| Abstrakt: |
Cantaloupe (Cucumis melo var. cantalupensis) is a member of the family Cucurbitaceae. Under Egyptian condition, this crop is cultivated under protected plastic tunnels to produce an off-season crop for mainly exportation, as well as local consumption during the Autumn and Winter seasons. During harvesting time of cantaloupe (October, 2017) grown at Wadi El Natron Farm, Faculty of Agriculture, Cairo Univ., a collapse of cantaloupe plants was noticed as yellowing of older leaves, great reduction in green growth, corky and decayed areas on roots, after 70 days of transplanting. Isolation trials from naturally infected cantaloupe roots resulted in the presence of 6 different fungi. These fungi were identified as Plectosphaerella melonis, Sclerotium bataticola, Rhizoctonia solani, Botryodiplodia sp., Monosporascus cannonballus and Fusarium solani. The most dominant fungus in Behera governorats was Plectosphaerella melonis. Through light microscopy of the isolated fungus the conidia formed on phyalides were observed. The chlamydospores were also obvious. Scanning electron microscopy of the fungal colonies of Plectosphaerella melonis clearly revealed the intensive formation of the characteristic chlamydospores. Pathogenicity test carried out by using the six testes fungi either singly or in different double combination under greenhouse condition in pots and in plots near the greenhouse revealed that these fungi had the ability to cause the typical symptoms of cantaloupe decline (root rot with different disease severity degrees) in Gal 290 cv. This was accompanied with great reduction in some plant growth parameters tested. On the basis of these data, it is considered that Plectosphaerella melonis may cause cantaloupe decline under Egyptian condition during winter plantation and this is the first record of the fungus in Egypt. [ABSTRACT FROM AUTHOR] |
