Amplified Fragment Length Polymorphism Diversity in Cephalosporium maydis from Egypt

Abstract

Cephalosporium maydis, the causal agent of late wilt of maize, was first described in Egypt in the 1960s, where it can cause yield losses of up to 40% in susceptible plantings. We characterized 866 isolates of C. maydis collected from 14 governates in Egypt, 7 in the Nile River Delta and 7 in southern (Middle and Upper) Egypt, with amplified fragment length polymorphism (AFLP) markers. The four AFLP primer-pair combinations generated 68 bands, 25 of which were polymorphic, resulting in 52 clonal haplotypes that clustered the 866 isolates into four phylogenetic lineages. Three lineages were found in both the Nile River Delta and southern Egypt. Lineage IV, the most diverse group (20 haplotypes), was recovered only from governates in the Nile River Delta. In some locations, one lineage dominated (up to 98% of the isolates recovered) and, from some fields, only a single haplotype was recovered. Under field conditions in Egypt, there is no evidence that C. maydis reproduces sexually. The nonuniform geographic distribution of the pathogen lineages within the country could be due to differences in climate or in the farming system, because host material differs in susceptibility and C. maydis lineages differ in pathogenicity.

Diagnosis and Control of <i>Harpophora maydis</i>, the Cause of Late Wilt in Maize

“…Zeller et al [19] identified four AFLP primer pairs that could be used as markers to determine the distribution of H. maydis lineages and to identify new lineages in field populations. Here, we used this H. maydis-unique nucleotide sequence, which proved earlier to be species-specific [17], as a diagnostic tool. As previously described [9], the pathogen spreads in moderately resistant Royalty cv.…”

“…This new sequence is a major part of a larger AFLP fragment that was proven earlier to be species-specific [9,17,19]. The A200a primer set-[A200a-for (forward primer): 5'-CCTAGTA-GTCCCGACTGTTAGG-3', A200a-rev (reverse primer): 5'-TTGGTTCACCGTCTTTTGTAGG-3'] amplifies a specific [14] H. maydis segment.…”

“…The Egyptian, Indian and Hungarian isolates of H. maydis differ in morphology, pathogenicity and route of infection [15]. The four clonal lineages of Egyptian isolates of H. maydis show diversity in amplification fragment length polymorphism (AFLP), and differ in colonization ability and virulence on maize [16][17][18][19]. Three of the lineages are widely distributed throughout the country.…”

Plant growth hormones suppress the development of Harpophora maydis, the cause of late wilt in maize

“…The Egyptian, Indian and Hungarian isolates of H. maydis differ in morphology, pathogenicity and route of infection (Warren 1983). In Egypt, there are four clonal lineages of H. maydis that differ in colonization ability and virulence on maize (El-Assiuty et al 1999;Saleh et al 2003;Zeller et al 2000Zeller et al , 2002.…”

Cercospora zeae-maydis: esporulação, diversidade morfo-genética e reação de linhagens de milho.

“…Marcadores fundamentados em diferenças na molécula de DNA são mais eficientes na detecção de diversidade genética. Mais recentemente, a técnica baseada na amplificação de polimorfismo de comprimento via reação em cadeia da polimerase (AFLP -Amplified fragment length polymorphisms) vem sendo utilizada para estudos desta natureza em diversos organismos (Müeller & Wolfenbarger, 1999), entre eles os fungos fitopatogênicos (Majer et al, 1998;Wang et al, 1998;Dunkle & Levy, 2000;Borie et al, 2002;Tooley et al, 2002;Saleh et al, 2003). Esta técnica combina a especificidade, a resolução e o poder de amostragem genômica das enzimas de restrição com a rapidez e praticidade da detecção de polimorfismos da PCR (Ferreira & Grattapaglia, 1995).…”