Survey of seed borne fungi of pearl millet (pennisetum Glaucum L. Syn.) in the sudan

Abstract

Pearl millet seeds samples collected from Kordofan, Gezira ,Gedarif and Damazin States were investigated for seed- borne fungi. The methods used were: the dry inspection method, the Blotter method, the Agar Plate Method and the washing test method. The dry inspection method revealed an average of 6.10 % discolored seeds,% 6.25 malformed seeds and 3.8% damaged seeds for all samples. The samples were tested as normal and discolored seeds. Sixteen fungal species were isolated from pearl millet i.e. four Drechslera species: Drechslera sp; D. halodes;D. rostarata and D. holmii. Three Aspergillus species: A. flavus; A. nidulans and A. niger. Two Fusarium spe ies: F. oxysporum and F. moniliforme. In addition to Alternaria alternata, Auerobasidium pullular, Rhizopus sp, Curvularia lunata,Penicillium sp, Phoma sp , Cladosporium oxysporum and Macrophomina sp. This is the first report of the following fungi to be isolated from millet D. halodes, D. holmii, Fusarium oxysporum, Aureobasidium pullulans and Cladosporium oxysporum. The most important pathogens of millet were also not reported in this study Cercospora fusimaculans, Pyricularia grisea, Tolyposporium penicillariae Sclerospora graminicola, Puccinia penneiseti, Tolyposporium ehrenbergii and Gleocercospora sorghi. v All the sixteen fungi were reported using the Blotter method, while only nine were reported using the agar plate method. The blotter method proved better than the agar plate method for testing for seed-borne fungi in pearl millet. The incidence of pathogenic fungi increased over saprophytic fungi when chlorine was used to surface disinfect the seeds. A pest Risk Analysis was carried out for the fungal pathogens not known to be reported in the Sudan to evaluate the risk of their introduction with seeds of pearl millet. The pathogens are Gloeocercospora sorghi, Pyricularia grisea, Myrothecium roridum, Phyllachora penniseti, Plasmopara penniseti, Dactuliophora elongate and Sphacelia sorghi. All of them are not known to be seed transmitted expect Sphacelia sorghi. There is a very low risk to be introduced with imported seeds for planting. Sphacelia sorghi has a medium risk to be introduced with seeds. The risk can be mitigated by importing from disease free areas or by chemical treatment.