Genetic Variability, Population Differentiation, and Correlations for Thermal Tolerance Indices in the Minute Wasp, Trichogramma cacoeciae

Temperature is a main driver of the ecology and evolution of ectotherms. In particular, the ability to move at sub-lethal low temperatures can be described through three thermal tolerance indices—critical thermal minimum (CTmin), chill coma temperature (CCT), and activity recovery (AR). Although these indices have proven relevant for inter-specific comparisons, little is known about their intraspecific variability as well as possible genetic correlations between them. We thus investigated these two topics (intraspecific variability and genetic correlations between thermal tolerance indices) using the minute wasp, Trichogramma cacoeciae. Strains from T. cacoeciae were sampled across three geographic regions in France—two bioclimatic zones along a sharp altitudinal cline in a Mediterranean context (meso-Mediterranean at low elevations and supra-Mediterranean at higher elevations) and a more northwestern area characterized by continental or mountainous climates. Our results evidenced a significant effect of both the longitude and the severity of the cold during winter months on CCT. Results were however counter-intuitive since the strains from the two bioclimatic zones characterized by more severe winters (northwestern area and supra-Mediterranean) exhibited opposite patterns. In addition, a strong positive correlation was observed between CCT and CTmin. Neither strain differentiation nor the covariations between traits seem to be linked with the molecular diversity observed on the part of the mitochondrial marker COI.

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Genetic control of liability to infection with Nematospiroides dubius in mice: direct and correlated responses to selection of mice for faecal parasite egg count

Parasitology ◽

10.1017/s003118200005246x ◽

1983 ◽

Vol 87 (1) ◽

pp. 113-127 ◽

Cited By ~ 12

Author(s):

P. J. Brindley ◽

C. Dobson

Keyword(s):

Genetic Control ◽

Primary Infection ◽

Genetic Correlations ◽

Strong Positive Correlation ◽

Correlated Responses ◽

Antibody Titres ◽

Refractory State ◽

Selection Limit ◽

Nematospiroides Dubius ◽

Positive Correlations

SUMMARYMice selected as liable (L) and refractory (R) over 10 generations voided significantly more and less Nematospiroides dubius eggs compared with randomly mated (Rd) mice after primary infection with 100 larvae. Strong positive correlation was found between the numbers of N. dubius eggs in mouse faeces and the numbers of adult N. dubius recovered from mice culled from the R, Rd and L colonies. Selection limit based on a faecal e.p.g. was reached in the L mice after 9 generations whereas the faecal N. dubius e.p.g. voided by the R mice continued to decline throughout selection. In contrast, no change in worm numbers was found in L or R mice after 6 generations. The refractory state of the trait, liability to infection with N. dubius, was inherited as a dominant character with a realized heritability value of ~ 0∣2. Differential correlated responses from N. dubius infectivity compared with N. dubius fecundity and growth indicated murine genetic control of this trait by 2 major genetic units. In general, there were negative phenotypic and genetic correlations between the faecal N. dubius e.p.g. of mice and murine morphological conformation, but positive correlations between the faecal N. dubius e.p.g. of selected mice and establishment, growth and fecundity of N. dubius populations in these mice. There was little correlation between the faecal N. dubius e.p.g. after primary infection and anti-N. dubius antibody titres and parasite female/male sex-ratio.

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Aluminium tolerance of different Paxillus involutus Fr. strains originating from polluted and nonpolluted sites

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1998.015 ◽

2014 ◽

Vol 67 (1) ◽

pp. 115-122 ◽

Cited By ~ 9

Author(s):

Maria Rudawska ◽

Tomasz Leski

Keyword(s):

Metal Tolerance ◽

Intraspecific Variability ◽

Dry Weight ◽

Ectomycorrhizal Fungus ◽

Control Site ◽

Polluted Site ◽

Lower Amount ◽

Aluminium Tolerance ◽

Aluminium Level ◽

Tolerance Indices

The caps of the sporocarps of P. involutus originating from the polluted site (Luboń) and from the control site in Kórnik and Puszcza Nadnotecka accumulated high amounts of aluminium and revealed symptoms of bioconcentration. However in caps of the sporocarps from the control sites a lower amount of Al was accumulated than in caps from the polluted site (Luboń). A significantly lower concentration of Al was found in stems of sporocarps originating from the special control site in Puszcza Nadnotecka. Mycelia of 11 strains isolated from sporocarps collected at the polluted and control sites were cultivated on a liquid medium containing 100 mg L-1 Al. All strains showed high bioconcentration of Al despite of the place of origin. In a subsequent experiment 10 strains of P. involutus originating from polluted soil and 8 strains derived from the control sites were grown in agar media containing 10, 100, 500 and 1000 mg/L-1 of Al. The radial growth rates during culture, the final colony dry weight and the metal tolerance indices calculated on the basis of measured parameters were determined. P. involutus strains appeared to be very tolerant to the presence of Al in the medium and were able to grow even at the highest Al concentration. Increasing aluminium level in the medium to different extent influenced growth of tested strains, however the site of the origin did not influence the response of P. involutus to aluminium: among 18 strains tested, the most tolerant were selected both from the polluted and from the unpolluted sites. The results are discussed with reference to the high intraspecific variability of different physiological features of the ectomycorrhizal fungus P. involutus.

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Patterns of Larval Development

Developmental Biology and Larval Ecology ◽

10.1093/oso/9780190648954.003.0006 ◽

2020 ◽

pp. 165-194 ◽

Cited By ~ 1

Author(s):

Ole Sten Møller ◽

Klaus Anger ◽

Guillermo Guerao

Keyword(s):

Life Cycle ◽

Larval Development ◽

Adult Life ◽

Intraspecific Variability ◽

Molting Cycle ◽

Developmental Patterns ◽

Development Patterns ◽

Arthropod Evolution ◽

Main Driver ◽

Larval Traits

In this chapter, we explore the different patterns of development following the hatching of the crustacean larvae. For many groups of crustaceans, the free-living, postembryonic, and prejuvenile phase is by far the most important part of their life cycle, providing the link between different life modes in successive phases (e.g., between a sessile adult life and the need for long-range planktonic dispersal). Among the aspects covered, we discuss the specific criteria for what a “larva” is, including the necessity for defining specific larval traits that are lacking in other phases of the life cycle. We examine the typical anamorphic and hemianamorphic developmental patterns based on larval examples from a wide selection of groups from Decapoda to Copepoda, Thecostraca to Branchiopoda. In these groups, we examine the most common larval development patterns (including intraspecific variability) of, for example, the zoea, furcilia, copepodite, nauplius, and cypris larvae. We also expand on the importance of the molting cycle as the main driver in larval ontogeny and evolution. Finally, we discuss some of the more general trends of crustacean larval development in light of the general patterns and latest knowledge on tetraconate and arthropod evolution.

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Geographic variation in larval cold tolerance and exposure across the invasion front of a widely established forest insect

10.1101/2021.12.08.471760 ◽

2021 ◽

Author(s):

Petra Hafker ◽

Lily M Thompson ◽

Dylan Parry ◽

Jonathan A Walter ◽

Kristine L Grayson

Keyword(s):

Cold Tolerance ◽

Thermal Tolerance ◽

Sublethal Effects ◽

Single Point ◽

Cold Climate ◽

Cold Temperature ◽

Growth Responses ◽

Forest Insect ◽

Cold Temperatures ◽

Chill Coma

As the global climate changes, high and low temperature extremes can drive changes in species distributions. Across the range of a species, thermal tolerance can experience plasticity and may undergo selection, shaping resilience to temperature stress. In this study, we measured variation in the lower thermal tolerance of early instar larvae of an invasive forest insect, Lymantria dispar dispar L. (Lepidoptera: Erebidae), using populations sourced from the climatically diverse invasion of the Eastern United States. In two chill coma recovery experiments, we recorded recovery time following a period of exposure to a non-lethal cold temperature. A third experiment quantified growth responses after chill coma recovery to evaluate sublethal effects. Our results indicate that cold tolerance is linked to regional climate, with individuals from cold climate populations recovering faster from chill coma. While this geographic gradient is seen in many species, detecting this pattern is notable for an introduced species founded from a single point-source introduction. We demonstrate that the cold temperatures used in our experiments occur in nature from cold snaps after spring hatching, but negative impacts to growth and survival appear low. We expect that population differences in cold temperature performance manifest more from differences in temperature-dependent growth than acute exposure. Evaluating intraspecific variation in cold tolerance increases our understanding of the role of climatic gradients on the physiology of an invasive species, and contributes to tools for predicting further expansion.

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A lack of repeatability creates the illusion of a trade-off between basal and plastic cold tolerance

10.1101/2021.09.24.461715 ◽

2021 ◽

Author(s):

Erica O’Neill ◽

Hannah E. Davis ◽

Heath A. MacMillan

Keyword(s):

Cold Tolerance ◽

Thermal Tolerance ◽

Regression To The Mean ◽

Trade Off ◽

Physiological Constraints ◽

Chill Coma ◽

Physiological Constraint ◽

The Mean ◽

High And Low Temperatures ◽

The Individual

AbstractThe thermotolerance-plasticity trade-off hypothesis predicts that ectotherms with greater basal thermal tolerance have a lower acclimation capacity. This hypothesis has been tested at both high and low temperatures but the results often conflict. If basal tolerance constrains plasticity (e.g. through shared mechanisms that create physiological constraints), it should be evident at the level of the individual, provided the trait measured is repeatable. Here, we used chill-coma onset temperature and chill-coma recovery time (CCO and CCRT; non-lethal thermal limits) to quantify cold tolerance of Drosophila melanogaster across two trials (pre- and post-acclimation). Cold acclimation improved cold tolerance, as expected, but individual measurements of CCO and CCRT in non-acclimated flies were not (or only slightly) repeatable. Surprisingly, however, there was still a strong correlation between basal tolerance and plasticity in cold-acclimated flies. We argue that this relationship is a statistical artefact (specifically, a manifestation of regression to the mean; RTM) and does not reflect a true trade-off or physiological constraint. Thermal tolerance trade-off patterns in previous studies that used similar methodology are thus likely to be impacted by RTM. Moving forward, controlling and/or correcting for RTM effects is critical to determining whether such a trade-off or physiological constraint truly exists.

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(252) Correlation of Pungency, Thiosulfinates, Antiplatelet Activity, and Total Soluble Solids in Two Garlic Families

HortScience ◽

10.21273/hortsci.40.4.1019e ◽

2005 ◽

Vol 40 (4) ◽

pp. 1019E-1019 ◽

Cited By ~ 1

Author(s):

Pablo Cavagnaro ◽

Douglas Senalik ◽

Claudio Galmarini ◽

Philipp Simon

Keyword(s):

Genetic Correlations ◽

Soluble Solids ◽

Organosulfur Compounds ◽

Strong Positive Correlation ◽

Soluble Solids Content ◽

Antiplatelet Activity ◽

Total Soluble Solids ◽

Positive Correlation ◽

Solids Content

Allium plants possess organosulfur compounds and carbohydrates that provide unique flavor and health-enhancing properties. In previous studies of onion F3 families, significant phenotypic and genetic correlations have been reported between pungency, in vitro antiplatelet activity (IVAA), and soluble solids content (SSC); although in other studies SSC and pungency have not always been correlated. In this study we analyzed SSC, pungency, garlic-induced in vitro antiplatelet activity and the content of three predominant thiosulfinates in bulbs from two garlic families obtained from unrelated self-pollinated plants. A strong positive correlation was observed between pungency and IVAA for both sample sets, indicating that it will be difficult to develop garlic populations with low pungency and high IVAA. Allicin was the most abundant thiosulfinate and its content was positively correlated with pungency and IVAA (r= 0.70 and 0.74, respectively). The thiosulfinates AllS(O)SPropenyl and AllS(O)SMe were also positively correlated with pungency and IVAA. When compared with IVAA, AllS(O)SMe had higher r values than AllS(O)SPropenyl (0.88 and 0.50, respectively). These differences could reflect differential platelet anti-aggregatory properties of different thiosulfinates. SSC was not correlated with IVAA, pungency, or thiosulfinates content, suggesting that soluble solids in garlic can be independently selected.

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Stiffness of Douglas-fir lumber: effects of wood properties and genetics

Canadian Journal of Forest Research ◽

10.1139/x11-039 ◽

2011 ◽

Vol 41 (6) ◽

pp. 1160-1173 ◽

Cited By ~ 42

Author(s):

Vikas Vikram ◽

Marilyn L. Cherry ◽

David Briggs ◽

Daniel W. Cress ◽

Robert Evans ◽

...

Keyword(s):

Stress Wave ◽

Transverse Vibration ◽

Genetic Correlations ◽

Genetic Selection ◽

Microfibril Angle ◽

Wood Properties ◽

Douglas Fir ◽

Bending Stiffness ◽

Wood Products ◽

Strong Positive Correlation

Because stiffness (modulus of elasticity (MOE)) is important for structural wood products, breeders and silviculturists seek to efficiently measure and improve this trait. We studied MOE in a 25-year-old progeny test of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) using field-based tools (ST300 and HM200) to measure stress wave MOE of standing trees and logs. We measured density, static bending MOE, and transverse vibration MOE on 2 × 4s, and density, SilviScan MOE, and SilviScan microfibril angle on small clearwood samples. Bending MOE had moderate to strong phenotypic and genetic correlations with stress wave MOE of trees and logs, transverse vibration MOE of 2 × 4s, and the densities of 2 × 4s and basal wood discs but was weakly correlated with the numbers and sizes of knots. The best lumber grade had the highest bending stiffness and smallest edge knots. Bending stiffness had a strong positive correlation with the density of small clearwood samples and a moderate negative correlation with microfibril angle. Compared with microfibril angle and edge knots, path analyses indicated that density had the strongest direct effect on bending MOE. We recommend that breeders measure and select for stress wave velocity to improve bending stiffness in Douglas-fir. Genetic gains can be increased by including wood density, but genetic selection for fewer or smaller knots will be ineffective.

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Chill coma onset and recovery fail to reveal true variation in thermal performance among populations of Drosophila melanogaster

Scientific Reports ◽

10.1038/s41598-021-90401-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hannah E. Davis ◽

Alexandra Cheslock ◽

Heath A. MacMillan

Keyword(s):

Drosophila Melanogaster ◽

Cold Exposure ◽

Thermal Tolerance ◽

Recovery Time ◽

Population Level ◽

Onset Temperature ◽

Chill Coma ◽

Population Pair ◽

Geographic Origins ◽

Insect Populations

AbstractSpecies from colder climates tend to be more chill tolerant regardless of the chill tolerance trait measured, but for Drosophila melanogaster, population-level differences in chill tolerance among populations are not always found when a single trait is measured in the laboratory. We measured chill coma onset temperature, chill coma recovery time, and survival after chronic cold exposure in replicate lines derived from multiple paired African and European D. melanogaster populations. The populations in our study were previously found to differ in chronic cold survival ability, which is believed to have evolved independently in each population pair; however, they did not differ in chill coma onset temperature and chill coma recovery time in a manner that reflected their geographic origins, even though these traits are known to vary with origin latitude among Drosophila species and are among the most common metrics of thermal tolerance in insects. While it is common practice to measure only one chill tolerance trait when comparing chill tolerance among insect populations, our results emphasise the importance of measuring more than one thermal tolerance trait to minimize the risk of missing real adaptive variation in insect thermal tolerance.

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A lack of repeatability creates the illusion of a trade-off between basal and plastic cold tolerance

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.2121 ◽

2021 ◽

Vol 288 (1964) ◽

Author(s):

Erica O'Neill ◽

Hannah E. Davis ◽

Heath A. MacMillan

Keyword(s):

Cold Tolerance ◽

Thermal Tolerance ◽

Regression To The Mean ◽

Trade Off ◽

Physiological Constraints ◽

Chill Coma ◽

Physiological Constraint ◽

The Mean ◽

High And Low Temperatures ◽

The Individual

The thermotolerance–plasticity trade-off hypothesis predicts that ectotherms with greater basal thermal tolerance have a lower acclimation capacity. This hypothesis has been tested at both high and low temperatures but the results often conflict. If basal tolerance constrains plasticity (e.g. through shared mechanisms that create physiological constraints), it should be evident at the level of the individual, provided the trait measured is repeatable. Here, we used chill-coma onset temperature and chill-coma recovery time (CCO and CCRT; non-lethal thermal limits) to quantify cold tolerance of Drosophila melanogaster across two trials (pre- and post-acclimation). Cold acclimation improved cold tolerance, as expected, but individual measurements of CCO and CCRT in non-acclimated flies were not (or only slightly) repeatable. Surprisingly, however, there was still a strong correlation between basal tolerance and plasticity in cold-acclimated flies. We argue that this relationship is a statistical artefact (specifically, a manifestation of regression to the mean; RTM) and does not reflect a true trade-off or physiological constraint. Thermal tolerance trade-off patterns in previous studies that used similar methodology are thus likely to be impacted by RTM. Moving forward, controlling and/or correcting for RTM effects is critical to determining whether such a trade-off or physiological constraint exists.

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Assessment of molecular diversity in landraces of bread wheat (Triticum aestivum L.) held in an ex situ collection with Diversity Arrays Technology (DArT™)

Australian Journal of Agricultural Research ◽

10.1071/ar07010 ◽

2007 ◽

Vol 58 (12) ◽

pp. 1174 ◽

Cited By ~ 20

Author(s):

B. J. Stodart ◽

M. C. Mackay ◽

H. Raman

Keyword(s):

Genetic Diversity ◽

Molecular Diversity ◽

Polymorphic Information Content ◽

Ex Situ ◽

Dart Markers ◽

Strong Positive Correlation ◽

High Genetic Diversity ◽

Diversity Arrays Technology ◽

Wheat Landraces ◽

Landrace Accessions

Diversity Arrays Technology (DArT™) was evaluated as a tool for determining molecular diversity of wheat landraces held within the Australian Winter Cereals Collection (AWCC). Initially, a set of 44 wheat landraces was evaluated with 256 DArT markers. The dataset was compared with the results obtained using 16 amplified fragment length polymorphism (AFLP) primer combinations and 63 simple sequence repeat (SSR) markers, mapped on the 21 chromosomes, from a previous study. The DArT markers exhibited a strong positive correlation with AFLP and SSR, with each marker type distinguishing similar relationships among the 44 landrace accessions. The DArT markers exhibited a higher polymorphic information content than AFLP, and were comparable with that obtained with SSR. Three hundred and fifty-five DArT markers were then used to evaluate genetic diversity among 705 wheat landrace accessions from within the AWCC, chosen to represent 5 world regions. DArT analysis was capable of distinguishing accessions from different geographic regions, and suggested that accessions originating from Nepal represent a unique gene pool within the collection. A statistical resampling of DArT loci indicated that 10–20 loci were enough to distinguish the maximum molecular diversity present within the collection. This research demonstrates the efficacy of the DArT platform as a tool for efficient examination of wheat diversity. As an ex situ germplasm repository, the AWCC contains wheat accessions of high genetic diversity, from genetically differentiated collection sites, even though diversity was under-represented in some countries represented in the repository.

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