Index

Description

An old grape variety from the area around Conthey-Savièse-Sion (Valais), revived in 2005.

General and History

The Diolle grape variety was first mentioned in 1654 in the vineyards of Sion in the Valais region under its local dialect name Jiolaz and later appeared in several documents relating to the vineyards around Conthey-Savièse-Sion in various spellings. The last written record dates from 1903, after which the grape variety was considered extinct. In 2005, while the author was compiling a database of all DNA profiles of grape varieties cultivated in Switzerland (Swiss Vitis Microsatellite Database, https://www.actahort.org/books/827/827_82.htm), he was contacted by the late Germain Héritier, a winegrower and cellar master from Granois (Savièse). Héritier had discovered two unknown vines growing in a vineyard wall near Balletière, between Conthey and Savièse. DNA analysis revealed that both vines had the same profile, which did not correspond to any known grape variety. A paternity test showed that this unknown variety was descended from Rèze (or at least from one of its parent varieties, with Rèze considered a parent due to its age), suggesting that the variety did indeed originate from Valais. An ampelographic description in an early 20th-century work finally allowed for the identification of this unknown variety: it was Diolle, a grape variety from the Conthey-Savièse region, which at the time was considered a possible natural cross between Rèze and Fendant (Chasselas). Although the DNA test refuted any relationship with Fendant, the enigmatic Savièse grape variety perfectly matched the description. Thus, it joins the ranks of old Valais grape varieties: Diolle has been rediscovered!

Distribution in the past and today

0.03 ha in Chamoson (Valais).

Cultivation

The Diolle grape variety was first mentioned in 1654 in the vineyards of Sion in the Valais region under its local dialect name Jiolaz and later appeared in several documents relating to the vineyards around Conthey-Savièse-Sion in various spellings. The last written record dates from 1903, after which the grape variety was considered extinct. In 2005, while the author was compiling a database of all DNA profiles of grape varieties cultivated in Switzerland (Swiss Vitis Microsatellite Database, https://www.actahort.org/books/827/827_82.htm), he was contacted by the late Germain Héritier, a winegrower and cellar master from Granois (Savièse). Héritier had discovered two unknown vines growing in a vineyard wall near Balletière, between Conthey and Savièse. DNA analysis revealed that both vines had the same profile, which did not correspond to any known grape variety. A paternity test showed that this unknown variety was descended from Rèze (or at least from one of its parent varieties, with Rèze considered a parent due to its age), suggesting that the variety did indeed originate from Valais. An ampelographic description in an early 20th-century work finally allowed for the identification of this unknown variety: it was Diolle, a grape variety from the Conthey-Savièse region, which at the time was considered a possible natural cross between Rèze and Fendant (Chasselas). Although the DNA test refuted any relationship with Fendant, the enigmatic Savièse grape variety perfectly matched the description. Thus, it joins the ranks of old Valais grape varieties: Diolle has been rediscovered!

Suitability

Diolle is the result of a natural cross between Rèze and an unknown, probably extinct, grape variety. It is therefore a half-sister of Grosse Arvine from the Martigny-Fully area.

Literature

·Vouillamoz, J. (2017). Cépages suisses, histoires et origines. Ed. Favre