25 research outputs found
Fusarium and allied fusarioid taxa (FUSA). 1
Seven Fusarium species complexes are treated, namely F. aywerte species complex (FASC) (two species), F. buharicum species complex (FBSC) (five species), F. burgessii species complex (FBURSC) (three species), F. camptoceras species complex (FCAMSC) (three species), F. chlamydosporum species complex (FCSC) (eight species), F. citricola species complex (FCCSC) (five species) and the F. concolor species complex (FCOSC) (four species). New species include Fusicolla elongata from soil (Zimbabwe), and Neocosmospora geoasparagicola from soil associated with Asparagus officinalis (Netherlands). New combinations include Neocosmospora akasia, N. awan, N. drepaniformis, N. duplosperma, N. geoasparagicola, N. mekan, N. papillata, N. variasi and N. warna. Newly validated taxa include Longinectria gen. nov., L. lagenoides, L. verticilliforme, Fusicolla gigas and Fusicolla guangxiensis. Furthermore, Fusarium rosicola is reduced to synonymy under N. brevis. Finally, the genome assemblies of Fusarium secorum (CBS 175.32), Microcera coccophila (CBS 310.34), Rectifusarium robinianum (CBS 430.91), Rugonectria rugulosa (CBS 126565), and Thelonectria blattea (CBS 952.68) are also announced her
Genetic diversity and differentiation of coexisting populations of Quercus robur L.and Q. petraea (Matt.) Liebl.
Pedunculate and sessile oaks (Quercus robur L.; Q. petraea [Matt] Liebl.) often coexist in mixed forest stands.
However, species-specific investigations and forest management actions in such populations require reliable
methods of identification of the species status of individuals. We investigated genetic diversity and species dif-
ferentiation of adult and naturally established seedling cohorts in a mixed forest stand composed of Q. robur and
Q. petraea, located in the Jamy Nature Reserve in north-central Poland. Using nineteen nuclear microsatellite
loci and a model-based clustering approach as a tool for species delineation, we efficiently identified 105 and
60 adults, as well as 191 and 456 seedlings of pedunculate and sessile oaks, respectively. While the adult trees
of both species were randomly distributed throughout the sample plot, the seedlings demonstrated significant
spatial clustering, which was particularly evident for Q. petraea. The two oak species exhibited similar levels of
genetic diversity in adult and offspring cohorts. Inbreeding was found to be low and significant only at the stage of
seedlings. The estimates of effective population size were higher for Q. robur than Q. petraea, despite the overall
greater reproductive success of the later one. There was a significant level of differentiation between the studied
oak species, as measured by Fst coefficient (0.084 – adults; 0.099 – seedlings). The results on genetic diversity and
species differentiation obtained in the studied indigenous near-natural stand of Q. robur and Q. petraea could be
considered as a reference for other population genetic studies of oaks
Functional analysis of three adjacent open reading frames from the right arm of yeast: Chromosome XVI
A 7.24 kb genomic DNA fragment from the yeast Saccharomyces cerevisiae chromosome XVI was isolated by complementation of a new temperature-sensitive mutation tsa1. We determined the nucleotide sequence of this fragment located on the right arm of chromosome XVI. Among the three, complete open reading frames: YPR041w, YPR042c and YPR043w contained within this fragment, the gene YPR041w was shown to complement the tsa1 mutation and to correspond to the TIF5 gene encoding an essential protein synthesis initiation translation factor. The YPR042c gene encodes a hypothetical protein of 1075 amino acids containing four putative transmembrane segments and is non-essential for growth. The gene YPR043c encoding the 10 kDa product, highly similar to the human protein L37a from the 60S ribosomal subunit, was found to be essential and a dominant lethal. We conclude that three tightly linked yeast genes are involved in the translation process. (C) 1998 John Wiley & Sons, Ltd