Foundation Plant Services Banner
UC Davis Logo and link
CAES logo and link
Foundation Plant Services Banner

Grape Variety: UCD GRN-1

Variety Name UCD GRN-1
Common Synonyms 8909-05
All Synonyms 8909-05, Walker 8909-05
Countries of Origin USA
Species V. rupestris x Muscadinia rotundifolia
Breeder Dr. Andy Walker
Institution University of California, Davis
Year Released 2008
Status of Ownership Proprietary to UC Regents
Pedigree Vitis rupestris x Muscadinia rotundifolia
Uses Rootstock
Comments This selection is one of five nematode resistant rootstocks released by Dr. Andy Walker in 2008. This selection is the most resistant of the five and is a Vitis rupestris x Muscadinia rotundifolia hybrid. One of the the rare sources of resistance to ring nematode, this cultivar has extremely strong and broad nematode resistance, and is a member of a group of Vitis species x M. rotundifolia selections currently being tested for their ability to induce fanleaf tolerance. Mother vines have sterile flowers, moderately-long shoots with shorter internodes and more laterals than the other four rootstocks. Though GRN-1™ was originally thought to be "too rotundafolia-like" to allow it to root well, it has rooted and grafted at 80% success from dormant cuttings.

UCD GRN-1 Selections

Information about:          Selection Numbers     |     Registration Status
  UCD GRN-1 01 (proprietary)
Registration Status Registered Registered is the ultimate status in the California Department of Food & Agricultures Grapevine Registration & Certification Program. Registered selections have successfully completed all disease testing required by the regulations. Registered selections have also been confirmed as true to variety by experts using visual observations, DNA-based testing or both.
Source Department of Viticulture & Enology, University of California, Davis
Treatments None
Proprietary Proprietary- cannot be distributed without written permission from owner.
Patented / Proprietary Proprietary Patented
Comments This rootstock selection was developed by University of California, Davis, Viticulture Professor Andy Walker and was released in 2008. It was formerly known as 8909-05 (Walker 8909-05). For a complete explanation of the selections in this series, see the article entitled 'Walker Nematode-resistant Rootstock Releases' in the October 2008 FPS Grape Program Newsletter at, in the Publications section.