scholarly journals Why are not all chilies hot? A trade-off limits pungency

2011 ◽  
Vol 279 (1735) ◽  
pp. 2012-2017 ◽  
Author(s):  
David C. Haak ◽  
Leslie A. McGinnis ◽  
Douglas J. Levey ◽  
Joshua J. Tewksbury
Keyword(s):  
Seed Production ◽  
Stomatal Density ◽  
Natural Populations ◽  
Pathogenic Fungi ◽  
Adaptive Divergence ◽  
High Moisture ◽  
Reducing Gas ◽  
Trade Offs ◽  
Use Efficiency ◽  
Capsicum Chacoense

Evolutionary biologists increasingly recognize that evolution can be constrained by trade-offs, yet our understanding of how and when such constraints are manifested and whether they restrict adaptive divergence in populations remains limited. Here, we show that spatial heterogeneity in moisture maintains a polymorphism for pungency (heat) among natural populations of wild chilies ( Capsicum chacoense ) because traits influencing water-use efficiency are functionally integrated with traits controlling pungency (the production of capsaicinoids). Pungent and non-pungent chilies occur along a cline in moisture that spans their native range in Bolivia, and the proportion of pungent plants in populations increases with greater moisture availability. In high moisture environments, pungency is beneficial because capsaicinoids protect the fruit from pathogenic fungi, and is not costly because pungent and non-pungent chilies grown in well-watered conditions produce equal numbers of seeds. In low moisture environments, pungency is less beneficial as the risk of fungal infection is lower, and carries a significant cost because, under drought stress, seed production in pungent chilies is reduced by 50 per cent relative to non-pungent plants grown in identical conditions. This large difference in seed production under water-stressed (WS) conditions explains the existence of populations dominated by non-pungent plants, and appears to result from a genetic correlation between pungency and stomatal density: non-pungent plants, segregating from intra-population crosses, exhibit significantly lower stomatal density ( p = 0.003), thereby reducing gas exchange under WS conditions. These results demonstrate the importance of trait integration in constraining adaptive divergence among populations.

Sex ratio and life history traits at reaching sexual maturity in the dioecious shrub Fuchsia parviflora: field and common garden experiments

2021 ◽  
pp. 1-6
Author(s):  
Jessica S. Ambriz ◽  
Clementina González ◽  
Eduardo Cuevas
Keyword(s):  
Natural Population ◽  
Sexual Maturity ◽  
Sex Ratios ◽  
Natural Populations ◽  
Common Garden ◽  
Common Garden Experiment ◽  
Trade Offs ◽  
Reproductive Biomass ◽  
Common Garden Experiments ◽  
Growth And Reproduction

Abstract Fuchsia parviflora is a dioecious shrub that depends on biotic pollination for reproduction. Previous studies suggest that the male plants produce more flowers, and male-biased sex ratios have been found in some natural populations. To assess whether the biased sex ratios found between genders in natural populations are present at the point at which plants reach sexual maturity, and to identify possible trade-offs between growth and reproduction, we performed a common garden experiment. Finally, to complement the information of the common garden experiment, we estimated the reproductive biomass allocation between genders in one natural population. Sex ratios at reaching sexual maturity in F. parviflora did not differ from 0.5, except in one population, which was the smallest seedling population. We found no differences between genders in terms of the probability of germination or flowering. When flowering began, female plants were taller than males and the tallest plants of both genders required more time to reach sexual maturity. Males produced significantly more flowers than females, and the number of flowers increased with plant height in both genders. Finally, in the natural population studied, the investment in reproductive biomass was seven-fold greater in female plants than in male plants. Our results showed no evidence of possible trade-offs between growth and reproduction. Despite the fact that female plants invest more in reproductive biomass, they were taller than the males after flowering, possibly at the expense of herbivory defence.

Tales of lizard tails: effects of tail autotomy on subsequent survival and growth of free-ranging hatchling Uta stansburiana

1997 ◽  
Vol 75 (4) ◽  
pp. 542-548 ◽  
Author(s):  
P. H. Niewiarowski ◽  
J. D. Congdon ◽  
A. E. Dunham ◽  
L. J. Vitt ◽  
D. W. Tinkle
Keyword(s):  
Natural Populations ◽  
Reproductive Investment ◽  
Experimental Manipulation ◽  
Costs And Benefits ◽  
Growth And Survival ◽  
Large Sample ◽  
Uta Stansburiana ◽  
Tail Autotomy ◽  
Trade Offs ◽  
Free Ranging

Potential costs and benefits of tail autotomy in lizards have been inferred almost exclusively from experimental study in semi-natural enclosures and from indirect comparative evidence from natural populations. We present complementary evidence of the costs of tail autotomy to the lizard Uta stansburiana from detailed demographic study of a natural population. On initial capture, we broke the tails of a large sample of free-ranging hatchlings (560) and left the tails of another large sample (455) intact, and then followed subsequent hatchling growth and survival over a 3-year period. Surprisingly, in 1 out of the 3 years of study, survival of female hatchlings with broken tails exceeded that of female hatchlings with intact tails. Furthermore, no effects of tail loss on survivorship were detected for male hatchlings. However, in 2 years when recaptures were very frequent (1961, 1962), growth rates of hatchlings with broken tails were significantly slower than those of their counterparts with intact tails. We discuss our results in the broader context of estimating the relative costs and benefits of tail autotomy in natural populations, and suggest that long-term demographic studies will provide the best opportunity to assess realized fitness costs and benefits with minimum bias. We also describe how experimentally induced tail autotomy can be used as a technique to complement experimental manipulation of reproductive investment in the study of life-history trade-offs.

Yield, resource use efficiency or flavour: Trade-offs of varying blue-to-red lighting ratio in urban plant factories

2022 ◽  
Vol 295 ◽  
pp. 110802
Author(s):  
Hao Zhou ◽  
Rhydian Beynon-Davies ◽  
Nicola Carslaw ◽  
Ian C. Dodd ◽  
Kirsti Ashworth
Keyword(s):  
Resource Use ◽  
Resource Use Efficiency ◽  
Trade Offs ◽  
Use Efficiency

scholarly journals Evolutionary inference from QST-FST comparisons: disentangling local adaptation from altitudinal gradient selection in snapdragon plants

2018 ◽  
Author(s):  
Sara Marin ◽  
Juliette Archambeau ◽  
Vincent Bonhomme ◽  
Mylène Lascoste ◽  
Benoit Pujol
Keyword(s):  
Local Adaptation ◽  
Natural Populations ◽  
Common Garden ◽  
Global Scale ◽  
Structured Populations ◽  
Adaptive Divergence ◽  
Adaptation To Climate Change ◽  
Phenotypic Differentiation ◽  
Multiple Populations ◽  
Environmental Demand

ABSTRACTPhenotypic differentiation among natural populations can be explained by natural selection or by neutral processes such as drift. There are many examples in the literature where comparing the effects of these processes on multiple populations has allowed the detection of local adaptation. However, these studies rarely identify the agents of selection. Whether population adaptive divergence is caused by local features of the environment, or by the environmental demand emerging at a more global scale, for example along altitudinal gradients, is a question that remains poorly investigated. Here, we measured neutral genetic (FST) and quantitative genetic (QST) differentiation among 13 populations of snapdragon plants (Antirrhinum majus) in a common garden experiment. We found low but significant genetic differentiation at putatively neutral markers, which supports the hypothesis of either ongoing pervasive homogenisation via gene flow between diverged populations or reproductive isolation between disconnected populations. Our results also support the hypothesis of local adaptation involving phenological, morphological, reproductive and functional traits. They also showed that phenotypic differentiation increased with altitude for traits reflecting the reproduction and the phenology of plants, thereby confirming the role of such traits in their adaptation to environmental differences associated with altitude. Our approach allowed us to identify candidate traits for the adaptation to climate change in snapdragon plants. Our findings imply that environmental conditions changing with altitude, such as the climatic envelope, influenced the adaptation of multiple populations of snapdragon plants on the top of their adaptation to local environmental features. They also have implications for the study of adaptive evolution in structured populations because they highlight the need to disentangle the adaptation of plant populations to climate envelopes and altitude from the confounding effects of selective pressures acting specifically at the local scale of a population.

scholarly journals Diffuse light weakens the dorsoventral asymmetry of photosynthesis in sorghum leaves

2018 ◽  
Author(s):  
Xiaolin Wang ◽  
Huifeng Yan ◽  
Yuanzheng Li
Keyword(s):  
Stomatal Density ◽  
Transmitted Light ◽  
Energy Crop ◽  
Diffuse Light ◽  
Use Patterns ◽  
Use Efficiency ◽  
Stomatal Sensitivity ◽  
The Impact ◽  
Changing Light ◽  
Sorghum Bicolor L

Dorsoventral asymmetry of photosynthesis is important for light use patterns, but the asymmetry changes with environments. Photosynthetic asymmetry was have been intensively studied for their role in light use efficiency, but less is know about the impact of light properties on asymmetry. Aimed at the current changing fraction of diffuse light in sky radiation, this study investigated dorsoventral asymmetry of photosynthetic traits in direct, diffuse and self-transmitted light (residual light intercepted by one surface) respectively in an important food and energy crop, Sorghum bicolor L. An unique designed method was used to investigate the specific gas exchange of two surfaces in different light properties. We found that anatomical and morphological traits were obviously different in sorghum leaves, which might cause the photosynthetic asymmetry, the variation of photosynthetic rates and stomatal conductance was significant between two surfaces in direct and self-transmitted light, but insignificant in diffuse light. The abaxial stomatal sensitivity of single stoma was lower, while the higher stomatal density in abaxial surface compensated the weakness in stomatal sensitivity. Comparing to direct and self-transmitted light, diffuse light reduced the stomatal sensitivity, while the degree of decline was higher in adaxial surface, which caused weak dorsoventral asymmetry in photosynthesis. Taken together, the finding of this study suggested that stomatal sensitivity determined the degree of dorsoventral asymmetry in the susceptibility to light properties. The different stomatal sensitivity regulated photosynthetic variation, which was benefit to remain high photosynthetic rate in high and changing light. The findings provided new insight in to dorsoventral asymmetry and impact of diffuse light on photosynthesis in isobilateral leaves.

scholarly journals Genome-wide shifts in climate-related variation underpin responses to selective breeding in a widespread conifer

2021 ◽  
Vol 118 (10) ◽  
pp. e2016900118
Author(s):  
Ian R. MacLachlan ◽  
Tegan K. McDonald ◽  
Brandon M. Lind ◽  
Loren H. Rieseberg ◽  
Sam Yeaman ◽  
...  
Keyword(s):  
Gene Flow ◽  
Selective Breeding ◽  
Natural Populations ◽  
Cold Injury ◽  
Nucleotide Polymorphisms ◽  
Phenotypic Differences ◽  
Climatic Regions ◽  
Breeding Populations ◽  
Trade Offs ◽  
Growth Initiation

Locally adapted temperate tree populations exhibit genetic trade-offs among climate-related traits that can be exacerbated by selective breeding and are challenging to manage under climate change. To inform climatically adaptive forest management, we investigated the genetic architecture and impacts of selective breeding on four climate-related traits in 105 natural and 20 selectively bred lodgepole pine populations from western Canada. Growth, cold injury, growth initiation, and growth cessation phenotypes were tested for associations with 18,600 single-nucleotide polymorphisms (SNPs) in natural populations to identify “positive effect alleles” (PEAs). The effects of artificial selection for faster growth on the frequency of PEAs associated with each trait were quantified in breeding populations from different climates. Substantial shifts in PEA proportions and frequencies were observed across many loci after two generations of selective breeding for height, and responses of phenology-associated PEAs differed strongly among climatic regions. Extensive genetic overlap was evident among traits. Alleles most strongly associated with greater height were often associated with greater cold injury and delayed phenology, although it is unclear whether potential trade-offs arose directly from pleiotropy or indirectly via genetic linkage. Modest variation in multilocus PEA frequencies among populations was associated with large phenotypic differences and strong climatic gradients, providing support for assisted gene flow polices. Relationships among genotypes, phenotypes, and climate in natural populations were maintained or strengthened by selective breeding. However, future adaptive phenotypes and assisted gene flow may be compromised if selective breeding further increases the PEA frequencies of SNPs involved in adaptive trade-offs among climate-related traits.

scholarly journals Introduction. Antarctic ecology: from genes to ecosystems. Part 2. Evolution, diversity and functional ecology

2007 ◽  
Vol 362 (1488) ◽  
pp. 2187-2189 ◽  
Author(s):  
Alex D Rogers ◽  
Eugene J Murphy ◽  
Nadine M Johnston ◽  
Andrew Clarke
Keyword(s):  
Climate Change ◽  
Life Histories ◽  
Natural Populations ◽  
Environmental Parameters ◽  
Functional Ecology ◽  
Antarctic Species ◽  
Trade Offs ◽  
Genes To Ecosystems ◽  
Micro Organisms ◽  
The Antarctic

The Antarctic biota has evolved over the last 100 million years in increasingly isolated and cold conditions. As a result, Antarctic species, from micro-organisms to vertebrates, have adapted to life at extremely low temperatures, including changes in the genome, physiology and ecological traits such as life history. Coupled with cycles of glaciation that have promoted speciation in the Antarctic, this has led to a unique biota in terms of biogeography, patterns of species distribution and endemism. Specialization in the Antarctic biota has led to trade-offs in many ecologically important functions and Antarctic species may have a limited capacity to adapt to present climate change. These include the direct effects of changes in environmental parameters and indirect effects of increased competition and predation resulting from altered life histories of Antarctic species and the impacts of invasive species. Ultimately, climate change may alter the responses of Antarctic ecosystems to harvesting from humans. The unique adaptations of Antarctic species mean that they provide unique models of molecular evolution in natural populations. The simplicity of Antarctic communities, especially from terrestrial systems, makes them ideal to investigate the ecological implications of climate change, which are difficult to identify in more complex systems.

scholarly journals Increased water use efficiency and water productivity of arabidopsis by abscisic acid receptors from Populus canescens

2019 ◽  
Vol 124 (4) ◽  
pp. 581-589 ◽  
Author(s):  
Michael Papacek ◽  
Alexander Christmann ◽  
Erwin Grill
Keyword(s):  
Abscisic Acid ◽  
Water Use Efficiency ◽  
Water Use ◽  
Water Productivity ◽  
Trade Offs ◽  
Enhanced Expression ◽  
Physiological Analysis ◽  
Specific Receptors ◽  
Use Efficiency ◽  
Aba Receptors

Abstract Background and Aims Water deficit is the single most important factor limiting plant productivity in the field. Poplar is a crop used for second-generation bioenergy production that can be cultivated on marginal land without competing for land use in food production. Poplar has a high demand for water, which makes improving its water use efficiency (WUE) an attractive goal. Recently, we showed that enhanced expression of specific receptors of arabidopsis for the phytohormone abscisic acid (ABA) can improve WUE in arabidopsis and water productivity, i.e. more biomass is formed per unit of water over time. In this study, we examined whether ABA receptors from poplar can enhance WUE and water productivity in arabidopsis. Methods ABA receptors from poplar were stably introduced into arabidopsis for analysis of their effect on water use efficiency. Physiological analysis included growth assessment and gas exchange measurements. Key Results The data presented here are in agreement with the functionality of poplar ABA receptors in arabidopsis, which led to ABA-hypersensitive seed germination and root growth. In addition, arabidopsis lines expressing poplar RCAR10, but not RCAR9, showed increased WUE by up to 26 % compared with the wild type with few trade-offs in growth that also resulted in higher water productivity during drought. The improved WUE was mediated by reduced stomatal conductance, a steeper CO2 gradient at the leaf boundary and sustained photosynthesis resulting in an increased intrinsic WUE (iWUE). Conclusions The analysis is a case study supporting the use of poplar ABA receptors for improving WUE and showing the feasibility of using a heterologous expression strategy for generating plants with improved water productivity.

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