest etiological anomalies in CLB and PSS. In population genetic studies, an array of markers–AFLP, RAPD, and DNA sequences from a single or few loci–suggested remarkable differences in genetic structure among populations, distribution of pathogenicity ‘groups’ or ‘lineages’, and uneven prevalence throughout the Americas [ 15 , 18 , 19 ]; some of those lineages were absent from Japan [ 20 ]. Besides, there were conflicting reports on isolate-dependent conditions for sporulation in vitro [ 21 ], and phenotypic variation among axenic cultures has been observed [ 18 , 22 ].…”

Genetic diversity ofCercospora sojinarevealed by amplified fragment length polymorphism markers

“…& Cooke (Martins et al, 2008), and C. kikuchii (Matsumoto & Tomoy.) Gardner (Almeida et al, 2005;Cai & Schneider, 2005;Lura et al, 2011). Conversely, C. zeae-maydis Tehon & Daniels and C. zeina Crous & Braun (originally reported as C. zeae-maydis Group I and Group II, respectively) (Wang et al, 1998;Dunkle & Levy, 2000;Okori et al, 2003;Crous et al, 2006) and C. sorghi Ellis & Everh.…”

Genetic Diversity of Cercospora arachidicola Associated with Peanut Early Leaf Spot in Shandong Province of China

“…However, at the late stage of peanut growth and development, peanut plants are infected by leaf spots which evidently reduce the yields. Genetic diversity of plant pathogen populations present in a particular locality is especially valuable to enhance epidemiological studies and implement effective control strategies (Lurá et al 2011).…”