Ecotypic mode of regional differentiation caused by restricted gene migration: a case in black cottonwood (Populus trichocarpa) along the Pacific Northwest coast

2009 ◽  
Vol 39 (3) ◽  
pp. 519-525 ◽  
Author(s):  
Chang-Yi Xie ◽  
Cheng C. Ying ◽  
Alvin D. Yanchuk ◽  
Diane L. Holowachuk
Keyword(s):  
Genetic Differentiation ◽  
Pacific Northwest ◽  
Populus Trichocarpa ◽  
Common Garden ◽  
Northern Region ◽  
Regional Differentiation ◽  
Black Cottonwood ◽  
Gene Migration ◽  
Geographic Patterns ◽  
Leaf Flushing

Genetic differentiation of black cottonwood ( Populus balsamifera subsp. trichocarpa (Torr. & A. Gray ex Hook) Brayshaw) across a “no-cottonwood” belt on the coast of central British Columbia (BC), Canada, was examined using data on 3 year height, severity of infection by Valsa sordida Nitschke and Melampsora occidentalis H. Jacks., and abnormality of leaf flushing. The data were collected in a common-garden test consisting of 180 provenances of 36 drainages ranging from northern BC to Oregon, USA. The results demonstrated an ecotypic mode, north–south regional differentiation. Valsa sordida and M. occidentalis infected 41% and 89%, respectively, of the trees from the northern region, while 66% showed flushing abnormality. In contrast, only 1% and 27% of their southern counterparts were infected by the same diseases, and 1% had abnormal flushing. Trees from the northern region averaged 87% shorter than those from the south. Regional differentiation accounted for the highest amount of variation observed in all traits, with 60% in 3 year height, 34% in V. sordida, 76% in M. occidentalis, and 50% in abnormal leaf flushing. Regression analysis revealed geographic patterns that essentially reflected regional differentiation along the no-cottonwood belt. The species’ distribution biography, ecological characteristics, and life history suggest that restricted gene migration was the main factor responsible for the observed geographic patterns of genetic differentiation.

Cold hardiness in coastal, montane, and inland populations of Populus trichocarpa

2000 ◽  
Vol 30 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Thaddeus McCamant ◽  
R Alan Black
Keyword(s):  
Pacific Northwest ◽  
Freezing Tolerance ◽  
Laboratory Tests ◽  
Cold Hardiness ◽  
Populus Trichocarpa ◽  
Hybrid Poplar ◽  
Field Tests ◽  
Common Garden ◽  
Freezing Injury ◽  
Black Cottonwood

Freezing tolerance was studied in laboratory and field tests using black cottonwood, Populus trichocarpa Torr. & Gray, clones collected from eight populations within the coastal, montane, and inland regions of the Pacific Northwest. Freezing tolerance varied among different populations and was dependent on growing environment. Clones from coastal populations grown in a coastal common garden (Puyallup, Wash.) had 50% less injury in laboratory tests compared with the same clones grown in an inland common garden (Pullman, Wash.). In contrast, clones from inland populations grown in an inland common garden had 50% less injury in laboratory tests compared with the same clones grown in a coastal common garden. Freezing tolerance also varied between coastal populations. In field tests at the inland common garden, clones from inland and montane populations had less freezing injury compared with clones from coastal populations. Leaves on 50% of the clones with coastal origins were killed by the first fall frosts compared with 25% for clones with inland origins. Subsequently, 50% of the coastal clones exhibited winter injury following the winters of 1993-1994 and 1994-1995 at the inland common garden. Clones from inland populations exhibited little or no winter injury. The specific tissues injured during freezing tests varied among clones. Populus trichocarpa is a species offering considerable variation for selection to local environments, and therefore, the source of material should be an important consideration in hybrid poplar breeding programs.

Genetic variation in red alder (Alnusrubra) in relation to native climate and geography

1993 ◽  
Vol 23 (9) ◽  
pp. 1930-1939 ◽  
Author(s):  
A. A. Ager ◽  
P. E. Heilman ◽  
R. F. Stettler
Keyword(s):  
Genetic Variation ◽  
Pacific Northwest ◽  
Growth Traits ◽  
Common Garden ◽  
Sympatric Species ◽  
Red Alder ◽  
Geographic Patterns ◽  
The Pacific ◽  
Shoot Phenology ◽  
River Drainages

Genetic variation was examined within and among populations of red alder (Alnusrubra Bong.) from elevational gradients in four river drainages of the Pacific Northwest. Wind-pollinated progenies of 120 trees were grown for 3 years in a common garden environment and measured for growth and shoot phenology. Variation in top weight, bud flush, and leaf abscission was analyzed in relation to native climate and elevation and compared with sympatric species. Strong geographic patterns of variation were observed for all measured traits, apparently reflecting adaptations to highly variable climates within the region studied. Growth traits were correlated with temperature amplitude and length of growing season. Growth rhythm in bud flushing and growth cessation was related to two important environmental cues, spring thermal sums and fall frost dates. Overall levels of variation in red alder appeared to be similar to several sympatric conifers, although variation within populations of red alder was lower. The latter finding may be due to the demography of the riparian populations sampled, or perhaps a characteristic of the species and its colonizing life history.

scholarly journals Mechanisms of methane transport through <i>Populus trichocarpa</i>

2016 ◽  
Author(s):  
Ellynne Kutschera ◽  
Aslam Khalil ◽  
Andrew Rice ◽  
Todd Rosenstiel
Keyword(s):  
Pacific Northwest ◽  
Populus Trichocarpa ◽  
Transport Processes ◽  
Ch4 Emission ◽  
Transport Mechanisms ◽  
Black Cottonwood ◽  
The Pacific ◽  
Average Flux ◽  
The Common ◽  
Hydroponic Conditions

Abstract. Although the dynamics of methane (CH4) emission from croplands and wetlands have been fairly well investigated, the contribution of trees to global CH4 emission and the mechanisms of tree transport are relatively unknown. CH4 emissions from the common wetland tree species Populus trichocarpa (black cottonwood) native to the Pacific Northwest were measured under hydroponic conditions in order to separate plant transport mechanisms from the influence of soil processes. Roots were exposed to CH4 enriched water and canopy emissions of CH4 were measured. The average flux for 34 trials (at temperatures ranging from 17 to 25 °C) was 2.8 ± 2.2 μg CH4 min−1 (whole canopy). Flux increased with temperature. Compared to the isotopic composition of root water CH4, δ13C values were depleted for canopy CH4 where the warmest temperatures (24.4–28.7 °C) resulted in an epsilon of 2.8 ± 4.7 ‰; midrange temperatures (20.4–22.1 °C) produced an epsilon of 7.5 ± 3.1 ‰; and the coolest temperatures (16.0–19.1 °C) produced an epsilon of 10.2 ± 3.2 ‰. From these results it is concluded that there are likely multiple transport processes at work in CH4 transport through trees and the dominance of these processes changes with temperature. The transport mechanisms that dominate at low temperature and low flux result in a larger fractionation, while the transport mechanisms that prevail at high temperature and high flux produce a small fractionation. Further work would investigate what combination of mechanisms are specifically engaged in transport for a given fractionation of emitted CH4.

scholarly journals First report of Armillaria cepistipes causing root disease on Populus trichocarpa (black cottonwood) in Oregon, USA.

Plant Disease ◽  
2021 ◽  
Author(s):  
Brandon Alveshere ◽  
Patrick Bennett ◽  
Mee-Sook Kim ◽  
Ned B. Klopfenstein ◽  
Jared M. LeBoldus
Keyword(s):  
North America ◽  
Pacific Northwest ◽  
North American ◽  
Tree Species ◽  
Populus Trichocarpa ◽  
Phylogenetic Study ◽  
Malt Extract ◽  
Black Cottonwood ◽  
The Pacific ◽  
Armillaria Cepistipes

Populus trichocarpa Torr. and Gray (black cottonwood) is an economically and ecologically important tree species native to western North America. It serves as a model tree species in biology and genetics due to its relatively small genome size, rapid growth, and early reproductive maturity (Jansson and Douglas 2007). Black cottonwood is susceptible to root rot caused by at least one species of Armillaria (Raabe 1962), a globally distributed genus that exhibits diverse ecological behaviors (Klopfenstein et al. 2017) and infects numerous woody plant species (Raabe 1962). However, several Armillaria spp. have been isolated from Populus spp. in North America (Mallet 1990), and the most recent report of Armillaria on P. trichocarpa used the now ambiguated name A. mellea (Vahl.) Quel. (see Raabe 1962). In April 2016, mycelial fans and rhizomorphs of an unknown Armillaria species (isolate WV-ARR-3) were collected from P. trichocarpa in a riparian hardwood stand ca. 5.5 km east of Springfield, Oregon, USA (44°3'21.133"N, 122°49'39.935"W). The host was dominant in the canopy, large in diameter (ca. 90-cm dbh) relative to neighboring trees, and exhibited minimal crown dieback (ca. < 5%). A mycelial fan was observed destroying living cambium beneath the inner bark, indicating pathogenicity. The isolate was cultured on malt extract medium (3% malt extract, 3% dextrose, 1% peptone, and 1.5 % agar) and identified as A.cepistipes on the basis of somatic pairing tests and translation elongation factor 1α (tef1) sequences (GenBank Accession No. MK172784). DNA extraction, PCR, and tef1 sequencing followed protocols of Elías-Román et al. (2018). From nine replications of somatic incompatibility tests (18 tester isolates representing six North American Armillaria spp.), the isolate showed high intraspecific compatibility (colorless antagonism) with three A. cepistipes tester isolates (78%), but low compatibility with the other Armillaria spp. (0 – 33%) that occur in the region. Isolate WV-ARR-3 yielded tef1 sequences with a 99% identity to A. cepistipes (GenBank Accession Nos. JF313115 and JF313121). A second isolate (WV-ARR-1; GenBank Accession No. MK172783) with a nearly identical sequence was collected from a maturing P. trichocarpa in a riparian stand ca. 8 km northeast of Monroe, Oregon (44°21’47.57”N, 123°13’14.415”W) along the Willamette River, downstream from the McKenzie river tributary where WV-ARR-3 was collected. Armillaria cepistipes has been reported on Alnus rubra (red alder) in Washington, USA (Banik et al. 1996) and on broad-leaved trees in British Columbia, Canada (Allen et al. 1996). It is generally considered to be a weak pathogen on broad-leaved trees in the Pacific Northwest, but it is also associated with pathogenicity on both coniferous and deciduous trees in Europe (e.g., Lygis et al. 2005). However, a recent phylogenetic study suggested that North American A. cepistipes is phylogenetically distinct from Eurasian A. cepistipes (Klopfenstein et al. 2017), butadditional studies are needed to determine the formal taxonomic status of North American A. cepistipes. To our knowledge, A. cepistipes has not been previously confirmed on P. trichocarpa in the U.S.A. or formally reported as a pathogen of any Populus species in North America. Continued studies are needed to determine the distribution, host range, and ecological role of A. cepistipes in riparian forests of the Pacific Northwest, while monitoring its populations under changing climates.

Geographic variation in ecophysiological traits of black cottonwood (Populus trichocarpa)This article is one of a selection of papers published in the Special Issue on Poplar Research in Canada.

2007 ◽  
Vol 85 (12) ◽  
pp. 1202-1213 ◽  
Author(s):  
Jemma L. Gornall ◽  
Robert D. Guy
Keyword(s):  
Water Use ◽  
Stomatal Density ◽  
Isotope Composition ◽  
Populus Trichocarpa ◽  
Stable Carbon Isotope ◽  
Common Garden ◽  
Leaf Nitrogen ◽  
Black Cottonwood ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

Variation in traits related to photosynthesis and water-use were examined within and between geographic sources (provenances) of black cottonwood in two range-wide common garden experiments in British Columbia, Canada. In the first experiment, CO2 assimilation (A), stomatal conductance (gs), instantaneous intrinsic water use efficiency (WUEi), stomatal density, specific leaf area, growth height, and foliar N were measured on five 2-year-old trees of 20 clones from five widely separated provenances (i.e., 4 clones per source). Leaf disks were analysed for stable carbon isotope composition (δ13C) to provide a more long-term measure of WUE. Photosynthetic rate per unit leaf nitrogen was used as a measure of nitrogen use efficiency (NUE). A differed between (p < 0.001), but not within provenances, and increased with latitude of origin (R2 = 0.70). NUE and WUEi also varied between (p = 0.034 and p = 0.039, respectively), but not within provenances. In contrast, no variation among provenances was detected for δ13C, but there were strong differences between clones within provenances (p < 0.001). Variation in A was well correlated with foliar nitrogen, gs, and stomatal density and adaxial:abaxial distribution ratio; hence, WUEi, δ13C and NUE were mostly unrelated to latitude or associated climate variables. Species-wide patterns in stomatal density and distribution were confirmed in the second experiment which utilized 140 clones. Stomatal density on the adaxial (but not the abaxial) leaf surface was strongly correlated with latitude (p <0.001). We speculate that northern provenances may have inherently higher A and gs to compensate for shorter growing seasons.

scholarly journals A peroxisomal β-oxidative pathway contributes to the formation of C6–C1 aromatic volatiles in poplar

2021 ◽  
Author(s):  
Nathalie D Lackus ◽  
Axel Schmidt ◽  
Jonathan Gershenzon ◽  
Tobias G Köllner
Keyword(s):  
Cinnamic Acid ◽  
Aromatic Compounds ◽  
Populus Trichocarpa ◽  
Alternative Pathway ◽  
Gene Families ◽  
Defense Responses ◽  
In Planta ◽  
Black Cottonwood ◽  
Oxidative Pathway

AbstractBenzenoids (C6–C1 aromatic compounds) play important roles in plant defense and are often produced upon herbivory. Black cottonwood (Populus trichocarpa) produces a variety of volatile and nonvolatile benzenoids involved in various defense responses. However, their biosynthesis in poplar is mainly unresolved. We showed feeding of the poplar leaf beetle (Chrysomela populi) on P. trichocarpa leaves led to increased emission of the benzenoid volatiles benzaldehyde, benzylalcohol, and benzyl benzoate. The accumulation of salicinoids, a group of nonvolatile phenolic defense glycosides composed in part of benzenoid units, was hardly affected by beetle herbivory. In planta labeling experiments revealed that volatile and nonvolatile poplar benzenoids are produced from cinnamic acid (C6–C3). The biosynthesis of C6–C1 aromatic compounds from cinnamic acid has been described in petunia (Petunia hybrida) flowers where the pathway includes a peroxisomal-localized chain shortening sequence, involving cinnamate-CoA ligase (CNL), cinnamoyl-CoA hydratase/dehydrogenase (CHD), and 3-ketoacyl-CoA thiolase (KAT). Sequence and phylogenetic analysis enabled the identification of small CNL, CHD, and KAT gene families in P. trichocarpa. Heterologous expression of the candidate genes in Escherichia coli and characterization of purified proteins in vitro revealed enzymatic activities similar to those described in petunia flowers. RNA interference-mediated knockdown of the CNL subfamily in gray poplar (Populus x canescens) resulted in decreased emission of C6–C1 aromatic volatiles upon herbivory, while constitutively accumulating salicinoids were not affected. This indicates the peroxisomal β-oxidative pathway participates in the formation of volatile benzenoids. The chain shortening steps for salicinoids, however, likely employ an alternative pathway.

scholarly journals Using Discrete-Point LiDAR to Classify Tree Species in the Riparian Pacific Northwest, USA

2021 ◽  
Vol 13 (14) ◽  
pp. 2647
Author(s):  
Julia Tatum ◽  
David Wallin
Keyword(s):  
Pacific Northwest ◽  
Tree Species ◽  
3D Structure ◽  
Alnus Rubra ◽  
Populus Balsamifera ◽  
Segmentation Method ◽  
Black Cottonwood ◽  
Riparian Landscape ◽  
Individual Trees ◽  
Species Mapping

Practical methods for tree species identification are important for both land management and scientific inquiry. LiDAR has been widely used for species mapping due to its ability to characterize 3D structure, but in structurally complex Pacific Northwest forests, additional research is needed. To address this need and to determine the feasibility of species modeling in such forests, we compared six approaches using five algorithms available in R’s lidR package and Trimble’s eCognition software to determine which approach most consistently identified individual trees across a heterogenous riparian landscape. We then classified segments into Douglas fir (Pseudotsuga menziesii), black cottonwood (Populus balsamifera ssp. trichocarpa), and red alder (Alnus rubra). Classification accuracies based on the best-performing segmentation method were 91%, 92%, and 84%, respectively. To our knowledge, this is the first study to investigate tree species modeling from LiDAR in a natural Pacific Northwest forest, and the first to model Pacific Northwest species at the landscape scale. Our results suggest that LiDAR alone may provide enough information on tree species to be useful to land managers in limited applications, even under structurally challenging conditions. With slight changes to the modeling approach, even higher accuracies may be possible.

Organ culture with black cottonwood: morphogenetic response of female catkin primordia

1972 ◽  
Vol 50 (7) ◽  
pp. 1627-1631 ◽  
Author(s):  
K. S. Bawa ◽  
R. F. Stettler
Keyword(s):  
Organ Culture ◽  
Vegetative Growth ◽  
Callus Formation ◽  
Populus Trichocarpa ◽  
General Tendency ◽  
Black Cottonwood ◽  
Axillary Shoots ◽  
Female Sex ◽  
Female Catkin

Female catkin primordia of black cottonwood (Populus trichocarpa T. & G. ex Hook.) were cultured for 70 days on a modified Murashige and Skoog's (1962) medium in vitro. Explants 2–3 mm long, and with bud scales removed, gave the best results, many of them developing floral structures characteristic of the female sex. There was a general tendency to callus formation with increasing age of the culture, occasionally followed by a reversal to vegetative growth. Catkin primordia raised on Wolter's medium without auxin or kinetin, but with 6-benzylaminopurine, and at 250 ft-c for a 16-h photoperiod, proliferated axillary shoots in loco of pistils.

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