Festuca auriculata in North America

Festuca auriculata Drob., published by Alexeev from one place in Alaska and besides known from the Arctic part of Asia, is shown to occur in several localities in Alaska and the north–western part of Yukon, Canada.     

Molecules and morphology in concert. II. The Festuca brachyphylla complex (Poaceae) in Svalbard

We used a combined molecular and morphological approach to unravel variation in the autogamous Festuca brachyphylla polyploid complex in the arctic archipelago of Svalbard. Forty populations were analyzed for random amplified polymorphic DNAs (RAPDs) and 46 morphological characters. Eighteen RAPD multilocus phenotypes were observed in the 86 plants analyzed, based on 30 polymorphic markers. Multivariate analyses of the RAPD data revealed four distinct groups of multilocus phenotypes; in contrast, the variation was more or less continuous in multivariate analyses of the morphological data. However, we identified several individual morphological characters that unambiguously discriminated among the four groups of RAPD multilocus phenotypes. Analysis of type material suggests that the four groups in Svalbard can be referred to Festuca baffinensis, F. brachyphylla, F. hyperborea, and F. edlundiae. This study shows that concerted analysis of molecules and morphology is a powerful tool in low-level taxonomy.     

Variation in the Festuca brachyphylla (Poaceae) complex in Svalbard, elucidated by chromosome numbers and isozymes

Contrasting with former taxonomic treatments, chromosome numbers and isozyme data support the delimitation of the seminiferous representatives of the Festuca brachyphylla complex in Svalbard into four species: F. baffinensis, F. brachyphylla, F. hyperborea and F. edlundiae. Unique enzyme markers were found for all species. Festuca brachyphylla proved hexaploid, and the others, tetraploid. The chromosome numbers of F. hyperborea and F brachyphylla (as circumscribed at present) are new to Svalbard. Festuca baffinensis is the most distinct species within the complex, probably representing a separate evolutionary lineage. The three other species seem closely related, showing mutually equidistant relationships. Some deviating plants found on disturbed ground might represent hybrid derivatives or an introduced foreign strain of the elsewhere variable F. brachyphylla. Materials of diploid F. ovina from northern Fennoscandia was enzymatically closely related to the F brachyphylla complex in Svalbard. Festuca brachyphylla, F. edlundiae , and F. hyperborea all had a stronger affinity to F ovina than to F baffinensis , indicating that the F brachyphylla complex is an artificial taxonomic group. There are reasons to believe that the origin of the polyploid taxa of the F brachyphylla complex can be traced to diploid species of the F. brachyphylla and F ovina complexes.     

Jahnula species from North and Central America, including three new species

Three new species of loculoascomycetes collected from freshwater habitats in North America are described as new species of Jahnula (Jahnulales, Dothideomycetes). All three share these morphological features: hyaline to blackish translucent, membranous ascomata with subtending, wide, septate brown, spreading hyphae; peridia composed of large angular cells; hamathecium of septate pseudoparaphyses; 8-spored, clavate to cylindrical asci; and 1-septate, broadly fusiform, brown, multiguttulate ascospores. Four additional species, J. aquatica, J. bipolaris, J. potamophila, and J. seychellensis, are reported for the first time from the western hemisphere.     

Sudden-death syndrome of soybean is caused by two morphologically and phylogenetically distinct species within the Fusarium solani species complex--F. virguliforme in North America and F. tucumaniae in South America

Soybean sudden-death syndrome has become a serious constraint to commercial production of this crop in North and South America during the past decade. To assess whether the primary etiological agent is panmictic in both hemispheres, morphological and molecular phylogenetic analyses were conducted on strains selected to represent the known pathogenic and genetic diversity of this pathogen. Maximum-parsimony analysis of DNA sequences from the nuclear ribosomal intergenic spacer region and the single copy nuclear gene translation elongation factor 1-α, together with detailed morphological comparisons of conidial features, indicate that SDS of soybean in North and South America is caused by two phylogenetically and morphologically distinct species. Fusarium virguliforme sp. nov., formally known as F. solani f. sp. glycines, is described and illustrated for the SDS pathogen in North America, and F. tucumaniae sp. nov. is proposed for the South American pathogen. The molecular phylogenetic results challenge the forma specialis naming system because pathogenicity to soybean might have evolved convergently in F. tucumaniae and F. virguliforme. Phylogenetic evidence indicates the two SDS pathogens do not share a most recent common ancestor, since F. tucumaniae was resolved as a sister to a pathogen of Phaseolus vulgaris, F. phaseoli comb. nov. All three pathogens appear to have evolutionary origins in the southern hemisphere since they are deeply nested within a South American clade of the F. solani species complex.     

NewLeptographium species from Indonesia and Eastern North America

Leptographium species have predominantly been described from North America, Canada and Europe. These fungi generally occur on conifers and many cause blue-stain of lumber. MostLeptographium species are also associated with insects and in particular, bark beetles (Coleoptera: Scolytidae). Recently, an unknown species ofLeptographium was isolated from pine infested with anIps sp. in Indonesia. In addition, two unknown species have been collected from red spruce (Picea rubra) and balsam fir (Abies balsamea) roots from high elevation sites in Eastern North America. The latter isolates are unusual in that they are associated with the feeding wounds made by the conifer swift mothKorscheltellus gracilus (Lepidoptera: Hepialidae), which is a habitat unique for species ofLeptographium. Comparison with knownLeptographium species has revealed that the isolates from Indonesia and those from Eastern North America represent three previously undescribed taxa. They are, therefore, described in this study asL. pineti sp. nov,L. abieticolens sp. nov. andL. peucophilum sp. nov.     

Cladonia petrophila,a new species from eastern North America

Cladonia petrophila, an overlooked, usually sterile species, morphologically similar toC. apodocarpa andC. caespiticia, is described as new on the basis of its distinctive chemistry, perlatolic and fumarprotocetraric acids, and habitat preference for moist non-calcareous rock.     

Evolution of hydraulic traits in closely related species pairs from Mediterranean and nonMediterranean environments of North America

Chaparral shrubs in California experience cool, wet winters and hot, dry summers characteristic of mediterranean-type climates; by contrast, morphologically similar close relatives in central Mexico experience summer rainfall. A comparison of closely related species pairs was conducted to examine whether evolutionary divergences in plant hydraulic conductivity were associated with contrasting seasonality of precipitation. Six species pairs in Santa Barbara, California and Tehuacan, Mexico were chosen to test for repeated directional divergences across the habitat contrast. Additionally, evolutionary correlations were examined using phylogenetically independent contrasts (PICs) among a suite of hydraulic traits, including stem- and leaf-specific conductivity, resistance to embolism, wood density, inverse Huber value, and minimum seasonal water potential. Leaf-specific conductivity was generally higher in California, but for most hydraulic traits the species pairs exhibited varied evolutionary trajectories across the climate contrast. A significant correlation was found between divergences in xylem resistance to embolism and minimum seasonal water potential, but no evolutionary trade-off was found between resistance and stem conductivity. Higher leaf-specific conductivity may be adaptive in California, where soil and atmospheric droughts coincide during summer months. This response is consistent with a hydraulic strategy of high leaf water supply under high evaporative demand to prevent excessive drops in water potential.     

Physical mapping of ribosomal DNA sites in Festuca arundinacea and related species by in situ hybridization.

The positions of the 18S-5.8S-26S and 5S rRNA genes have been physically mapped on the chromosomes of diploid, tetraploid, and hexaploid Festuca species by in situ hybridization. The number and position of the rDNA sites in the species were compared. The results confirm some of the earlier phylogenetic studies of these species but suggest that some structural rearrangements have occurred and that sites have been lost during polyploidization. Keywords: Festuca, in situ hybridization, phylogeny, physical mapping, rDNA.     

Six new Eimeria species from vespertilionid bats of North America.

Twenty species of bats (Molossidae, Vespertilionidae) were collected from California, New Mexico, Oregon, South Carolina, Utah, and Baja California Norte (Mexico), and 29 of 404 (7%) animals, including Antrozous pallidus, Eptesicus fuscus, Myotis auriculus, Myotis californicus, Myotis ciliolabrum, Myotis evotis, Myotis lucifugus, Myotis thysanodes, Myotis vivesi, Myotis volans, Myotis yumanensis, and Nycticeius humeralis were infected with Eimeria spp., which represent 6 new species. Sporulated oocysts of a new species from A. pallidus are subspheroidal, 24.8 x 21.6 (22-27 x 19-24) microm with a polar granule and a large globular residuum. The oocyst wall is sculptured, with 2 layers, approximately 1.5 thick. Ovoidal sporocysts are 11.5 x 7.8 (9-13 x 7-10) microm, with Stieda body and residuum of many large granules. Sporulated oocysts of a new species from M. californicus are subspheroidal, 20.7 x 18.2 (19-23 x 16-20) microm, with 1-7 tiny polar granules, but without oocyst residuum. The oocyst wall is rough, with 2 layers, approximately 1.4 thick. Ovoidal sporocysts are 11.2 x 7.3 (10-12 x 7-8) microm, with Stieda body and a globular residuum. Sporulated oocysts of a second new species from M. californicus are subspheroidal, 23.1 x 20.7 (20-26 x 19-23) microm, with residuum and 1 polar granule, but a micropyle is absent. The oocyst wall is rough with 2 layers, approximately 1.5 thick. Ovoidal sporocysts are 12.5 x 7.2 (11-14 x 7-8) microm, with a Stieda body and residuum. Sporulated oocysts of a new species from M. ciliolabrum are subspheroidal, 24.9 x 20.1 (18-27 x 17-23) microm, with 1-2 polar granules, but without micropyle and residuum. The oocyst wall is rough with 2 layers, approximately 1.5 thick. Ellipsoidal sporocysts are 12.5 x 9.0 (8-14 x 7-10) microm, with Stieda and substieda bodies and residuum. Sporulated oocysts of a new species from M. evotis are subspheroidal, 21.3 x 18.6 (20-24 x 15-20) microm, with a prominent polar granule, but without micropyle and residuum. The oocyst wall is smooth with 2 layers, approximately 1.0 thick. Ovoidal sporocysts are 12.2 x 8.0 (11-13 x 7.5-9) microm, with Stieda and substieda bodies and residuum. Sporulated oocysts of the new species from N. humeralis are subspheroidal, 22.4 x 18 (21-24 x 17-20) microm, with 1-3 polar granules, but residuum and micropyle are absent. The oocyst wall is lightly sculptured with 2 layers, approximately 1.4 thick. Ovoidal sporocysts are 10.9 x 7.7 (9-12 x 6-8) microm, with Stieda body and residuum. Sporulated oocysts of E. pilarensis Scott and Duszynski, 1997 and those of at least 12 other morphological forms were seen in the other infected bats; these latter forms were seen in too few numbers to be adequately described as new species.     

The ecology of Potamogeton species in central North America

The distribution of 17 Potamogeton species was examined at 430 sites in central North America with respect to water body type, bottom substrate and 8 water chemistry parameters (pH, total dissolved solids, total alkalinity, chloride, sulphate, phosphorus, combined nitrate and nitrite, and dissolved organic matter). All except 2 of the species showed statistically significant distributions with respect to some of the environmental parameters examined. Each species occupied a different combination of chemical parameter ranges. The species formed a distribution spectrum with respect to water chemistry, with P. epihydrus and P. obtusifolius frequenting low inorganic concentrations at one end of the scale, and P. filiformis, P. pectinatus and P. vaginatus at the other end, these species characterized by high mean inorganic values and occurring most often in saline or alkaline habitats. While 41 significant positive interspecific associations were found within the genus in lentic waters, only 4 were apparent in lotic habitats. Potamogeton species richness (PR) was related to water body and bottom type, with lakes and sand bottoms showing the highest mean PR values. Stepwise multiple regression analysis showed that, in the area as a whole, the water chemistry parameters examined accounted for <25% of the observed variability in PR. The relative importance of individual chemical parameters in relation to PR varied in different water body types.     

Genetic regulation of diploid-like chromosome pairing in the hexaploid species,Festuca arundinacea Schreb. and F. rubra L. (Gramineae)

The basis of diploid-like chromosome pairing in hexaploid (2n=6x=42) Festuca arundinacea Schreb. and hexaploid F. rubra L. has been investigated. On the combined evidence derived from chromosome pairing in some euploid (2n=42) and monosomic (2n=41) hybrids from a diallel set of crosses between ten geographically diverse ecotypes of tall fescue, intergeneric hybrids involving tall fescue as well as red fescue, and euploid (2n=56) and aneuploid (2n=52, 53, 54, 55) amphiploids between Lolium multiflorum and F. arundinacea, it is concluded that diploid-like meiosis in these hexaploid species as well as in other natural polyploid species of Festuca is under genetic control. It is further inferred that this diploidizing gene(s) system must at least be disomic in dosage to be effective in suppressing homoeologous pairing and, therefore, had no influence upon pairing in haploid complements of the hybrids, i.e., it is haplo-insufficient or hemizygous-ineffective. — It has also been shown that sterility in hybrids between some geographically isolated ecotypes of tall fescue results from irregular meiosis due to the breakdown of the regulatory mechanism, rather than from chromosomal differentiation of the parental ecotypes as widely believed so far. The evolutionary significance of such a gene-repressing effect of certain genotypes or genes is indicated. — It is further suggested that the hemizygous ineffectiveness of the genetic control of bivalent pairing is of evolutionary significance and could have major implications on the cytogenetic relationships and the breeding of the entire Lolium-Festuca complex.     

Polytypic species and hybridization in quaternary freshwater ostracods of North America

Quaternary fresh-water ostracods of nominal species Candona patzcuaro and C. rawsoni (each including several synonyms) are considered to belong to a single, polytypic species on the basis of geographic distribution and hybridization evident in faunas from Missouri. Data are insufficient to permit designation of subspecies. “C. patzcuaro” and “C. rawsoni” thus are treated informally, as phena. Occurrences of these phena in North America indicate shifting of ranges and secondary intergradation at middle latitudes which can be correlated broadly with glacial advances and retreates and associated climatic change.