Isozyme and amplified fragment length polymorphisms fromCephalosporium maydis in Egypt

Abstract

Isoenzyme and amplified fragment length polymorphisms (AFLP) variation within a set of 48 isolates ofCephalosporium maydis was characterized. These isolates included ten cultures that have served as standards in the Egyptian maize resistance breeding program and 38 additional strains collected from 11 governates in Egypt during the 1997 growing season. Eight isozymes also were tested, but only five (acid phosphatase, fumerase, gtucose 4-phosphate isomerase, isocitrate dehydrogenase, and malate dehydrogenase) produced identifiable bands and all five of these enzymes were monomorphic. Sixty-eight AFLP primer-pair combinations were used and 865 bands were scored, of which 288 (33%) were polymorphic and could be used to discriminate four distinct subgroups, or lineages. Representatives from only two of the four lineages are included in the set of ten strains that has been used to challenge new lines in the Egyptian maize breeding program. From among these 68 primer-pair combinations, we identified a set of four AFLP primer-pairs that were strongly correlated (Pearson‘sr > 0.85) with the full data set that can be used as markers to determine the distribution of these lineages and to identify new lineages in field populations.