Rose Rosette Disease Challenges Dr. Tom Evans, Professor of Plant Pathology Nancy Gregory, Plant Disease Diagnostician Danielle Novick, Graduate Student Terry Mhora, Graduate Student Department of Plant and Soil Sciences University of Delaware With the Help of the entire RRD Team
Disease Management Virus has no treatment Historically the vector was not controlled well with acaricides Disease reservoir is still expanding in range. Diseased plants must be removed as soon as possible. Goal = Resistance/tolerance to virus and better vector management
Significance 2013 U.S. market for landscape roses $928 million 2014 U.S. wholesale value of container & bare-root roses $400 million Private Consumers Taxpayers Public Gardens Stakeholder s Landscape Companies Breeders Growers 2010/2011 renovation of Cranford Rose Garden at Brooklyn Botanic Garden because of widespread RRD infection. Consumer surveys in 2014 of 1500 consumers indicated that disease resistance is the most desired trait in new cultivars. Survey by Brickman, landscape firm located in 33 states won t plant more roses in areas of high RRD pressure Southlake TX spending $500,000 to replace thousands of infected roses in medians and parks According to USDA data, roses are the most economically important ornamental plant in the U.S.
Symptoms & Significance Abnormal reddening Leaf and bud distortion Increased succulence Excessive thorniness Shoot elongation Blossom blight Witches broom Stunting Dieback Plant death
Symptoms of RRD
Key Problem and Diagnostic = Symptoms (and eventual death) RRD causes elongated rose shoots, leaf distortion and an unusual red or yellow mottle of the leaves. An excessive number of thorns on shoots is another symptom of RRD.
Key Problem and Diagnostic = Symptoms (and eventual death) Rosetting and red shoots and leaves. Parts of plants look healthy and other parts show typical sympotms
Rosa multiflora and Rose Rosette Disease 1700s: imported to North America as rootstock and ornamental and erosion control 1940: RRD symptoms first described in Manitoba, Canada; reported in California and Wyoming in 1941 1940s 1960s: promoted to combat erosion, form living fence, and provide wildlife habitat; 34 million planted in WV & NC alone Up to half a million seeds in a year Spread by birds and small mammals Seeds remain viable 20+ years Root suckering & layering produce thickets Repository for virus and vector of RRD Rose rosette is NOT a good biocontrol agent for multiflora rose 1994: RRD proposed as biological control for multiflora rose 2006: multiflora infests approximately 45 million acres in eastern United States EDDMapS. 2015. Distribution of Non-Native Rose in the US
The March of RRD from West to East WA MT ND OR ID CA 1941 NV 1953 UT AZ WY NM SD 1959 NE KS OK MN WI ME VT MI NH NY MA IA T PA IL IN OH NJ MD DE MO 1986 WV 1996 KY VA 1978 1985 1982 TN AR AL 1985 MS GA TX LA NC 2001 AK FL HI Large Reservoir of Virus in Large Populations of Rosa multiflora
The Distribution of RRD in U.S. Now reported in garden roses in India
Aerial View of Rose Field Block 1 Block 2 Block 3
Resistance Trial at the University of Delaware More than 300 unique rose genotypes planted in randomized 3-block design since May 2015 All roses augmented 5 times over 2 years Symptomatic roses confirmed for RRD with endpoint RT-PCR
Mite location and detection where do they hide?
Rose Genotypes That Have Not Yet been Tested Positive for RRV and may be Resistant Cultivar Where Assessed Comments 10037N046 TN TAMU10-69, WOB26xOB212xHomerun 10043N019 TN TAMU7-20, Sweet Chariot x M4-4, Basye Thornless parentage 10043N49 TN TAMU7-30, Sweet Chariot x M4-4, Basyes Thornless parentage 218-97-17 TN Moore, VisViolet x Magseed, rugosa parentage via Rugosa Magnifica 2-30-07 TN, DE Moore selection, Sequoia Ruby x Ginas Rose, carolina/rugosa parentage via Basyes Legacy 4-48-07 TN Moore, Show N Tell x Ginas Rose, carolina/rugosa parentage via Basyes Legacy 66-84-18 TN, DE Moore selection, Anytime x Rugosa Magnifica 88-3A TN Basye, rugosa hybrid 90-82 TN, DE Basye, carolina, rugosa/basyethornless parentage via 86-7 Brite Eyes Very fertile, already some families, climber, maternal parent of Sunny Knockout FF TN Basye, carolina parentage, possibly rugosa and Basye Thornless Fru Dagmar Hastrup TN, DE Rugosa hybrid Fuzzy Wuzzy Red TN, DE Moore, rugosa hybrid, Scarlet Moss selfed, Dortmund in parentage G02-2-1 TN, DE Sequioa Ruby x 90-82, carolina, rugosa/basyethornless parentage via 86-7 Hansa TN Rugosa hybrid
Rose Genotypes That Have Not Yet been Tested Positive for RRV and may be Resistant Cultivar Where Assessed Comments M4-4 TN, DE Basye Thornless parentage via WOB26 John Davis TN, DE Canadian cv, 3x, rugosa via kordesii and laxa/spinosissima via Suzanne Lafter TN, DE OGR, wichuraina in parentage Little Buckaroo TN, DE Miniature, 3x, Rosa wichuraiana in parentage, poor fertility M4-4 TN, DE Basye Thornless parentage via WOB26 Manetti TN, DE Rootstock Moje Hammerberg TN Rugosa parentage Morden Centennial TN, DE Canadian, Rosa arkansana in parentage Morden Fireglow TN, DE Canadian, Rosa arkansana in parentage Purple Pavement TN, DE Rugosa hybrid Sorcerer TN Star Delight TN, DE Rugosa hybrid, fertility?, Yellow Jewell x Rosa magnifica Sunny Knockout TN Parentage of Brite Eyes Therese Bugnet TN, DE Rugosa hybrid Winnipeg Parks TN Canadian, Parkland series,db,mpk, Rosa arkansana parentage, gd R to blackspot, pmildew,rust in Canada Wintersun TN Eleganza,HT,db,or-yel,Kordes Unreported parentage
New Genotypes of Rose Confirmed RRV-Susceptible by Symptoms and Endpoint PCR Testing Sept 2018 - Delaware Nearly Wild Lady Shallot Easy Elegance Screaming Neon Red Easy Elegance Como Park Easy Elegance Mystic Fairytale Easy Elegance Brick Red Easy Elegance High Voltage First Edition A+B Tequila Sunrise x15680-6 13FA7
Phenotyping Group Measure the strength of resistance that a rose has to the Rose Rosette Emaravirus. {
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Thank You! Danielle Novick (aka Juniper Lake) Nicole Donofrio David Frey Brian Kunkel Nancy Gregory Bill Bartz Rodney Dempsey Terence Mhora Nilwala Abeysekara Vidhya Raman Jen Olson (Oklahoma State) Francisco Ochoa Corona (Oklahoma State)
The Rose Rosette Team { USDA National Institute of Food and Agriculture (NIFA) Specialty Crop Research Initiative project, Combating Rose Rosette Disease: Short Term and Long Term Approaches (2014-51181-22644/SCRI)