Phytopathologia Mediterranea 2012 Volume 52 Issue 1 Pages 16-29
Researcher
Description
. Late wilt of maize, caused by the fungus Harpophora maydis, is one of the most important fungal diseases
in Egypt. The disease has also been reported from India, Hungary, Spain and Portugal. The pathogen survives for
long periods in soil. Late wilt is currently controlled using maize varieties with reduced sensitivity, but virulent
variants of the fungus may threaten these varieties. Common disease symptoms have been documented over
20 years in Upper Galilee (northern Israel), particularly the Hula Valley. Recently, prevalence of the disease has
increased. This is the first confirmed report of the direct and primary cause of the disease in Israel. Isolates of the
pathogen obtained from wilting maize plants were morphologically identical to those of strains found in Egypt
and India. We modified a molecular method as a diagnostic assay of disease progress in an infested field in northern Israel. The assay identified the pathogen 50 d after seeding, before the emergence of disease symptoms, both
in susceptible and partially resistant host plants. DNA assessment was consistent with the disease progress in a
susceptible maize variety, and the pathogen also spread in partially resistant plants that showed no symptoms.
Seeds of apparently healthy, partially resistant plants may therefore also spread the disease. A modified molecular
method presented here is a preliminary step in developing a seed health assay.
in Egypt. The disease has also been reported from India, Hungary, Spain and Portugal. The pathogen survives for
long periods in soil. Late wilt is currently controlled using maize varieties with reduced sensitivity, but virulent
variants of the fungus may threaten these varieties. Common disease symptoms have been documented over
20 years in Upper Galilee (northern Israel), particularly the Hula Valley. Recently, prevalence of the disease has
increased. This is the first confirmed report of the direct and primary cause of the disease in Israel. Isolates of the
pathogen obtained from wilting maize plants were morphologically identical to those of strains found in Egypt
and India. We modified a molecular method as a diagnostic assay of disease progress in an infested field in northern Israel. The assay identified the pathogen 50 d after seeding, before the emergence of disease symptoms, both
in susceptible and partially resistant host plants. DNA assessment was consistent with the disease progress in a
susceptible maize variety, and the pathogen also spread in partially resistant plants that showed no symptoms.
Seeds of apparently healthy, partially resistant plants may therefore also spread the disease. A modified molecular
method presented here is a preliminary step in developing a seed health assay.