A Study on Seed-Borne Fungi of Sunflower (Helianthus annuus L.)

Abstract

Sunflower is an important economic oil crop in Sudan. Recently, the area under the crop is increasing steadily. The production and yield of the crop is constrained by many problems the main of which are the fungal diseases. Hence this urgent research was conducted to study and identify the fungi associated with the seeds of sunflower Helianthus annuus L. on five varieties Panar 75-55, Panar 75-51, Hysun 33, Hysun 38, and Local collected from different localities in Sudan; Damazin , Rahad, Sinnar and Gadarif. Twenty samples of untreated and surface-sterilized seeds were examined for fungal infection, by using the standard blotter test and the agar plate method (Potato Dextrose Agar). The results revealed the presence of the following important fungi which were identified by microscope examination: Aspergillus niger, A. flaves, Penecillium sp., Phoma sp., Alternaria zinniae, Cladosporium oxysporum., Rhizopus sp., Macrophomina phasiolina, Drecheslera sp., and Curvularia sp. It is worth mentioning that, this is the first report of Cladosporium oxysporum and also for association of Curvularia sp. with the seeds of sunflower of these varieties under test in Sudan. Growth and survival percentages were recorded and analyzed in the study. The study pointed out to the importance of the quarantine measures to avoid the spread of seed-borne diseases, especially the destructive pathogen Plasmopara halstedii which was reported in seven countries neighboring the Sudan.