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Aim: Intraspecific trait variation is fundamental to understanding a species' adaptive capacity. Assessing phenotypic variation at different ecological scales is useful for evaluating species' vulnerability to changing environmental conditions. Here, we quantify the ecological scale of variation of phenotypic functional traits for a widespread dryland tree species and evaluate the strength of trait‐environment relationships across spatial gradients and in response to interannual variability in weather conditions. Location: Western United States. Taxon: Conifer tree (Pinaceae): Pinus monophylla. Methods: Nine reproductive and foliar morphological traits were measured from 23 sampling locations in nine mountain ranges, stratified across broad‐scale gradients of precipitation timing and quantity and local gradients of elevation. We partitioned trait variation within and among nested ecological scales (mountain range, site, tree, and tree growth year). We then used multivariate methods to quantify the association between environmental variables and ecological trade‐offs associated with both reproductive and foliar traits. Results: Most variation was explained at the scale of individual trees (18%–46%) and between growth years (20%–30%), with smaller but variable contributions at the scale of sites (8%–25%) and mountain ranges (0%–15%). Trait values had low correlation with environmental variables (13%); however, 94% of the trait‐environment covariance was explained by two major axes of variation: (1) the drought‐stress gradient covarying with reproductive traits, and (2) precipitation patterns covarying with foliar morphology. Main conclusions High levels of individual trait variation indicate within‐population adaptive capacity. Consistent relationships among range‐wide patterns of foliar and reproductive traits and broad‐scale climate gradients provide indirect evidence of local adaptation and may inform seed sourcing for restoration or the potential for assisted migration efforts. Quantification of intraspecific trait variation across multiple ecological scales is important for understanding the potential climate change response of dryland tree species. [ABSTRACT FROM AUTHOR]

Premise: Floral scent is a complex trait that mediates many plant–insect interactions, but our understanding of how floral scent variation evolves, either independently or in concert with other traits, remains limited. Assessing variation in floral scent at multiple levels of biological organization and comparing patterns of variation in scent to variation in other floral traits can contribute to our understanding of how scent variation evolves in nature. Methods: We used a greenhouse common garden experiment to investigate variation in floral scent at three scales—within plants, among plants, and among populations—and to determine whether scent, alone or in combination with morphology and rewards, contributes to population differentiation in Oenothera cespitosa subsp. marginata. Its range spans most of the biomes in the western United States, such that variation in both the abiotic and biotic environment could contribute to trait variation. Results: Multiple analytical approaches demonstrated substantial variation among and within populations in compound‐specific and total floral scent measures. Overall, populations were differentiated in morphology and reward traits and in scent. Across populations, coupled patterns of variation in linalool, leucine‐derived compounds, and hypanthium length are consistent with a long‐tongued moth pollination syndrome. Conclusions: The considerable variation in floral scent detected within populations suggests that, similar to other floral traits, variation in floral scent may have a heritable genetic component. Differences in patterns of population differentiation in floral scent and in morphology and rewards indicate that these traits may be shaped by different selective pressures. [ABSTRACT FROM AUTHOR]

Seed germination is a vital process in the plant life cycle. It directly influences seedling establishment and subsequently determines population persistence and species distribution. Germination is highly sensitive to climatic conditions, and germination traits may vary among species and populations within the same species. This study aims to improve our understanding of intraspecific and interspecific variation in temperature dependence of seed germination and how this variation relates to the environment where seeds were collected. We focused on four conifer species (Pinus contorta , Picea engelmannii , Pinus ponderosa , and Pseudotsuga menziesii) and seeds collected at 20 sites spanning the elevation range of each species in the Western United States. We conducted seed germination tests at temperatures from 5 to 40°C in 5°C intervals and tracked germination for 30 days. We used the log-logistic time-to-event model and Gaussian function to fit germination data and analyze their temperature dependence. The climate variables at the seed-collecting sites were summarized by long-term normals (1971–2000) covering most seed-collection years. Climate variables were correlated and thus were combined via Principal Component Analysis (PCA) into several uncorrelated principal components (PC scores) that describe climate at the seed collection sites. The estimated optimal temperature (T o), shape coefficient (b), and maximum value at optimal temperature (GP max) of germination percentages and median germination rates (GR 50) were then fit to linear models to determine whether they varied with species identity and the climate-derived PC scores. Results showed that seed germination traits from different species exhibit climate gradients that are correlated with their ecological niche. However, seeds from different elevations within the same species had variable germination traits irrespective of environmental gradients. We also found that variation in germination was more significant near upper and lower temperature limits. Including inter- and intra-specific temperature dependence of seed germination would improve predictions of population dynamics and range shifts under climate warming and could inform forest management, seed transfer, and assisted migration practices. • Interspecific germination traits exhibit their ecological niches correlated with climatic gradients. • Intraspecific germination traits varied with seeds from different elevations and occasionally correlated with environments. • Variations in germination traits increased as the temperature approached the upper and lower limits. • Temperature and precipitation combined can better predict the variation within species. [ABSTRACT FROM AUTHOR]

Characterizing variation in plant functional traits is often key to understanding community‐level processes and predicting ecosystem responses to environmental change. Trait‐based ecology has focused on interspecific trait variation, but sources and consequences of within‐species ontogenetic trait variation, particularly during early stages of development, remain understudied.Using a manipulative greenhouse experiment, we investigated trait variation during early stages of seedling development in seven dominant perennial plant species in the western United States. We examined variability in key trait values (i.e. SLA, root:shoot ratio (RSR), specific root length (SRL) and root dry matter content (RDMC)) of 20‐ to 62‐day‐old seedlings grown under low and high levels of water availability. We also compared these to compiled trait databases to assess how representative these readily available data sources are of seedling trait values.Early seedling trait values shifted greatly during early stages of development and generally differed from average plant trait database values. Trait shifts were greatest in forbs versus grasses. Overall, observed trait shifts suggested a transition from fast‐growing resource acquisitional strategies towards more slow‐growing conservative strategies over time. For example, seedling SLA decreased while RSR and RDMC increased over time.That seedling trait values aconsistently differed from trait database values indicates that plant trait database values may be poor predictors of seedling trait values. Such mismatches in species trait information could result in inaccurate predictions of community assembly outcomes or incongruities between seedling traits and environmental filters experienced by seedlings during early stages of recruitment in applied settings.We suggest that additional work is needed to characterize intraspecific trait variation across plant ontogeny, and that this information should be incorporated into studies ranging from understanding early plant growth and survival to evaluating the outcomes of ecological restoration. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Alligator weed, Alternanthera philoxeroides (Mart.) Griseb., is one of the worst invasive weeds in the world. In the present study, the genome size of seven forms/biotypes of alligator weed from Argentina (native area), the USA (introduced area), and China (introduced area) was analyzed using flow cytometers; the ribosomal DNA internal transcribed spacer region (ITS) was cloned and sequenced. We found that the genome size of A. philoxeroides ranged from 5.72 to 8.50 pg/2C nucleus, consisting of four levels of genome and three kinds of ploidy. Among them, three levels and two kinds (tetraploid and hexaploid) were found in samples from Argentina, two levels and one kind (pentaploid) in US samples, and one level and one kind (hexaploid) in samples from China. Contrary to the significant variation in genome size, we found that the intraspecific differentiation of the ITS sequences in the seven forms/biotypes was extremely low, and that six of them shared ITS sequences with no or one single substitution. These results show that the change of genome size played a major role in the differentiation of A. philoxeroides, and that forms/biotypes with higher ploidy seem to have stronger invasive ability. Furthermore, the differences of A. philoxeroides in ploidy between samples from the USA and China showed that alligator weeds from these two invaded areas certainly have different native progenitors. [ABSTRACT FROM AUTHOR]

Defining units of conservation below the species level is a widely accepted conservation priority, but is especially challenging for widespread taxa that have experienced diverse geographic histories and exist across heterogenous environments. The lake chub (Pisces: Couesius plumbeus) is a widespread freshwater fish in North America and occurs from the southcentral USA to northwestern Alaska and Canada. We used mtDNA sequence analysis to test for divergent lineages predicted to occur as a result of survival of lake chub in distinct glacial refugia. Lake chub consisted of two major mtDNA lineages separated by 3.8% sequence divergence which are probably late to pre-Pleistocene in origin. We combined these data with those consistent with thermal adaptation in fish living in thermal springs versus those living in a lake with wide seasonal temperature variation, and with data on distribution of lake chub in major watershed units. We assessed these data against objective criteria developed to identify conservation units under Canadian endangered species legislation. Our analysis identified twelve major units of conservation within C. plumbeus that could be assessed under Canada's Species-at-Risk Act. Our study illustrates how different character traits manifested at very different spatial scales can be used to define conservation units within widely-distributed taxa. [ABSTRACT FROM AUTHOR]

Phenotypic variation within species is widespread among salt marsh plants. For Spartina alterniflora, the dominant species of low intertidal wetlands across the Altantic and Gulf coasts of the US, distinct phenological and morphological differences among populations from different latitudes have been found . To determine whether S. alterniflora plants from lower latitudes and those regenerated from Delaware tissue cultures would maintain differences from that of native plants, we conducted a field study in a natural salt marsh in Delaware, US. After two growing seasons, plant height, stem density, above- and belowground biomass, elemental composition, and nutrient resorption were measured. Natural variation in porewater salinity influenced physiological traits of Na/K ratio regulation and nitrogen resorption efficiency similarly across populations. While plant height exhibited plasticity where populations tended to converge to a similar height, several other traits remained distinct. Delaware plants had a greater rate of rhizome growth than Georgia and Louisiana plants, which correlated with a greater magnitude of fall senescence. If traits such as seasonal translocation are plastic and can change with the length of the growing season, climate warming may alter belowground biomass production of S. alterniflora in wetlands of the mid-Atlantic. [ABSTRACT FROM AUTHOR]

Abstract: Laricobius nigrinus (Coleoptera: Derodontidae) was first collected near the coastal city of Victoria, British Columbia, Canada for release as a biological control agent to suppress tree-killing densities of hemlock woolly adelgid, Adelges tsugae (Hemiptera: Adelgidae), in the eastern United States. Beetles established in warm areas of the invaded range of A. tsugae, but had a low probability of establishment in cold areas. With the goal of locating beetles with greater cold-tolerance, we collected hundreds of adults in the northern Rocky Mountains. To support planned releases of these inland L. nigrinus, the cold tolerance of field-collected coastal (Seattle, WA) and inland (Coeur d’Alene and Moscow, ID) adults and climate match index scores (CLIMEX v.2) of these collection areas and parts of the eastern United States were compared. We found that individuals of inland L. nigrinus were more cold tolerant than those of coastal L. nigrinus, based on higher survival in a winter field cage study in Massachusetts and a lower supercooling point in a laboratory assay. Inland L. nigrinus also had higher survival than coastal L. nigrinus after an 18h exposure to sub-zero temperatures in another laboratory assay. Areas of the eastern United States infested with A. tsugae and receiving L. nigrinus releases matched the climate of Seattle and Coeur d’Alene reasonably well, but Coeur d’Alene had higher index values over a considerably larger area than Seattle. Accordingly, inland L. nigrinus appears preferable for release in the colder portions of A. tsugae’s invaded range in the eastern United States. [Copyright &y& Elsevier]

1. Female preferences for particular male ornaments may shift between populations as a consequence of ecological differences that change the reliability and detectability of the ornament, but few studies have examined how ornaments function in different populations. 2. We examined the signalling function of male plumage ornaments in a warbler, the common yellowthroat ( Geothlypis trichas), breeding in New York (NY) and Wisconsin (WI), USA. Males have two prominent ornaments: a black facial mask pigmented with melanin and a yellow bib pigmented by carotenoids. Previous studies in WI indicate that the size of the mask, and not the bib, is primarily related to female choice and male reproductive success. In NY, however, the pattern is reversed and attributes of the bib (size and colour), and not the mask, are the target of sexual selection. 3. We found that brightness of the yellow bib was the best signal of humoral immunity (immunoglobulin G) in NY and mask size was the best signal in WI, after controlling for breeding experience and capture date. Thus, similar aspects of male quality appeared to be signalled by different ornaments in different populations. 4. There was no difference between populations in the level of plasma carotenoids or the prevalence of malarial parasites, which may affect the costs and benefits of choosing males with particular ornaments in each location. 5. Even though females in different populations prefer different ornaments produced by different types of pigments, these ornaments appear to be signalling similar aspects of male quality. Our results caution against inferring the function of particular ornaments based simply on their type of pigment. [ABSTRACT FROM AUTHOR]

The fatty acid (FA) composition of nine potentially important forage species was determined ( n = 330): red drum ( Sciaenops ocellatus), spot ( Leiostomus xanthurus), spotted seatrout ( Cynoscion nebulosus), striped mullet ( Mugil cephalus), pinfish ( Lagodon rhomboides), Atlantic croaker ( Micropogonias undulatus), star drum ( Stellifer lanceolatus), striped anchovy ( Anchoa hepsetus), and brief squid ( Lolliguncula brevis). Samples were collected from estuarine and nearshore coastal waters around Charleston, South Carolina, USA, from March 2002–February 2003. Twenty-nine of 125 identified FAs were included in multivariate analyses of FA profiles. Despite existing intraspecific variation, the PRIMER routine analysis of similarity (ANOSIM) indicated each species was distinct, and discriminant function analysis correctly classified 99.5% of the training data set samples ( n = 221) and 98.2% of the validation samples ( n = 109). Most species could be characterized by distinctive levels of a suite of FAs. Our results indicated FA profiles can be used to reliably distinguish even closely related forage species in this southeastern US estuarine ecosystem. The information gained from this study not only provides insight into the biochemical composition of these important species but also provides fundamental information to support studies on the feeding ecology of local higher-level predators. [ABSTRACT FROM AUTHOR]

Abstract: Reduced levels of estrogen receptor alpha (ERα) in the medial amygdala (MeA) and bed nucleus of stria terminalis (BST) have been hypothesized to play a significant role in the expression of male behaviors associated with monogamy. Therefore, the regulation of ERα could be a critical factor in determining male behavior and the evolution of monogamy. Central expression of ERα immunoreactivity was compared in hybrid offspring from crosses between two phenotypically distinct populations of prairie voles (Microtus ochrogaster). Illinois voles (IL) are socially monogamous and display low levels of ERα, while Kansas voles (KN) display some characteristics associated with polygyny and have higher levels of ERα. In offspring from hybrid crosses, the pattern of ERα expression was dependent upon parentage; the two types of hybrid crosses did not produce the same ERα pattern in the offspring. In the BST and MeA, hybrid males expressed ERα patterns consistent with those of males from their mother’s population, while hybrid females had ERα patterns typical of females belonging to their father’s population. The parental-specific patterns of ERα expression are suggestive of genomic imprinting, therefore, the vole ERα (Esr1) gene was cloned and sequenced, and examined for allele-specific expression. Results from this study indicate that while maternal factors may play a major role the expression of ERα in their male offspring, genomic imprinting is unlikely to be involved, suggesting another mechanism is responsible. [Copyright &y& Elsevier]

Tomato, Solanum lycopersicum (formerly Lycopersicon esculentum), has long been one of the classical model species of plant genetics. More recently, solanaceous species have become a model of evolutionary genomics, with several EST projects and a tomato genome project having been initiated. As a first contribution toward deciphering the genetic information of tomato, we present here the complete sequence of the tomato chloroplast genome (plastome). The size of this circular genome is 155,461 base pairs (bp), with an average AT content of 62.14%. It contains 114 genes and conserved open reading frames ( ycfs). Comparison with the previously sequenced plastid DNAs of Nicotiana tabacum and Atropa belladonna reveals patterns of plastid genome evolution in the Solanaceae family and identifies varying degrees of conservation of individual plastid genes. In addition, we discovered several new sites of RNA editing by cytidine-to-uridine conversion. A detailed comparison of editing patterns in the three solanaceous species highlights the dynamics of RNA editing site evolution in chloroplasts. To assess the level of intraspecific plastome variation in tomato, the plastome of a second tomato cultivar was sequenced. Comparison of the two genotypes (IPA-6, bred in South America, and Ailsa Craig, bred in Europe) revealed no nucleotide differences, suggesting that the plastomes of modern tomato cultivars display very little, if any, sequence variation. [ABSTRACT FROM AUTHOR]

A total of 13 representative isolates of Fusarium oxysporum f. sp. melonis (FOM) from Iran, USA and France, eight isolates of seven formae speciales from Iran and one isolate of F. oxysporum f. sp. niveum from the USA were compared based on isozyme analysis and soluble mycelial protein pattern. Isozyme analyses of alkaline phosphatase (ALP), catalase (CAT), esterase (EST), malate dehydrogenase (MDH), superoxide dismutase (SOD) and xanthine dehydrogenase (XDH) revealed polymorphism among the F. oxysporum isolates in which 22 electrophoretic phenotypes (EP) were determined. At least 10 putative loci for these six enzymes were detected and they were all polymorphic. Maximum genetic diversity was observed in CAT, EST and XDH loci. Using UPGMA, the 22 isolates were separated into three main groups with one of the groups divided into two subgroups. Group I included isolates belonging to five formae speciales from Iran, whereas group II that included FOM isolates from both Iran and the USA was divided into two subgroups each containing the vast majority of the respective isolates from either country. Group III constituted FOM isolates from France and one pathogenic isolate on pepper from Iran. FOM isolates representing five different geographical regions from Iran belonged to two different races of 1 and 1,2Y and one vegetative compatibility group (VCG)0134 and thus were genetically homologous. Isozyme polymorphism in these isolates was highly correlated with VCG and geographical origins and to a lesser extent with races. Variations in soluble protein profile in FOM isolates were correlated with genetic distances determined in isozyme analysis. This study suggests that isozyme analysis could be a useful tool for identifying genetic diversity not only in FOM but also several formae speciales of F. oxysporum. [ABSTRACT FROM AUTHOR]

Roehler's Coryphodon Catastrophe Quarry (Wasatch Formation, lower Eocene) in the Washakie Basin, Wyoming is a paucispecific assemblage containing a minimum of 10 individuals from a single population of cf. Coryphodon anthracoideus. The RCCQ Coryphodon assemblage provides a relatively rare opportunity to assess intraspecific variation in a genus that has historically been difficult to classify due to variation from specimen to specimen and species to species. Variation in metric features of the dentition (i.e., length, width, and molar area) in the RCCQ Coryphodon is within the range observed in comparable sexually dimorphic extant species. The RCCQ Coryphodon assemblage is also compared to another paucispecific, single population assemblage of Coryphodon molestus from New Mexico. Intraspecific metric variation characterizing these two assemblages is also comparable. In both assemblages, overall intraspecific metric variation is most pronounced in the third molar, suggesting sexual dimorphism as the source of variation. [ABSTRACT FROM AUTHOR]