In this study, sixteen isolates of Magnaporthiopsis maydis were isolated from infected maize (Zea mays L.) plants collected from different governorates in Egypt. These isolates were identified at the molecular level using a specific primer. All isolates have the same growth pattern form (rhizoid), growth elevation (raise) and growth margin (filiform) on PDA medium but differed in color. The faster isolate in growing on PDA medium was isolate S3 while the slower one was A2. The analysis of variance showed significant differences among isolates. The pathogenicity test was carried out under greenhouse conditions using a Single cross pioneer 3062 hybrid. Isolates F13 and F14 were highly aggressive (33.33%), while isolate Mi5 was the lowest (10%). No correlation was detected between disease incidence and radial growth of M. maydis isolates. Genetic diversity among isolates was studied using six RAPD markers and showed a high similarity percentage (95%) between isolate F13 and F14 and between isolate F14 and F15.Whereas, the lowest similarity percentage (26%) was between isolate A2 and KS11. The Cluster analysis using the Dice coefficient divided the studied isolates into five clusters. Cluster 1 contains isolates nos. F14, F15, F13, B12, KS7, and KS16, cluster 2 contains isolates nos. F9, M10, Mi5, and M8, cluster3 contains isolates nos. S3, KS6, and F1-B4, cluster 4 contains isolate number KS11 and cluster 5 contains isolate number A2.

The basidiomycete fungus Ganoderma Karst., a polyporoid genus within the family Ganodermataceae of the order Aphyllophorales, is worldwide in distribution, growing on numerous coniferous, deciduous and palmaceous hosts. The genus encompasses an extensive and various complex of fungi, a significant number of which are wood rot and others are pathogenic to economically crops and trees. Ganoderma give rise to root and stem rots disease that has long been recognized to cause large losses of many equatorial crops such as oil palm (Elaeis guineensis), coconut (Cocos nucifera), grapevines (Vitis vinfera), betelnut (Areca catechu), tea (Camellia sinensis),

Alternaria porri (Ellis). Ciffen causes serious problems in onion plants. It is transmitted with naturally infected seeds and bulbs from the previous crop to infect the new flower stalk of the next crop. Also, onion bulb infection decreases seed vitality. Infected sample were collected from four locations; Giza, Sharkia, Kalubia and Menofia governorates to measure disease severity. Experiments have been done on naturally infected seeds and bulbs from the previous year by cultivating infected bulbs. Infection was classified into five categories based on the percentage of disease severity. Pathogen transmission by the onion seed was investigated, either as internal or external infection type, Five different ratios of blub infection was determined as; 14.2%, 25.2%, 41.5%, 61.1%, 87.5%. Also, trials were carried out in the current study to evaluate the efficiency of some botanical, biological and chemical as seed dressing treatments for infected seeds before sowing it, i.e. (Achook, Bougainvillea sp., Bacillus sp., Trichoderma sp. and Score). Results showed that disease severity was increased in the blub produced from previous crop, the number of flower stalk was reduced, and its disease severity was increased. Seeds produced from infected blub showed reduction in germination percentage. The most effective seed dressing treatment on seed germination were obtained by using score & Achook treatment compared with other seed dressing treatments. All treatments including Score, Achook, Bacillus sp., Bougainvillea sp., and Trichoderma sp.; respectively showed variable seed stimulation of germination compared with plants in the control treatment.