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Diseases of Native plants
Ram Sampangi
Krishna Mohan
University of Idaho, Parma ID 83660
and
Clinton C. Shock
Oregon State University
Malheur Exptl. Stn. Ontario, OR 97914
Forb Diseases
Objectives: Conduct surveys for new and/or emerging disease problems. Identify unknown or little understood diseases in native systems. Evaluation of plant cultivars for disease resistance/susceptibility. Study the ecological and epidemiological aspects of diseases.
Significance:
Diseases of economic crops are well known and studied but not the diseases affecting native plants.
Diseases of native plants are also part of the ecosystem. Prescreen plant materials for natural resistance to pests and diseases. Develop disease management practices.
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Forb species Malheur Experiment Station, [OSU], Ontario, OR.
Species Common name
Eriogonum umbellatum Sulfur buckwheat
Penstemon acuminatum Sand penstemon
Penstemon deustus Hotrock penstemon
Penstemon speciosus Royal or sagebrush penstemon
Lomatium dissectum Fern leaf biscuitroot
Lomatium triternatum Nine leaf desert parsley
Lomatium grayi Gray's lomatium
Sphaeralcea coccinea Scarlet Globemallow
Sphaeralcea grossulariifolia Gooseberry Globemallow
Sphaeralcea parvifolia Small flower Globemallow
Acnatherum thurberianum Thurber’s needlegrass
Dalea ornata Blue mountain prairie clover
Astralagus filipes Basalt milkvetch
Cleome hassleriana Spider flower, Pinkqueen
Crepis intermedia Limestone Hawksbeard
Balsamorhiza sagittata Arrowleaf balsamroot3
Powdery Mildew of Globe Mallow (red globe mallow) (Sphaeralcea coccinea)
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Powdery Mildew of Globemallow (Sphaeralcea coccinea) 5
PM of Globemallow (gooseberry leaf)(Sphaeralcea grossulariifolia) 6
Powdery mildew of Cleome hassleriana by Leveillula taurica(Pink queen, Spider flower) 7
[Chasmothecia-Sexual fruit bodies]
PM on other hosts & weeds
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Cleome luteaYellow beeplant
Cleome serrulataRocky Mountain beeplant Mentzelia laevicaulis
Giant blazing star
Powdery mildew on Astragalus filipes
[basalt milkvetch]
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Powdery mildew on Cleome spp.[Spiderflower] and Dalea ornata [prairie clover] by Leveillula taurica
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Co infection/Dual infection of Globemallow [Sphaeralcea grossulariifolia] with Rust [Puccinia
sherardiana] and powdery mildew [Leveillula taurica].
11Rust spores
Lomatium Rust-Puccinia jonesii
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Rust of Lomatium dissectum-Puccinia jonesii
13Rust spores
Alternaria leaf blight of Lomatium
14Alternaria SporesL. dissectum, L. triternatum and L. grayi
Leaf spot of Penstemon acuminatus by CMV [Cucumber Mosaic Virus]
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Leaf spot (Virus-CMV-Cucumber Mosaic Virus) of Penstemon acuminatus(Sharpleaf penstemon, Sand-Dune Penstemon) 16
Hollyhock Rust: Puccinia malvacearumHost: Alcea rosea; others in Malvaceae 17
Wilt of Stevia rebaudiana[Pathogen-unknown]
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Leaf spot and blight of Veratrum californicum19
Enhancing Beneficial Insects with Native Plants
• Bumble Bees
• Honey Bees
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Accomplishments:
Several diseases [leaf spots, blights, rusts, wilts and
powdery mildews] were recorded on forbs.
New and reemerging plant pathogens were noticed.
Fungal, bacterial and viral diseases were recorded.
Arid [hot and dry] conditions prevailing in PNW is
favorable for powdery mildew disease cycle [germination,
infection, production and release of generation/s of conidia ].
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Publications related to this study
• Sampangi, R.K, M.C. Aime. S. K. Mohan .and C.C.Shock.2010.New and re-emerging rust diseases from Idaho and Oregon. Phytopathology 100:S113
• Sampangi, R.K, M.C. Aime and S. K. Mohan. 2010. First Report of Rust Caused by Puccinia similis on Artemisia tridentata in Idaho and Oregon. Plant disease 94,380, 2010[http://dx.doi.org/10.1094/PDIS-94-3-0380B]
• Sampangi, R. K. C. Almeyda, K. L. Druffel, S. K. Mohan, C. C. Shock, and H. R. Pappu. 2009. First Report of Natural Infection of Penstemon acuminatus with Cucumber mosaic virus in the Treasure Valley Region of Idaho and Oregon. Plant Disease 93,762, 2009
• Sampangi, R.K, Glawe, D. A., and Mohan, S. K. 2007. First North American record of powdery mildew of Cleome hasslerianacaused by Leveillula taurica. Online. Plant Health Progress doi:10.1094/PHP-2007-02XX-01-BR.
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Questions ?
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Thank You
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Symptoms of PM on Onion
Symptoms: sunken and bleached necrotic lesions with endophytic mycelium.
No chasmothecia or sexual fruit bodies on Onions.
Discovery of the chasmothecia on several forbs suggests that it may contribute to genetic
variability of L. taurica in this region .
Diversity of crops with susceptible hosts & availability of inoculum source can often leads to Increased potential for economic losses.
Inoculum on forbs could play a role in overwintering of this pathogen in this region.
New disease/pathogen reports
New host –pathogen reports are vital in the quick and accurate diagnosis of new plant diseases.
Helps improve our knowledge of biogeography, pathogen biology and host range in the region.
New reports assist in establishing the baseline information about any emerging plant diseases.
New reports also contribute to taxonomic studies, including revision of species descriptions and production of keys for identification.
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Unanswered questions?
Risk factors associated with these Plant pathogens:
Pathogens/species invasive?: unknownAre they adaptable to different environments?:
unknownDo they have high reproductive potential?: unknownCan they survive winters ?can the inoculum remain
viable for more than one year?: unknown Increased host range/cross infectivity to other crops?
unknown