Final diagnosis


Didymella bryoniae

<i><b>Didymella bryoniae</b></i>
This young grafted melon plant has withered; he has a chancre at the graft site. <i> <b> Didymella bryoniae </b> </i> (gummy stem blight)
A canker lesion gradually spreads over the stem of this grafted melon plant. The tissues have browned, even reddened locally, while tiny black structures dot it. <i> <b> Didymella bryoniae </b> </i> (gummy stem blight)
Pycnidia and perithecia of <i> <b> Didymella bryoniae </b> </i> formed on this portion of rotten stem (gummy stem blight)
Several rather circular spots, located or not at the edge of the blade and sometimes confluent, are visible on this melon leaf. Brown to tawny in color, they gradually necrotize, dry out and split. <i> <b> Didymella bryoniae </b> </i>
<i><b>Didymella bryoniae</b></i>
A wet and dark lesion surrounds this young melon plant several centimeters. Numerous black dots the dots, they are fruiting bodies of <i> <b> Didymella bryoniae </b> </i>.
<i><b>Didymella bryoniae</b></i>
<i><b>Didymella bryoniae</b></i>
The lesion has spread, it now surrounds two branches. the altered tissues, in addition to being damp, took on a brownish to black tint. Gummy exudates, and fruiting bodies are present on the tissues. <i> <b> Didymella bryoniae </b> </i>
<i><b>Didymella bryoniae</b></i>
Weathering first wet, then dark brown, covering a significant portion of this melon stem. Note the large amount of gummy exudates and small black dots (perithecia or pycnidia) on the latter. </b> <i> Didymella bryoniae </i> </b>
A necrotic lesion extends over a large section of this melon stem. Beige to brown in color, it is partially covered with conspicuous reddish-brown gummy exudates. <i> <b> Didymella bryoniae </b> </i>
A large, moist, dark brown to blackish lesion gradually spreads over this partially split melon. <i> <b> Didymella bryoniae </b> </i> (black rot)
The development of <i> <b> Didymella bryoniae </b> </i> inside this melon gave its flesh a rather characteristic black tint. (black rot)
Numerous, tiny, black, contiguous structures are present at the periphery of these two fruit lesions. These are fruiting bodies of <i> <b> Didymella bryoniae </b> </i>
<i><b>Didymella bryoniae</b></i> (gummy stem blight) 1
Fruiting bodies of <i> <b> Didymella bryoniae </b> </i> observed with a binocular magnifying glass progressively melanating (gummy cankers on stem, gummy stem blight)
Fruiting bodies of <i> <b> Didymella bryoniae </b> </i> observed with a binocular magnifying glass; they are black because they are now well mixed. (gummy stem blight)
Fruiting bodies of <i> <b> Didymella bryoniae </b> </i> observed under a light microscope (gummy stem blight)
Appearance under a photonic microscope of a <i> <b> Didymella bryoniae </b> </i> pycnidia; conidia are being released.
Pycnidus and its ostiole under the light microscope <i> <b> Phoma cucurbitacearum </b> </i>; conidia were released (gummy stem blight)
This perithecium of <i> <b> Didymella bryoniae </b> </i> was squeezed to release asci containing ascospores which are clearly visible under a light microscope.
<i><b>Didymella bryoniae</b></i> (gummy stem blight)