Electron Microscopic Analysis of the Penetration Process ofFusarium nygamai,a Hyperparasite ofStriga hermonthica

In a previous study we showed that the facultative fungal parasiteFusarium nygamaiwas able to reduce the germination of seeds of the root-parasitic weedStriga hermonthicaand kill more than 70% of the germinatedStrigaby attacking the parasiteʹs germ tube. As a result,Strigaemergence was reduced by about 90%. We are now providing electron microscopic evidence of the infection process. The free, mature conidia of the fungus was able to infectS. hermonthica.The mycelium penetrated the seed coat and destroyed the endosperm. The fungus was also detected in the weedʹs germ tube. As a soilborne pathogen,F. nygamaicould be very effective in controlling the parasitic weed sinceStrigaseeds are attacked underground. A further advantage is that the application of the fungus as a bioherbicide could be done to any crop under crop rotation.