Genetic variation and productivity of Populustrichocarpa and its hybrids.: IV. Performance in short-rotation coppice

1990 ◽  
Vol 20 (9) ◽  
pp. 1257-1264 ◽  
Author(s):  
Paul E. Heilman ◽  
R. F. Stettler
Keyword(s):  
Genetic Variation ◽  
Rapid Growth ◽  
Common Garden ◽  
Dry Weight ◽  
Subsequent Growth ◽  
Cumulative Mortality ◽  
Short Rotation ◽  
Cultural Systems ◽  
Major River ◽  
River Drainages

Resprouting after harvest and rapid growth of sprouts are often considered essential for success of close-spaced, short-rotation cultural systems. This study examined resprouting, subsequent growth, and dry weight production following the initial 4-year harvest of a "common garden" trial of 50 clones of Populustrichocarpa Torr. & Gray. The clones were selected from 10 populations (sources) from major river drainages from western British Columbia, Washington, and Oregon. Additionally, three P. trichocarpa × P. deltoides (Bartr.) hybrids, a 'Robusta' clone, and a previously selected P. trichocarpa clone from Cottage Grove, Oregon, were included in the experiment. Mean yield of P. trichocarpa clones was 11.3 Mg•ha−1•year−1 (CV among clones = 61%) in the coppice rotation vs. 12.6 Mg•ha−1•year−1 (CV among clones = 40%) in the initial rotation; a difference that may, at least in part, be due to the use of less fertilizer in the coppice rotation. Nevertheless, a number of clones including the hybrids had higher yields in the coppice than in the initial rotation. Yield of clones in the coppice rotation was only moderately correlated with yield in the initial harvest (r2 = 0.48), but the same two clones, hybrids 11-11 and 11-05, were the top-producing clones in both rotations. Cumulative mortality of P. trichocarpa at the end of the experiment, including failed cuttings, averaged 36%, but was highly variable (range = 7–66% among clones). Yield in both harvests differed significantly among sources of P. trichocarpa. As with other components of productivity reported earlier, performance in coppice varied significantly among the 50 P. trichocarpa clones, and more so than in the first rotation. Populustrichocarpa clones identified as superior in coppicing in this experiment represent potential parents for new hybrids intended for short-rotation systems involving coppicing.

Genetic Variation in Chamaecyparis nootkatensis from Coastal British Columbia1

1992 ◽  
Vol 7 (1) ◽  
pp. 25-29 ◽  
Author(s):  
M. L. Cherry ◽  
D. T. Lester
Keyword(s):  
Genetic Variation ◽  
Growth Traits ◽  
Weight Ratio ◽  
Common Garden ◽  
Dry Weight ◽  
Frost Damage ◽  
Chamaecyparis Nootkatensis ◽  
Shoot Dry Weight ◽  
Lateral Branches ◽  
Port Orford Cedar

Abstract Genetic variation in several traits of Alaska-cedar (Chamaecyparis nootkatensis) was measured in progeny from seven coastal B.C. provenances, each represented by three open-pollinated families. The common-garden nursery trial also included one provenance of Port-Orford cedar (Chamaecyparis lawsoniana). Growth traits and frost hardiness were measured at the end of the first growing season, and morphological traits after the second year. Provenances varied in percentage germination, shoot dry weight, shoot to root dry weight ratio, number of lateral branches per stem, and cold injury to a minimum temperature of -20°C in December. Families differed in height, root collar diameter, and in the number of nodes of primary foliage. Port-Orford cedar exhibited much greater height, stem caliper, and dry weight than any Alaska-cedar provenance, but was more susceptible to frost damage. West. J. Appl. For. 7(1):25-29.

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.

Genetic variation and productivity of Populustrichocarpa and its hybrids. II. Biomass production in a 4-year plantation

1985 ◽  
Vol 15 (2) ◽  
pp. 384-388 ◽  
Author(s):  
Paul E. Heilman ◽  
R. F. Stettler
Keyword(s):  
Clonal Selection ◽  
Dry Weight ◽  
N Fertilization ◽  
Genetic Constitution ◽  
Black Cottonwood ◽  
Short Rotation ◽  
Major River ◽  
Source Populations ◽  
High Yields ◽  
River Valleys

Productivities of 5 black cottonwood clones from each of 10 source populations (50 clones in total) were compared at one plantation site in western Washington. The source populations are located west of the Cascade Mountains, between central Oregon and southern British Columbia. Most source stands represented populations in major river valleys. Individual clones were selected for superior form and growth rate. Spacing was 1.2 × 1.2 m (6944 stems•ha−1) and trees were harvested after 4 years. Considerable variation in mortality, height, and productivity were found among clones within individual stands and among stands. Southwestern clones were generally more productive. Heights of individual clones averaged between 8.5 and 11.8 m at 4 years. Average dry weight production of black cottonwood clones was 12.5 Mg•ha−1•year−1 and varied between 5.2 and 23.1 Mg•ha−1•year−1 for individual clones. Three new Populustrichocarpa × P. deltoides hybrids planted in the trial were generally more productive than black cottonwood or the 'Robusta' hybrid, with average heights varying from 11.5 to 12.2 m and dry weight production ranging from 15.6 to 27.8 Mg•ha−1•year−1 for an average of 23.6 Mg•ha−1•year−1. The high yields in this experiment are attributed to favorable climate (1940 degree-days•year−1)3, cultural treatments (irrigation, N fertilization) and genetic constitution of certain clones. The data promise substantial gains in short-rotation productivity from combining clonal selection with interspecific hybridization.

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

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.

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.

scholarly journals Genetic specificity of a plant–insect food web: Implications for linking genetic variation to network complexity

2016 ◽  
Vol 113 (8) ◽  
pp. 2128-2133 ◽  
Author(s):  
Matthew A. Barbour ◽  
Miguel A. Fortuna ◽  
Jordi Bascompte ◽  
Joshua R. Nicholson ◽  
Riitta Julkunen-Tiitto ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Food Web ◽  
Host Plant ◽  
Trophic Interactions ◽  
Common Garden ◽  
Ecological Networks ◽  
Experimental Population ◽  
Trait Variation ◽  
Intraspecific Genetic Variation ◽  
Food Web Complexity

Theory predicts that intraspecific genetic variation can increase the complexity of an ecological network. To date, however, we are lacking empirical knowledge of the extent to which genetic variation determines the assembly of ecological networks, as well as how the gain or loss of genetic variation will affect network structure. To address this knowledge gap, we used a common garden experiment to quantify the extent to which heritable trait variation in a host plant determines the assembly of its associated insect food web (network of trophic interactions). We then used a resampling procedure to simulate the additive effects of genetic variation on overall food-web complexity. We found that trait variation among host-plant genotypes was associated with resistance to insect herbivores, which indirectly affected interactions between herbivores and their insect parasitoids. Direct and indirect genetic effects resulted in distinct compositions of trophic interactions associated with each host-plant genotype. Moreover, our simulations suggest that food-web complexity would increase by 20% over the range of genetic variation in the experimental population of host plants. Taken together, our results indicate that intraspecific genetic variation can play a key role in structuring ecological networks, which may in turn affect network persistence.

The effect of two audible sound frequencies on the germination and growth of a spring and winter wheat

1968 ◽  
Vol 46 (9) ◽  
pp. 1151-1158 ◽  
Author(s):  
Pearl Weinberger ◽  
Mary Measures
Keyword(s):  
Growth Response ◽  
Germination Rate ◽  
Dry Weight ◽  
Continuous Exposure ◽  
Subsequent Growth ◽  
Sound Exposure ◽  
Audible Sound ◽  
Total Plant ◽  
Accelerated Growth ◽  
Germination And Growth

The effect of sound of 5 kc/s and 12 kc/s on the germination and growth of grains and seedlings of vernalized spring (Marquis) and winter (Rideau) wheats was investigated. Untreated controls were simultaneously followed, and all experimental series were replicated at least three times. Growth cabinets were systematically interchanged with the replications to eliminate other variables. Sound at both frequencies significantly stimulated the germination of Marquis grains maintained at 2° and 10 °C. At 25 °C the rate of germination was unchanged. An indication of a slightly elevated germination rate was observed in Rideau grains held at 2° and exposed to 5 kc/s. Neither frequency significantly affected germination at 10° or 25 °C.Growth of plants derived from fully vernalized grains was followed by measuring total plant height, wet and dry weight of "tops", number of roots, and their fresh and dry weights. Rideau wheat grew more vigorously at both sound frequencies. Continuous exposure to 5 kc/s both during vernalization and subsequent growth resulted in a 200% or greater increase in all parameters followed. The growth response of Marquis wheat was dependent upon treatment. Some conditions of sound exposure accelerated growth, whereas in others growth was depressed.

scholarly journals Leaf Canopy Layers Affect Spectral Reflectance in Silver Birch

2019 ◽  
Vol 11 (24) ◽  
pp. 2884 ◽  
Author(s):  
Maya Deepak ◽  
Sarita Keski-Saari ◽  
Laure Fauch ◽  
Lars Granlund ◽  
Elina Oksanen ◽  
...  
Keyword(s):  
Principal Component ◽  
Common Garden ◽  
Dry Weight ◽  
Leaf Traits ◽  
Tree Canopy ◽  
Canopy Reflectance ◽  
Canopy Layer ◽  
Leaf Reflectance ◽  
Individual Trees ◽  
Reflectance Indices

The availability of light within the tree canopy affects various leaf traits and leaf reflectance. We determined the leaf reflectance variation from 400 nm to 2500 nm among three canopy layers and cardinal directions of three genetically identical cloned silver birches growing at the same common garden site. The variation in the canopy layer was evident in the principal component analysis (PCA), and the influential wavelengths responsible for variation were identified using the variable importance in projection (VIP) based on partial least squares discriminant analysis (PLS-DA). Leaf traits, such as chlorophyll, nitrogen, dry weight, and specific leaf area (SLA), also showed significant variation among the canopy layers. We found a shift in the red edge inflection point (REIP) for the canopy layers. The canopy layers contribute to the variability in the reflectance indices. We conclude that the largest variation was among the canopy layers, whereas the differences among individual trees to the leaf reflectance were relatively small. This implies that within-tree variation due to the canopy layer should be taken into account in the estimation of intraspecific variation in the canopy reflectance.

scholarly journals Selection Criteria for Drought-Tolerant Bread Wheat Genotypes at Seedling Stage

2019 ◽  
Vol 11 (9) ◽  
pp. 2584 ◽  
Author(s):  
Hafiz Ahmed ◽  
Muhammad Sajjad ◽  
Mingju Li ◽  
Muhammad Azmat ◽  
Muhammad Rizwan ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Selection Criteria ◽  
Dry Weight ◽  
Shoot Length ◽  
Seedling Stage ◽  
Chlorophyll B ◽  
Fresh Weight ◽  
Drought Tolerant ◽  
Selection For ◽  
Thermo Stability

Diminishing water resources as a result of excessive use of water for irrigation and climate change posture a severe global threat to food security. Herein, an experiment was conducted to determine the selection criteria for drought-tolerant bread wheat genotypes at the seedling stage using morphological and photosynthetic pigmentation-related traits. A panel of 105 wheat landraces, historical Pakistani varieties, and advance breeding lines were evaluated under normal and drought stress using factorial completely randomized design. The root length, fresh weight, dry weight, cell membrane thermo-stability, and chlorophyll b were positively correlated among themselves under both normal and stress conditions. Hence, selection of any one of these traits enhances the performance of other traits. The shoot length was non-significant and negatively associated with all other studied characters except relative water content. The results suggested that selection for shoot length could not improve genetic gain for drought tolerance. Out of 10 principal components (PCs), the first three PCs were showed significant genetic variation under both conditions. The first three PCs showed 74.6% and 76% cumulative genetic variation under normal and drought conditions, respectively. Based on PCA, 10 drought-tolerant and five drought-susceptible genotypes were identified. Overall results suggested that selection for root length, fresh weight, dry weight, cell membrane thermo-stability, and chlorophyll b at the seedling stage would improve genetic gain for drought tolerance. The outperforming genotypes under drought stress conditions can be useful in future wheat breeding programs, and early selection for the traits recommended in this study will be effective for developing high-yielding and drought-tolerant wheat varieties.

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