scholarly journals White Pine Blister Rust in British Columbia III. Effects on the Gene Pool of Western White Pine

1985 ◽  
Vol 61 (6) ◽  
pp. 484-488 ◽  
Author(s):  
R. S. Hunt ◽  
J. F. Manville ◽  
E. von Rudloff ◽  
M. S. Lapp

Cluster analyses of relative terpene abundance in foliage of western white pine (Pinus monticola Dougl.) trees from throughout the Pacific Northwest geographic range of the species were produced. Terpene patterns were randomly distributed among populations; no geographic or site trends were evident. Although blister rust is devastating to stands, the gene pool is widely distributed and may well be preserved without establishing gene banks.About 40-50 trees selected at random would yield offspring with nearly all possible terpene patterns characteristic of the species and would thus constitute a broad genetic base. Therefore seed orchards do not necessarily need to be composed of many individuals, rather, they should contain highly selected individuals with multiple desirable traits including multiple blister rust resistance mechanisms. Key words: terpenes, dendrogram

1998 ◽  
Vol 28 (3) ◽  
pp. 412-417 ◽  
Author(s):  
Abul KM Ekramoddoullah ◽  
Joanne J Davidson ◽  
Doug W Taylor

A 19-kDa protein, Pin m III, was recently shown to be associated with overwintering and frost hardiness of western white pine (Pinus monticola Dougl. ex D. Don) seedlings. Here, we report that this protein is up-regulated by the fungus Cronartium ribicola Fisch, the causal agent of white pine blister rust in western white pine trees. Between 1991 and 1994, bark samples of mature western white pine trees (resistant with no stem cankers and susceptible with stem cankers) were collected in winter, spring, and fall. Proteins were extracted and analyzed by Western immunoblot utilizing specific rabbit polyclonal anti-Pin l I (a homologue of Pin m III) antibodies. During all collection dates, but particularly in the spring, susceptible trees had more Pin m III than resistant trees. In July 1995, 43 previously inoculated 7-year-old white pine seedlings were also analyzed. In all susceptible seedlings (cankered) tested, cankered tissue had high levels of Pin m III, and samples collected from the outside edge of the canker margin had low levels of Pin m III; this protein was also detected in some healthy bark of cankered trees. Since the level of Pin m III in healthy white pine trees is normally lowest in summer months, the high level Pin m III in summer samples of infected tissues is a consequence of the fungal infection.


2003 ◽  
Vol 93 (6) ◽  
pp. 691-694 ◽  
Author(s):  
Bohun B. Kinloch ◽  
Richard A. Sniezko ◽  
Gayle E. Dupper

The distribution and frequency of the Cr2 gene for resistance to white pine blister rust (Cronartium ribicola) in western white pine (Pinus monticola) was surveyed in natural populations of the host by inoculation of open-pollinated seedlings from 687 individual seed parents from throughout most of the species' range. Because Cr2 is dominant and results in a conspicuous hypersensitive reaction (HR) in pine needles, the phenotype can readily be detected in offspring of susceptible seed parents fertilized by unknown Cr2 donors in the ambient pollen cloud. Gametic frequencies of Cr2 were thus determined as the proportion of total challenged seedlings that were pollen receptors exhibiting the Cr2 phenotype. Zygotic frequencies, the proportion of seed parents with progeny that segregated in Mendelian ratios for the Cr2 phenotype to the total number of parents, were a complementary, though less precise, measure. Cr2 frequency was rare overall, ranging from 0.004 to 0.008 in the Sierra Nevada to about 0.001 in the central Cascade Range; it was undetectable further north in the Cascades, as well as in the Rocky Mountains and Coast Mountains of the United States and Canada. The diminishing frequency of Cr2 from the southern and central Sierra Nevada northward mirrors that of Cr1 in sugar pine (P. lambertiana) and points to this region as the origin of both genes. We rationalize that this coincidence may have resulted from protection that these genes may have conferred on both species to an endemic pine stem rust congeneric with C. ribicola (C. occidentale) in recent geologic epochs.


2000 ◽  
Vol 10 (3) ◽  
pp. 530-532 ◽  
Author(s):  
R.S. Hunt ◽  
G.D. Jensen

For the white pine blister rust disease (WPBR), reports conflict concerning the time of year the pathogen, Cronartium ribicola J.C. Fisch., infects western white pine (Pinus monticola D. Don) and what needle age increments are most susceptible. To determine timing of infection, western white pine seedling were placed under infected currants (Ribes nigrum L.) for 1-week periods from May to November. Needles became spotted and stems cankered after exposure to diseased currants from early summer until leaf drop in November. To determine what foliage age increment was most susceptible, 5-year-old seedlings were placed in a disease garden, and older trees were inoculated in situ. All age increments of pine foliage were susceptible to infection. For young seedlings, all age increments were about equally susceptible, but on some older seedlings and trees, the current year's foliage appeared more resistant than older foliage.


2000 ◽  
Vol 10 (3) ◽  
pp. 523-527 ◽  
Author(s):  
John A. Muir ◽  
Richard S. Hunt

Introductions of white pine blister rust (WPBR, causal fungus: Cronartium ribicola J.C. Fischer) to eastern and western North America before 1915 caused such extensive damage that western white pine (Pinus monticola D. Don) was essentially abandoned as a manageable forest tree species for over 60 years. Recent results from WPBR resistance selection and breeding programs, and from field trials of tree spacing, pruning and bark excision treatments have supported efforts to increase establishment and to intensively manage western white pine. Western white pine is a desirable component in many forested areas because of its faster growth and much higher value compared to many other associated tree species. It also has a low susceptibility to armillaria root disease caused by Armillaria ostoyae (Romagnesi) Herink and laminated root rot, caused by Phellinus weirii (Murr.) Gilb. Some regulations, e.g., Forest Practices Code of British Columbia (BC) Act, require anyone who harvests timber on provincial forestland and uses western white pine for reforestation to either plant genetically resistant western white pine stock or prune susceptible young trees for protection. Risks of increased WPBR associated with increased commercial cultivation of gooseberries and currants (Ribes L.) have yet to be determined. However, major threats appear to include 1) increase in local amounts of spores for nearby infection of pines; and 2) possible introductions or development of new, virulent races of C. ribicola, particularly from eastern to Pacific northwestern North America. In view of these possible threats, we recommend that existing regulations and legislation should be amended, or possibly new measures enacted, to permit propagation and commercial cultivation only of varieties of Ribes that are immune or highly resistant to WPBR.


1991 ◽  
Vol 67 (3) ◽  
pp. 284-287 ◽  
Author(s):  
R. S. Hunt

Line surveys were conducted in 13 young western white pine (Pinus monticola D. Don) stands throughout British Columbia to determine the effectiveness of lower branch removal in controlling blister rust (Cronartium ribicola Fischer). Uninfected trees and most trees with infected branches were protected from future stem infections. In general, effectiveness and efficiency could have been improved by (a) earlier treatment to reduce stem infections, (b) not treating trees with infected stems, (c) treating all other trees, and (d) removing infected branches above the treatment height. Some stands were spaced during treatment; however, untrained fallers failed to distinguish between healthy trees and those with infected stems. Frequently healthy trees were felled while diseased trees were left standing. A pre-treatment survey is recommended to determine the level of crew training needed and treatment prescription.


1983 ◽  
Vol 59 (1) ◽  
pp. 30-33 ◽  
Author(s):  
R. S. Hunt

Twelve to 30-year-old western white pine (Pinus monticola Dougl.) in 23 stands in British Columbia were surveyed for blister rust (Cronartium ribicola J.C. Fisch. ex Rab.) cankers. Canker length, mid-point diameter, and height above ground were measured. The number of cankers per tree tended to increase with tree diameter, was variable within stands, and on 15 to 20 cm diameter trees ranged from a mean of one to 14 per stand and the overall mean was four cankers per tree. Large branches bore longer cankers and tended to be higher in the tree than small branches which bore short cankers. Incidence of cankers above 2.5 m tended to increase with increasing slope and they were on the side of the tree subject to evening breezes. Based on Idaho standards all sites in British Columbia were rated as low hazard, but trees growing on slopes had a higher risk than those on flat sites.Key words:Cronartium, Pinus monticola, hazard rating


2000 ◽  
Vol 10 (3) ◽  
pp. 519-522 ◽  
Author(s):  
Richard A. Sniezko ◽  
Andrew Bower ◽  
Jude Danielson

Seedlings from 12 sugar pine (Pinus lambertiana Dougl.) and 13 western white pine (Pinus monticola Dougl.) families were planted at Happy Camp, Calif., in 1996. Assessment in Summer 1999 indicated moderate levels of white pine blister rust (Cronartium ribicola Fischer) infection. This paper focused on the species differences and showed that sugar pine had a higher incidence of stem infection (active and inactive cankers) and more stem infections per tree than western white pine. An unexpected result was the very high percentage of infections that were bark reactions (completely inactivated infections), despite the fact that only some of the families of both species were selected for this mechanism. Assessments in subsequent years will track the future performance of the two species and of the individual families.


1982 ◽  
Vol 58 (3) ◽  
pp. 136-138 ◽  
Author(s):  
R. S. Hunt

White pine blister rust (Cronartium ribicola J.C. Fisch. ex Rab.) branch cankers on 12- to 30-year-old western white pines (Pinus monticula Dougl.) in British Columbia were measured for distance from the stem, and cankers on branches and stems were measured for height above ground. Most stem cankers originated from branch cankers within 60 cm of the stem and within 2.5 m of the ground. Trees on slopes tended to have cankers higher into the crown than those on flat sites. Removal of lower branches from young western white pines will greatly reduce the possibility of death from blister rust infection. Treatment recommendations are given for western white pine as a minor or major component of the stand. Keywords: Cronartium; Pinus monticola


1972 ◽  
Vol 104 (11) ◽  
pp. 1713-1715 ◽  
Author(s):  
Malcolm M. Furniss ◽  
R. D. Hungerford ◽  
E. F. Wicker

AbstractInsects present in western white pine blister rust cankers in northern Idaho were: two weevils, Cylindrocopturus n. sp. and Pissodes sp. near swartzi Hopk.; two bark beetles, Pityophthorus sp. near nitidulus (Mann.), and Procryphalus ? sp.; a drosophilid fly, Paracacoxenus guttatus Hardy and Wheeler; and a phycitid moth, Dioryctria abietivorella (Grote). Mites associated with insect infestation were: Lasioseius ? n. sp., Ameroseius longitrichus Hirschmann, and Histiogaster arborsignis Woodring.


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