Stem galls and witch’s broom–like growths are locally abundant on the highly invasive Brazilian peppertree (Schinus terebinthifolia) at field sites in southern Florida where a thrips biological control agent (Pseudophilothrips ichini) is being released to reduce the invasive potential of the plant. Galls have also been observed on potted plants in nursery stock grown to feed laboratory colonies of the agent. Herein, our objective was to isolate and identify the causal agent of the galls and assess its ability to induce galls in naive plants. We obtained stem galls from both field- and nursery-grown plants, aseptically isolated a fungus in acidic potato dextrose agar, and purified fungal colonies. Stems of potted naive saplings were wound-inoculated with purified hyphal fragments from the purified colonies, which readily induced galls like those observed in the field and nursery. Simultaneous molecular analysis of the fungal DNA obtained from the galls of field and nursery plants, experimentally induced galls, and fungal colony isolates identified this gall-inducing fungus as Cophinforma sp.. We demonstrated that this Cophinforma sp. can infect S. terebinthifolia stems via mechanical wounds and induce visibly discernible stem galls in saplings within 3 mo. This will serve as a model for galled plant production for assessing the impacts of the gall-inducing fungus on S. terebinthifolia, with potential for further study to investigate interactions between the thrips and this naturalized fungus, which may synergistically and/or additively enhance S. terebinthifolia management efficacy.

The importance of tall fescue as a pasture grass is diminished when infected with the fescue endophyte. The availability of fungus-free seed has necessitated the development of systems to kill the infected sod before interseeding fungus-free seed. Field studies were conducted to evaluate the response of fescue sod to foliar-applied herbicides as single and sequential applications during the fall and spring. Sequential applications of paraquat at 0.14, 0.28, and 0.56 kg ai/ha in September and October and glyphosate at 0.84 and 1.7 kg/ha applied as single or sequential applications in September and October resulted in more than 90% kill of the tall fescue sod. Spring treatments of paraquat and glyphosate were less effective than those applied in the fall. Dalapon, fluazifop-P, HOE-39866 [glufosinate (proposed name)], sethoxydim, and simazine did not effectively kill the sod.

Purification of α-1,4-glucan lyase from red algae and fungi has previously been reported. The α-glucan lyase converts α-glucans to 1,5-anhydro-D-fructose. In this study, an endophyte was detected between the algal cells of Gracilariopsis sp., but not penetrating the cell walls. Histological staining was consistent with the endophyte being fungal and immunohistochemistry revealed that it possessed an α-1,4-glucan lyase differing from that of the host. The endophyte α-glucan lyase was recognized by antisera against both fungal and red algal α-glucan lyases, whereas the α-glucan lyase found in the algal tissue was recognized only by the antisera against algal α-glucan lyase. The lyases occur independently in the host and in the endophyte, and were sometimes detected simultaneously. The endophyte was only observed in Gracilariopsis sp. collected in China; no endophyte could be detected in Gracilariopsis sp. from California or in Gracilaria chilensis.

Fungal endophytes associated with the palm, Trachycarpus fortunei, within and outside its natural geographic range were investigated. Endophytes were relatively common with colonization rates of 23–57% at the four sites sampled. The endophyte assemblages at the different sites were diverse with 75 fertile species of ascomycetes and mitosporic fungi. The assemblage composition at each site was similar and between seven and 13 species comprised 81–89% of the taxa present in relative frequencies of >1%. Glomerella cingulata and Phomopsis spp., were consistently dominant, and a large number of rare species were recorded. The diversity at each site was similar in number, but the abundance of isolates varied. The results obtained were comparable to those of previous studies of palm endophyte assemblages, but the assemblages showed more affinity with unrelated temperate hosts than with tropical palm hosts. Quantitative and qualitative differences in endophyte assemblages from old and young tissues were observed, and more isolates were recovered from old tissues independent of the age of the palm. The composition of the assemblage varied with several taxa being exclusively or more commonly isolated from old tissues (e.g. xylariaceous taxa, Oxydothis sp. nov.) or young tissues (e.g. Stagonospora spp., Phoma multirostrata). Some differences in the composition of the assemblage and in relative frequencies of various species were observed in trees and saplings. Significantly more isolates were recovered from the vein than intervein tissues, independent of leaf age or tree age. Tissue specificity was not exhibited by any taxa isolated from either leaf or petiole tissues, except for xylariaceous taxa in leaf tissues. Some other taxa showed a preference for leaf tissues or petioles, whereas others were equally distributed amongst all tissues. Endophyte assemblages of palms from continuous distributions were similar, but those from disjunct distributions (i.e. outside the natural geographic range of the palm, such as Australia and Switzerland), differed significantly from each other and from assemblages within continuous distributions. The relative importance values of endophyte species at the two sites in China indicates the site-specific nature of the endophyte assemblages. Most previous studies on the endophytes of palm hosts have concentrated on tropical palms. However, this study examines the endophytes of the warm temperate palm Trachycarpus fortunei, and investigates the relative importance of host and climate related processes.

Endophytes of the genus Epichloë (Clavicipitaceae, Ascomycota) are systemic symbionts of cool-season grasses. Their interactions with grass hosts may vary between mutualistic and pathogenic depending on the mode of endophyte reproduction. Sexual strains prevent flowering and seed set (choke disease) of the host and can be horizontally transmitted by ascospores, while asexual strains remain asymptomatic and are vertically transmitted through seeds. In Switzerland nearly all plants of Brachypodium sylvaticum (Huds.) P.B. are infected by Epichloë sylvatica Leuchtmann & Schardl, but choke symptoms are formed very rarely, and are restricted to particular locations and to a minority of plants at those locations. Earlier research has revealed that E. sylvatica is genetically differentiated into sexual and asexual subpopulations. Given the high level of infection and assuming horizontal transmission of sexual strains, multiple host infections have been predicted. In this study, 25 plants out of 63 examined by isozyme analysis were found to be infected by two or three different endophyte genotypes. In most cases endophyte genotypes appeared to be correlated with the symptom type of a particular tiller, suggesting that the fungal genome controls choke formation and that the sexual and asexual subpopulations are separated at the ramet (tiller) level rather than at the genet (plant) level. These conclusions were further supported by analyses with log-linear models of the population structure of E. sylvatica at four locations where choke symptoms were present. These analyses also revealed a geographic structure in the asexual subpopulation but not in the sexual subpopulation which could be caused by the different dispersal ranges of their propagules. The rare occurrence of sexually reproducing strains and the dominance of a single genotype in asymptomatic plant populations may be explained by the colonization history of B. sylvaticum and its endophyte in Switzerland.

Little is known about non-mycorrhizal endophytic fungi in tropical orchids; still less is known about how endophytes vary within and between individual orchid plants. Fungal endophytes were isolated from roots and leaves of epiphytic and lithophytic orchids in the genus Lepanthes; seven species, from rainforests in Puerto Rico, were sampled. The endophytes observed most frequently were Xylaria species and Rhizoctonia-like fungi, found in 29% of roots and 19% of leaves, and 45% of roots and 31% of leaves, respectively. Five deuteromycete genera were also isolated, occurring in 19% of roots and 43% of leaves (combined). At least nine species of Xylaria were found, with several species sometimes occurring in a single plant. Differences between roots and leaves in frequency of Xylaria and Rhizoctonia isolates were not significant, although differences among orchid species in number and types of endophytes were. Heterogeneity of endophytes in single plants and plant organs was greater than differences between species. Many Lepanthes species are very restricted in distribution, and knowledge of their interactions with endophytes might be useful in species management.