Final diagnosis

Eutypa lata (Eutypiose)

This vine presents a dead arm.  The shoots developing on the still functional arm are stunted, with small, distorted, chlorotic leaves.  <i> <b> Eutypa lata </b> </i> (eutypia)
Shoots from an arm infected with <i> <b> Eutypa lata </b> </i> show stunted growth, short internodes and crisp, chlorotic leaves.
On vines affected by <i> <b> Eutypa lata </b> </i>, the young leaves are smaller and chlorotic, deformed, and sometimes necrotic.  (eutypiosis)
Numerous brown necrotic lesions, interveinal veins, materialize the effects of <i> <b> Eutypa lata </b> </i> toxin on the vine (eutypiosis)
Another aspect of sectorial necrosis in wood caused by <b> <i> Eutypa lata </i> </b> (eutypia)
Wood necrosis caused by <i> <b> Eutypa lata </b> </i> always occurs in sectoral form.  They are brown, sometimes slightly purplish to reddish.
Many perithecia are present inside the stroma that covers part of this vine, giving it the appearance of an elephant skin.  <i> <b> Eutypa lata </b> </i> (eutypia)
Perithecia formed within this stroma present under the bark.  The latter gives the surface of the vine the appearance of an elephant skin.  <i> <b> Eutypa lata </b> </i> (eutypia)
Vine wood affected by eutypiosis loses its bark.  In these areas of dead wood, the fruiting bodies of <b> <i> Eutypa lata </i> </b> develop, in the form of bumpy blackish patches.
When we cut the black and superficial stroma present on the vine, we can observe white or black circular cubicles corresponding to the perithecia seen in section.  <i> <b> Eutypa lata </b> </i> (eutypia)
Detail of perithecia of <b> <i> Eutypa lata </i> </b> cut transversely.  (eutypiosis)
Eight hyaline and arched ascospores are visible in an ascus of <i> <b> Eutypa lata </b> </i> (eutypiosis)
La colonie mycélienne d'<b><i>Eutypa lata</i></b> présente d'abord une coloration blanche. En vieillissant, celle-ci devient grisâtre et des pycnides noires apparaissent en surface.
A few <i> <b> Eutypa lata </b> </i> pycnidia have formed <i> in vitro </i>;  viscous cirrhia mark their location.
A cirrh containing very many conidia emerges from a pycnidia of <b> <i> Eutypa lata </i> </b>.  (eutypiosis)
Optical microscopic appearance of the conids or stylospores of <i> <b> Eutypa lata </b> </i>.  They are hyaline, tapering and arching.  (eutypiosis)