Breeding Cold Tolerance
April 20, 2016 By Dr. Alireza Rahemi Mike McArthur Phil Ryan and Andrea Kilian
Dr. Alireza Rahemi with some of the Frost grape genotypes currently being propagated at the Simcoe Research Station.
Grapes (Vitis vinifera) are the most widely cultivated horticultural crops in the world and the viticulture industry is developing rapidly in Canada. Ontario has approximately 17,000 acres of vineyards, and in recent years vineyards have been established in Norfolk County.
Cold winters can damage cultivated grapes and, therefore, grapes with a higher freezing tolerance are desirable and growers are looking for ways to improve the winter hardiness of conventional grape cultivars.
Hybridization of common grapes with wild grapes is one way to increase the freezing tolerance of grapes. Also, appropriate rootstock enhances the grapevine’s ability to provide cold tolerant roots and trunk and is expected to increase cold hardiness.
Frost grape (Vitis vinifera) is a native, freeze tolerant wild grape in North America and is distributed in New Brunswick, Quebec, Ontario and Manitoba. It is reported that some genotypes of this grape can tolerate -50 C during winter and those, or hybrids of them, have been used as a rootstock for the grapes. Some genetic factors in these grapes increase abiotic stress tolerance and these factors lead to the expression of some genes that help the cell to survive periods of freezing. It is assumed that some genes from Frost grapes are responsible for the superior frost tolerance of this grape.
In 2012, about 900 genotypes of Frost grapes were collected to identify new potential rootstock candidates. The clones were collected from sandy regions throughout southern Ontario (Norfolk, Elgin, Middlesex, Oxford, Brant, Kent, Haldimand, Essex, Prince Edward, Hastings, Frontenac and Grey counties). These genotypes have been propagated and are planted at Simcoe Research Station. At present, Simcoe Research Station has a very broad collection of Frost grape genetic material. The genetic diversity of this collection is being studied in collaboration with Cornell University. Also, morphological characteristics in plant structure have been evaluated in the last three years and the genetic material showed diversity in the population.
Drought resistance, based on the morphological characteristics, is also under evaluation on 12 pre-selected genotypes. Biochemical assay along with other physiological and morphological characteristics have been used to assess drought resistance in controlled environments in the greenhouse with three different drought levels. Pinot noir grapevines have been grafted on these selections and the grafted vines were planted in the field for more evaluations.
These rootstocks will increase the competitiveness of grape growers and provide them with better choices of rootstocks for grapes.
This project was funded in part through Growing Forward 2 (GF2), a federal-provincial-territorial initiative. The Ontario Grape and Wine Research Incorporation (OGWRI), Grape Growers of Ontario (GGO), Ontario South Coast Wineries and Growers Association (OSCWGA), VineTech Nursery, and Dubois Agrinovation Company also have co-operated and assisted in the project.
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