Generation and evaluation of Juglans Microcarpa hybrids and paradox stock selections for crown gall resistance
Project Number: 5306-22000-015-24
Start Date: May 01, 2011
End Date: Apr 30, 2012
1. Identify and characterize a novel source of crown gall (CG) resistance in the species Juglans microcarpa germplasm and associated hybrids maintained in the USDA/ARS National Clonal Germplasm Repository in Davis, CA.
2. Characterize crown gall resistant phenotypes of clonally propagated cuttings from genotypes exhibiting crown gall resistance.
3. Produce clonal copies of promising hybrids and conduct "large scale" greenhouse and field evaluation to identify promising genotypes.
Open pollinated seeds will be stratified, germinated and grown under glasshouse conditions. Once the seedlings reach a trunk diameter of at least 0.5cm the crown of the tree will be inoculated with A. tumefaciens strain EC1. Observations on tumor development will be recorded at monthly intervals by noting first-appearance and then percent trunk/crown girdled.