TITLE:
Diagnosis and Control of Harpophora maydis, the Cause of Late Wilt in Maize
AUTHORS:
Ofir Degani, Gilad Cernica
KEYWORDS:
Flutriafol; Fungus; Fungicide; Harpophora maydis; Late Wilt; Maize; Molecular Diagnosis
JOURNAL NAME:
Advances in Microbiology,
Vol.4 No.2,
January
21,
2014
ABSTRACT: Late wilt, a severe vascular
disease of maize caused by the fungus Harpophora maydis, is
characterized by relatively rapid wilting of maize plants, before tasseling and
until shortly before maturity. In Israel, the disease becomes a major problem
in recent years. The pathogen currently controlled using varieties of maize has reduced sensitivity. In earlier work,
we modified a molecular method for use as a diagnostic tool to evaluate the
disease progress in field infested plants. Several fungicides suppressed H.
maydis in vitro and in a detached root pathogenicity assay. Seedling
pathogenicity assay enables us to identified H. maydis DNA in the host root and stem tissues
18 days after sowing in both susceptible and tolerant maize plants. Although
the infested plants exhibited no wilt symptoms, their roots were significantly
shorter in length. This seedling assay was used to demonstrate the suppressive
effect of the fungicide Flutriafol on H. maydis virulence. The method of
assaying the pathogen in a series of trials starting in a plate assay, followed
by a detached root and resulting in a seedlings pathogenicity assay, using
molecular and morphological approaches could be generalized to other plant
pathogens.