U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Crops Pathology and Genetics Research: Davis, CA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    Outreach Events
                        UC Davis Picnic Day
                                    Kinders go to College
                                    STEM Girls
                                    Future Scientist Program
                                    Agriculture Future of America
                                    Wallace-Carver Fellowship
                                    Young Scholars Program
                                    Annual Awards Banquet
                    About Us
                        About Us
                                    Our Mission
                                    Principal InvestigatorsSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Pacific West Area Davis, California Crops Pathology and Genetics Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications
- Etiology and Biology of Tree Crop Diseases
- Rice Genetics
- Sustainable Floriculture
- Sustainable Viticulture

Title:   Author  item
                                            Browne, Gregitem
                                            GRANT, JOE - University Of Californiaitem
                                            Schmidt, Leighitem
                                            LESLIE, CHARLES - University Of Californiaitem
                                            MCGRANAHAN, GALE - University Of California
  Submitted to: HortScience
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 10/1/2011
                                    Publication  Date: 3/1/2011
                                    Citation: Browne, G.T., Grant, J.A., Schmidt, L.S., Leslie, C.A., Mcgranahan, G.H. 2011. Resistance to phytophthora and graft compatibility with persian walnut among seedlings of chinese wingnut from different sources. HortScience. 46:371-376.Interpretive Summary: Seedlings from seven selections of Chinese wingnut (WN) representing collections of the USDA-ARS National Clonal Germplasm Repository at Davis CA and the University of California at Davis were evaluated as walnut rootstocks.  They were tested for their resistance to Phytophthora cinnamomi and P. citricola and for their graft compatibility with important Persian walnut (Juglans regia) varieties.  Seedlings of Northern California black walnut (NCB) (J. hindsii) and Paradox hybrid (PH) (typically J. hindsii × J. regia), which are used widely in commercial walnut orchards as standard rootstocks, were used in this research for comparisons with WN.  All selections of WN seedlings were relatively resistant to P. cinnamomi and P. citricola (means of 0 to 36% of root and crown length rotted), compared to NCB (44 to 100%) and PH seedlings (11 to 100%).  In 9-year graft compatibility trials in an orchard, NCB and PH rootstocks supported relatively good survival and growth of all tested walnut varieties (‘Chandler’, ‘Hartley’, ‘Serr’, ‘Tulare’, and ‘Vina’; mean scion survival 80 to 100%, mean scion circumference increase 442 to 630 mm), whereas results with WN were mixed.  Wingnut rootstocks from all sources were incompatible with ‘Chandler’ (scion survival 20 to 60%, scion circumference increase 7 to 161 mm).  Conversely, all WN rootstocks from all sources were compatible with ‘Tulare’ and ‘Vina’ (scion survival 80 to 100%, scion circumference increase 380 to 620 mm).  Use of the WN rootstocks produced variable results in ‘Hartley’ and ‘Serr’ (mean scion survival 10 to 100%, mean scion circumference increase 0 to 554 mm). Among trees with surviving scions, rootstock sprouts were more prevalent on WN than on NCB or PH rootstocks.  In a commercial walnut orchard infested with P. cinnamomi, ‘Hartley’ survived and grew markedly better on WN selections than on PH.  It was concluded that WN selections may be useful in walnut rootstock breeding efforts.  Also, in soils infested with P. cinnamomi or P. citricola, selections of WN may be useful as rootstocks for the walnut varieties ‘Hartley’, ‘Tulare’, and ‘Vina’.
                                Technical Abstract: Seedlings from seven open-pollinated selections of Chinese wingnut (Pterocarya stenoptera) (WN) representing collections of the USDA-ARS National Clonal Germplasm Repository at Davis CA and the University of California at Davis were evaluated as rootstocks for resistance to Phytophthora cinnamomi and P. citricola and graft compatibility with scions of five cultivars of Persian walnut (Juglans regia).  Seedlings of Northern California black walnut (NCB) (J. hindsii) and Paradox hybrid (PH) (typically J. hindsii × J. regia) were used as standards.  In greenhouse experiments potted plants of the rootstocks were subjected to intermittent flooding in soil artificially infested with the pathogens.  All WN seedlings were relatively resistant to the pathogens (means of 0 to 36% of root and crown length rotted), compared to NCB (44 to 100%) and PH seedlings (11 to 100%).  Negligible disease occurred in flooded control soil without the pathogens.  In 9-year graft compatibility trials in an orchard, NCB and PH rootstocks supported relatively good survival and growth of all tested scion cultivars (‘Chandler’, ‘Hartley’, ‘Serr’, ‘Tulare’, and ‘Vina’; mean scion survival 80 to 100%, mean scion circumference increase 442 to 630 mm), whereas results with WN were mixed.  Wingnut rootstocks from all sources were incompatible with ‘Chandler’ (scion survival 20 to 60%, scion circumference increase 7 to 161 mm).  Conversely, all WN rootstocks from all sources were compatible with ‘Tulare’ and ‘Vina’ (scion survival 80 to 100%, scion circumference increase 380 to 620 mm).  Use of the WN rootstocks produced variable results in ‘Hartley’ and ‘Serr’ (mean scion survival 10 to 100%, mean scion circumference increase 0 to 554 mm). Among trees with surviving scions, rootstock sprouts were more prevalent on WN than on NCB or PH rootstocks.  In a commercial walnut orchard infested with P. cinnamomi, ‘Hartley’ survived and grew markedly better on WN selections than on PH.   Resistance to P. cinnamomi and P. citricola was highly conserved among WN selections, which may be useful in walnut rootstock breeding efforts.  Also, in soils infested with these pathogens, selections of WN may be useful as rootstocks for ‘Hartley’, ‘Tulare’, and ‘Vina’.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov