Evaluation of Antifungal Activity of Oil Extracted from Two Varieties of Tomato Seeds against Fungal organisms Causing Rot in Tomato Fruits

Abstract

Evaluation of the antifungal activity of oil extracted from two varieties of tomato seeds against fungal organisms causing rot in tomato fruits was carried out in Makurdi. The presence of decay caused by Fungi on tomatoes results in postharvest losses. Riogrande and Roma VF tomato seeds were washed, dried at 50˚C for 3 days in an oven, and milled. With the aid of a soxhlet extractor, using n-Hexane at 40-60°C for 6 hours, oil was extracted from the milled samples. Analysis of the oil revealed that oil is stable, translucent, and highly penetrating. A portion of tomatoes showing signs and symptoms of rot were detached, sterilized, and placed in a medium of Potato Dextrose Agar for one week for fungal growth. Fungi growths were identified macroscopically and microscopically and matched with standards. Fungi such as Curvularia affinis, Aspergillus flavus, Aspergillus niger, and Penicillium waksmanii were isolated. The pour plate method was used for fungi growth in the presence of the oil extracted. At days 3-7, the Riogrande seed oil media inhibit the growth of the isolated fungi with Aspergillus niger having the highest inhibition ranging from 1.333 to 1.733 mm and the Roma seed oil media inhibit the growth of Curvularia affinis with the highest inhibition ranging from 1.266 to 1.950 mm and while the control ranged from 3.533 to 8.100 mm. The results showed that numerous fungi are involved in rot of tomatoes and the extracted oil contains phytochemicals that are responsible for inhibiting fungal growth in the plates.