LINKAGE RELATIONSHIPS AMONG 19 POLYMORPHIC ALLOZYME LOCI IN COASTAL DOUGLAS-FIR (PSEUDOTSUGA MENZIESII var. MENZIESII)

1982 ◽  
Vol 24 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Y. A. El-Kassaby ◽  
O. Sziklai ◽  
F. C. Yeh
Keyword(s):  
Pseudotsuga Menziesii ◽  
Genetic Linkage ◽  
Douglas Fir ◽  
Conifer Species ◽  
Polymorphic Loci ◽  
Allozyme Loci ◽  
Linkage Relationships

Linkage relationships among 19 different polymorphic loci in coastal Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) were studied. A total of 115 of 171 possible two-locus combinations were tested. Out of the 115 combinations, a total of 106 conform to the hypothesis of independence between loci indicating that no linkage exists between these pairs. Of the remaining nine pairs, two were tightly linked with recombination frequencies of 0.02 (Aat2:Pgi2) and 0.22 (Aat3:Sod). The remaining were loosely linked, with recombination frequencies varying between 0.33 and 0.42. Two of these nine linked pairs have been detected in other conifer species. It was not possible to study three-point linkages due to the lack of appropriate combinations. To our knowledge, these results provide the first demonstration of genetic linkage in Douglas-fir.

scholarly journals Vigilantreg; herbicide for control of two wilding conifer species contorta pine and Douglas fir

2004 ◽  
Vol 57 ◽  
pp. 94-97
Author(s):  
M. Newfield ◽  
B.G. Ward
Keyword(s):  
Pseudotsuga Menziesii ◽  
Death Rate ◽  
Pinus Contorta ◽  
Douglas Fir ◽  
Conifer Species ◽  
Leaf Distortion

Wilding conifers are usually killed without herbicide by severing the stem below the lowest green needles This is difficult for example when multistemmed trees are growing on unstable or rocky substrates Under such circumstances a picloram gel formulation (Vigilantreg; herbicide gel) was applied to freshly cut surfaces of stumps of contorta pine (Pinus contorta) and Douglas fir (Pseudotsuga menziesii) Stumps were pruned so that some green needles remained on the stump below the cut Treatments were applied in May 2002 After 6 months many herbicidetreated plants showed leaf distortion and yellowing After 18 months 97 of the 75 herbicidetreated contorta pine plants were dead compared with only 13 (n30) of those receiving no herbicide The herbicide killed 100 of the 15 treated Douglas fir plants compared with 3 death rate for the 15 receiving no herbicide

Identification and dendrochronology of wood found at the Ziegler Reservoir fossil site, Colorado, USA

2014 ◽  
Vol 82 (3) ◽  
pp. 575-579 ◽  
Author(s):  
Peter M. Brown ◽  
Stephen E. Nash ◽  
Douglas Kline
Keyword(s):  
Climate Variability ◽  
Pseudotsuga Menziesii ◽  
Environmental Conditions ◽  
Douglas Fir ◽  
Annual Growth ◽  
Similar Data ◽  
Conifer Species ◽  
Growth Rings ◽  
Annual Growth Rings ◽  
Fossil Site

AbstractOver 300 wood fossils were collected from the Ziegler Reservoir fossil site near Snowmass Village in central Colorado, USA. Wood fossils range from fragments of stems and branches only a few centimeters in diameter and length to whole logs >50 cm diameter and >10 m length. Many of the fossils were collected from a “beach” horizon, where they appear to have been washed up on the side of the interglacial lake and buried. The wood is mainly fir (Abies sp.) or Douglas-fir (Pseudotsuga menziesii), with some spruce (Picea sp.), pine (Pinus sp.), and at least one other unidentified conifer species. Douglas-fir and species of fir, spruce, and pine are common in the area today. Dendrochronological analyses compared annual growth rings in fossil wood to similar data from modern trees. Results suggest that fossil trees from the beach horizon grew under similar environmental conditions and annual climate variability as today. Three Douglas-firs and several fir logs also appear to have been alive at the same time based on crossdating of ring widths and other ring characteristics. These trees may have died at the same time, suggesting a stand mortality event in the surrounding forest that resulted in numerous logs being buried synchronously in the beach horizon.

scholarly journals GENETIC DIVERSITY AND DIFFERENTIATION OF Pseudotsuga menziesii (Mirb.) Franco POPULATIONS IN MÉXICO

2011 ◽  
Vol 34 (4) ◽  
pp. 233 ◽  
Author(s):  
Jorge Cruz-Nicolás ◽  
J. Jesús Vargas-Hernández ◽  
Porfirio Ramírez-Vallejo ◽  
Javier López-Upton
Keyword(s):  
Genetic Diversity ◽  
Pseudotsuga Menziesii ◽  
In Situ Conservation ◽  
Mantel Test ◽  
Douglas Fir ◽  
Population Divergence ◽  
Central Mexico ◽  
Gene Pools ◽  
Polymorphic Loci ◽  
Northwestern Mexico

Mexican populations of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] constitute valuable gene pools for conservation and breeding programs of this species. Genetic diversity and population divergence were estimated using 18 isozyme loci and samples from 11 natural Douglas-fir populations in México. Genetic diversity was high at the species level (83.3 % polymorphic loci and 2.9 alleles per locus), but low at the population level (28.3 % polymorphic loci and 1.52 alleles per locus), particularly for populations from central México. A high level of population differentiation was found (Fst = 0.298), indicating that each population shares only a small fraction of the genetic diversity within the species and that genetic drift might have an important role in shaping the structure of genetic diversity in these populations. Genetic distances among populations in the Sierra Madre Oriental were positively correlated with geographic distances (r = 0.849), but the association was not significant according to the Mantel test. Populations from northeastern México separated from all others, whereas population Mohinora from northwestern México, joined those from central México. These results emphasize the priority for in situ conservation of Douglas-fir populations in central México.

scholarly journals Pathogenicity and Virulence of Pythium Species Obtained from Forest Nursery Soils on Douglas-Fir Seedlings

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 744-748 ◽  
Author(s):  
Jerry E. Weiland ◽  
Bryan R. Beck ◽  
Anne Davis
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Survival ◽  
The United States ◽  
Douglas Fir ◽  
Tree Seedlings ◽  
Pythium Species ◽  
Forest Nursery ◽  
Damping Off ◽  
Greenhouse Study ◽  
Forest Nurseries

Pythium species are common soilborne oomycetes that occur in forest nursery soils throughout the United States. Numerous species have been described from nursery soils. However, with the exception of P. aphanidermatum, P. irregulare, P. sylvaticum, and P. ultimum, little is known about the potential for other Pythium species found in nursery soils to cause damping-off of tree seedlings. A greenhouse study was conducted to evaluate the pathogenicity and virulence of 44 Pythium isolates representing 16 species that were originally recovered from soil at three forest nurseries in Washington and Oregon. Seeds of Douglas-fir (Pseudotsuga menziesii) were planted into soil infested with each of the isolates. Seedling survival, the number of surviving seedlings with necrotic root lesions, and taproot length were evaluated 4 weeks later. Responses of Douglas-fir to inoculation varied significantly depending on Pythium species and isolate. Eight species (P. dissotocum, P. irregulare, P. aff. macrosporum, P. mamillatum, P. aff. oopapillum, P. rostratifingens, P. sylvaticum, and P. ultimum var. ultimum) significantly reduced the number of surviving seedlings compared to the noninoculated treatment. However, all Pythium species caused a greater percentage of seedlings to develop root lesions (total mean 40%) than was observed from noninoculated seedlings (17%). Taproot length varied little among Pythium treatments and was not a useful character for evaluating pathogenicity. Results confirm the ability of P. irregulare, P. mamillatum, and P. ultimum var. ultimum to cause damping-off of Douglas-fir seedlings, and are indicative that other species such as P. dissotocum, P. aff. macrosporum, P. aff. oopapillum, P. rostratifingens, and P. sylvaticum may also be responsible for seedling loss.

Cylindrocarpon and Fusarium root colonization of Douglas-fir seedlings from British Columbia reforestation sites

1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Root Colonization ◽  
Linear Trend ◽  
Poor Performance ◽  
Douglas Fir ◽  
Root Infection ◽  
Significant Linear Trend ◽  
Conifer Seedlings ◽  
Cylindrocarpon Destructans

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.

scholarly journals Linkage relationships of allozyme loci in Pinus sylvestris

Hereditas ◽  
2008 ◽  
Vol 111 (2) ◽  
pp. 91-97 ◽  
Author(s):  
ALFRED E. SZMIDT ◽  
OUTI MUONA
Keyword(s):  
Pinus Sylvestris ◽  
Allozyme Loci ◽  
Linkage Relationships

Distribution of leaf orientations in six conifer species

2001 ◽  
Vol 79 (4) ◽  
pp. 389-397 ◽  
Author(s):  
Hugh J Barclay
Keyword(s):  
Pseudotsuga Menziesii ◽  
Pinus Contorta ◽  
Goodness Of Fit ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
The Other ◽  
Thuja Plicata ◽  
Leaf Angle ◽  
Conifer Species ◽  
Abies Grandis

Leaf angle distributions are important in assessing both the flexibility of a plant's response to differing daily and seasonal sun angles and also the variability in the proportion of total leaf area visible in remotely sensed images. Leaf angle distributions are presented for six conifer species, Abies grandis (Dougl. ex D. Don) Lindl., Thuja plicata Donn. ex D. Don, Tsuga heterophylla (Raf.) Sarg., Pseudotsuga menziesii (Mirb.) Franco, Picea sitchensis (Bong.) Carr. and Pinus contorta Dougl. ex Loud. var. latifolia. The leaf angles were calculated by measuring four foliar quantities, and then the distributions of leaf angles are cast in three forms: distributions of (i) the angle of the long axis of the leaf from the vertical for the range 0–180°; (ii) the angle of the long axis of the leaf for the range 0–90°; and (iii) the angle of the plane of the leaf for the range 0–90°. Each of these are fit to the ellipsoidal distribution to test the hypothesis that leaf angles in conifers are sufficiently random to fit the ellipsoidal distribution. The fit was generally better for planar angles and for longitudinal angles between 0° and 90° than for longitudinal angles between 0° and 180°. The fit was also better for Tsuga heterophylla, Pseudotsuga menziesii, Picea sitchensis, and Pinus contorta than for Abies grandis and Thuja plicata. This is probably because Abies and Thuja are more shade tolerant than the other species, and so the leaves in Abies and Thuja are preferentially oriented near the horizontal and are much less random than for the other species. Comparisons of distributions on individual twigs, whole branches, entire trees, and groups of trees were done to test the hypothesis that angle distributions will depend on scale, and these comparisons indicated that the apparent randomness and goodness-of-fit increased on passing to each larger unit (twigs up to groups of trees).Key words: conifer, leaf angles, ellipsoidal distribution.

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