THE COMBINED EFFECT OF FUSARIUM OXYSPORUM F. SP. CEPAE AND TRICHODERMA HARZIANUM ON THE HISTOLOGY OF ONION ROOTS

ABOU-ZAID, MOHAMED I.; ABDEL-KADER, DAWLAT A.; TOHAMY, MOHAMED R. A.; HANNA, ALBER I.

doi:10.21608/ejar.1993.462478

THE COMBINED EFFECT OF FUSARIUM OXYSPORUM F. SP. CEPAE AND TRICHODERMA HARZIANUM ON THE HISTOLOGY OF ONION ROOTS

Document Type : Original Article

Authors

¹ Faculty of Agriculture, Zagazig University, Zagazig, Egypt

² Plant Pathology Research Institute, Agricultural Research Centre, Giza, Egypt.

10.21608/ejar.1993.462478

Abstract

Effect of Fusarium oxysporum f. sp. cepae, Trichoderma harzia‌num and their combined effect on the anatomical structure of onion roots was followed up after 12, 18, 24 hrs and 3, 5, 7, 10 days from in‌oculation with T.harzianum. It revealed that the mycelial growth of T.harzianum surrounded the epidermal tissues of the root without pene‌tration. The epidermis, cortex layers and the vascular bundles, were nor‌mal in their structure. No anatomical changes were noticed in the roots inoculated with Fusarium up to 24 hrs following inoculation. Three days after inoculation the fungus penetrated the epidermal layer towards the ground tissue. Five days after inoculation it destroyed the cortex tissue with a noticea‌ble invasion of the fungal mycelium through the cortex cells either inter‌cellularly and/or intracellularly. The mycelial mats aggregated in the peri‌cycle layer and progressed towards the vascular bundles. After ten days it completely destroyed the tissues which was occupied with the fungal chlamydospores. Root tissues inoculated with F. oxysporum f. sp. cepae and T. har‌zianum after 12, 18, 24 hrs and 3, 5, 7, 10 days looked as the control. The epidermis, cortex layers and vascular bundles were normal in their structure and seemed slightly hypertrophic.