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.

From branch to bench: establishing wild spruce budworm populations into laboratory colonies for the exploration of local adaptation and plasticity

2021 ◽  
Vol 153 (3) ◽  
pp. 374-390 ◽  
Author(s):  
K. Perrault ◽  
A.A. Wardlaw ◽  
J.N. Candau ◽  
C.L. Irwin ◽  
M. Demidovich ◽  
...  
Keyword(s):  
Regional Variation ◽  
Life History Traits ◽  
Choristoneura Fumiferana ◽  
Common Garden ◽  
Spruce Budworm ◽  
Population Differences ◽  
Wild Populations ◽  
Laboratory Colonies ◽  
Common Garden Experiments ◽  
Disease Free

AbstractSpruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), is a destructive defoliator found throughout the Nearctic boreal forest. This pest has a broad geographic range and shows regional variation in key life history traits. These population differences may represent important adaptations to local environmental conditions and reflect underlying genetic diversity. Existing laboratory colonies of spruce budworm do not capture this regional variation, so we established five new spruce budworm colonies from across its range to explore regional adaptations among spruce budworm populations within common garden experiments. We present methods for establishing new spruce budworm laboratory colonies from wild populations. We describe the process of flushing, rearing, and disease screening used on these new populations to produce healthy disease-free laboratory stocks.

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.

scholarly journals Fruit Quality Characters of Myrtle (Myrtus communis L.) Selections: Review of a Domestication Process

2021 ◽  
Vol 13 (16) ◽  
pp. 8785
Author(s):  
Silvia Medda ◽  
Maurizio Mulas
Keyword(s):  
Raw Materials ◽  
Phenotypic Selection ◽  
Second Step ◽  
Myrtus Communis ◽  
Wild Populations ◽  
Phenotypic Characters ◽  
Myrtus Communis L ◽  
Mother Plants ◽  
Domestication Process ◽  
Fruit Characters

Interest in myrtle (Myrtus communis L.) by food, cosmetics, and pharmaceutic industries generated the integration of biomasses harvested from wild populations as raw materials with yields of cultivated orchards. The domestication process is reviewed considering shoot, fruit, and leaf biometric characters of selections obtained in three steps of the program. The first step started in Sardinia (Italy) in 1995 by the analysis of wild germplasm variability. Seventy accessions were the object of the first studied population of mother plants. Agamic propagation tests, as well quality evaluations of fruit and leaves, were integrated into the first step. In the second step, a field of comparison of forty-two agamically propagated cultivars functional to biomass production and to food uses was planted and evaluated for phenotypic characters. In the third step, a new population of twenty selections was obtained by open cross-pollination of some of the cultivars and further phenotypic selection in seedling population. In this review, the three populations are compared for biometric shoot, leaves and fruit characters, in order to verify the pressure of domestication process on these traits. Wild populations showed high variability only partially used during the first step, while the hybridization may create new variability for use in the genetic improvement of myrtle.

scholarly journals Estimated six per cent loss of genetic variation in wild populations since the industrial revolution

2019 ◽  
Vol 12 (8) ◽  
pp. 1505-1512 ◽  
Author(s):  
Deborah M. Leigh ◽  
Andrew P. Hendry ◽  
Ella Vázquez‐Domínguez ◽  
Vicki L. Friesen
Keyword(s):  
Genetic Variation ◽  
Industrial Revolution ◽  
Wild Populations

scholarly journals Cryptic variation and its manifestation in the Lower Trentonian Rafinesquina lineage (Ordovician, New York State)

1992 ◽  
Vol 6 ◽  
pp. 292-292
Author(s):  
Robert Titus
Keyword(s):  
New York ◽  
Genetic Variation ◽  
Natural Selection ◽  
New York State ◽  
Ecological Factors ◽  
Stabilizing Selection ◽  
Rapid Population Growth ◽  
York State ◽  
Cryptic Variation ◽  
Adaptive Peak

Species populations commonly carry a great deal of genetic variation which is not expressed in individual phenotypes. Cryptic variation can be carried in recessive alleles, in cases of heterosis, or where modifier genes inhibit expression of the hidden trait. Other genetic and ecological factors also allow cryptic variation. Stabilizing selection prevents the expression of hidden traits; normalizing selection weeds out the deviants and canalizing selection suppresses their traits. Together the two keep the species near the top of the adaptive peak. Cryptic variation balances a species' need to be well-adapted to its environment and also for it to maintain a reserve of variation for potential environmental change. Expression of cryptic traits is rare and is usually associated with times of greatly reduced natural selection and rapid population growth, when the lower slopes of the adaptive peak are exposed.A possible example of the manifestation of cryptic traits occurs within the lower Trentonian Rafinesquina lineage of New York State. The two most commonly reported species of the genus have been reappraised in terms of cryptic variation. Extensive collections of Rafinesquina “lennoxensis” reveal far more intergrading morphotypes than had hitherto been recognized. The form which Salmon (1942) described is broadly U-shaped with sulcate margins. It grades into very convex forms as well as sharply-defined or convexly geniculate types. Of great importance, all forms grade into the flat, U-shaped, alate R. trentonensis, which is, by far, the most common and widespread lower Trentonian member of the genus. The R. “lennoxensis” assemblage has a very narrow biostratigraphy, being confined to a few locations in the upper Napanee Limestone. This places it in a quiet, protected, low stress, lagoonal setting behind the barrier shoal facies of the Kings Falls Limestone.The R. “lennoxensis” assemblage does not constitute a natural biologic species; it is reinterpreted as an assemblage of phenodeviants occupying a low stress, low natural selection lagoon facies. All such forms should be included within R. trentonensis. Given the evolutionary plasticity of this genus, extensive cryptic variation is not surprising.

scholarly journals Do living ex situ collections capture the genetic variation of wild populations? A molecular analysis of two relict tree species, Zelkova abelica and Zelkova carpinifolia

2014 ◽  
Vol 23 (12) ◽  
pp. 2945-2959 ◽  
Author(s):  
Camille Christe ◽  
Gregor Kozlowski ◽  
David Frey ◽  
Laurence Fazan ◽  
Sébastien Bétrisey ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Molecular Analysis ◽  
Tree Species ◽  
Ex Situ ◽  
Wild Populations ◽  
Ex Situ Collections

scholarly journals Evolution and evolvability: celebrating Darwin 200

2008 ◽  
Vol 5 (1) ◽  
pp. 44-46 ◽  
Author(s):  
John F.Y Brookfield
Keyword(s):  
Genetic Variation ◽  
Natural Selection ◽  
Time Scales ◽  
Evolutionary Change ◽  
Adaptive Mutation ◽  
Genetic Covariances ◽  
The Relationship ◽  
The Way

The concept of ‘evolvability’ is increasingly coming to dominate considerations of evolutionary change. There are, however, a number of different interpretations that have been put on the idea of evolvability, differing in the time scales over which the concept is applied. For some, evolvability characterizes the potential for future adaptive mutation and evolution. Others use evolvability to capture the nature of genetic variation as it exists in populations, particularly in terms of the genetic covariances between traits. In the latter use of the term, the applicability of the idea of evolvability as a measure of population's capacity to respond to natural selection rests on one, but not the only, view of the way in which we should envisage the process of natural selection. Perhaps the most potentially confusing aspects of the concept of evolvability are seen in the relationship between evolvability and robustness.

scholarly journals The genomics of adaptation

2012 ◽  
Vol 279 (1749) ◽  
pp. 5024-5028 ◽  
Author(s):  
Jacek Radwan ◽  
Wiesław Babik
Keyword(s):  
Genetic Variation ◽  
Natural Selection ◽  
Royal Society ◽  
Genetic Basis ◽  
Genomic Data ◽  
Evolutionary Change ◽  
Introductory Article ◽  
Technological Advances ◽  
A Genome ◽  
Genome Level

The amount and nature of genetic variation available to natural selection affect the rate, course and outcome of evolution. Consequently, the study of the genetic basis of adaptive evolutionary change has occupied biologists for decades, but progress has been hampered by the lack of resolution and the absence of a genome-level perspective. Technological advances in recent years should now allow us to answer many long-standing questions about the nature of adaptation. The data gathered so far are beginning to challenge some widespread views of the way in which natural selection operates at the genomic level. Papers in this Special Feature of Proceedings of the Royal Society B illustrate various aspects of the broad field of adaptation genomics. This introductory article sets up a context and, on the basis of a few selected examples, discusses how genomic data can advance our understanding of the process of adaptation.

Sign in / Sign up

Export Citation Format

Share Document