Molecular and morphological evidence for a new grass genus,Dupontiopsis (Poaceae tribe Poeae subtribe Poinae s.l.), endemic to alpine Japan,and implications for the reticulate origin of Dupontia and Arctophila within Poinae s.l.

Phylogenetic analyses within Poaceae tribe Poeae subtribes Puccinellinae (=Coleanthinae), Phleinae, Poinae s.l. (including Alopecurinae), and Miliinae (PPAM clade), revealed that one species formerly placed in Poa represents a new monotypic genus belonging to subtribe Poinae s.l., Dupontiopsis gen. nov., D. hayachinensis comb. nov. (based on Poa hayachinensis), endemic to wet, gravelly, serpentine, alpine habitats in northern Japan. This genus forms a strongly supported clade (DAD) with two circumarctic Poinae genera, Arctophila and Dupontia, in phylogenetic analyses of plastid and nuclear ribosomal DNA sequence data. Both morphology and DNA sequence analyses provide support for D. hayachinensis as a lineage distinct from either Arctophila or Dupontia, with moderate DNA support for a position as sister to these two genera. Dupontiopsis resembles these other monotypic genera in its several-flowered spikelets, lemmas usually 3-nerved, with frequently awned attenuate scarious apices (as in Dupontia) and calluses with a crown of hairs around the base of the lemma, but differs in its keeled lemmas, scabrous palea keels, glumes shorter than the first lemma. Our investigation suggests that the most recent shared ancestor of the DAD clade evolved from a single hybridization event, as a hexaploid, probably in western Beringia. The probable parentage of the ancestor is considered to be within the Poinae–Alopecurinae clade excluding Poa. We provide evidence for possible secondary hybridization and introgression of duodecaploid Dupontia fisheri with Puccinellia. A key to perennial genera of PPAM with hairy calluses, and a supplemental table of morphological characters in the genera accepted in PPAM are provided.     

The intergeneric hybrid origin ofPoa labradorica (Poaceae)

Phytogeographic, ecological, morphological, anatomical, cytological, isozyme, and endonuclease restriction site evidence is presented demonstrating thatPoa labradorica is of intergeneric hybrid origin betweenDupontia fisheri subsp.psilosantha (pistillate parent) andPoa eminens (staminate parent).Poa labradorica is endemic to recently deglaciated areas of northern Quebec and Labrador which are within the overlapping range of the putative parents. Incapable of sexual reproduction,P. labradorica dominates large areas of coastal marsh through vigorous production of rhizomes. Most morphological, anatomical, cytological, isozyme, and DNA characters studied inP. labradorica showed states intermediate or additive to those of the putative parents.     

On polyphyly of the former section Ochlopoa and the hybridogenic section Acroleucae (Poa,Poaceae): insights from molecular phylogenetic analyses

In this study, sequence data from the inert nuclear region ITS1‐5.8S rDNA‐ITS2 and the chloroplast region trnL–F, as well as a few morphological characters, are analysed to the relationships among known annual Poa (bluegrasses). It is shown that all taxa from the Poa annua aggregate distinguished by lemma characters and growth form have identical ITS and trnL–trnF sequences, all ITS sequences of this aggregate are the same as thethose of P. supina, and all trnL–trnF sequences are homologous with those of P. infirma. Furthermore, no differences were found between unusual morphotypes of P. supina with short spinules on their panicle branches and typical plants, but Siberian samples were found to have a slightly differentiated trnL–trnF region. These results suggest a hybrid origin of the Asian annual bluegrasses. Their maternal genome is close to that of P. sect. Homalopoa, but their ITS sequences are different. Some ITS sequences from annual Asian bluegrasses are resolved among representatives of P. sect. Stenopoa while for other (morphologically closely similar) species they fall in a clade with representatives of P. sect. Malacanthae. The latter group is distant from P. sect. Ochlopoa and is better treated as a separate section, viz P. sect. Acroleucae. The American annual bluegrasses are heterogeneous and also rather distant from P. sect. Ochlopoa. Poa chapmaniana, a species with cleistogamic flowers, is nested among the basal Subantarctic sections, far away from the taxa with which it has previously been considered related. It is indeed closer to P. sect. Ochlopoa than to other annual American bluegrasses. Thus, the studied annual species in fact belong to four independent evolutionary lines (or six including the separate genus Eremopoa and the Turkish Poa jubata), one of which, Acroleucae, has gone through three reticulation events. As in previous studies, our analysis did not support the generic status of P. sect. Ochlopoa.     

The Role of Thermal Regime in Tundra Plant Community Restoration

Mineral extraction activities in the Arctic regions of the world produce long-lasting ecological disturbances. Assisted recovery from such disturbances may require restoration of the tundra thermal regime. We transplanted plugs of entire root zone and live tundra plants to a disturbed site in Alaska oil fields. The dominant species were Carex aquatilis, Eriophorum angustifolium, Dupontia fisheri, Poa glauca, Festuca rubra, Salix ovalifolia, S. reticulata, and Sphagnum spp. We studied plant responses in the plugs to thermal regime manipulations by means of greenhouse and of single- or double-plug treatments. All plugs continued to produce new plants with time and expanded in area and canopy volume. Plants responded differently to treatments and generally reversed those responses when we reversed the greenhouse treatment the third year after transplant. Our small-scale experiment showed that the native thermal regime of a plant community is vital in revegetating a disturbed tundra. But large-scale restoration using transplants requires resources of modern extraction technology, engineering, and planning to salvage the extensive live tundra mats now routinely destroyed under gravel fills of roads, structures, and mine-site stockpiles.     

Numerical analyses of distributions of Iberian and Balearic endemic monocotyledons

Chorological information concerning 182 taxa of monocotyledons endemic to the Iberian Peninsula and Balearic Islands was compiled and related to the 100×100 km, 50×50 km and 10×10 km UTM grids. Distributions were analysed using multivariate methods (two-way indicator species analysis and detrended correspondence analysis) for each scale. Comparison of results allows recognition of several floristic elements and sectors (i.e. Balearic, Murcian-Almerian, south western) common to all three scales, whereas other regions are assigned to different sectors depending on the grid size considered. As a consequence of the increase in detail, characteristics such as number of sectors, the outline of boundaries and continuity or fragmentation of the areas also change. These factors are discussed.     

Flow Cytometric Determination of Genome Size in some Old World Lupinus Species (Fabaceae)

Abstract: Genome size determinations using propidium iodide flow cytometry were conducted in Lupinus anatolicus, L. pilosus, L. luteus, L. hispanicus ssp. hispanicus and L. hispanicus ssp. hispa-nicus × L. luteus (a complex hybridization product ofL. hispanicus ssp. hispanicus and L. luteus ). Using Glycine max "Ceresia" (1C = 1.134pg) and an accession of L. pilosus (1C = 0.649pg) as internal standards the following 1C values were obtained: L. anatolicus: 0.606 pg; L. pilosus: 0.620–0.678 pg; L. luteus: 1.173 pg; L. hispanicus: 1.043 pg; L. hispanicus ssp. hispanicus × L luteus: 1.036 pg. Lupinus anatolicus is a newly described taxon with smooth seeds whose genome is approximately as small as the smallest genomes measured in the related L. pilosus , a taxon with rough seeds. The genomes in the related smooth-seeded taxa L. luteus, L. hispanicus and L. hispanicus ssp. hispanicus × L. luteus are considerably larger. There is a 1.13-fold difference between L. luteus (crop) and L. hispanicus (wild). The genome size of L. hispanicus ssp. hispanicus × L. luteus , however, is not intermediate, it is close to L. hispanicus .     

Effects of overhead canopy on macroinvertebrate production in a Utah stream

SUMMARY. 1. Macroinvertebrate abundance and production were compared between an open and shaded site of a stream in the Wasatch Mountains, Utah. Mean biomass was significantly higher at the open site for midges (Chironomidae), 4.6×; Baetis bicaudatus , 5.7×; Baetis tricaudatus , 2.3×; Drunella coloradensis , 12× and Cinygmula sp., 1.6×, Abundance of most other macroinvertebrates (except black flies: Simuliidae) was also greater at the open site, but differences were not significant. Black fly biomass was 1.7× greater at the shaded site.
2. Seasonal production, estimated by the size-frequency and instantaneous growth rate methods, was greater at the open site than the shaded site for most taxa (except black flies) and reflected differences in standing crops between the sites rather than differences in rate of growth. Excluding black flies, production at the open site was twice as high as at the shaded site.
3. The greater abundance and production of most invertebrate taxa at the open site is probably associated with either higher quality food (algae and algal detritus), or a phototactic attraction to sunlit areas.
4. Sampling of large cobbles was an efficient method of sampling all taxa except Cinygmula sp. which was more abundant on smaller substrate particles.     

Towards a Transferable and Cost-Effective Plant AFLP Protocol

Amplified fragment length polymorphism (AFLP) is a powerful fingerprinting technique that is widely applied in ecological and population genetic studies. However, its routine use has been limited by high costs associated with the optimization of fluorescently labelled markers, especially for individual study systems. Here we develop a low-cost AFLP protocol that can be easily transferred between distantly related plant taxa. Three fluorescently labelled EcoRI-primers with anchors that target interspecifically conserved genomic regions were used in combination with a single non-labelled primer in our AFLP protocol. The protocol was used to genotype one gymnosperm, two monocot and three eudicot plant genera representing four invasive and four native angiosperm species (Pinus pinaster (Pinaceae), Pennisetum setaceum and Poa annua (Poaceae), Lantana camara (Verbenaceae), Bassia diffusa (Chenopodiaceae), Salvia lanceolata, Salvia africana-lutea, and Salvia africana-caerulea (Lamiaceae)). Highly polymorphic and reproducible genotypic fingerprints (between 37–144 polymorphic loci per species tested) were obtained for all taxa tested. Our single protocol was easily transferred between distantly related taxa. Measures of expected heterozygosity ranged from 0.139 to 0.196 for P. annua and from 0.168 to 0.272 for L. camara which compared well with previously published reports. In addition to ease of transferability of a single AFLP protocol, our protocol reduces costs associated with commercial kits by almost half. The use of highly conserved but abundant anchor sequences reduces the need for laborious screening for usable primers that result in polymorphic fingerprints, and appears to be the main reason for ease of transferability of our protocol between distantly related taxa.     

Widespread hybridization among species of Indian major carps in hatcheries, but not in the wild

Twenty‐one allozyme loci in samples of wild‐caught and hatchery‐reared Indian major carps from Bangladesh were analysed. Bayesian model‐based clustering analysis revealed the presence of four taxa, corresponding to the three known species along with a fourth unknown taxon present in two hatchery samples. Individual admixture coefficients showed that 24% of all hatchery‐reared fishes were hybrids, whereas a single hybrid was observed in the wild‐caught samples. Only catla Catla catla × rohu Labeo rohita and mrigal Cirrhinus cirrhosus × rohu hybrids were observed, the vast majority of which were F₁ hybrids, though five individuals represented putative backcrosses. Mitochondrial DNA analysis revealed that catla × rohu hybridization primarily involved catla males and rohu females, whereas mrigal × rohu hybrids primarily resulted from rohu males and mrigal females. Despite the high percentage of F₁‐hybrids in hatchery samples, reproductive barriers among species have so far precluded widespread introgression. Continued hybridization may eventually lead to a breakdown of species barriers, thereby compromising the genetic integrity of the species in the wild, and leading to production losses in aquaculture.     

Ancient lakes as hotspots of diversity: a morphological review of an endemic species flock of <Emphasis Type="Italic">Tylomelania</Emphasis> (Gastropoda: Cerithioidea: Pachychilidae) in the Malili lake system on Sulawesi,Indonesia

The viviparous freshwater gastropod Tylomelania (Caenogastropoda: Cerithioidea: Pachychilidae) endemic to the Indonesian island Sulawesi has radiated extensively in two ancient lake systems. We here present the first systematic species-level review of taxa in the five lakes of the Malili lake system, which contains the most diverse and best studied freshwater fauna on Sulawesi. Our results indicate a significantly higher diversity of Tylomelania in these lakes than previously perceived based on morphological evidence for delimiting the taxa. We describe nine new species, thus increasing the number of taxa known from the Malili lakes to 25. Tylomelania species are inhabiting all available substrates in the lakes, and the diversity of habitats is reflected in an unparalleled range of radula types in this closely related group. Several species show a high intraspecific variability in some characters, and their closer investigation will probably lead to the discovery of more cryptic species. As it is, this species flock on Sulawesi is among the largest freshwater mollusc radiations known. Since the Malili lake system also contains other large endemic species flocks of e.g. crustaceans and fishes, it is a major hotspot of freshwater biodiversity in Asia to become a conservation priority. Handling editor: K. Martens     

Effects of daylength and temperature on root elongation in tundra graminoids

Summary Effects of soil temperature and daylength on root elongation of Carex aquatilis, Dupontia fischeri, and Eriophorum angustifolium were studied under both field and phytotron conditions. Late season decrease in root elongation rate and cessation of root elongation in Dupontia and Eriophorum are shown to be controlled by decreasing daylength. During the growing season, low temperature is not a direct factor in limiting root growth in any of the three species despite the presence of permafrost and low soil temperatures in the shallow thawed soil layer. In the phytotron, temperature-dependence of root elongation is related to experimental conditions characterized by continuous light. Plants of all three species are capable of root growth at near-freezing temperatures.     

Breeding systems and phylogeny in Poa,with special attention to Northeast Asia: The problem of Poa shumushuensis and sect. Nivicolae (Poaceae)

Poa sect. Poa subsect. Nivicolae (Prob.) Tzvelev was circumscribed to include four species of the Soviet Union: Poa shumushuensis, Poa caucasica, Poa irkutica, and Poa veresczaginii. Bayesian phylogenetic analyses of plastid and nuclear‐ribosomal DNA revealed that it is polyphyletic, none of these species are closely related. Poa shumushuensis, type of sect. Nivicolae, or its ancestor, likely displayed the nrDNA genotype characteristic of the higher polyploid P. sect. Malacanthae. Genotype codes are designated for each species: Hx, C c, Php, and Shp. Poa sect. Nivicolae s.s. is restricted to P. shumushuensis; P. sect. Irkuticae is restricted to P. irkutica; P. caucasica is moved to P. subg. & sect. Caucasicae nov.; and P. sect. Dschungaricae is resurrected for P. veresczaginii and two other species. Although diclinous breeding systems are known in many western hemisphere species of Poa, dicliny is infrequent and little studied in Asian Poa. Poa shumushuensis is judged to be either sequentially gynomonoecious or gynodioecious. A ratio of 2 perfect‐, to 2 mixed‐, to 1 pistillate‐flowered inflorescences from different plants in P. shumushuensis is suggestive of a recessive allele for stamen suppression, and this is associated with subtle sexual‐dimorphism. Poa irkutica is diclinous with a breeding system between simple gynomonoecy and sequential gynomonoecy; P. caucasica is perfectly flowered; and P. veresczaginii has infrequent abortive anthers, indicative of limited dicliny, or sterility for other reasons possibly related to its reticulate origin. In total, 23 Asian species are here reported to be diclinous and their breeding systems are characterized. A lectotype is designated for P. fauriei.     

The long unknown: Rediscovery of the long sunskink,Lampropholis elongata (Squamata: Scincidae)—After almost a decade,and after 50 years of data deficiency

Conservation management cannot proceed in the absence of the basic ecological data necessary to develop conservation strategies for a species. Species considered Data Deficient and possibly extinct are poorly known, and are often overlooked in conservation planning. This is despite a growing body of evidence indicating that Data Deficient species are more likely to be threatened by extinction compared to well-studied taxa. Hence, there is an immediate need to resolve data deficiency, and to search for species that are possibly extinct. Here, we conducted the first systematic search for a Data Deficient Australian skink, Lampropholis elongata (long sunskink), which prior to our study, had not been seen for approximately 9 years. A combination of pitfall trapping and active searches was used in attempt to detect the species. We rediscovered L. elongata at four sites within its known distribution on the southern edge of the New England Tablelands Bioregion in New South Wales, Australia. Our findings suggest that the species can be detected relatively easily using active survey methods, especially by inspecting tussock bases. We further highlight that areas of high canopy openness and high cover of Poa sieberiana (grey tussock-grass) appear to be key habitat for the species.     

Leaf Respiration in Light and Darkness (A Comparison of Slow- and Fast-Growing Poa Species)

We investigated whether leaf dark respiration (nonphotorespiratory mitochondrial CO2 release) is inhibited by light in several Poa species, and whether differences in light inhibition between the species are related to differences in the rate of leaf net photosynthesis. Four lowland (Poa annua L., Poa compressa L., Poa pratensis L., and Poa trivialis L.), one subalpine (Poa alpina L.), and two alpine (Poa costiniana Vick. and Poa fawcettiae Vick.) Poa species differing in whole plant relative growth rates were grown under identical controlled conditions. Nonphotorespiratory mitochondrial CO2 release in the light (Rd) was estimated according to the Laisk method. Photosynthesis was measured at ambient CO2 partial pressure (35 Pa) and 500 [mu]mol photons m-2 s-1. The rate of photosynthesis per unit leaf mass was positively correlated with the relative growth rate, with the slow-growing alpine Poa species exhibiting the lowest photosynthetic rates. Rates of both Rd and respiration in darkness were also substantially lower in the alpine species. Nonphotorespiratory CO2 release in darkness was higher than Rd in all species. However, despite some variation between the species in the level of light inhibition of respiration, no relationship was observed between the level of inhibition and the rate of photosynthesis. Similarly, the level of inhibition was not correlated with the relative growth rate. Our results support the suggestion that rates of leaf respiration in the light are closely associated with rates in darkness.     

Genome relationships in polyploid Poa pratensis and other Poa species inferred from phylogenetic analysis of nuclear and chloroplast DNA sequences.

The genus Poa comprises approximately 500 species that occur throughout the world, including the widely grown Kentucky bluegrass (P. pratensis L.). Hybridization and polyploidization have played a prominent role in the evolution of this complex genus, but limited information is available regarding genome relationships in Poa. Thus, we amplified, cloned, and compared the DNA sequences of 2 nuclear genes (CDO504 and thioredoxin-like protein) and 2 chloroplast genome loci (ndhF and trnT-trnF) from 22 Poa species. Four distinct classes of sequences corresponding to 4 putative homoeologous loci from each nuclear gene were found within polyploid P. pratensis. Nuclear sequences from 15 other Poa species were found to group with at least 1 P. pratensis homoeolog, whereas 6 species displayed sequences not present in P. pratensis. The nuclear genome phylogenies presented here show the first evidence of diverse and related genomes in the genus Poa.     

Leaf-Associated Bacterial and Fungal Taxa Shifts in Response to Larvae of the Tree Hole Mosquito, <Emphasis Type="Italic">Ochlerotatus triseriatus</Emphasis>

Larvae of the eastern tree hole mosquito, Ochlerotatus triseriatus (Say), and related container-breeding species are known to feed upon substrate-associated microorganisms. Although the importance of these microbial resources to larval growth has been established, almost nothing is known about the taxonomic composition and dynamics of these critical microbial food sources. We examined bacterial and fungal community compositional changes on oak leaves tethered in natural tree hole habitats of O. triseriatus. We eliminated larvae experimentally in a subset of the tree holes and examined 16S rDNA gene sequences for bacteria and ergosterol concentrations and 18S rRNA gene sequences for fungi collected from leaf material subsamples. Leaf ergosterol content varied significantly with time, but not treatment. Principal component analysis (PCA) was used to compare microbial taxonomic patterns found in leaves incubated with or without larvae present, and we found that larval presence affected both bacterial and fungal groups, either from loosely attached or strongly adherent categories. Bacterial communities generally grouped more tightly when larvae were present, and class level taxa proportions changed when larvae were present, suggesting selection by larval feeding or activities for particular taxa such as members of the Bacteroidetes, Alphaproteobacteria, and Betaproteobacteria classes. Fungal taxa composite scores also separated along PC axes related to the presence of larvae and indicated larval feeding effects on several higher taxonomic groups, including Saccharomycetes, Dothideomycetes, and Chytridiomycota. These results support the hypothesis that larval mosquito feeding and activities altered microbial communities associated with substrate surfaces, potentially leading to decreased food value of the resource and affecting decomposition of particulate matter in the system.