Genetic variation and productivity of Populustrichocarpa and its hybrids. VII. Two-year survival and growth of native black cottonwood clones from four river valleys in Washington

1994 ◽  
Vol 24 (8) ◽  
pp. 1539-1549 ◽  
Author(s):  
J.M. Dunlap ◽  
P. E. Heilman ◽  
R.F. Stettler
Keyword(s):  
Genetic Variation ◽  
Common Garden ◽  
Stem Volume ◽  
Black Cottonwood ◽  
Tarnished Plant Bug ◽  
Selection Gradient ◽  
Genetic Components ◽  
Lower Elevation ◽  
Microsite Heterogeneity ◽  
River Valleys

A common-garden study of Populustrichocarpa Torr. & Gray was initiated in 1985 when clonal material from 128 trees was collected from sites distributed along two mesic (Hoh and Nisqually) and two xeric (Dungeness and Yakima) river valleys. This material was grown for 1 year at Puyallup, Wash. In spring 1986, cuttings from this material were used to establish two replicate plantations, one at Puyallup and one at Wenatchee, Wash. Over the 2 year period, trees were assessed for survival, damage, and growth. Two-year survival was 86% at Puyallup and 59% at Wenatchee; survival was higher for mesic-origin trees at both sites. At Wenatchee, mortality was mainly due to a droughty soil and hot, dry climate in the first year, and damage was due to the tarnished plant bug (Lygus spp.), field voles (Microtus spp.), and grasshoppers (Family Acrididae). At both locations, Melampsoraoccidentalis Jacks. leaf rust was found mainly on trees originating from Yakima. Mean 2-year height and diameter at Puyallup were 457 cm and 40 mm, respectively; corresponding values at Wenatchee were 320 cm and 29 mm. At Puyallup, 2-year stem volume (diameter2 × height) decreased significantly in this order: Nisqually (13 500 cm3) = Hoh > Dungeness > Yakima (4700 cm3). Within the Nisqually trees, clones from lower, milder climate elevations grew more than those from the upper elevations. The reverse was true for the Yakima trees, presumably because the lower elevation trees are adapted to an arid climate and are very susceptible to Melampsora rust. At Wenatchee, high microsite heterogeneity masked much of the genetic variation. The genetic variance component (among rivers, sites, and clones) for stem volume at Puyallup increased from 27 to 51% over the second year. In analyses of each river valley, genetic components (elevational group and clone) were also high at 27–63%; however, for the Yakima trees, the elevational group variance (40%) was much larger than for the other valleys (0–7%) and suggests a steep selection gradient midway along the river transect.

Variation in leaf epidermal and stomatal traits of Populus trichocarpa from two transects across the Washington Cascades

2001 ◽  
Vol 79 (5) ◽  
pp. 528-536 ◽  
Author(s):  
J M Dunlap ◽  
R F Stettler
Keyword(s):  
Genetic Variation ◽  
Populus Trichocarpa ◽  
Black Cottonwood ◽  
Common Gardens ◽  
Lower Elevation ◽  
Stomatal Traits ◽  
Cell Densities ◽  
Old Trees ◽  
Eastern Washington ◽  
River Valleys

Epidermal and stomatal cell traits were examined on late leaves of 40 black cottonwood (Populus trichocarpa Torr. & Gray) clones originating from the mesic Nisqually, and xeric Yakima river valleys of Washington. Four leaves per clone were collected from 1-year-old trees in two replicated common gardens located in Puyallup (western Washington) and Wenatchee (eastern Washington). In Puyallup-grown material, Yakima clones had abaxially 14% smaller epidermal cell diameters (CDIAM) and 27% greater cell densities (CDEN; No. per mm2), and 25% smaller leaves than Nisqually clones (p [Formula: see text] 0.03). Abaxial stomatal densities (STDEN; No. per mm2) were highest (206) in the lower elevation, xeric-origin Yakima clones, as compared with an average of 120 in Nisqually clones. A higher proportion of Yakima leaves had shorter stomates than those from the Nisqually at both sites (p [Formula: see text] 0.002). Besides shorter stomates (p [Formula: see text] 0.030), the lower elevation Yakima clones generally had higher STDEN and ratios of STDEN to CDEN than those clones from the upper group (p [Formula: see text] 0.098). Acclimation of Wenatchee-grown clones to the hotter, drier summer climate was also evident, as they generally had smaller CDIAM, and higher CDEN and STDEN than those grown at Puyallup. Genetic variances (among rivers, groups within river, and clones within group within river) ranged from 42 to 84% with clone being dominant for epidermal traits while the other two components were dominant for stomatal traits. In the Yakima leaves, much of the genetic variance (group and clone within group) resided in the group component. Broad-sense heritabilities averaged 72%, indicating moderately strong genetic control in most traits. This study provides further evidence of genetic variation in P. trichocarpa at the regional and local scales across the Washington Cascades.Key words: Populus trichocarpa, black cottonwood, stomata, adaptation, acclimation, genetic variation.

Genetic Variation in Incense-Cedar (Calocedrus decurrens): I. Provenance Differences in a Twelve-Year-Old Common-Garden Study

1994 ◽  
Vol 9 (4) ◽  
pp. 113-117
Author(s):  
Deborah L. Rogers ◽  
David E. Harry ◽  
William J. Libby
Keyword(s):  
Genetic Variation ◽  
Population Genetic ◽  
Common Garden ◽  
Tree Improvement ◽  
The Other ◽  
Stem Volume ◽  
Native Range ◽  
Calocedrus Decurrens ◽  
Population Genetic Variation ◽  
Crown Form

Abstract Results are reported from a provenance study of incense-cedar (Calocedrus decurrens), a tree species native to forested regions of Oregon, California, and Baja California. Seedlings from six geographically distinct regions were measured over a 12 yr period in a common-garden study located near the center of the species' native range. In general, among-region genetic variation was small. However, differences in height, stem volume, and crown form between trees from the southernmost region sampled and trees from the other five study regions were large and significant. Further studies of within-population genetic variation are recommended prior to initiating any tree improvement activities. West. J. Appl. For. 9(4):113-117.

Genetic variation and productivity of Populustrichocarpa and its hybrids. VIII. Leaf and crown morphology of native P. trichocarpa clones from four river valleys in Washington

1995 ◽  
Vol 25 (10) ◽  
pp. 1710-1724 ◽  
Author(s):  
J.M. Dunlap ◽  
R.F. Stettler ◽  
P.E. Heilman
Keyword(s):  
Drainage System ◽  
Branch Length ◽  
Common Garden ◽  
Leaf Traits ◽  
Sharp Change ◽  
Selection Gradient ◽  
Single Leaf ◽  
Yakima River ◽  
River Valleys ◽  
Crown Traits

A common-garden study of Populustrichocarpa Torr. & Gray was initiated in 1985, when clonal material from 128 trees was collected from sites distributed along two mesic (Hoh, Nisqually) and two xeric (Dungeness, Yakima) river valleys. This material was grown for 1 year at Puyallup, Wash. In spring 1986, cuttings from this material were used to establish two replicate plantations, one at Puyallup and the other at Wenatchee, Wash. Data were collected from a subset of 80 clones on 8 single-leaf and 14 crown traits after two growing seasons. Analyses of variance revealed significant (p ≤ 0.10) differences among rivers in nearly all single-leaf traits by the second year at both plantations. Two-year leaf sizes at Puyallup significantly declined in this order: Hoh (388 cm2) > Nisqually > Dungeness > Yakima (194 cm2). At Wenatchee, a similar mesic > xeric pattern was found among river sources, but leaves were smaller there. When grown at Puyallup, leaves of clones from lower elevations in the Yakima valley were significantly (p ≤ 0.10) smaller, lighter, thinner, and weighed less per unit area than upper elevation clones. Chi-square tests showed that abaxial leaf surfaces were greener in Yakima trees than in trees from other locations, especially in those from the the lower Yakima valley. In the crown traits of trees grown in Puyallup, river and clone-within-site-within-river effects were significant for all traits, whereas site-within-river effects were significant for only 8 traits. Mesic-origin trees were significantly larger in size traits, e.g., branch length, than xeric-origin trees. Trees from the Yakima drainage system were leafier and branchier (p ≤ 0.10) than both Nisqually and Hoh trees. Values for most crown traits were greater (p ≤ 0.10) in the xeric, lower Yakima clones than in the mesic, upper Yakima clones. These mesic-xeric differences were similar for Dungeness trees, although there were few significant differences between the lower and upper elevational groups. Single-leaf and crown traits of trees from the four river valleys seem to be adapted to the respective mesic and xeric conditions of the source environments. Within the Yakima river valley, a sharp change in leaf and crown traits and in atmospheric moisture levels coincide midway along the transect, suggesting the presence of a steep selection gradient in the Bristol Canyon area.

Intraspecific variation in photosynthetic traits of Populus trichocarpa

1993 ◽  
Vol 71 (10) ◽  
pp. 1304-1311 ◽  
Author(s):  
J. M. Dunlap ◽  
J. H. Braatne ◽  
T. M. Hinckley ◽  
R. F. Stettler
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Populus Trichocarpa ◽  
High Light ◽  
Black Cottonwood ◽  
Photosynthetic Rates ◽  
Light Levels ◽  
Lower Elevation ◽  
Use Efficiency ◽  
River Valleys

Three experiments were conducted to evaluate net photosynthesis in black cottonwood (Populus trichocarpa Torrey & Gray) from mesic and xeric regions of Washington. In 1986, six clones each from the lower Nisqually (mesic) and Yakima (xeric) river valleys and growing in a common garden were measured for their photosynthetic rates. On 2 clear days in summer, Yakima clones had significantly (p ≤ 0.10) higher rates (means: 32 and 25μmol CO2 m−2 s−1) than Nisqually clones (means: 25 and 22μmol CO2 m−2 s−1). The next year, cuttings from these clones were potted, grown separately for 2 months in a maritime (Puyallup, Wash.) and a continental climate (Wenatchee, Wash.), and then transferred to growth chambers in Seattle, Wash. Photosynthetic rates were determined at four light levels (200, 500, 800, and 1500 μmol m−2 s−1) and two temperatures (24 and 32 °C). Yakima plants had significantly (p ≤ 0.05) higher rates at high light (20μmol CO2 m−2 s−1) and also at moderate light in high temperature than Nisqually plants (16 μmol CO2 m−2 s−1 in high light). Significant acclimation (p ≤ 0.01) was also revealed: at the two moderate light levels in high temperatures the Wenatchee-grown plants, regardless of source, had higher rates than those grown at Puyallup. In 1991, eight clones from the lower elevation, xeric region of the Yakima and eight from the upper elevation, mesic region were selected in a Puyallup stoolbed, and their photosynthesis and water-use efficiency were measured on a clear summer day. Lower elevation plants had a higher photosynthetic rate than those from the upper elevations along the Yakima; values were similar to those of 1986. The pattern for water-use efficiency was reversed; values were 56 μmol CO2/mol H2O for the lower and 84 μmol CO2/mol H2O for the upper Yakima plants. These three experiments provide evidence for significant genetic variation in photosynthetic processes both between and within river valleys. Key words: Populus trichocarpa, black cottonwood, poplar, photosynthesis, water-use efficiency, adaptation.

scholarly journals Host–parasitoid evolution in a metacommunity

2016 ◽  
Vol 283 (1831) ◽  
pp. 20160477 ◽  
Author(s):  
Denon Start ◽  
Benjamin Gilbert
Keyword(s):  
Natural Enemies ◽  
Patch Size ◽  
Common Garden ◽  
Species Traits ◽  
Dispersal Ability ◽  
Isolated Populations ◽  
Selection Gradient ◽  
Phenotypic Differences ◽  
Dispersal Abilities ◽  
Phenotypic Shift

Patch size and isolation are predicted to alter both species diversity and evolution; yet, there are few empirical examples of eco-evolutionary feedback in metacommunities. We tested three hypotheses about eco-evolutionary feedback in a gall-forming fly, Eurosta solidaginis and two of its natural enemies that select for opposite traits: (i) specialization and poor dispersal ability constrain a subset of natural enemies from occupying small and isolated patches, (ii) this constraint alters selection on the gall fly, causing phenotypic shifts towards traits resistant to generalist and dispersive enemies in small and isolated patches, and (iii) reduced dispersal evolves in small, isolated populations. We sampled patches in a natural metacommunity and found support for all hypotheses; Eurosta 's specialist wasp parasitoid attacked fewer galls in small and isolated patches, generating a selection gradient that favoured small galls resistant to predation by a dispersive and generalist bird predator. Phenotype distributions matched this selection gradient, and these phenotypic differences were maintained in a common garden experiment. Finally, we found lower dispersal abilities in small and isolated patches, a phenotypic shift that aids in the maintenance of local adaptation. We suggest that the trophic rank and the species traits of consumers are central to evolution in metacommunities.

scholarly journals Evidence of between-population differences in natural selection on extra-floral nectaries of the shrub Anemopaegma album (Bignoniaceae)

Botany ◽  
2016 ◽  
Vol 94 (3) ◽  
pp. 201-213
Author(s):  
Anselmo Nogueira ◽  
Pedro J. Rey ◽  
Julio M. Alcántara ◽  
Lúcia G. Lohmann
Keyword(s):  
Genetic Variation ◽  
Natural Selection ◽  
Evolutionary Ecology ◽  
Common Garden ◽  
Phenotypic Selection ◽  
Population Differences ◽  
Wild Populations ◽  
Neotropical Savanna ◽  
Foliar Damage ◽  
Floral Nectaries

Extra-floral nectaries (EFNs) are thought to represent protective adaptations against herbivory, but studies on the evolutionary ecology of EFNs have seldom been conducted. Here we investigate the patterns of natural selection and genetic variation in EFN traits in two wild populations of Anemopaegma album Mart. ex DC. (Bignoniaceae) that have been previously described as contrasting EFN – ant adapted localities in the Neotropical savanna (Cristália and Grão Mogol). In each population, four EFN descriptors, foliar damage, and reproductive success variables were measured per plant (100–120 plants per population). To estimate the heritability of EFN traits, we crossed reproductive plants in the field, and grew offspring plants in a common garden. The results showed that ant assemblages differed between populations, as did the range of foliar herbivory. Genetic variation and positive phenotypic selection in EFN abundance were only detected in the Cristália population, in which plants with more EFNs were more likely to reproduce. An evaluation of putative causal links conducted by path analysis corroborated the existence of phenotypic selection on EFNs, which was mediated by the herbivory process in the Cristália population. While EFNs could be currently under selection in Cristália, it is possible that past selection may have driven EFN traits to become locally adapted to the local ant assemblage in the Grão Mogol population.

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.

scholarly journals High differentiation in functional traits but similar phenotypic plasticity in populations of a soil specialist along a climatic gradient

2020 ◽  
Vol 125 (6) ◽  
pp. 969-980 ◽  
Author(s):  
Silvia Matesanz ◽  
Marina Ramos-Muñoz ◽  
Mario Blanco-Sánchez ◽  
Adrián Escudero
Keyword(s):  
Genetic Variation ◽  
Phenotypic Plasticity ◽  
Functional Traits ◽  
Common Garden ◽  
Population Level ◽  
General Purpose ◽  
Climatic Conditions ◽  
Environment Interaction ◽  
Moisture Variation ◽  
Neutral Genetic Variation

Abstract Background and Aims Plants experiencing contrasting environmental conditions may accommodate such heterogeneity by expressing phenotypic plasticity, evolving local adaptation or a combination of both. We investigated patterns of genetic differentiation and plasticity in response to drought in populations of the gypsum specialist Lepidium subulatum. Methods We created an outdoor common garden with rain exclusion structures using 60 maternal progenies from four distinct populations that substantially differ in climatic conditions. We characterized fitness, life history and functional plasticity in response to two contrasting treatments that realistically reflect soil moisture variation in gypsum habitats. We also assessed neutral genetic variation and population structure using microsatellite markers. Key Results In response to water stress, plants from all populations flowered earlier, increased allocation to root tissues and advanced leaf senescence, consistent with a drought escape strategy. Remarkably, these probably adaptive responses were common to all populations, as shown by the lack of population × environment interaction for almost all functional traits. This generally common pattern of response was consistent with substantial neutral genetic variation and large differences in population trait means. However, such population-level trait variation was not related to climatic conditions at the sites of origin. Conclusions Our results show that, rather than ecotypes specialized to local climatic conditions, these populations are composed of highly plastic, general-purpose genotypes in relation to climatic heterogeneity. The strikingly similar patterns of plasticity among populations, despite substantial site of origin differences in climate, suggest past selection on a common norm of reaction due to similarly high levels of variation within sites. It is thus likely that plasticity will have a prevalent role in the response of this soil specialist to further environmental change.

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