White pine blister rust:
the nemesis of North American white pines
A presentation by
Kristen M. Baker
Blister rust cankers:
sugar pine
whitebark pine
Top kill in whitebark pine
Cronartium ribicola:
the causal agent
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Complex system involving 5 spore stages and two hosts
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Pinus and Ribes
Introduced into North America around 1900 on infected
eastern white pine stock; separate introductions on east
and west coasts
Native and Asia
C. ribicola life cycle
A Few Pathogen Details
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Low genetic diversity in N.A.
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High diversity between subpopulations
Indicative of frequent founder events and little gene flow
Genetic center: Asia
To infect white pines: 48 hours <68 F, 100% relative
humidity
Attempts to control WPBR
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Ribes eradication
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Use of Risk Zones for planting and management
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potential pitfalls: must also account for airflow patterns
Pruning
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Not successful except a few isolated incidents
Can be successful; costly; may need repeated entries; probably would
not work in whitebark
Genetics: probably most successful method
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Sugar and western white pines
Whitebark pine work in progress
Widespread mortality in western white pine
before...
Pruning research in sugar pine
Pruning research in sugar pine
...after
The tree host: white pines
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Genus Pinus
Hapoxylon subgroup
Five-needled
Eastern and western white pines, whitebark, sugar, limber,
southwestern white, foxtail (and potentially the bristlecone
pines)
Whitebark is closely related to European stone pines, where rust
is endemic
Some details on Pinus
Eastern white pine (P. strobus)
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Largely cut over prior to rust, so loss due to rust minimal, but
regenerating difficult
Only tree where Ribes control was mildly successful
Most land managers won’t risk it in high risk zones
Whitebark pine (P. albicaulis)
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High elevations in the western US and Canada
Keystone species; slow growth
Mutualistic relationship
with nutcracker
Wildlife dependence on nuts
Restoration treatments: a helping hand for a tree with a
bleak future
Western white pine (P. monticola)
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Largely disappeared from the Inland Northwest, where it
was once most valuable timber species
Like eastern, avoided in plantings
Changing species comp. and structure made forest more
susceptible to fire, insects and other pathogens
Sugar pine (P. lambertiana)
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CA and PNW
Tree of largest stature in mixed-conifer forests
Few native pests, none causing such widespread
mortality
Also avoided in some planted settings
Tree resistance
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Major gene for resistance
Found in sugar, western white, and southwestern white so far
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Thought to be gene-for-gene (because virulent race of pathogen
neutralizes this gene)
Gene-for-gene typically indicates a pathosystem in which the host and
pathogen have evolved over long time periods- so what is going on in
this system?
A quick review of gene-for-gene resistance
Pathogen
genotype
Host
genotype
RR
Rr
rr
VV
-
-
+
Vv
-
-
+
vv
+
+
+
Lesion types: sugar pine
Additional types of tree resistance
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Sugar pine
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Slow rusting resistance - many components of resistance combined
into a single phenotypic expression, exhibited as amount and type of
infection with moderately strong inheritance and independently
inherited expressions (low infection # and high infection abortion)
Ontogenetic resistance - another phenotypic expression that develops
as the tree ages; under genetic controls; offspring may be fully
susceptible
Additional types of tree resistance, cont’d
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Western white pine
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Slow canker growth - non race specific trait; produces
abnormally small cankers; may reduce pruning necessity
(due to success)
Reduced needle lesion frequency - also non race specific
trait; few individual infection sites per seedling; may only be
juvenile trait (seen in cotyledons)
References
Dahir, S.E. and J.E. Cummings Carlson. 2001. Incidence of white pine blister rsut in a high-hazard region of Wisconsin. Nor. J. App. For. 18:(3): 81-86.
Ekramoddoullah, A.K.M. and Y. Tan. 1998. Differential accumulation of proteins in resistant and susceptible sugar pine (Pinus lambertiana) seedlings
inoculated with the white pine blister rust fungus (Cronartium ribicola). Can. J. Plant Path. 20:(3): 308-318.
Ekramoddoullah, A.K.M., Y. Tan, X. Yu, D.W. Taylor and S. Misra. 1999. Identification of a protein secreted by the blister rust fungus Cronartium
ribicola in infected white pines and its cDNA cloning and characterization. Can. J. Bot. 77:(6): 800-808.
Et-touil, K., L. Bernier, J. Beaulieu, J.A. Berube, A. Hopkin and R.C. Hamelin. 1999. Genetic structure of Cronartium ribicola populations in eastern
Canada. Phytopathology 89:(10): 915-919.
Gitzendanner, M.A., E.E. White, B.M. Foord, G.E. Dupper, P.D. Hodgskiss and B.B. Kinloch. 1996. Genetics of Cronartium ribicola: III. Mating system.
Canadian Journal of Botany 74:(11): 1852-1859.
Hamelin, R.C., M. Dusabenyagasani and K. Et-Touil. 1998. Fine-level genetic structure of white pine blister rust populations. Phytopathology 88:(11):
1187-1191.
Hamelin, R.C., R.S. Hunt, B.W. Geils, G.D. Jensen, V. Jacobi and N. Lecours. 2000. Barrier to gene flow between eastern and western populations of
Cronartium ribicola in North America. Phytopathology 90:(10): 1073-1078.
Harkins, D.M., G.N. Johnson, P.A. Skaggs, A.D. Mix, G.E. Dupper, M.E. Devey, B.B. Kinloch and D.B. Neale. 1998. Saturation mapping of a major gene
for resistance to white pine blister rust in sugar pine. Theor. App. Gen. 97:(8): 1355-1360.
Hessburg, P.F., B.G. Smith, R.B. Salter, R.D. Ottmar and E. Alvarado. 2000. Recent changes (1930's-1990's) in spatial patterns of interior northwest forests,
USA. For. Ecol. Man. 136:53-83.
Hoff, R. and S. Hagle. 1990. Diseases of whitebark pine with special emphasis on white pine blister rust. Pp. 179-190. In: W.C. Schmidt & K.J. McDonald
(ed.) Proceedings-Symposium on whitebark pine ecosystems: Ecology and management of a high-mountain resource, USDA For. Serv. Int. Res. Stn. Gen.
Tech. Rep. INT-270
Hoff, R.J., R.T. Bingham and G.I. McDonald. 1980. Relative blister rust resistance of white pines. European J. For. Path. 10:307-316.
Hoff, R.J. and G.I. McDonald. 1971. Resistance to Cronartium ribicola in Pinus monticola: short shoot fungicidal reaction. Can. J. Bot. 49:1235-1239.
Hunt, R.S. 1998. Pruning western white pine in British Columbia to reduce white pine blister rust losses: 10-year results. W. J. App. For. 13:(2): 60-63.
Hunt, R.S. 2000. White pine blister rust, root disease, and bears. Western Journal of Applied Forestry 15:(1): 38-39.
Hunt, R.S. 2002. Relationship between early family-selection traits and natural blister rust cankering in western white pine families. Can. J. Plant Path.
24:200-204.
Hunt, R.S. and G.D. Jensen. 2001. Frequency of resistant western white pine seedlings from parents of different phenotypes. West. J. Appl. For. 16:(4):
149-152.
References, cont’d
Kinloch, B.B. and G.E. Dupper. 1996. Genetics of Cronartium ribicola. I. Axenic culture of haploid clones. Canadian Journal of Botany 74:(3): 456-460.
Kinloch, B.B. and G.E. Dupper. 1999. Evidence of cytoplasmic inheritance of virulence in Cronartium ribicola to major gene resistance in sugar pine.
Phytopathology 89:(3): 192-196.
Kinloch, B.B., Jr. and G.E. Dupper. 2002. Genetic specificity in the white pine-blister rust pathosystem. Phytopathology 92:278-280.
Kinloch, B.B., Jr. and J.L. Littlefield. 1977. White pine blister rust: hypersensitive resistance in sugar pine. Can. J. Bot. 55:1148-1155.
Kinloch, B.B., R.D. Westfall, E.E. White, M.A. Gitzendanner, G.E. Dupper, B.M. Foord and P.D. Hodgskiss. 1998. Genetics of Cronartium ribicola: IV.
Population structure in western North America. Canadian Journal of Botany 76:(1): 91-98.
Kliejunas, J.T. 1985. Spread and intensification of white pine blister rust in the southern Sierra Nevada. Phytopathology 75:(11): 1367.
Maloy, O.C. 1997. White pine blister rust control in North America: A case history. Ann. Rev. Phytopath. 35:87-109.
McDonald, G.I. and R.J. Hoff. 1971. Resistance to Cronartium ribicola in Pinus monticola: Genetic control of needle-spots-only resistance factors. Can. J.
For. Res. 1:(4): 197-202.
Ostrofsky, W.D., T. Rumpf, D. Struble and R. Bradbury. 1988. Incidence of white pine blister rust in Maine after 70 years of a Ribes eradication program.
Plant Dis. 72:(11): 967-970.
Smith, J.P. and J.T. Hoffman. 2001. Site and stand characteristics related to white pine blister rust in high-elevation forests of southern Idaho and estern
Wyoming. West. Nor. Am. Nat. 61:(4): 409-416.
Smith, R.S., Jr. 1992. Spread and intensification of blister rust in the range of sugar pine. Pp. 112-118. In: B.B. Kinloch, Jr., M. Marosy & M.E. Huddleston
(ed.) Sugar pine: Status, vaues, and roles in ecosystems, University of California Div. of Ag. and Nat. Res., University of California, Davis Pub. 3362.
White, E.E., B.M. Foord and B.B. Kinloch. 1996. Genetics of Cronartium ribicola. II. Variation in the ribosomal gene cluster. Canadian Journal of Botany
74:(3): 461-468.
Woo, K.S., L. Fins, G.I. McDonald and M.V. Wiese. 2001. Differences in needle morphology between blister rust resistant and susceptible western white pine
stocks. Can. J. For. Res. 31:1880-1886.
Yu, X., A.K.M. Ekramoddoullah, D.W. Taylor and N. Piggott. 2002. Cloning and characterization of a cDNA of cro rI from the white pine blister rust fungus
Cronartium ribicola. Fungal Gen. Biol. 35:53-66.
Zeglen, S. 2002. Whitebark pine and white pine blister rust in British Columbia, Canada. Can. J. For. Res. 32:1265-1274.