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
 Horticultural Crops Research Unit: Corvallis, OR
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    Other
                        History
                                    Useful Links
                    HortHappenings News PageSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Pacific West Area Corvallis, Oregon Horticultural Crops Research Unit 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

Title:   Author  item
                                            Grunwald, Niklaus

                                                         - *Nik*item
                                            SCHEUERELL, STEVEN - OREGON STATE UNIVitem
                                            Davis, Elizabethitem
                                            Linderman, Robert
  Submitted to: Sudden Oak Death Science Symposium
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 12/15/2004
                                    Publication  Date: 12/15/2004
                                    Citation: Grunwald, N.J., Scheuerell, S., Davis, E.A., Linderman, R.G. 2004. Variation in phenotype for resistance to Phytophthora ramorum in a range of species and cultivars of the genus Viburnum [abstract]. Sudden Oak Death Science Symposium II. p. 29.Interpretive Summary:
                                Technical Abstract: To date it is well established that the ornamental plant Viburnum plicatum var. tomentosum cv. 'Mariesii' and other Viburnum species or cultivars are highly susceptible to Phytophthora ramorum. What is not known is whether all cultivars in the genus Viburnum are equally susceptible, whether they are field- or container-grown. The objective of our research was to evaluate 9 species of field-grown Viburnum, including V. burkwoodii, V. dentatum, V. lantana, V. opulus, V. plicatum, V. lentago, V. nudum, V. sargentii, and V. trilobium, for a total of 23 cultivars for resistance to P. ramorum in detached leaf tests. Foliage of Viburnum was obtained from Carlton Plants nursery on September 20, 2004. Detached leaves were wound-inoculated with 6 mm agar plugs of 1-week old colonies of P. ramorum using strains 4123 (isolated from Rhododendron macrophyllum, predominant US genotype of mating type A2) and 03-74-D12-A (isolated of V. plicatum var. tomentosum 'Mariesii' European genotype of mating type A1) grown on dilute V-8 agar. While two mycelial agar plugs were used to inoculate one side of a leaf, a control plug of the same medium was inoculated on the other side of the leaf. Leaves were incubated in moist chambers at 20o C for 8 days before measurements were taken. Lesion area was determined as the percentage of infected leaf area of the total leaf area using the Assess program (APS, St. Paul, MN). We obtained significant differences for levels of resistance based on percentages of leaf areas affected (P < 0.001) and no significant differences for isolates and interactions between isolates and cultivars. The percentages of lesion areas affected ranged from 95% (cvs. V. burkwoodii cv. unkown, V. plicatum var. tomentosum cv. Mariesii, and V. trilobium cvs. Alfredo and Bailey), to intermediate responses between 25-90% (cvs. V. burkwoodii cv. Mohawk, V. lantana cv. Mohican, V. opulus cvs. Compacta and Hanum, V. lentago cv. unkown, V. sargentii cv. Onandaga, V. trilobium cv. Redwing) to less than 15% infection (V. dentatum cvs. Autumn Jazz, Blue Muffin, Chicago Lustre, and Burgundy; V. opulus cv. Sterile, V. plicatum cv. Newport, Popcorn, Shasta, and Shoshon; V. nudum cv. Winterthur, V. trilobium cv. Wentworth). Our data indicate that there is a considerable range of resistance phenotypes in the genus Viburnum from high susceptibility to resistance.


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