Intraspecific Relationships Research Articles

The intraspecific relationship between wood density, vessel diameter and other traits across environmental gradients

Abstract Wood density (WD), a key trait in the trait‐based approach of plant ecology, represents a carbon investment trait that varies across species and reflects a trade‐off between metabolism and longevity. Across species, WD has been found to vary with phylogeny, moisture, temperature and xylem anatomy (e.g. vessel diameter). However, we know little about WD variation at the intraspecific level. Here, we examined how ecologically important functional traits vary in relation to WD in three generalist, exceptionally wide‐niche breadth tree species from southern Chile, making use of broad precipitation and temperature gradients. We collected branches from Embothrium coccineum and Nothofagus antarctica across a wide W–E precipitation gradient (2,500–600 mm of annual precipitation) and from N. pumilio across an elevational gradient (from low to treeline elevation). For each individual, we determined WD, several xylem anatomical features, for example, mean vessel diameter (MVD), hydraulic diameter (Dh), hydraulic conductivity (Kt), mean vessel area (MVA), vessel size distribution (MVA/VD) and other traits including concentrations of non‐structural carbohydrates (NSCs), secondary growth, leaf traits, water‐use efficiency (iWUE) and growth rate (AI). We quantified the correlation between WD and other traits and evaluated whether WD‐trait relationships differed across species using linear mixed‐effects models. We found consistent and significant negative relationships between WD and several xylem anatomy traits, including Dh, Kt, MVA and MVD. Contrary to our expectations, WD was not related to leaf traits, NSCs, iWUE and AI. Wood density had a significantly negative relationship to MVA/VD (and to a lesser extent, MVD) for both E. coccineum and N. antarctica (the precipitation gradient), while these relationships were positive for N. pumilio (the temperature gradient). Few of the WD and other trait relationships examined at the intraspecific level in this study paralleled those found across species. At the intraspecific level, WD proved to be much more related to xylem anatomical traits than to other traits. Importantly, in some cases, WD‐xylem anatomical trait relationships showed opposite trends depending on the environmental gradient. We must be cautious when using interspecific studies as the basis for inferring trait‐based responses to environmental change across other organisation levels. Read the free Plain Language Summary for this article on the Journal blog.

A target Capture Probe Set Useful for Deep- and Shallow-Level Phylogenetic Studies in Cactaceae.

The molecular phylogenies of Cactaceae have enabled us to better understand their systematics, biogeography, and diversification ages. However, most of the phylogenetic relationships within Cactaceae major groups remain unclear, largely due to the lack of an appropriate set of molecular markers to resolve its contentious relationships. Here, we explored the genome and transcriptome assemblies available for Cactaceae and identified putative orthologous regions shared among lineages of the subfamily Cactoideae. Then we developed a probe set, named Cactaceae591, targeting both coding and noncoding nuclear regions for representatives from the subfamilies Pereskioideae, Opuntioideae, and Cactoideae. We also sampled inter- and intraspecific variation to evaluate the potential of this panel to be used in phylogeographic studies. We retrieved on average of 547 orthologous regions per sample. Targeting noncoding nuclear regions showed to be crucial to resolving inter- and intraspecific relationships. Cactaceae591 covers 13 orthologous genes shared with the Angiosperms353 kit and two plastid regions largely used in Cactaceae studies, enabling the phylogenies generated by our panel to be integrated with angiosperm and Cactaceae phylogenies, using these sequences. We highlighted the importance of using coalescent-based species tree approaches on the Cactaceae591 dataset to infer accurate phylogenetic trees in the presence of extensive incomplete lineage sorting in this family.

Phylogenomic Analyses Show Repeated Evolution of Hypertrophied Lips Among Lake Malawi Cichlid Fishes.

Cichlid fishes have repeatedly evolved an astounding diversity of trophic morphologies. For example, hypertrophied lips have evolved multiple times in both African and Neotropical cichlids and could have even evolved convergently within single species assemblages such as African Lake Malawi cichlids. However, the extremely high diversification rate in Lake Malawi cichlids and extensive potential for hybridization has cast doubt on whether even genome-level phylogenetic reconstructions could delineate if these types of adaptations have evolved once or multiple times. To examine the evolution of this iconic trait using protein-coding and noncoding single nucleotide polymorphisms (SNPs), we analyzed the genomes of 86 Lake Malawi cichlid species, including 33 de novo resequenced genomes. Surprisingly, genome-wide protein-coding SNPs exhibited enough phylogenetic informativeness to reconstruct interspecific and intraspecific relationships of hypertrophied lip cichlids, although noncoding SNPs provided better support. However, thinning of noncoding SNPs indicated most discrepancies come from the relatively smaller number of protein-coding sites and not from fundamental differences in their phylogenetic informativeness. Both coding and noncoding reconstructions showed that several “sand-dwelling” hypertrophied lip species, sampled intraspecifically, form a clade interspersed with a few other nonhypertrophied lip lineages. We also recovered Abactochromis labrosus within the rock-dwelling “mbuna” lineage, starkly contrasting with the affinities of other hypertrophied lip taxa found in the largely sand-dwelling “nonmbuna” component of this radiation. Comparative analyses coupled with tests for introgression indicate there is no widespread introgression between the hypertrophied lip lineages and taken together suggest this trophic phenotype has likely evolved at least twice independently within-lake Malawi.

A genome-wide assessment of the genetic diversity, evolution and relationships with allied species of the clonally propagated crop Vanilla planifolia Jacks. ex Andrews

The Vanilla genus is a complex taxonomic group characterized by a vegetative reproduction mode combined with intra- and inter-specific hybridizations, and polyploidy events. These factors strongly impact the diversification of the genus and complicate the delimitation of taxa. Among the hundred Vanilla species, Vanilla planifolia Jacks. ex Andrews and Vanilla × tahitensis J. W. Moore are the main cultivated aromatic species. We applied Genotyping-by-Sequencing to explore the genetic diversity of these two cultivated vanilla species, seven closely related species and nineteen interspecific hybrids. The inter- and intra-specific relationships of 133 vanilla accessions were examined based on 2004 filtered SNPs. Our results showed a strong genetic structuring between the nine species studied, with wild species showing much lower heterozygosity levels than cultivated ones. Moreover, using Bayesian clustering analyses, the kinship of several hybrids could be verified. We evidenced in particular that Vanilla sotoarenasii and Vanilla odorata C.Presl may be the parental species of V. x tahitensis. The analysis of 1129 SNPs for 84 V. planifolia accessions showed a clear genetic demarcation between the vegetatively propagated traditional vanilla cultivars compared to the accessions derived from sexual reproduction, and a higher genetic diversity and lower heterozygosity of the latter (Ho = 0.206) compared to the former (Ho = 0.362). Our data are consistent with a single-step domestication for V. planifolia in accordance with the recent history of its cultivation. It also opens avenues to breed new V. planifolia varieties adapted to biotic and abiotic constraints and to reduce mutational load induced by clonal propagation.

Comparative Analysis of Chloroplast Genome Structure and Phylogenetic Relationships Among Six Taxa Within the Genus Catalpa (Bignoniaceae)

Species within the Genus Catalpa are mostly semievergreen or deciduous trees with opposite or whorled leaves. C. bungei, C. fargesii f. duclouxii and C. fargesii are sources of traditional precious wood in China, known as the “kings of wood”. Due to a lack of phenotypic and molecular studies and insufficient sequence information, intraspecific morphological differences, common DNA barcodes and partial sequence fragments cannot clearly reveal the phylogenetic or intraspecific relationships within Catalpa. Therefore, we sequenced the complete chloroplast genomes of six taxa of the genus Catalpa and analyzed their basic structure and evolutionary relationships. The chloroplast genome of Catalpa shows a typical tetrad structure with a total length ranging from 157,765 bp (C. fargesii) to 158,355 bp (C. ovata). The length of the large single-copy (LSC) region ranges from 84,599 bp (C. fargesii) to 85,004 bp (C. ovata), that of the small single-copy (SSC) region ranges from 12,662 bp (C. fargesii) to 12,675 bp (C. ovata), and that of the inverted repeat (IR) regions ranges from 30,252 bp (C. fargesii) to 30,338 bp (C. ovata). The GC content of the six chloroplast genomes were 38.1%. In total, 113 unique genes were detected, and there were 19 genes in IR regions. The 113 genes included 79 protein-coding genes, 30 tRNA genes and four rRNA genes. Five hypervariable regions (trnH-psbA, rps2-rpoC2, rpl22, ycf15-trnl-CAA and rps15) were identified by analyzing chloroplast nucleotide polymorphisms, which might be serve as potential DNA barcodes for the species. Comparative analysis showed that single nucleotide polymorphisms (SNPs) and simple sequence repeats (SSRs) were highly diverse in the six species. Codon usage patterns were highly similar among the taxa included in the present study. In addition to the stop codons, all codons showed a preference for ending in A or T. Phylogenetic analysis of the entire chloroplast genome showed that all taxa within the genus Catalpa formed a monophyletic group, clearly reflecting the relationships within the genus. This study provides information on the chloroplast genome sequence, structural variation, codon bias and phylogeny of Catalpa, which will facilitate future research efforts.

Effects of Interannual Environmental Changes on Juvenile Fish Settlement in Coastal Nurseries: The Case of the Adriatic Sea

This study tested generality in the settlement and recruitment patterns of juvenile fish in the coastal Mediterranean as driven by interannual environmental differences. A multivariate analysis of juvenile fish community data, sampled over three consecutive years, was conducted to elucidate the interannual changes of new settlers’ occurrence and abundance in different nurseries along the eastern Adriatic coast. Sites were assigned to four groups of nurseries based on water type (marine or transitional) and geographical position (north or south). Statistically significant interannual differences were found in temperature but not in salinity. In general, species occurrence significantly fluctuated between years and seasons. The highest total abundance of juveniles was observed in the significantly warmer year 2018 within all study groups. Defined groups expressed significant annual differences in species richness and abundance related to variations in water temperature and salinity as environmental factors for the same consecutive years. Nurseries within transitional waters in the north are more prone to interannual water temperature changes. The associated community composition differed most from those recorded in southern marine waters, where groups were mostly defined by salinity influence and were least sensitive to interannual temperature fluctuations. The cold and rainy spring in 2019 caused late settlement and longer retention of specific economically and ecologically important fish species in the nurseries. The results suggested that settlers’ delay or retention due to negative temperature deviation in the spawning period were linked to the nurseries located in the northern transitional waters that are under a stronger coastal influence. These delays can have ecological consequences on population dynamics and on inter- and intraspecific relationships within specific nursery communities.

Intraspecific Relationships and Nest Mound Shape Are Affected by Habitat Features in Introduced Populations of the Red Wood Ant Formica paralugubris.

Simple SummaryRed wood ants (Formica rufa goup) are dominant ant species widespread in the Eurasian continent. These species have a strong ecological impact on the habitats they dwell in, being top-ranked predators. One of the most striking features of these ants is represented by the large nest mounds they build. In this study, we investigated how nest mound shape and colony organization of imported populations of Formica paralugubris varied in three different habitat types. We found that nest mounds differed in size, number and shape in the three habitats. In all the three sites, nests were connected by trails of workers, but the size of these nest-networks differed. We also investigated the pattern of intraspecific aggression among ants from different nests, and we showed that aggressiveness was higher within each population than between separate populations, a finding in line with a ‘nasty neighbor’ behavior.Ants belonging to the Formica rufa group build large nest mounds, which aid their survival during severe winters. We investigated whether different environmental features of the habitats affected the nest mound shape and the population structure. We assessed the shape of all the nest mounds and mapped inter-nest trails connecting mounds for three imported populations of Formica paralugubris in three forest habitats: fir-dominated, beech-dominated, and a mixture of fir and beech. Single-nest mounds were averagely smaller and flatter in the beech-dominated forest, probably because of lighter building materials. Nonetheless, by summing the volumes of all interconnected nests, the size was similar among all three sites. In fir- and beech-dominated forests, large nests were also central in the networks, suggesting a central place foraging model with these nests as reference. We finally performed aggression tests, and found that aggressiveness was significantly higher among nests belonging to the same population than between populations. The results highlight the plasticity of the species to adapt nest and colony structure to different environments. Additionally, it appears that none of these populations is unicolonial, as observed in various alpine sites, there and the observed patterns of aggression are coherent with the ‘nasty neighbor’ effect.

Potentially misleading phylogenetic signal and its explanation in single species studies – contrasting Loeskypnum badium, Sarmentypnum exannulatum and Warnstorfia fluitans

Incongruence among morphological and different molecular data sets can be troublesome for species and genus circumscriptions and may cause problems in interpreting intraspecific relationships. Based on the nuclear ITS1 and 2, and the plastid rpl16, trnG and trnL-trnF, it is shown that while such incongruence is not detected if the individual species Loeskypnum badium, Sarmentypnum exannulatum or Warnstorfia fluitans are studied, it may be striking when analyzed in a wider context within the Calliergonaceae. The wider context did not affect the interpretation of internal relationships within L. badium, but many specimens of the other two species were suggested to belong to different species by either marker set. For a large minority of S. exannulatum (8% of specimens), ITS suggested W. fluitans and for 28% of W. fluitans the plastid markers suggested S. exannulatum or (one case) S. sarmentosum. The found pattern agrees with a scenario where archegonia of female plants of S. exannulatum or S. sarmentosum were fertilized by W. fluitans spermatozoids. The produced spores all have the maternally inherited Sarmentypnum plastids, but nuclear genome portions from either the involved Sarmentypnum species or W. fluitans. If foreign plastids affect the functionality of plants less than foreign nuclear portions in plants with mixed genomes, morphological W. fluitans plants with Sarmentypnum plastids should survive to a higher degree than vice versa.

Leaf hydraulics coordinated with leaf economics and leaf size in mangrove species along a salinity gradient

Independence among leaf economics, leaf hydraulics and leaf size confers plants great capability in adapting to heterogeneous environments. However, it remains unclear whether the independence of the leaf traits revealed across species still holds within species, especially under stressed conditions. Here, a suite of traits in these dimensions were measured in leaves and roots of a typical mangrove species, Ceriops tagal, which grows in habitats with a similar sunny and hot environment but different soil salinity in southern China. Compared with C. tagal under low soil salinity, C. tagal under high soil salinity had lower photosynthetic capacity, as indicated directly by a lower leaf nitrogen concentration and higher water use efficiency, and indirectly by a higher investment in defense function and thinner palisade tissue; had lower water transport capacity, as evidenced by thinner leaf minor veins and thinner root vessels; and also had much smaller single leaf area. Leaf economics, hydraulics and leaf size of the mangrove species appear to be coordinated as one trait dimension, which likely stemmed from co-variation of soil water and nutrient availability along the salinity gradient. The intraspecific leaf trait relationship under a stressful environment is insightful for our understanding of plant adaption to the multifarious environments.

Effect of daily salinity fluctuation on the intraspecific interactions of a euhalophyte (Suaeda salsa) along a salinity gradient

AbstractHeterogeneity of soil salinity is a prominent environmental characteristic in the intertidal zone of estuaries, affecting the plant growth and the shift of biotic interactions in the salt marsh. This study aims to examine the interactive effects of a salinity gradient and salinity fluctuations on intraspecific interactions of a euhalophyte. We assessed the impact of daily fluctuating salinity on the outcome of intraspecific interactions by cultivating seeds of Suaeda salsa (Chenopodiaceae) in river sand. The experiment was conducted in a greenhouse with three treatments: daily salinity fluctuations (static and fluctuating salinity), a salinity gradient (200 and 400 mmol L−1) and three planting densities (1, 2 and 4 plants/pot). First, height and biomass of plants were measured at both the start and end of the experiment. Then, the growth indexes and log response ratio of S. salsa were analyzed. The outcome of intraspecific interactions of S. salsa shifted from competition in low salinity to facilitation in high salinity, and high conspecific density strengthened the competition and facilitation intensities. Daily salinity fluctuation did not significantly affect the plant growth and the outcome of intraspecific interactions, but did have a significant influence on belowground biomass. Our results suggest that the stress-gradient hypothesis may apply to predicting the variation of the intraspecific relationship of a salt-tolerant species along a salinity gradient, and the magnitude of this variation is density dependent. These findings help us understand how individuals and populations of a euhalophyte species respond to the natural variation or human modification of salinity conditions.

Phylogenomic analysis of evolutionary relationships in Ranitomeya poison frogs (Family Dendrobatidae) using ultraconserved elements

The use of genome-scale data in phylogenetics has enabled recent strides in determining the relationships between taxa that are taxonomically problematic because of extensive morphological variation. Here, we employ a phylogenomic approach to infer evolutionary relationships within Ranitomeya (Anura: Dendrobatidae), an Amazonian lineage of poison frogs consisting of 16 species with remarkable diversity in color pattern, range size, and parental care behavior. We infer phylogenies with all described species of Ranitomeya from ultraconserved nuclear genomic elements (UCEs) and also estimate divergence times. Our results differ from previous analyses regarding interspecific relationships. Notably, we find that R. toraro and R. defleri are not sister species but rather distantly related, contrary to previous analyses based on smaller genetic datasets. We recover R. uakarii as paraphyletic, designate certain populations formerly assigned to R. fantastica from Peru as R. summersi, and transfer the French Guianan and eastern Brazilian R. amazonica populations to R. variabilis. By clarifying both inter- and intraspecific relationships within Ranitomeya, our study paves the way for future tests of hypotheses on color pattern evolution and historical biogeography.

Metal accumulation in relation to size and body condition in an all-alien species community

Metal pollution is one of the main environmental threats in freshwater ecosystems. Aquatic animals can accumulate these substances and transfer them across the food web, posing risks for both predators and humans. Accumulation patterns strongly vary depending on the location, species, and size (which in fish and crayfish is related to age) of individuals. Moreover, high metal concentrations can negatively affect animals’ health. To assess the intraspecific relationship between metal accumulation and size and health (proxied by the body condition) of individuals, the concentration of 14 metals (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Se, Zn) was analyzed in six alien species from the highly anthropogenically altered Arno River (Central Italy): five fish (Alburnus alburnus, Pseudorasbora parva, Lepomis gibbosus, Ictalurus punctatus, and Silurus glanis) and one crayfish (Procambarus clarkii). We found that in P. clarkii, Cu was negatively related to size, as well as Al in L. gibbosus and Mg for adult I. punctatus. Positive size-dependent relationships were found for Hg in L. gibbosus, Fe in S. glanis, and Cr in juvenile I. punctatus. Only Co and Mg in S. glanis were found to negatively correlate with individual health. Since metal concentrations in animal tissue depend on trade-offs between uptake and excretion, the few significant results suggest different types of trade-offs across different species and age classes. However, only predatory fish species (L. gibbosus, I. punctatus, and S. glanis) presented significant relationships, suggesting that feeding habits are one of the primary drivers of metal accumulation.

SSR-Sequencing Reveals the Inter- and Intraspecific Genetic Variation and Phylogenetic Relationships among an Extensive Collection of Radish (Raphanus) Germplasm Resources.

Raphanus has undergone a lengthy evolutionary process and has rich diversity. However, the inter- and intraspecific phylogenetic relationships and genetic diversity of this genus are not well understood. Through SSR-sequencing and multi-analysis of 939 wild, semi-wild and cultivated accessions, we discovered that the European wild radish (EWR) population is separated from cultivated radishes and has a higher genetic diversity. Frequent intraspecific genetic exchanges occurred in the whole cultivated radish (WCR) population; there was considerable genetic differentiation within the European cultivated radish (ECR) population, which could drive radish diversity formation. Among the ECR subpopulations, European primitive cultivated radishes (EPCRs) with higher genetic diversity are most closely related to the EWR population and exhibit a gene flow with rat-tail radishes (RTRs) and black radishes (BRs)/oil radishes (ORs). Among Asian cultivated radishes (ACRs), Chinese big radishes (CBRs) with a relatively high diversity are furthest from the EWR population, and most Japanese/Korean big radishes (JKBRs) are close to CBR accessions, except for a few old Japanese landraces that are closer to the EPCR. The CBR and JKBR accessions are independent of RTR accessions; however, phylogenetic analysis indicates that the RTR is sister to the clade of CBR (including JWR), which suggests that the RTR may share the most recent common ancestry with CBRs and JWRs. In addition, Japanese wild radishes (JWRs), (namely, R. sativus forma raphanistroides) are mainly scattered between CBRs and EPCRs in PCoA analysis. Moreover, JWRs have a strong gene exchange with the JKBR, OR and RTR subpopulations. American wild radishes (AWRs) are closely related to European wild and cultivated radishes, and have a gene flow with European small radishes (ESRs), suggesting that the AWR developed from natural hybridization between the EWR and the ESR. Overall, this demonstrates that Europe was the origin center of the radish, and that Europe, South Asia and East Asia appear to have been three independent domestication centers. The EPCR, AWR and JWR, as semi-wild populations, might have played indispensable transitional roles in radish evolution. Our study provides new perspectives into the origin, evolution and genetic diversity of Raphanus and facilitates the conservation and exploitation of radish germplasm resources.

Stomatal density in Pinus sylvestris as an indicator of temperature rather than CO2 : Evidence from a pan-European transect.

The commonly observed negative relationship between stomatal density (SD) and atmospheric CO2 has led to SD being proposed as an indicator of atmospheric CO2 concentration. The use of SD as a proxy for CO2 , however, has been hampered by an insufficient understanding of the intraspecific variation of this trait. We hypothesized that SD in Pinus sylvestris, a widely distributed conifer, varies geographically and that this variation is determined by major climatic variables. By sampling needles from naturally growing trees along a latitudinal range of 32.25°, equivalent to 13.7°C gradientof mean annual temperature (MAT) across Europe, we found that SD decreased from the warmest southern sites to the coldest sites in the north at a rate of 4 stomata per mm2 for each 1°C, with MAT explaining 44% of the variation. Additionally, samples from a provenance trial exhibited a positive relationship between SD and the MAT of the original localities, suggesting that high SD is an adaptation to warm temperature. Our study revealed one of the strongest intraspecific relationships between SD and climate in any woody species, supporting the utility of SD as a temperature, rather than direct CO2 , proxy. In addition, our results predict the response of SD to climate warming.

Diversification, spread, and admixture of octoploid strawberry in the Western Hemisphere.

PremisePolyploid species often have complex evolutionary histories that have, until recently, been intractable due to limitations of genomic resources. While recent work has further uncovered the evolutionary history of the octoploid strawberry (Fragaria L.), there are still open questions. Much is unknown about the evolutionary relationship of the wild octoploid species, Fragaria virginiana and Fragaria chiloensis, and gene flow within and among species after the formation of the octoploid genome.MethodsWe leveraged a collection of wild octoploid ecotypes of strawberry representing the recognized subspecies and ranging from Alaska to southern Chile, and a high‐density SNP array to investigate wild octoploid strawberry evolution. Evolutionary relationships were interrogated with phylogenetic analysis and genetic clustering algorithms. Additionally, admixture among and within species is assessed with model‐based and tree‐based approaches.ResultsPhylogenetic analysis revealed that the two octoploid strawberry species are monophyletic sister lineages. The genetic clustering results show substructure between North and South American F. chiloensis populations. Additionally, model‐based and tree‐based methods support gene flow within and among the two octoploid species, including newly identified admixture in the Hawaiian F. chiloensis subsp. sandwicensis population.Conclusions F. virginiana and F. chiloensis are supported as monophyletic and sister lineages. All but one of the subspecies show extensive paraphyly. Furthermore, phylogenetic relationships among F. chiloensis populations supports a single population range expansion southward from North America. The inter‐ and intraspecific relationships of octoploid strawberry are complex and suggest substantial gene flow between sympatric populations among and within species.

Intraspecific ecological relationships harmonious and inharmonious of parasitoids Class Insect Order Hymenoptera and a review

The aim of this study was to perform a bibliographic summary on the harmonic and disharmonious intraspecific ecological relationships of parasitoids (Insect: Hymenoptera). The mini review consists of bibliographical research on the parasitoids of the Hymenoptera Parasitic group. The research was conducted in studies related to quantitative aspects of the Superfamily, Family, Genus and Species (taxonomic groups) and in conceptual aspects such as: parasitism, parasitoidism, mutualism, spider parasitoids, "cockroaches karate kick parasitoid wasps to avoid becoming zombies", kicking defense by the cockroach, Wasp 'walking' a roach and ant parasitoids. A literature search was carried out containing articles published from 1982 to 2021. The mini review was carried out in Goiânia, Goiás, from August to September 2021, through the Online Scientific Library (Scielo) and internet.

Genetic Identity, Diversity, and Population Structure of CIP's Sweetpotato (I. batatas) Germplasm Collection.

The in trust sweetpotato collection housed by the International Center of Potato (CIP) is one of the largest assemblages of plant material representing the genetic resources of this important staple crop. The collection currently contains almost 6,000 accessions of Ipomoea batatas (cultivated sweetpotato) and over 1,000 accessions of sweetpotato crop wild relatives (CWRs). In this study, the entire cultivated collection (5,979 accessions) was genotyped with a panel of 20 simple sequence repeat (SSR) markers to assess genetic identity, diversity, and population structure. Genotyping and phenotyping of in vitro plantlets and mother plants were conducted simultaneously on 2,711 accessions (45% of the total collection) to identify and correct possible genetic identity errors which could have occurred at any time over the thirty plus years of maintenance in the in vitro collection. Within this group, 533 accessions (19.6%) had errors in identity. Field evaluations of morphological descriptors were carried out to confirm the marker data. A phylogenetic tree was constructed to reveal the intraspecific relationships in the population which uncovered high levels of redundancy in material from Peru and Latin America. These genotypic data were supported by morphological data. Population structure analysis demonstrated support for four ancestral populations with many of the accessions having lower levels of gene flow from the other populations. This was especially true of germplasm derived from Peru, Ecuador, and Africa. The set of 20 SSR markers was subsequently utilized to examine a subset of 189 accessions from the USDA sweetpotato germplasm collection and to identify and reconcile potential errors in the identification of clones shared between these collections. Marker analysis demonstrated that the USDA subset of material had 65 unique accessions that were not found in the larger CIP collection. As far as the authors are aware, this is the first report of genotyping an entire sweetpotato germplasm collection in its entirety.

Evidence of cryptic diversity inPodarcis peloponnesiacusand re‐evaluation of its current taxonomy; insights from genetic, morphological, and ecological data

The Peloponnese wall lizard, Podarcis peloponnesiacus, is endemic to the Peloponnese. Although the phylogeny and species diversity of the Balkan species of Podarcis have been extensively studied, the intraspecific relationships of P. peloponnesiacus are not yet well defined. The aim of this study was to investigate the intraspecific diversity in this species and clarify its taxonomic status by analyzing eight gene fragments (two mitochondrial and six nuclear) and several morphological traits, typically used for systematic inferences within the genus Podarcis. Together with ecological niche modeling, we provided an integrative evaluation of the differentiation between lineages. The combination of several phylogenetic, species delimitation, and chronophylogenetic analyses revealed the existence of two highly supported and divergent clades with a distinct geographical and parapatric distribution and high niche overlap. The differentiation of the two clades dates back to the Pleistocene and is probably correlated with the paleogeography of the Peloponnese. These clades also differed in several phenotypic traits, which, however, exhibit extensive overlap and are not fully diagnostic. The combination of the above results allowed us to identify the two revealed clades as distinct species.

Intraspecific Abundance\u2013Occupancy\u2013Patchiness Relations in the Intertidal Benthic Macrofauna of a Cool-Temperate North Sea Mudflat

The macroecological variable of patchiness (Lloyd’s Ip index of patchiness, P) has recently been shown to be related inter- and intraspecifically to those of abundance (numbers m−2, A), and occupancy (% occurrence in samples, O) in lower latitude seagrass macrofaunas. For the first time in higher latitudes, intraspecific relationships between three spatial variables were investigated in the intertidal mudflat macrobenthos of the Scolt Head barrier island, southern North Sea (53° N, 01° E). Sampling was conducted between early July and late September 2009–2013 using 710-µm mesh for sample processing. Strong positive interspecific A-O and negative interspecific P-O and P-A relationships were present. Two of the most numerous and widespread assemblage components, however, occurred with effectively constant occupancy (Peringia ulvae, 100%, and Tubificoides benedii, 93%) across the whole 20-ha locality and therefore could not show intraspecific relationships of occupancy with other macroecological metrics. These two apart, only one other dominant species failed to show a significant positive intraspecific A-O relationship; no species showed significant P-A relations of any form; and only two showed the negative P-O ones that have been described elsewhere. The intraspecific A-O patterns appear to contrast with those of an earlier study at another North Sea locality (the Dutch Wadden Sea), although differences are more apparent than real, but the Scolt Head fauna showed fewer intraspecific P-O and P-A relations than those characterising similar circumstances in the two lower-latitude localities previously investigated. Neither developmental mode nor variation in local abundance appears to influence these patterns. A-O-P relations therefore seem widespread but may be subject to latitudinal modification.

Are leaf, stem and hydraulic traits good predictors of individual tree growth?

Abstract A major foundation of trait‐based ecology is that traits have an impact on individual performance. However, trait–growth relationships have not been extensively assessed in trees, especially outside tropical ecosystems. In addition, measuring traits directly related to physiological processes remains difficult and the differences between inter‐ and intraspecific relationships are seldom explored. Here, we use individual‐level data on a set of hydraulic, leaf and stem traits to assess their ability to predict basal area increment (BAI) and growth efficiency (BAI per unit of tree leaf area, GE) among and within species for six dominant tree species along a water availability gradient under Mediterranean climate (Catalonia, NE Spain). Measured traits include: leaf mass per area (LMA), leaf nitrogen concentration (N), leaf C isotopic composition (δ13C), the leaf water potential at turgor loss (Ptlp), stem wood density (WD) and branch‐level estimates of the Huber value (Hv), sapwood‐ and leaf‐specific hydraulic conductivity (KS and KL) and resistance to xylem embolism (P50). Trait–growth associations were generally weak, particularly for BAI and within species. High values of both growth metrics were associated with ‘conservative’ leaf and hydraulic traits. In particular, BAI was negatively associated with KL (and wood density), while GE increased with LMA, allocation to sapwood relative to leaves (Hv) and resistance to xylem embolism (P50). Climate effects on BAI and GE were indirectly mediated by changes in traits, stand structure and tree basal area. Overall, these results suggest that maintaining functionality over extended periods of time may be more important than maximum gas exchange or hydraulic capacity to achieve high radial growth under Mediterranean climates. Our study reveals that widely used ‘functional traits’ may be poor predictors of tree growth variability along environmental gradients. Moreover, trait effects (when present) do not necessarily conform to simple hypotheses based on our understanding of organ‐level processes. An improved understanding of trait coordination along common axes of variation together with a revaluation of the variables that better reflect whole‐tree performance can greatly improve our understanding of trait–growth relationships. A free Plain Language Summary can be found within the Supporting Information of this article.