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

	UCD GRN-1 [01.1] (proprietary)
Registration Status	Registered
Source	Department of Viticulture & Enology, University of California, Davis
Proprietary	Proprietary- cannot be distributed without written permission from owner.
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 http://fps.ucdavis.edu/, in the Publications section. The original material underwent microshoot tip tissue culture therapy in 2010 to qualify for the Russell Ranch Foundation Vineyard, where it was planted in 2012 as UCD GRN-1™ FPS 01.1.