TY - JOUR T1 - Arthropod communities on hybrid and parental cottonwoods are phylogenetically structured by tree type: Implications for conservation of biodiversity in plant hybrid zones. JF - Ecology and evolution Y1 - 2017 A1 - Jarvis,Karl J A1 - Allan,Gerard J A1 - Craig,Ashley J A1 - Beresic-Perrins,Rebecca K A1 - Wimp,Gina A1 - Gehring,Catherine A A1 - Whitham,Thomas G AB -

Although hybridization in plants has been recognized as an important pathway in plant speciation, it may also affect the ecology and evolution of associated communities. Cottonwood species (Populus angustifolia and P. fremontii) and their naturally occurring hybrids are known to support different plant, animal, and microbial communities, but no studies have examined community structure within the context of phylogenetic history. Using a community composed of 199 arthropod species, we tested for differences in arthropod phylogenetic patterns within and among hybrid and parental tree types in a common garden. Three major patterns emerged. (1) Phylogenetic diversity (PD) was significantly different between arthropod communities on hybrids and Fremont cottonwood when pooled by tree type. (2) Mean phylogenetic distance (MPD) and net relatedness index (NRI) indicated that communities on hybrid trees were significantly more phylogenetically overdispersed than communities on either parental tree type. (3) Community distance (Dpw) indicated that communities on hybrids were significantly different than parental species. Our results show that arthropod communities on parental and hybrid cottonwoods exhibit significantly different patterns of phylogenetic structure. This suggests that arthropod community assembly is driven, in part, by plant-arthropod interactions at the level of cottonwood tree type. We discuss potential hypotheses to explain the effect of plant genetic dissimilarity on arthropod phylogenetic community structure, including the role of competition and environmental filtering. Our findings suggest that cottonwood species and their hybrids function as evolutionarily significant units (ESUs) that affect the assembly and composition of associated arthropod communities and deserve high priority for conservation.

VL - 7 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=28808554&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 15 ER - TY - CHAP T1 - IN PRESS: Using the Southwest Experimental Garden Array to enhance riparian restoration in response to global change: Identifying and deploying genotypes and populations for current and future environments. T2 - In Riparian research and management: Past, present, future. Y1 - 2017 A1 - Whitham, T.G. A1 - C.A. Gehring A1 - H.M. Bothwell A1 - H.F. Cooper A1 - J.B. Hull A1 - G.J. Allan A1 - K.C. Grady A1 - L. Markovchick A1 - S.M. Shuster A1 - J. Parker A1 - A.E. Cadmus A1 - D.H. Ikeda A1 - R.K. Bangert JF - In Riparian research and management: Past, present, future. PB - Gen. Tech. Rep. RMRS-GTR-inpress Fort Collins U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. CY - Fort Collins, CO, USA VL - 2 ER - TY - JOUR T1 - Bud phenology and growth are subject to divergent selection across a latitudinal gradient in Populus angustifolia and impact adaptation across the distributional range and associated arthropods. JF - Ecology and evolution Y1 - 2016 A1 - Evans,Luke M A1 - Kaluthota,Sobadini A1 - Pearce,David W A1 - Allan,Gerard J A1 - Floate,Kevin A1 - Rood,Stewart B A1 - Whitham,Thomas G AB -

Temperate forest tree species that span large geographical areas and climatic gradients often have high levels of genetic variation. Such species are ideal for testing how neutral demographic factors and climate-driven selection structure genetic variation within species, and how this genetic variation can affect ecological communities. Here, we quantified genetic variation in vegetative phenology and growth traits in narrowleaf cottonwood, Populus angustifolia, using three common gardens planted with genotypes originating from source populations spanning the species' range along the Rocky Mountains of North America (ca. 1700 km). We present three main findings. First, we found strong evidence of divergent selection (Q ST > F ST) on fall phenology (bud set) with adaptive consequences for frost avoidance. We also found evidence for selection on bud flush duration, tree height, and basal diameter, resulting in population differentiation. Second, we found strong associations with climate variables that were strongly correlated with latitude of origin. More strongly differentiated traits also showed stronger climate correlations, which emphasizes the role that climate has played in divergent selection throughout the range. We found population × garden interaction effects; for some traits, this accounted for more of the variance than either factor alone. Tree height was influenced by the difference in climate of the source and garden locations and declined with increasing transfer distance. Third, growth traits were correlated with dependent arthropod community diversity metrics. Synthesis. Overall, we conclude that climate has influenced genetic variation and structure in phenology and growth traits and leads to local adaptation in P. angustifolia, which can then impact dependent arthropod species. Importantly, relocation of genotypes far northward or southward often resulted in poor growth, likely due to a phenological mismatch with photoperiod, the proximate cue for fall growth cessation. Genotypes moved too far southward suffer from early growth cessation, whereas those moved too far northward are prone to fall frost and winter dieback. In the face of current and forecasted climate change, habitat restoration, forestry, and tree breeding efforts should utilize these findings to better match latitudinal and climatic source environments with management locations for optimal future outcomes.

VL - 6 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=27386097&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 13 ER - TY - JOUR T1 - Genetic variation in NIN1 and C/VIF1 genes is significantly associated with Populus angustifolia resistance to a galling herbivore, Pemphigus betae. JF - Journal of insect physiology Y1 - 2016 A1 - Zinkgraf,Matthew S A1 - Meneses,Nashelly A1 - Whitham,Thomas G A1 - Allan,Gerard J KW - Animals KW - Aphids KW - beta-Fructofuranosidase KW - Enzyme Inhibitors KW - Genes, Plant KW - Genetic Variation KW - Haplotypes KW - Herbivory KW - Plant Immunity KW - Plant Proteins KW - Plant Tumors KW - Polymorphism, Single Nucleotide KW - Populus AB -

The identification of genes associated with ecologically important traits provides information on the potential genetic mechanisms underlying the responses of an organism to its natural environment. In this study, we investigated the genetic basis of host plant resistance to the gall-inducing aphid, Pemphigus betae, in a natural population of 154 narrowleaf cottonwoods (Populus angustifolia). We surveyed genetic variation in two genes putatively involved in sink-source relations and a phenology gene that co-located in a previously identified quantitative trait locus for resistance to galling. Using a candidate gene approach, three major findings emerged. First, natural variation in tree resistance to galling was repeatable. Sampling of the same tree genotypes 20 years after the initial survey in 1986 show that 80% of the variation in resistance was due to genetic differences among individuals. Second, we identified significant associations at the single nucleotide polymorphism and haplotype levels between the plant neutral invertase gene NIN1 and tree resistance. Invertases are a class of sucrose hydrolyzing enzymes and play an important role in plant responses to biotic stress, including the establishment of nutrient sinks. These associations with NIN1 were driven by a single nucleotide polymorphism (NIN1_664) located in the second intron of the gene and in an orthologous sequence to two known regulatory elements. Third, haplotypes from an inhibitor of invertase (C/VIF1) were significantly associated with tree resistance. The identification of genetic variation in these two genes provides a starting point to understand the possible genetic mechanisms that contribute to tree resistance to gall formation. We also build on previous work demonstrating that genetic differences in sink-source relationships of the host influence the ability of P. betae to manipulate the flow of nutrients and induce a nutrient sink.

VL - 84 SN - 0022-1910 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=26518288&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. ER - TY - JOUR T1 - Genetically informed ecological niche models improve climate change predictions JF - Global Change Biology Y1 - 2016 A1 - DH Ikeda A1 - Max,TL A1 - GJ Allan A1 - Lau,MK A1 - SM Shuster A1 - TG Whitham ER - TY - JOUR T1 - Conservative leaf economic traits correlate with fast growth of genotypes of a foundation riparian species near the thermal maximum extent of its geographic range . JF - Functional Ecology Y1 - 2013 A1 - Grady,KC A1 - Laughlin,DC A1 - Ferrier,SM A1 - TE Kolb A1 - Hart,SC A1 - GJ Allan A1 - TG Whitham VL - 27 N1 - [Original String]:Grady KC, Laughlin DC, Ferrier SM, Kolb TE, Hart SC, Allan GJ, Whitham TG. 2013. Conservative leaf economic traits correlate with fast growth of genotypes of a foundation riparian species near the thermal maximum extent of its geographic range . Functional Ecology 27:427-438. ER - TY - JOUR T1 - Unique arthropod communities on different host-plant genotypes results in greater arthropod diversity JF - Arthropod-Plant Interactions Y1 - 2012 A1 - Ferrier,SM A1 - RK Bangert A1 - Hersch-Green,EI A1 - JK Bailey A1 - GJ Allan AB - Studies on the effect of plant-species diversity on various ecological processes has led to the study of the effects of plant-genetic diversity in the context of community genetics. Arthropod diversity can increase with plant-species or plant-genetic diversity (Wimp et al. in Ecol Lett 7:776鈥780, 2004 ). Plant diversity effects can be difficult to separate from other ecological processes, for example, complementarity. We asked three basic questions: (1) Are arthropod communities unique on different host-plant genotypes? (2) Is arthropod diversity greater when associated with greater plant-genetic diversity? (3) Are arthropod communities more closely associated with host-plant genetics than the plant neighborhood? We studied canopy arthropods on Populus fremontii trees randomly planted in a common garden. All trees were planted in a homogeneous matrix, which helped to reduce P . fremontii neighborhood effects. One sample was comprised of few P . fremontii genotypes with many clones. A second sample was comprised of many P . fremontii genotypes with few clones. A second data set was used to examine the relationships between the arthropod community with P . fremontii genetic composition and the neighborhood composition of the focal host plant. Unique arthropod communities were associated with different P . fremontii genotypes, and arthropod community diversity was greater in the sample with greater P . fremontii genotypic diversity. Arthropod community similarity was negatively correlated with P . fremontii genetic distance, but arthropod community similarity was not related to the neighborhood of the P . fremontii host plant. VL - 6 UR - http://link.springer.com/article/10.1007/s11829-011-9177-9 IS - 2 ER - TY - JOUR T1 - From genes to ecosystems: a synthesis of the effects of plant genetic factors across levels of organization. JF - Philosophical transactions of the Royal Society of London. Series B, Biological sciences Y1 - 2009 A1 - JK Bailey A1 - Jennifer A Schweitzer A1 - Ubeda,Francisco A1 - Koricheva,Julia A1 - LeRoy,Carri J A1 - Madritch,Michael D A1 - Rehill,Brian J A1 - RK Bangert A1 - Fischer,Dylan G A1 - Allan,Gerard J A1 - Whitham,Thomas G KW - Animals KW - Arthropods KW - Ecosystem KW - Genetic Variation KW - Genetics, Population KW - Models, Genetic KW - Plant Development KW - Plants AB -

Using two genetic approaches and seven different plant systems, we present findings from a meta-analysis examining the strength of the effects of plant genetic introgression and genotypic diversity across individual, community and ecosystem levels with the goal of synthesizing the patterns to date. We found that (i) the strength of plant genetic effects can be quite high; however, the overall strength of genetic effects on most response variables declined as the levels of organization increased. (ii) Plant genetic effects varied such that introgression had a greater impact on individual phenotypes than extended effects on arthropods or microbes/fungi. By contrast, the greatest effects of genotypic diversity were on arthropods. (iii) Plant genetic effects were greater on above-ground versus below-ground processes, but there was no difference between terrestrial and aquatic environments. (iv) The strength of the effects of intraspecific genotypic diversity tended to be weaker than interspecific genetic introgression. (v) Although genetic effects generally decline across levels of organization, in some cases they do not, suggesting that specific organisms and/or processes may respond more than others to underlying genetic variation. Because patterns in the overall impacts of introgression and genotypic diversity were generally consistent across diverse study systems and consistent with theoretical expectations, these results provide generality for understanding the extended consequences of plant genetic variation across levels of organization, with evolutionary implications.

VL - 364 SN - 0962-8436 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=19414474&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 1523 ER - TY - JOUR T1 - A dense linkage map of hybrid cottonwood (Populus fremontii x P. angustifolia) contributes to long-term ecological research and comparison mapping in a model forest tree. JF - Heredity Y1 - 2008 A1 - Woolbright,S A A1 - Difazio,S P A1 - Yin,T A1 - Martinsen,G D A1 - Zhang,X A1 - Allan,G J A1 - Whitham,T G A1 - Keim,P KW - Chimera KW - Chromosome Mapping KW - Ecology KW - Genetic Linkage KW - Genetic Markers KW - Genetics, Population KW - Genome, Plant KW - Linkage Disequilibrium KW - Models, Biological KW - Polymorphism, Restriction Fragment Length KW - Populus KW - Trees AB -

Cottonwoods are foundation riparian species, and hybridization among species is known to produce ecological effects at levels higher than the population, including effects on dependent species, communities and ecosystems. Because these patterns result from increased genetic variation in key cottonwood traits, novel applications of genetic tools (for example, QTL mapping) could be used to place broad-scale ecological research into a genomic perspective. In addition, linkage maps have been produced for numerous species within the genus, and, coupled with the recent publication of the Populus genome sequence, these maps present a unique opportunity for genome comparisons in a model system. Here, we conducted linkage analyses in order to (1) create a platform for QTL and candidate gene studies of ecologically important traits, (2) create a framework for chromosomal-scale perspectives of introgression in a natural population, and (3) enhance genome-wide comparisons using two previously unmapped species. We produced 246 backcross mapping (BC(1)) progeny by crossing a naturally occurring F(1) hybrid (Populus fremontii x P. angustifolia) to a pure P. angustifolia from the same population. Linkage analysis resulted in a dense linkage map of 541 AFLP and 111 SSR markers distributed across 19 linkage groups. These results compared favorably with other Populus linkage studies, and addition of SSR loci from the poplar genome project provided coarse alignment with the genome sequence. Preliminary applications of the data suggest that our map represents a useful framework for applying genomic research to ecological questions in a well-studied system, and has enhanced genome-wide comparisons in a model tree.

VL - 100 SN - 0018-067X UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=17895905&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 1 ER - TY - JOUR T1 - Genetic structure of a foundation species: scaling community phenotypes from the individual to the region. JF - Heredity Y1 - 2008 A1 - RK Bangert A1 - E V Lonsdorf A1 - Wimp,G M A1 - Shuster,S M A1 - Fischer,D A1 - Schweitzer,J A A1 - Allan,G J A1 - JK Bailey A1 - Whitham,T G KW - Animals KW - biodiversity KW - Ecosystem KW - Environment KW - Populus KW - Trees AB -

Understanding the local and regional patterns of species distributions has been a major goal of ecological and evolutionary research. The notion that these patterns can be understood through simple quantitative rules is attractive, but while numerous scaling laws exist (e.g., metabolic, fractals), we are aware of no studies that have placed individual traits and community structure together within a genetics based scaling framework. We document the potential for a genetic basis to the scaling of ecological communities, largely based upon our long-term studies of poplars (Populus spp.). The genetic structure and diversity of these foundation species affects riparian ecosystems and determines a much larger community of dependent organisms. Three examples illustrate these ideas. First, there is a strong genetic basis to phytochemistry and tree architecture (both above- and belowground), which can affect diverse organisms and ecosystem processes. Second, empirical studies in the wild show that the local patterns of genetics based community structure scale up to western North America. At multiple spatial scales the arthropod community phenotype is related to the genetic distance among plants that these arthropods depend upon for survival. Third, we suggest that the familiar species-area curve, in which species richness is a function of area, is also a function of genetic diversity. We find that arthropod species richness is closely correlated with the genetic marker diversity and trait variance suggesting a genetic component to these curves. Finally, we discuss how genetic variation can interact with environmental variation to affect community attributes across geographic scales along with conservation implications.

VL - 100 SN - 0018-067X UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=17047690&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 2 ER - TY - JOUR T1 - Tree hybridization and genotypic variation drive cryptic speciation of a specialist mite herbivore. JF - Evolution; international journal of organic evolution Y1 - 2008 A1 - Evans,Luke M A1 - Allan,Gerard J A1 - Shuster,Stephen M A1 - Woolbright,Scott A A1 - Whitham,Thomas G KW - Analysis of Variance KW - Animals KW - Base Sequence KW - Cluster Analysis KW - Crosses, Genetic KW - DNA Primers KW - Genetic Variation KW - Genetics, Population KW - Geography KW - Host-Parasite Interactions KW - Hybridization, Genetic KW - Mites KW - Molecular Sequence Data KW - Phylogeny KW - Populus KW - Sequence Analysis, DNA KW - Utah AB -

Few studies have investigated the roles that plant hybridization and individual plant genotype play in promoting population divergence within arthropod species. Using nrDNA sequence information and reciprocal transfer experiments, we examined how tree cross type (i.e., pure Populus angustifolia and P. angustifolia x P. fremontii F(1) type hybrids) and individual tree genotype influence host race formation in the bud-galling mite Aceria parapopuli. Three main findings emerged: (1) Strong genetic differentiation of mite populations found on pure P. angustifolia and F(1) type hybrids indicates that these mites represent morphologically cryptic species. (2) Within the F(1) type hybrids, population genetic analyses indicate migration among individual trees; however, (3) transfer experiments show that the mites found on heavily infested F(1) type trees perform best on their natal host genotype, suggesting that genetic interactions between mites and their host trees drive population structure, local adaptation, and host race formation. These findings argue that hybridization and genotypic differences in foundation tree species may drive herbivore population structure, and have evolutionary consequences for dependent arthropod species.

VL - 62 SN - 0014-3820 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=18752612&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 12 ER - TY - JOUR T1 - From genes to geography: a genetic similarity rule for arthropod community structure at multiple geographic scales. JF - Molecular ecology Y1 - 2006 A1 - RK Bangert A1 - Allan,G J A1 - Turek,R J A1 - Wimp,G M A1 - Meneses,N A1 - Martinsen,G D A1 - Keim,P A1 - Whitham,T G KW - Animals KW - Arthropods KW - biodiversity KW - Genetic Variation KW - Genetics, Population KW - Models, Genetic KW - Populus KW - Rivers KW - Southwestern United States AB -

We tested the hypothesis that leaf modifying arthropod communities are correlated with cottonwood host plant genetic variation from local to regional scales. Although recent studies found that host plant genetic composition can structure local dependent herbivore communities, the abiotic environment is a stronger factor than the genetic effect at increasingly larger spatial scales. In contrast to these studies we found that dependent arthropod community structure is correlated with both the cross type composition of cottonwoods and individual genotypes within local rivers up to the regional scale of 720,000 km(2) (Four Corner States region in the southwestern USA). Across this geographical extent comprising two naturally hybridizing cottonwood systems, the arthropod community follows a simple genetic similarity rule: genetically similar trees support more similar arthropod communities than trees that are genetically dissimilar. This relationship can be quantified with or without genetic data in Populus.

VL - 15 SN - 0962-1083 UR - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=17054514&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSumhttp://www.ncbi. IS - 13 ER -