بيان التأثير السمي و اختبار كفاءة المقاومة الكيميائية و الاحيائية على عزلات من أنواع الفطر Alternaria Sp. المعزولة من أشجار الحمضيات

الملخص EN

320 fungus isolations were obtained by isolation from different citrus trees leaves, and to indicate the toxic effect of the fungal filtrate of some studied species which belong to Alternaria species, an estimation of the chlorophyll content in the plant leaf were done to recognize the effect of the fungal filtrate on it.

The percentage of chlorophyll a, b and total chlorophyll were estimated, then the percentage of loss was calculated and it reached 74.32 % when the concentration was 100 % and the wet chlorophyll amount was 5.9 mg / g, whereas the percentage of loss reached 40.77 % at concentration of 50 % with a chlorophyll content of 13.61 mg / g wet weight, compared to the total chlorophyll of the comparison treatment which reached 22.98 % mg / g wet weight.

The local necrosis test was performed on 8 isolations to measure the efficiency of the fungal filtrate in inflicting infestation on the sound leaves.

The filtrate of the isolations manifested capability of infecting sound leaves; symptoms appeared in the form of brown to black spots at the spots of scratches and twinges.