Walnut Scion & Rootstock Improvement
Walnut Scion & Rootstock Improvement
Walnut Scion & Rootstock Improvement
University of California
Walnut Scion & Rootstock Improvement

Program History 1982 - 2009

In 1982, Gale McGranahan was hired by the US Department of Agriculture to breed for solutions to the blackline problem. In 1989, she joined the Department of Pomology and continued her activities of breeding walnuts and curating the Walnut Germplasm Collection.

The early years of her program were directed towards examining the inheritance of the hypersensitive response to the virus that causes the disease and beginning a backcross breeding program to develop hypersensitive cultivars, as well as introduction of germplasm so that the traditional cultivar improvement program could be continued. The new germplasm is now being used in the blackline resistance breeding program.

Professor McGranahan expanded her program in these areas:

  • Blackline resistance breeding
  • Chandler pollenizers
  • Blight resistance
  • Earlier harvest dates
  • Rootstock diversity and selection
  • Development of clonal rootstocks

 Professor McGranahan retired in 2009.

 

Prof. Gale McGranahan
Prof. Gale McGranahan
Walnut cultivars released by UC during Gale McGranahan's tenure as program leader.
Walnut cultivars released by UC during Gale McGranahan's tenure as program leader.

Webmaster Email: fruitsandnuts@ucdavis.edu