Effect of Aspergillus Niger Fungal Filtrate on Germination Rate and Seedling Growth of Corn Grains and its Biological Control by Garlic Extracts

Abstract

In the study, corn grains (Zea mays L.) were used to isolate associated fungi, which were randomly collected from some local markets in Misurata city. Potato Dextrose Agar (PDA) was used as a nutrient medium. The results showed that five fungal genera were obtained, namely Aspergillus niger, Alternaria alternata, Aspergillus flavus, Fusarium oxysporium, and Rhizopus sp. The results also showed the dominance of A. niger, with an appearance rate of 33.3% by direct isolation method compared to other fungal species. As for the effect of A. niger filtrate on the germination rate of treated corn grains, it was (10%) compared to the control, which was (96%). As for the effect of the filtrate on the root length, the treated corn grains had a diameter of (2.1 cm) and (1.8 cm), respectively, compared to the control, which was (13 cm) and (6.4 cm), respectively. This is due to the secretion of aflatoxins by the tested fungus A. niger, as shown by the results of our study. Regarding the biological resistance of the fungus with different garlic extracts (alcoholic, concentrated, and aqueous) on the PDA medium, the results showed an effective effect. The alcoholic extract was superior, with an inhibition rate of (78.94%) and an average growth rate of A. niger colony diameter of 1.6 cm. The concentrated extract followed with an inhibition rate of (59.07%) and an average growth rate of A. niger colony diameter of 3.11 cm. The least was the aqueous extract, with an inhibition rate of (51.18%) and a vegetative growth rate of 3.71 cm on the PDA medium, compared to the control, which was 7.6 cm for the tested fungus A. niger. As for the effect of Different garlic extracts on the dry and wet weight of A. niger on PDB medium, where the alcoholic extract also had the highest effect followed by the concentrate and the least of them was the aqueous extract with wet and dry weight (0.365, 0.045), (0.383, 0.119) and (1.458, 0.214) g/dry weight respectively compared to the control (4.461, 0.243) g/dry weight.