scholarly journals Genetic Analysis of Needle Morphological and Anatomical Traits among Nature Populations of Pinus Tabuliformis

2017 ◽  
Vol 6 (1) ◽  
pp. 62
Author(s):  
Mei Zhang ◽  
Jing-Xiang Meng ◽  
Zi-Jie Zhang ◽  
Song-Lin Zhu ◽  
Yue Li
Keyword(s):  
Genetic Variation ◽  
Geographic Variation ◽  
Stomatal Density ◽  
Common Garden ◽  
Central China ◽  
Ecological Studies ◽  
Coniferous Species ◽  
Pinus Tabuliformis ◽  
Geographic Populations ◽  
Resin Canals

The morphological and anatomical traits of needles are important to evaluate geographic variation and population dynamics of conifer species. Variations of morphological and anatomical needle traits in coniferous species are considered to be the consequence of genetic evolution, and be used in geographic variation and ecological studies, etc. Pinus tabuliformis is a particular native coniferous species in northern and central China. For understanding its adaptive evolution in needle traits, the needle samplings of 10 geographic populations were collected from a 30yr provenience common garden trail that might eliminate site environment effect and show genetic variation among populations and 20 needle morphological and anatomical traits were involved. The results showed that variations among and within populations were significantly different over all the measured traits and the variance components within population were generally higher than that among populations in the most measured needle traits. Population heritabilities in all measured traits were higher than 0.7 in common garden sampling among populations. Needle traits were more significantly correlated with longitude than other factors. First five principal components accounted for 81.6% of the variation with eigenvalues greater than 1; the differences among populations were mainly dependent on needle width, stomatal density, section areas of vascular bundle, total resin canals, and mesophyll, as well as area ratio traits. Ten populations were divided into two categories by Euclidean distance. Variations in needle traits among the populations have shown systematic microevolution in terms of geographic impact on P. tabuliformis. This study would provide empirical data to characterize adaptation and genetic variation of P. tabuliformis, which should be more available for ecological studies.

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 Analysis of genetic variation of porcine reproductive and respiratory syndrome virus (PRRSV) isolates in Central China

2016 ◽  
Vol 78 (4) ◽  
pp. 641-648 ◽  
Author(s):  
Can Liu ◽  
Yibao Ning ◽  
Binrui Xu ◽  
Wenzhi Gong ◽  
Dongdong Zhang
Keyword(s):  
Genetic Variation ◽  
Central China ◽  
Respiratory Syndrome Virus

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.

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 fall cold hardiness in coastal Douglas-fir in western Oregon and Washington

2006 ◽  
Vol 84 (7) ◽  
pp. 1110-1121 ◽  
Author(s):  
J. Bradley St. Clair
Keyword(s):  
Genetic Variation ◽  
Cold Hardiness ◽  
Environmental Gradients ◽  
Large Population ◽  
Common Garden ◽  
Cold Season ◽  
Douglas Fir ◽  
Bud Burst ◽  
Population Differences ◽  
Bud Set

Genetic variation in fall cold damage in coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii ) was measured by exposing excised branches of seedlings from 666 source locations grown in a common garden to freezing temperatures in a programmable freezer. Considerable variation was found among populations in fall cold hardiness of stems, needles, and buds compared with bud burst, bud set, and biomass growth after 2 years. Variation in fall cold hardiness was strongly correlated (r = 0.67) with cold-season temperatures of the source environment. Large population differences corresponding with environmental gradients are evidence that natural selection has been important in determining genetic variation in fall cold hardiness, much more so than in traits of bud burst (a surrogate for spring cold hardiness), bud set, and growth. Seed movement guidelines and breeding zones may be more restrictive when considering genetic variation in fall cold hardiness compared with growth, phenology, or spring cold hardiness. A regional stratification system based on ecoregions with latitudinal and elevational divisions, and roughly corresponding with breeding zones used in Oregon and Washington, appeared to be adequate for minimizing population differences within regions for growth and phenology, but perhaps not fall cold hardiness. Although cold hardiness varied among populations, within-population and within-region variation is sufficiently large that responses to natural or artificial selection may be readily achieved.

Genetic variation and parameter estimates in Taxusbrevifolia (Pacific yew)

1995 ◽  
Vol 25 (12) ◽  
pp. 1913-1927 ◽  
Author(s):  
N.C. Wheeler ◽  
K.S. Jech ◽  
S.A. Masters ◽  
C.J. O'Brien ◽  
R.W. Stonecypher ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Large Scale ◽  
Management Practices ◽  
Management Strategies ◽  
Genetic Selection ◽  
Common Garden ◽  
Regional Differentiation ◽  
Parameter Estimates ◽  
Gene Frequencies ◽  
Allozyme Diversity

Pacific yew (Taxusbrevifolia Nutt.) is a shade-tolerant gymnosperm native to the western United States and Canada. It recently gained attention as the source of Taxol® (paclitaxel), a promising new anticancer drug. Large-scale harvest of mature Pacific yew trees for the extraction of paclitaxel has resulted in the need for improved forest management practices and an increased understanding of the amount and distribution of genetic variation in the species. We partitioned estimates of genetic variance for allozyme, metric, and taxane traits into region, population, family, and within family components in seedling common-garden tests. Genetic diversity, genetic distance, and Nei's Gst values were estimated based on gene frequencies for 22 isozyme loci. Concentrations of taxanes were determined for needles and roots using HPLC. Populations of Pacific yew are more distinct from one another than is typical of long-lived, wind-pollinated conifers in western North America, but there is little regional differentiation. Yew populations have notably less allozyme diversity than most other gymnosperms with similar life-history characteristics. Most genetic variation in all traits occurs within the population, and much of that is within family. Heritabilities for growth and taxane traits ranged from low to moderately high. Gene conservation or management strategies should include broad sampling among and within populations of Pacific yew. Opportunities for genetic selection to develop improved lines or cultivars for the production of paclitaxel exist, but use of currently domesticated yew species is more time and cost efficient.

Microgeographic genetic variation of Sitka spruce in southeastern Alaska

1989 ◽  
Vol 19 (8) ◽  
pp. 1004-1013 ◽  
Author(s):  
Robert K. Campbell ◽  
William A. Pawuk ◽  
Arland S. Harris
Keyword(s):  
Genetic Variation ◽  
Standard Deviation ◽  
Principal Components ◽  
Principal Component ◽  
Extreme Case ◽  
Common Garden ◽  
Sitka Spruce ◽  
Slope Aspect ◽  
Factor Scores ◽  
Additive Genetic Variation

Microgeographic genetic variation among populations of Sitka spruce on Mitkof Island in southeastern Alaska is described. In two common-garden environments, we evaluated genotypes of 208 parent trees from 114 locations in a 17 000-ha area. Two principal components accounted for most of the variation among locations in 11 traits measured to evaluate growth vigor and rhythm of 2-year-old seedlings. Regression analyses of factor scores derived from principal components revealed genetic gradients associated with elevation, slope, aspect, and west–east and north–south direction. Large amounts of additive genetic variation in factor scores occurred among trees within locations. When this variation within locations was used as a scale, variation among locations was also large. In an extreme case, locations differed in factor scores of the first principal component by about 3.0 units of the standard deviation of additive genetic variation in factor scores. Of the total differentiation in this case, elevational range (600 m) contributed 0.7 units of standard deviation, aspect contributed 0.9 units, and distance (16 km) from north central to southeastern parts of the island contributed 1.4 units.

Sign in / Sign up

Export Citation Format

Share Document