Mee-Sook Kim

CONGRUENT CLIMATE-RELATED GENECOLOGICAL RESPONSES FROM MOLECULAR MARKERS AND QUANTITATIVE TRAITS FOR WESTERN WHITE PINE (PINUS MONTICOLA)

Analyses of molecular and quantitative genetic data demonstrate the existence of congruent climate‐related patterns in western white pine (Pinus monticola). Two independent studies allowed comparisons of amplified fragment length polymorphism (AFLP) markers with quantitative variation in adaptive traits. Principal component analyses were conducted on seedling traits in common gardens collected from 58 sites; principal coordinate analyses were conducted on AFLP data from 15 sites. Collection site eigenvector means were regressed on 35 climate variables to produce a genecological prediction for each data set. Both predictions explained a large percentage (>70%) of the genetic variation from the first eigenvector from similar predictors involving the interaction growing season precipitation and temperature. Both predictions were significant ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

Genetic diversity and structure of western white pine (Pinus monticola) in North America: a baseline study for conservation, restoration, and addressing impacts of climate change

P< 0.01

Identification of Alternaria alternata as a Causal Agent for Leaf Blight in Syringa Species

\end{document} ), and projected genecological maps were largely congruent. The predominant pattern from the first eigenvector was two major groups, a northern and a southern, connected by a steep cline across the crest of the southern Cascade Range of Oregon. This cline was associated with growth potential in the adaptive traits. These results suggest that divergent climatic selection has influenced phenotypic traits associated with growth. Furthermore, the congruence of AFLPs suggests a linkage between some loci and genomic regions under selection and/or climatic influences on postmating reproductive success.

Fusarium oxysporum Protects Douglas-fir (Pseudotsuga menziesii) Seedlings from Root Disease Caused by Fusarium commune

The rust fungus, Puccinia psidii, is a devastating pathogen of introduced eucalypts (Eucalyptus spp.) in Brazil where it was first observed in 1912. This pathogen is hypothesized to be endemic to South and Central America and to have first infected eucalypts via a host jump from native guava (Psidium guajava). Ten microsatellite markers were used to genotype 148 P. psidii samples from eucalypts and guava plus five additional myrtaceous hosts across a wide geographic range of south‐eastern Brazil and Uruguay. Principal coordinates analysis, a Bayesian clustering analysis and a minimum‐spanning network revealed two major genetic clusters among the sampled isolates, one associated with guava and another associated with eucalypts and three additional hosts. Multilocus genotypes infecting guava differed by multiple mutational steps at eight loci compared with those infecting eucalypts. Approximate Bayesian computation revealed that evolutionary scenarios involving a coalescence event between guava‐ and eucalypt‐associated pathogen populations within the past 1000 years are highly unlikely. None of the analyses supported the hypothesis that eucalypt‐infecting P. psidii in Brazil originated via host jump from guava following the introduction of eucalypts to Brazil approximately 185 years ago. The existence of host‐associated biotypes of P. psidii in Brazil indicates that this diversity must be considered when assessing the invasive threat posed by this pathogen to myrtaceous hosts worldwide.

Insights into the phylogeny of Northern Hemisphere Armillaria: Neighbor-net and Bayesian analyses of translation elongation factor 1-α gene sequences

Western white pine (Pinus monticola) is an economically and ecologically important species in western North America that has declined in prominence over the past several decades, mainly due to the introduction of Cronartium ribicola (cause of white pine blister rust) and reduced opportunities for regeneration. Amplified fragment length polymorphism (AFLP) markers were used to assess the genetic diversity and structure among populations at 15 sites (e.g., provenances) across the native range of western white pine. The level of genetic diversity was different among 15 populations tested using 66 polymorphic AFLP loci. Nei’s gene diversity (HE) at the population level ranged from 0.187 to 0.316. Genetic differentiation (GST) indicated that 20.1% of detected genetic variation was explained by differences among populations. In general, populations below 45oN latitude exhibited a higher level of genetic diversity than higher latitude populations. Genetic distance analysis revealed two major clades between northern and southern populations, but other well-supported relationships are also apparent within each of the two clades. The complex relationships among populations are likely derived from multiple factors including migration, adaptation, and multiple glacial refugia, especially in higher latitudes. Genetic diversity and structure revealed by this study will aid recognition and selection of western white pine populations for species management and conservation programs, especially in consideration of current and future climate changes.

Root Diseases in Coniferous Forests of the Inland West : Potential Implications of Fuels Treatments

Climate change will likely have dramatic impacts on forest health because many forest trees could become maladapted to climate. Furthermore, climate change will have additional impacts on forest health through changes in the distribution and severity of forest disease. Methods are needed to predict the influence of climate change on forest disease so that appropriate forest management practices can be implemented to minimize disease impacts. Initial approaches for predicting the future distribution of pathogens are dependent on reliable data sets that document the current, precise location of accurately identified pathogens and hosts. Precise distribution information can be used in conjunction with available climate surfaces to determine which climatic factors and interactions influence species distribution. This information can be used to develop bioclimatic models to predict the probability of suitable climate space for host and pathogen species across the landscape. A similar approach using climate surfaces under predicted future climate scenarios can be used to project suitable climate space for hosts and pathogens in the future. Currently such predictions are well developed for many forest host species, but predictive capacity is extremely limited for forest pathogens because of lacking distribution data. Continued surveys and research are needed to further refine bioclimatic models to predict influences of climate and climate change on forest disease.

Efficacy of washing treatments in the reduction of post- harvest decay of chestnuts (Castanea crenata 'Tsukuba') during storage

While many isolates of Alternaria alternata are common saprophytes on trees and shrubs, this study clearly demonstrated that A. alternata is a primary pathogen in lilac (Syringa sp.), causing a leaf-blight that affects different Syringa species. Isolates of Alternaria sp. were collected from leaf blight samples of lilacs in the field. The internal transcribed spacer (ITS) region and morphological characterization were used to identify lilac blight pathogen. Based on 100% ITS nucleotide sequence identities to the Alternaria genus in the GenBank and morphological features, these isolates were identified as A. alternata. Disease symptoms were reproduced in lilac plants inoculated with A. alternata mycelial plugs and sprayed with a fungus-free culture filtrate, indicating that pathogenesis in lilac involves secondary metabolites or toxins. Diagnostic primers were developed to detect Alternaria sp. and A. alternata in lilac leaf blight based on ITS region and four known genes associated with pathogenesis in A. alternata: mixed-linked glucanase precursor, endopolygalacturonase, hsp70, and histone genes. The results from our study indicated A. alternata is a primary pathogen in lilac leaf blight, and these diagnostic primers can be used as a tool for the fast detection of A. alternata associated with lilac leaf blight.

Impacts of Nonnative Invasive Species on US Forests and Recommendations for Policy and Management

Fusarium root disease can be a serious problem in forest and conservation nurseries in the western United States. Fusarium inoculum is commonly found in most container and bareroot nurseries on healthy and diseased seedlings, in nursery soils, and on conifer seeds. Fusarium spp. within the F. oxysporum species complex have been recognized as pathogens for more than a century, but attempts to distinguish virulence by correlating morphological characteristics with results of pathogenicity tests were unsuccessful. Recent molecular characterization and pathogenicity tests, however, revealed that selected isolates of F. oxysporum are benign on Douglas-fir (Pseudotsuga menziesii) seedlings. Other morphologically indistinguishable isolates, which can be virulent, were identified as F. commune, a recently described species. In a replicated greenhouse study, inoculating Douglas-fir seedlings with one isolate of F. oxysporum prevented expression of disease caused by a virulent isolate of F. commune. Moreover, seedling survival and growth was unaffected by the presence of the F. oxysporum isolate, and this isolate yielded better biological control than a commercial formulation of Bacillus subtilis. These results demonstrate that an isolate of nonpathogenic F. oxysporum can effectively reduce Fusarium root disease of Douglas-fir caused by F. commune under nursery settings, and this biological control approach has potential for further development.