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Premise: Arbuscular mycorrhizal fungi (AMF) can strongly influence host plant vegetative growth, but less is known about AMF effects on other plant traits, the relative impacts of AMF on vegetative growth versus floral traits, or AMF‐induced intraspecific variation in traits. Methods: In an experimental greenhouse study, we inoculated seven species of wildflowers with six species of AMF in a factorial design. We assessed how the AMF–forb combinations influenced plant survival, vegetative biomass, and floral traits and whether AMF effects on floral traits were similar in magnitude and direction to effects on vegetative biomass. For one forb species, we investigated intraspecific plant trait variation within and across AMF treatments. Results: AMF species varied from negative to positive in their effects on host plants. AMF often had inconsistent effects on vegetative biomass versus floral traits, and therefore, quantifying one or the other may provide a misleading representation of potential AMF effects. AMF treatments generated key variation in plant traits, especially floral traits, with potential consequences for plant–pollinator interactions. Given increased intraspecific trait variation in Linum lewisii plants across AMF species compared to uninoculated individuals or single AMF treatments, local AMF diversity and their host plant associations may scale up to influence community‐wide patterns of trait variation and species interactions. Conclusions: These results have implications for predicting how aboveground communities are affected by belowground communities. Including AMF effects on not just host plant biomass but also functional traits and trait variation will deepen our understanding of community structure and function, including pollination. [ABSTRACT FROM AUTHOR]

Premise: Most plants interact with mycorrhizal fungi and animal pollinators simultaneously. Yet, whether mycorrhizae affect traits important to pollination remains poorly understood and may depend on the match between host and fungal genotypes. Here, we examined how ericoid mycorrhizal fungi affected flowering phenology, floral traits, and reproductive success, among eight genotypes of highbush blueberry, Vaccinium corymbosum (Ericaceae). We asked three overarching questions: (1) Do genotypes differ in response to inoculation? (2) How does inoculation affect floral and flowering traits? (3) Are inoculated plants more attractive to pollinators and less pollen limited than non‐inoculated plants of the same genotype? Methods: To examine these questions, we experimentally inoculated plants with ericoid mycorrhizal fungi, grew the plants in the field, and measured flowering and floral traits over 2 years. In year 2, we conducted a hand‐pollination experiment to test whether plants differed in pollen limitation. Results: Inoculated plants had significantly higher levels of colonization for some genotypes, and there were significant floral trait changes in inoculated plants for some genotypes as well. On average, inoculated plants produced significantly larger floral displays, more fruits per inflorescence, and heavier fruits with lower sugar content, than non‐inoculated, control plants. Hand pollination enhanced the production of fruits, and fruit mass, for non‐inoculated plants but not for those that were inoculated. Conclusions: Our results demonstrate that inoculation with ericoid mycorrhizal fungi enhanced flowering and altered investment in reproduction in genotype‐specific ways. These findings underscore the importance of examining belowground symbionts and genotype‐specific responses in their hosts to fully understand the drivers of aboveground interactions. [ABSTRACT FROM AUTHOR]

Premise of the Study: The evolution of full mycoheterotrophy is one of the most interesting topics within plant evolution. The leafless orchid Cymbidium macrorhizon is often assumed to be fully mycoheterotrophic even though it has a green stem and fruit capsule. Here, we assessed the trophic status of this species by analyzing the chlorophyll content and the natural 13C and 15N abundance in the sprouting and the fruiting season. Methods: The chlorophyll content was measured in five sprouting and five fruiting individuals of C. macrorhizon that were co‐occurring. In addition, their 13C and 15N isotopic signatures were compared with those of neighboring autotrophic and partially mycoheterotrophic reference plants. Key Results: Fruiting individuals of C. macrorhizon were found to contain a remarkable amount of chlorophyll compared to their sprouting counterparts. In addition, the natural abundance of 13C in the tissues of the fruiting plants was slightly depleted relative to the sprouting ones. Linear two‐source mixing model analysis revealed that fruiting C. macrorhizon plants obtained approximately 73.7 ± 2.0% of their total carbon from their mycorrhizal fungi when the sprouting individuals were used as the 100% carbon gain standard. Conclusions: Our results indicated that despite its leafless status, fruiting plants of C. macrorhizon were capable of fixing significant quantities of carbon. Considering the autotrophic carbon gain increases during the fruiting season, its photosynthetic ability may contribute to fruit and seed production. These results indicate that C. macrorhizon should, therefore, be considered a partially mycoheterotrophic species rather than fully mycoheterotrophic, at least during the fruiting stage. [ABSTRACT FROM AUTHOR]

* Premise of the study: The presence of compatible fungi is necessary for epiphytic orchid recruitment. Thus, identifying associated mycorrhizal fungi at the population level is essential for orchid conservation. Recruitment patterns may also be conditioned by factors such as seed dispersal range and specific environmental characteristics. * Methods: In a forest plot, all trees with a diameter at breast height > 1 cm and all individuals of the epiphytic orchid Epidendrum rhopalostele were identified and mapped. Additionally, one flowering individual of E. rhopalostele per each host tree was randomly selected for root sampling and DNA extraction. * Key results: A total of 239 E. rhopalostele individuals were located in 25 of the 714 potential host trees. Light microscopy of sampled roots showed mycorrhizal fungi in 22 of the 25 sampled orchids. Phylogenetic analysis of ITS1-5.8S-ITS2 sequences yielded two Tulasnella clades. In four cases, plants were found to be associated with both clades. The difference between univariate and bivariate K functions was consistent with the random labeling null model at all spatial scales, indicating that trees hosting clades A and B of Tulasnella are not spatially segregated. The analysis of the inhomogenous K function showed that host trees are not clustered, suggesting no limitations to population-scale dispersal. χ²analysis of contingency tables showed that E. rhopalostele is more frequent on dead trees than expected. * Conclusions: Epidendrum rhopalostele establishes mycorrhizal associations with at least two different Tulasnella species. The analysis of the distribution patterns of this orchid suggests a microsite preference for dead trees and no seed dispersal limitation. [ABSTRACT FROM AUTHOR]

* Premise of the study: Orchids rely on mycorrhizal fungi for seed germination, and many species maintain associations during later stages in their life cycle. Because of the critical dependence of orchids on fungi it has been suggested that the degree of mycorrhizal specificity may be associated with rarity and long-term survival of orchid species, especially in highly degraded or fragmented landscapes. To test this hypothesis, we compared mycorrhizal communities in two species that differed significantly in decline in Belgium and other parts of Europe. * Methods: Mycorrhizal associations were investigated in five populations of Anacamptis morio and Dactylorhiza fuchsii in Belgium. ITS-based DNA arrays were used for simultaneous detection and identification of a wide range of basidiomycetous mycorrhizal fungi. Mycorrhizal specificity, measured as phylogenetic diversity, was assessed for each population and compared between species. * Key results: For both species, the degree of phylogenetic relatedness of the mycorrhizal partners was low, and both species were associated with a large number of fungal lineages related to clades of the Tulasnellaceae family. Contrary to expectations, the species that was apparently resilient to decline was associated with fewer fungal operational taxonomical units than the declining species was, and the phylogenetic relatedness of mycorrhizal communities among populations was higher in the stable than in the declining orchid. * Conclusions: Although our results do not present detailed insights into the causes of orchid persistence, they do suggest that orchid rarity and persistence are not necessarily related to fungal diversity and that other factors may be more important in determining orchid persistence. [ABSTRACT FROM AUTHOR]

* Premise of the study: Plants interact with above- and belowground organisms; the combined effects of these interactions determine plant fitness and trait evolution. To better understand the ecological and evolutionary implications of multispecies interactions, we explored linkages between soil fungi, pollinators, and floral larcenists in Polemonium viscosum (Polemoniaceae). * Methods: Using a fungicide, we experimentally reduced fungal colonization of krummholz and tundra P. viscosum in 2008-2009. We monitored floral signals and rewards, interactions with pollinators and larcenists, and seed set for fungicide-treated and control plants. * Key results: Fungicide effects varied among traits, between interactions, and with environmental context. Treatment effects were negligible in 2008, but stronger in 2009, especially in the less-fertile krummholz habitat. There, fungicide increased nectar sugar content and damage by larcenist ants, but did not affect pollination. Surprisingly, fungicide also enhanced seed set, suggesting that direct resource costs of soil fungi exceed indirect benefits from reduced larceny. In the tundra, fungicide effects were negligible in both years. However, pooled across treatments, colonization by mycorrhizal fungi in 2009 correlated negatively with the intensity and diversity of floral volatile organic compounds, suggesting integrated above- and belowground signaling pathways. * Conclusions: Fungicide effects on floral rewards in P. viscosum link soil fungi to ecological costs of pollinator attraction. Traitspecific linkages to soil fungi should decouple expression of sensitive and buffered floral phenotypes in P. viscosum. Overall, this study demonstrates how multitrophic linkages may lead to shifting selection pressures on interaction traits, restricting the evolution of specialization. [ABSTRACT FROM AUTHOR]

* Premise of the study: We investigated whether four widespread, photosynthetic Mediterranean meadow orchids (Ophrys fuciflora, Anacamptis laxiflora , Orchis purpurea, and Serapias vomeracea) had either nutritional dependency on mycobionts or mycorrhizal fungal specificity. Nonphotosynthetic orchids generally engage in highly specific interactions with fungal symbionts that provide them with organic carbon. By contrast, fully photosynthetic orchids in sunny, meadow habitats have been considered to lack mycorrhizal specificity. * Methods: We performed both culture-dependent and culture-independent ITS sequence analysis to identify fungi from orchid 13 15 roots. By analyzing stable isotope (C and N) natural abundances, we also determined the degree of autotrophy and mycoheterotrophy in the four orchid species. * Key results: Phylogenetic and multivariate comparisons indicated that Or . purpurea and Oph. fuciflora featured lower fungal diversity and more specific mycobiont spectra than A. laxiflora and S. vomeracea . All orchid species were significantly enriched in 15N compared with neighboring non-orchid plants. Orchis purpurea had the most pronounced N gain from fungi and differed from the other orchids in also obtaining C from fungi. * Conclusions: These results indicated that even in sunny Mediterranean meadows, orchids may be mycoheterotrophic, with correlated mycorrhizal fungal specificity. [ABSTRACT FROM AUTHOR]

• Premise of study: Previous studies testing pairwise interactions between plants, arbuscular mycorrhizal fungi (AMF) and soil have shown that the effectiveness of such interactions depends on the origins of the plants, soil, and AMF. Surprisingly, no study has yet looked at the three-way interaction between plants, soil, and AMF originating from the same and from different sites. Such knowledge could elucidate the determinants of local adaptations of plants and thus might help in various revegetation attempts. • Methods: Six populations of the obligately mycorrhizal plant species Aster amellus from two isolated regions were combined with the soil and the AMF ecotype from their sites and plant growth were monitored over 16 months. • Key results: For each combination of soil and native AMF, plants grown with their native AMF in their native soil had higher aboveground biomass, invested more to aboveground biomass and had higher numbers of flower heads than the other plants. The specificity of the relationship among plant populations. AMF, and soil was also observed for percentage of root colonization. • Conclusions: The study extends our knowledge of the specific interaction between plants and AMF by demonstrating that the positive effect of native AMF occurs only when the plants are also grown in their native soil. Thus, when attempting to facilitate plant growth, we need to consider the origin of the plants, the soil, and the AMF, because all three components are adapted to each other. [ABSTRACT FROM AUTHOR]

• Premise of the study: Most studies on orchid hybrids examine separately the effects of hybridization on interactions with pollinators or with mycorrhizal fungi. Here, we simultaneously investigated both interactions in the mediterranean food-deceptive Orchis simia, O. anthropophora, and their hybrid (O. xbergonii) and tested a possible breakdown of coevolution using a multidisciplinary approach. • Methods: We compared leaf growth, seed viability, emitted scent, and mycorrhizal fungi (species and rate of infection) among these three taxa. • Key results: We show that leaf surface is greater in adult hybrids than in the parental species, suggesting a heterosis effect for vegetative growth. We demonstrate that flowers of the two parental species emit well-differentiated bouquets of volatile organic compounds, while hybrids emit larger quantities, accumulating most compounds of the two parental species. However, hybrids fail to attract pollinators and have a 10 times lower fruit set. We determined that closely related Tulasnellales are mycorrhizal in the three taxa, suggesting that the mycorrhizal partner does not impair hybrid survival. We propose an interpretative model for O. xbergonii compared with its parents. • Conclusions: In hybrids, carbon resources normally devoted to reproduction may be reallocated to the mycorrhizal symbiosis as a result of the disruption of the pollination interaction in hybrids. Higher mycorrhizal infection may in turn enhance vegetative growth and scent emission. Such interplay between the two obligate biotic interactions yields new insights into hybridization among orchids. [ABSTRACT FROM AUTHOR]

• Premise of the study: An estimated 10% of plant species have evolved to steal C from their symbiotic fungal partners (mycoheterotrophy), and while physiological evidence for full and partial mycoheterotrophy is well developed in the Orchidaceae and Ericaceae, it is lacking for the majority of other mycoheterotrophic taxa. The family Gentianaceae not only contains several lineages of achlorophyllous mycoheterotrophs, but also contains species that are putative partially mycoheterotrophic. The North American genera Bartonia and Obolaria (Gentianaceae) are green but have leaves reduced to scales or foliose bracts and so have ambiguous mycoheterotrophic status. • Methods: We investigated the natural abundance 13C and 15N profiles of both genera along with total N and chlorophyll content and investigated mycorrhizal infection using light microscopy. • Key results: The shoots of B. virginica were significantly more enriched in 15N than the surrounding vegetation but not in 13C. In contrast, the shoots of O. virginica are not enriched in 15N compared to the surrounding vegetation but were significantly enriched in 13C. Total N concentrations were significantly higher than the surrounding vegetation in B. virginica, while the collaroid roots of both species were infected by arbuscular mycorrhizal fungi. • Conclusions: This microscopic evidence coupled with the natural abundance stable isotope profiles strongly suggests that both species are partially mycoheterotrophic. However, differences in the root-shoot stable isotopic patterns relative to surrounding vegetation between B. virginica and O. virginica are suggestive of the utilization of different physiological pathways or extent of commitment to mycoheterotrophic C gain. [ABSTRACT FROM AUTHOR]

Mycorrhizae are widespread mutualistic symbioses crucial for the functioning of terrestial ecosystems. Not all plants associate with mycorrhizae; most parasitic plants have been siggested to be nonmycorrhizal because they have developed alterantive strategies to obtain nutrients. In endophytiv parasitic plants, whose vegetative bodies grow completely inside their mycorrhizal host roots, the opportunity for establishing a tripartite association seems evident, but information on these systems is lacking. In studying natural associationc among hte endophytic holoparasite Cytinud hypocistis, their Cistaceae host species, and associated mycorhizal fungi, we found that mycorrhizae were associated wiht the hosts and the parasires, reaching high frequencies of colonization. In parasitic and host root tissues, mycorrhizal fungi spread in the parenchymatic cells by intracellular growth and formed hyphal coils and vesicles, while the cambium and the vascular tissues were never colonized. This report is the first on a tripatite association of an endophytic parasitic plant, its host, and nycorrhizae in natural conditions, representing a novel trophic interaction not previously reported within the angiosperms. Additional studies on the interactions occuring among these three players are needed because they may be crucial to our understanding of how this mutualistic – antagonistic system is functioning and evolving. [ABSTRACT FROM AUTHOR]

Mycorrhizae are widespread mutualistic symbioses crucial for the functioning of terrestial ecosystems. Not all plants associate with mycorrhizae; most parasitic plants have been siggested to be nonmycorrhizal because they have developed alterantive strategies to obtain nutrients. In endophytiv parasitic plants, whose vegetative bodies grow completely inside their mycorrhizal host roots, the opportunity for establishing a tripartite association seems evident, but information on these systems is lacking. In studying natural associationc among hte endophytic holoparasite Cytinud hypocistis, their Cistaceae host species, and associated mycorhizal fungi, we found that mycorrhizae were associated wiht the hosts and the parasires, reaching high frequencies of colonization. In parasitic and host root tissues, mycorrhizal fungi spread in the parenchymatic cells by intracellular growth and formed hyphal coils and vesicles, while the cambium and the vascular tissues were never colonized. This report is the first on a tripatite association of an endophytic parasitic plant, its host, and nycorrhizae in natural conditions, representing a novel trophic interaction not previously reported within the angiosperms. Additional studies on the interactions occuring among these three players are needed because they may be crucial to our understanding of how this mutualistic – antagonistic system is functioning and evolving. [ABSTRACT FROM AUTHOR]

We demonstrated that "orchid mycorrhiza," a specialized mycorrhizal type, appeared in the common ancestor of the largest plant family Orchidaceae and that the fungal partner shifted from Glomeromycota to a particular dade of Basidiomycota in association with this character evolution. Several unique mycorrhizal characteristics may have contributed to the diversification of the family. However, the origin of orchid mycorrhiza and the diversity of mycobionts across orchid lineages still remain obscure. In this study, we investigated the mycorrhizae of five Apostasia taxa, members of the earliest-diverging dade of Orchidaceae. The results of molecular identification using nrDNA ITS and LSU regions showed that Apostasia mycorrhizal fungi belong to families Botryobasidiaceae and Ceratobasidiaceae, which fall within the order Cantharellales of Basidiomycota. Most major clades in Orchidaceae also form mycorrhizae with members of Cantharellales, while the sister group and other closely related groups to Orchidaceae (i.e., Asparagales except for orchids and the "commelinid" families) ubiquitously form symbioses with Glomeromycota to form arbuscular mycorrhizae. This pattern of symbiosis indicates that a major shift in fungal partner occurred in the common ancestor of the Orchidaceae. [ABSTRACT FROM AUTHOR]

Liverworts form diverse associations with ëndophytic fungi similar to mycorrhizas in vascular plants. Whereas the widespread occurrence of glomeromycotes in the basal liverwort lineages is well documented, knowledge of the distribution of ascomycetes and basidiomycetes in derived thalloid and leafy clades is more fragmented. Our discovery that the ramified and septate rhizoids of the Schistochilaceae, the sister group to all other ascomycete-containing liverworts, are packed with fungal hyphae prompted this study on the effects of the fungi on rhizoid morphology, host specificity, the cytology of the association, and a molecular analysis of the endophytes. Two species of Pachyschistochila and their fungi were grown axenically. Axenic rhizoids were unbranched and nonseptate. Reinfected with their own fungus and that from the other species, both Pachyschistochila species pro- duced branched and septate rhizoids identical to those in nature. Woronin bodies and simple septa identified the fungus as an ascomycete referable, according to phylogenetic analyses of ITS sequences, to the Rhizoscyphus (Hymenoscyphus) ericae aggregate, also found in other liverwort-ascomycete associations and in mycorrhizas in the Ericales. Healthy hyphae and host cytoplasm suggest that the Schistochila-fungus association reflects a balanced mutualistic relationship. The recent dating of the divergence of the Jungermanniales from the fungus-free Porellales in the Permian and the origins of the Schistochilaceae in the Triassic indicate that these associations in liverworts predate the appearance of the Ericales. [ABSTRACT FROM AUTHOR]

Liverworts form endophytic associations with fungi that mirror mycorrhizal associations in tracheophytes. Here we report a worldwide survey of liverwort associations with glomeromycotean fungi (GAs), together with a comparative molecular and cellular analysis in representative species. Liverwort GAs are circumscribed by a basal assemblage embracing the Haplomitriopsida, the Marchantiopsida (except a few mostly derived clades), and part of the Metzgeriidae. Fungal endophytes from Haplomitrium, Conocephalum, Fossombronia, and Pellia were related to Glomus Group A, while the endophyte from Monoclea was related to Acaulospora. An isolate of G. mosseae colonized axenic thalli of Conocephalum, producing an association similar to that in the wild. Fungal colonization in marchantialean liverworts suppressed cell wall autofluorescence and elicited the deposition of a new wall layer that specifically bound the monoclonal antibody CCRC-M 1 against fucosylated side groups associated with xyloglucan and rhamnogalacturonan I. The interfacial material covering the intracellular fungus contained the same epitopes present in host cell walls. The taxonomic distribution and cytology of liverwort GAs suggest an ancient origin and multiple more recent losses, but the occurrence in widely separated liverwort taxa of fungi related to glomeromycotean lineages that form arbuscular mycorrhizas in tracheophytes, notably the Glomus Group A, is better explained by host shifting from tracheophytes to liverworts. [ABSTRACT FROM AUTHOR]

Plants support numerous root colonists that may share morphological characteristics with mycorrhizal fungi but may play different roles in the rhizosphere. To determine the function of one such root-colonizing fungus, Chactorniurn datum, the infectivity and composition of inoculum containing C. elatum were varied independently of and in association with the known mutualist Glomus intraradices under two light intensities. Maximum plant benefit occurred with mixtures of both G. intraradices and C. elatum and under high light intensity. Under low light intensity and in monoculture, C. elatum functioned as a weak pathogen that was able to kill host plants. Here, maximum plant mortality was associated with the highest levels of C. elatuni infectivity. When G. intraradices was present, no negative impact of C. datum was detected, Intraspecific interactions were important in predicting sporulation rates for both fungi, whereas no interspecific fungal interactions were detected. In the presence of G. intraradices, C. elatuni appears to function as a "commensalistic associate," neither impacting plant growth nor sporulation by G. intraradices. Overall, C. datum appears to be multifunctional, serving as both a rhizoplane and rhizophere fungus, opportunistically colonizing plant roots and only becoming pathogenic when resources are severely limited and intraspecific competition is high. This multifunctional strategy may be shared with other fungi that form similar structures in roots. [ABSTRACT FROM AUTHOR]

Thallus anatomy in three species of the primitive liverwort genus Treubia (Metzgeriidae, Treubiales) was studied by light and electron microscopy. The thallus exudes copious mucilage, a feature shared elsewhere in liverworts only with the mycotrophic subterranean axes of the allied genus Haplomitrium. The central strand in the thallus midrib has a unique histological organization and harbors an intra- and intercellular infection by a glomeromycotean fungus that is far more highly differentiated than most of the glomeromycotean associations described to date. The fungus enters the thallus via clefts in the ventral epidermis along the midrib and colonizes the parenchyma above, forming intracellular coils and prominent, relatively short-lived, hyphal swellings. Above the zone with intracellular colonization is a tissue area containing mucilage-filled intercellular spaces; here the fungus is entirely intercellular and forms abundant pseudoparenchymatous structures and, in more mature parts of the thalli, large hyphae with thick multistratose walls. Mucilage in Treubia differs in histochemistry and origin from that produced by apical papillae, via hypertrophied Golgi, in all other bryophytes. Remarkable parallels between fungal associations in Treubia, Haplomitrium, and Lycopodium, all members of very ancient lineages, suggest that these associations epitomize very early stages in the evolution of glomeromycotean symbioses. [ABSTRACT FROM AUTHOR]

The diversity of ectomycorrhizal communities associated with Quercus garryana on and off serpentine soils was compared and related to landscape-level diversity. Serpentine soils are high in magnesium, iron, and heavy metals and low in fertility. In plant communities on serpentine soils, a high proportion of flowering plant species are endemic. At three sites with paired serpentine and non serpentine soils in southwestern Oregon, we sampled Q. garryana roots and categorized ectomycorrhizas by morphotyping and by restriction fragment length patterns. Ectomycorrhizas were abundant at all sites; no single fungal species dominated in the ectomycorrhizas. Of 74 fungal species characterized by morphotype and pattern of restriction fragment length polymorphisms, 46 occurred on serpentine soils, and 32 were unique to serpentine soil. These species are potentially endemic to serpentine soil. Similarities in species composition between paired serpentine and nonserpentine soils were not significantly lower than among three serpentine sites or among three nonserpentine sites. We conclude that mycorrhizal communities associated with oaks on serpentine soil do not differ in species richness or species evenness from those on neighboring nonserpentine soil. [ABSTRACT FROM AUTHOR]

Presents a study which examined the effects of arbuscular mycorrhizal symbiosis on ramet and genet densities, vegetative growth rates, and flowering of tallgrass prairie forb species. Role of biotic interactions in plant species coexistence and community diversity; Materials and methods used; Reduction of mycorrhizal colonization in the roots of forb species; Result of the suppression of mycorrhizal fungi.

Presents a study which determined the interaction of mycorrhizae, ammonium and nitrate on the growth of a coastal sage scrub species Artemisia californica and exotic annual grass Bromus madritensis. Effect of anthropogenic nitrogen deposition on vegetation; Materials and methods used; Growth and colonization of mycorrhizal; Variation in nitrogen concentration between species.

Presents information on a study which addressed the influence of phylogeny and environmental factors on the mycorrhizal status of the genus Carex (Cyperaceae). Materials and methods; Results and discussion.

Presents the results of a study which examined plant growth, demographic, and community responses to mycorrhizal symbiosis of experimental microcosms containing an assemblage of eight tallgrass prairie grass and for species in native prairie soil. Suppression of mycorrhizas; Effect of mycorrhizae on vegetative production; Changes in mycorrhizal activity.

The article focuses on the parasitic effects of invasive plant species garlic mustard, Alliaria petiolata of the genus Brassicaceae, on mycorrhizal mutualisms and co-occurring mixotrophic parasites. Topics discussed include the processes by which Alliaria petiolata affects mycorrhizal mutualisms, the trophic role of Monotropa hypopitys, and the shade tolerance of Alliaria. The relationships between Monotropa hypopitys, Monotropa uniflora and Pterospora andromedea are described.

Presents an abstract of the study `Fossil arbuscular mycorrhizae from the Early Early Devonian,' by Thomas N. Taylor et al. and presented during the 1995 Annual Meeting of the Botanical Society of America.

Presents an abstract of the study `A reevaluation of a vesicular-arbuscular mycorrhiza from the Triassic of Antarctica,' by Carlie J. Phipps and Thomas N. Taylor and presented during the 1995 Annual Meeting of the Botanical Society of America.

Presents an abstract of the study `Ecological adaptations of mycorrhizal obligate ferns,' by Cindy L. Johnson-Groh, Dean P. Whittier and Donald R. Farrar, presented during the 1996 Annual Meeting of the Botanical Society of America at the University of Washington in Seattle, Washington.

Presents an abstract of the study `Nutrition and growth of a calcifuge plant in a model calcerous system: Effects of mycorrhization and rhizosphere oxalic acid,' by Gregory K. Eaton and Orson K. Miller Jr., presented during the 1996 Annual Meeting of the Botanical Society of America at the University of Washington in Seattle, Washington.

Presents an abstract of the study `Importance of Mycorrhizae in competition between Juniperus ashei and Quercus fusiformis,' by Janis K. Bush and Oscar W. Van Auken, presented during the 1996 Annual Meeting of the Botanical Society of America at the University of Washington in Seattle, Washington.