field results of white pine blister rust resistance in sugar pine and western white pine seedlings

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Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings Andrew D. Bower and Richard A. Sniezko USDA Forest Service, Dorena Genetic Resource Center.

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Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings. Andrew D. Bower and Richard A. Sniezko USDA Forest Service, Dorena Genetic Resource Center. Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings. - PowerPoint PPT Presentation

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Page 1: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Field Results of White Pine Blister Rust Resistance in Sugar Pine and

Western White Pine Seedlings

Andrew D. Bower and Richard A. Sniezko

USDA Forest Service, Dorena Genetic Resource Center.

Page 2: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

• Background

• Introduction

• Objectives

• Materials and Methods

• Results

• Discussion

• Conclusions

Page 3: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Background

• White pine blister rust (Cronartium ribicola) (WPBR) introduced to western N. America in 1910.

• WPBR affects western white pine (WWP)(Pinus monticola), sugar pine (SP)(P. lambertiana) and other 5 needle pines.

• Alternate hosts are Ribes spp.• Produces a diamond-shape canker that eventually can girdle

the stem, killing the tree.• Low level of naturally occurring resistance.• Major Gene Resistance and virulent strains of rust.

Page 4: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Introduction

• USDA Forest Service has been screening WWP and SP for WPBR resistance since the 1950’s.

• Progeny of over 10,000 phenotypic selections have been tested at the Dorena Genetic Resource Center (DGRC).

• <5% of these selections have >30% canker-free progeny, and 95% of the seedlings develop lesions and die within the 5-year evaluation period.

Page 5: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Objectives

• Investigation of field performance of progeny of individuals selected in short-term screening.

• Field validation of resistance mechanisms observed in artificial screening.

• Examination of the gains from WPBR resistance screening and breeding.

Page 6: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Materials and Methods

• Established in Spring 1996 at Happy Camp, California, with 1-0 container stock.

• 12 SP and 13 WWP families of varying resistance levels.

• 12 blocks.• Randomized complete-block design.• 4 tree row-plots, each family represented once in

each block.

Page 7: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Measurements

• Height

• Number of cankers on bole

• Type and number of infections

• Damage

• Tree vigor

Page 8: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Stem Infection Types

• Normal (N) – active stem infection.

• Bark Reaction (BR) – canker inactive or “corked out”.

• Partial Bark Reaction (PBR) – bark reaction with some area of canker still alive.

• Blight (BL) – inactive canker on a branch that was killed.

Page 9: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Analysis

• ANOVA used to test for differences between species and among families within a species.

–Infection % (using rep means)

–Height (using individuals)

–# infections per tree (using individuals)

• X2 test of independence to determine presence of an association between species and stem infection type.

Page 10: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Results

Results of analysis comparing species published as part of the proceedings of the “Ribes, Pines, and White Pine Blister Rust Conference” in Corvallis, Oregon. September 8-10, 1999.

HortTechnology 10(3):519-522

Page 11: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Survival and Growth

SP WWP

# Planted 560 616

# Surviving 555 607

% Survival 99.1% 98.5%

Height 34.8” (88.5cm) 29.8” (75.6cm)

Page 12: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Infection Percent

SP WWP

% of living trees infected 70.2% 34.3%

% with only 1 canker 27.5% 21.8%

% with >1 canker 42.7% 12.5%

Page 13: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Infection

SP WWP

Total # of cankers 953 356

Total # of infected trees 393 211

Mean # Infections/tree (infected trees only)

2.42 1.69

Range 0-17 0-9

Page 14: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Species Difference Results

P-value

Source % Infection Height # Cankers

Block 0.0068** 0.0829* 0.1433

Species 0.0001** 0.0005** 0.0014**

B x S - 0.0326** 0.2697

* Significant and = 0.1

** Significant and = 0.05

Page 15: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Family Analysis Results

P-value

Source % Infection Height # Cankers

Block 0.0068** 0.0063** 0.0975*

Species 0.0001** 0.0019** 0.0001**

B x S 0.8444 0.2815 0.0893*

Family(S) 0.0001** 0.0001** 0.1714

B x F(S) - 0.0001** 0.0001**

Page 16: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Observed and expected # of stem infections

Sugar Pine Western White Pine

Obs. Exp. Obs. Exp. Total

Normal 256 (26.9%) 267 111 (31.2%) 100 367

PBR 134 (14.1%) 148 69 (19.4%) 55 203

BR 394 (41.3%) 370 114 (32.0%) 138 508

BL 169 (17.7%) 168 62 (17.4%) 63 231

Total 953 356 1309

2 test for independence = 12.272, P = 0.007

Page 17: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Bark Reaction

• High incidence of Bark Reaction NOT expected.

Mean of family means SP WWP

% BR in screening 13.2 28.4

% BR in field 60.9 25.4

Correlation 0.336 -0.270

Page 18: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Discussion

• Reason for high incidence of BR unknown.• Hunt (1997) isolated several different fungi types

from BR phenotypes in WWP.– Most common was phoma wilt (Phoma herbarum),

which produces lesions identical to BR

• BR has been shown to be real and repeatable.• Other confounding biological or environmental

factors causing high level of BR.

Page 19: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Conclusions

• SP more susceptible than WWP at this site.

• Significant differences between species exist for infection percentage, height, and number of cankers/tree.

• Significant differences among families within a species exist for infection percentage, and height only.

Page 20: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Conclusions

• Both species exhibit moderate levels of BR.• A significant association exists between species and

infection type.

• Low correlation between family mean BR % in screening and field site.

SP WWPN < exp. > exp.PBR < exp. > exp.BR > exp. < exp.

Page 21: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Future Assessment

• 5th year measurements currently under way.• Differential rates of mortality following infection.• Long term differences in BR and tolerance

between species and families with species.• Essential validation of results of artificial

inoculation tests.• Information on current gains in rust resistance

from seed orchards.

Page 22: Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine Seedlings

Acknowledgements

• Dean Davis, and Deems Burton.

• Dr. B. B. Kinloch and Dr. R. Westfall

• Lee Riley, Jude Danielson, Bob Danchok, Sally Long, and Ann Willyard.

• USDA Forest Service, Forest Health and Protection Program