Patterns of allozyme and morphological differentiation in the Carex flava complex (Cyperaceae) in Fennoscandiaxs

Allozyme and morphological differentiation patterns within the Carex flava complex in Fennoscandia were described by means of multivariate analyses. As a result of these studies, and considering also data on ecology, distribution and hybridization, the following taxa were recognized: C. flava with no infraspecific taxa, C. lepidocarpa with two subspecies, ssp. lepidocarpa and ssp. jemtlandica, C. demissa with no infraspecific taxa, and C. oederi with three varieties, var. oederi , var. bergrothii , and var. pulchella. Carex lepidocarpa ssp. jemtlandica was allozymically divergent from ssp. lepidocarpa , indicating a long period of isolation of the two subspecies. A poor morphological separation in some localities is apparently due to secondary contacts in connection with recolonization of Fennoscandia after the last ice age, resulting in the formation of fertile hybrids and back-crosses. The subdivision of C. oederi into three varieties is supported by ecological data and it is suggested that they have originated by parallel ecotype formation under similar selective regimes in different areas. However, the varietal limits are not supported by differentiation in neutral (allozyme) characters. A phylogenetic hypothesis was constructed by means of neighbour-joining based allozyme data and it was indicated that C. demissa may be more closely related to C. lepidocarpa than to C. oederi. Previous treatments that have reduced the C. flava complex to one or two species may have been based on inappropriate species concepts, too coarse methods of analysis of morphological data, ignorance of patterns of co-occurrence and hybridization, or a combination of these factors.     

Morphological variability of Carex spicata Huds. utricles among plant communities

Differentiation in the size and number of seeds among populations or particular individuals of a given species may depend on genetic features and environmental conditions. The objective of our study was to answer two questions: whether any differences exist in the size and shape of utricles among Carex spicata populations growing in several plant communities and whether the hypothesized differences remain constant in ‘common garden’ conditions (i.e. if the sedges grown in different plant communities are evolving distinctly separate ecotypes). We studied utricle morphological traits (projected area, width, length, W/L ratio and projected perimeter) and number of utricles per spike collected from plants grown in five different plant communities (natural sites) and from plants transferred to common garden conditions. C. spicata utricles showed significant variability of morphological traits that depended on the plant community of origin. Among five plant communities, the largest utricles were found in Agropyron repens–Urtica dioica and Convolvulo arvensis–Agropyretum repentis communities, while the smallest ones were in plants from the Lolio-Plantaginetum community. The similarity of the analyzed populations regarding sedge utricle traits corresponded to the similarity of plant communities where the populations had grown. Moreover, the differences in utricle traits collected from natural conditions remained stable in common garden conditions. This indicated that differences in traits among utricles had a physiological dependence on different biotope conditions or different interspecific interactions prevailing in the particular plant communities. The relationship between the similarities in the diaspores of the populations studied and the similarities in the ecological conditions of the communities may also indicate that the variability of utricles is important for evolution and adaptation.The results support the hypothesis that C. spicata populations in different communities are producing separate ecotypes, i.e. specific species forms with genetically fixed traits adapted to narrowly determined habitat conditions.     

The taxonomic position and derivation of Cerastium adnivale Chiov. (Caryophyllaceae)

Detailed studies of comprehensive herbarium material confirmed that the afroalpine Cerastium adnivale Chiov. is too indistinctly delimited from the earlier described C. octandrum Hochst. ex A. Rich, to be given more than varietal rank. The restricted distribution of var. adnivale on only some of the high mountains harbouring C. octandrum s. lat. as well as results of experimental cultivation show that the reduced pubescence of the former cannot be due to environmental influence alone but must result from genetic differences. The derivation of var. adnivale from C. octandrum s. lat. is discussed.     

Variations in shape-sensitive restriction points mirror differences in the regeneration capacities of avian and mammalian ears

When inner ear hair cells die, humans and other mammals experience permanent hearing and balance deficits, but non-mammalian vertebrates quickly recover these senses after epithelial supporting cells give rise to replacement hair cells. A postnatal decline in cellular plasticity appears to limit regeneration in mammalian balance organs, where declining proliferation responses are correlated with decreased spreading of supporting cells on artificial and native substrates. By culturing balance epithelia on substrates that differed in flexibility, we assessed spreading effects independent of age, showing a strong correlation between shape change and supporting cell proliferation. Then we made excision wounds in utricles cultured from young and old chickens and mice and compared quantified levels of spreading and proliferation. In utricles from young mice, and both young and old chickens, wounds re-epithelialized in <24 hours, while those in utricles from mature mice took three times longer. More cells changed shape in the fastest healing wounds, which accounted for some differences in the levels of proliferation, but inter-species and age-related differences in shape-sensitive restriction points, i.e., the cellular thresholds for shape changes that promote S-phase, were evident and may be particularly influential in the responses to hair cell losses in vivo.     

我国土壤动物与土壤环境要素相互关系研究进展

土壤动物与土壤生态系统的环境要素密切相关,探明土壤动物与环境要素之间的相互关系对深刻认识土壤生态系统的运行机制、评价土壤生态系统功能具有重要意义.影响土壤动物的环境要素可以分为土壤性质和土壤外部环境两方面,前者主要指土壤基本理化性质、土壤水分和土壤污染状况,后者包括植被、土地利用、地貌和气候等环境要素.本文从以上角度对我国土壤动物与土壤环境要素关系研究进行总结和归纳,认为当前我国相关研究中主要存在以下若干问题：与环境指示作用整合性研究较少,研究方法有待改进,对环境要素的综合性及其时空变异性认识不足.并提出了相应的建议：与实际研究需要相结合,借鉴国外先进方法经验,进行多要素综合研究以及开展大区域长期监测等.     

Studies in the Goodeniaceae and the Brunoniaceae with a discussion of their relationship to Asteraceae and Calyceraceae

The relationships between Asteraceae, Calyceraceae, Goodeniaceae, and Brunoniaceae are discussed, and some SEM-observations of microcharacters within the two latter families are presented. Based on morphological evidence neither Goodeniaceae s.str. nor Goodeniaceae s.lat. (i.e., incl. Brunonia) appear to be the putative sister taxon of Asteraceae. A cladistic analysis demonstrates that Brunonia australis may constitute a separate, monotypic family or alternatively be deeply nested within Goodeniaceae s.lat Brunonia shares a number of potential synapomorphies with Asteraceae. Of special interest are the peculiar hairs and feathery pappus bristles which very much resemble those found within Asteraceae subfam. Barnadesioideae. However, studies with SEM disclose that these structures rather constitute autapomorphies for the taxa in question. In conclusion, Calyceraceae remain to be the best sister candidate of the sunflower family.     

Chromosome counts in the Carex flava complex (Cyperaceae) in Finland

Chromosome numbers from 17 Finnish populations of six taxa in the Carex flava complex were examined. Special attention was given to taxa claimed to be endemic to Fennoscandia. The meiotic counts for C. flava n = 30, C. viridula var. viridula n = 35 and var. pulchella n = 35 are in accordance with previous reports. The counts for C. jemtlandica n = 34, C. bergrothii n = 35, and C. kotilaini n = 34 are new. The hybrid C. flava × kotilaini reveals severely disturbed meiosis with many uni- and multivalents. The results are briefly discussed in relation to morphological data. Carex jemtlandica should evidently be included in C. lepidocarpa. Carex bergrothii and C. kotilaini belong to the polymorphic C. viridula , but the latter probably consitute a specific cytotype.     

Ascomycetes on Myrica gale in Sweden

The Ascomycete flora on Myrica gale has been investigated, mainly on the basis of Swedish material. It is found to be largely host specific. Four Discomycetes and nine Pyrenomycetes s. lat. are recorded as true, ± exclusive Myrica fungi; ten plurivorous Pyrenomycetes have occasionally been met with. The mycoflora on Myrica gale seems to be of a rather recent origin, composed of fairly modern species. Six new names are published: Gibbera gemmarum sp. nov., G. minutissima sp. nov., Melanomma myricae sp. nov., Semisphaeria sigmundii gen. nov. et sp. nov., Stomiopeltis myricae sp. nov., and Trichopezizella myricae comb. nov.     

Comparative study of dark respiration in plants inhabiting arctic (Wrangel Island) and temperate climate zones

Comparative analysis of dark respiration was carried out for 18 plant species inhabiting arctic zone (Wrangel Island, lat. 71° N) and temperate zone (Leningrad oblast, lat. 59° N). For 15 pairs of species examined, the Stocker’s rule was proved valid; i.e., respiration rates of identical species were equal at average temperatures of their natural habitats. The concept of respiratory features in boreal and mountain plants is described in its historic development. The possible causes for controversial data are explained. It is concluded that gas exchange measurements in natural plant habitats are the only valid means for characterizing plant respiration. Only such measurements should provide the basis for the discussion of global climate changes.     

Growth of a dissociated, filamentous stage of Codium species in laboratory culture

Unialgal cultures were established from isolated utricles for all five Codium species occurring in the British Isles and growth studies performed under different conditions of temperature (10-30 °C), photon irradiance (0-175 μmol m-2 s-1) and salinity (0-100% seawater growth medium). The species studied were C. fragile ssp. tomentosoides, C. fragile ssp. atlanticum, C. adhaerens, C. bursa, C. tomentosum and C. vermilara. All cultures developed into growth forms comprised of branched, dissociated, coenocytic filaments. All grew rapidly in culture, although the conditions for optimum growth sometimes differed for the individual entities. The development of typical Codium plants, with utricles, similar to the parental material, occurred only occasionally. The rapid growth of the dissociated, filamentous forms in laboratory culture led to the provision of sufficient quantities of plant material to enable detailed studies to be made of the lectins present in several of the species. This revised version was published online in August 2006 with corrections to the Cover Date.     

The seashore sedges of the Russian Kola Peninsula: How many species?

A necessary basis for environmental protection is thorough knowledge of the biodiversity to be protected. Setting conservation priorities in taxonomically complex groups is an especially difficult task. The seashore sedges of the Carex salina group (Cyperaceae) of the Russian White and Barents Seas form important parts of the coastal ecosystems and include species listed as rare and endangered. However, their taxonomy is poorly understood and supposed to be blurred by hybridization, also including the closely related C. aquatilis and possibly other species of sect. Phacocystis (C. bigelowii, C. nigra s. lat.). We address the taxonomic situation in the C. salina group in the Kola Peninsula with emphasis on taxa of supposed hybrid origin (C. salina and C. recta coll.). We analyzed 92 plants from 28 sites for 101 amplified fragment length polymorphisms (AFLPs) and 10 morphological characters. The plants referred to three supposedly “pure” species (C. aquatilis, C. paleacea and C. subspathacea) formed different extreme parts of the morphological and molecular variation. These species could be discriminated by a combination of morphological characters. The two taxa of proposed hybrid origin had extremely variable morphology and could not be clearly distinguished from each other or from the supposedly “pure” species. Our results demonstrate extensive gene flow between all taxa, suggesting that the entire C. salina group including C. aquatilis acts as a single large biological species.     

PROBLEMS WITH TESTING INBREEDING AVOIDANCE: THE CASE OF THE COLLARED FLYCATCHER

Four year's data on collared flycatchers, Ficedula albicollis, breeding in a nestbox plot on the island of Gotland, Sweden, was used to investigate whether individuals avoid mating with close kin (i.e., parents or sibs). Only one case of close inbreeding (0.5% of all pairs) was observed during the years of study. The observed frequency of close inbreeding was compared to expected frequencies based on two different null models. Assuming no inbreeding avoidance behaviors (e.g., dispersal or kin recognition), but taking into account the fact that mortality, and different arrival and pairing times of individuals reduce the probability of mating with close kin, the expected frequency of close inbreeding is 10% and 15% for female and male recruits (i.e., born in the study plot), respectively. However, assuming mating to be random within the study plot reduced the expected frequency of close inbreeding to 1% or less for both males and females. Consequently, conclusions drawn concerning inbreeding avoidance depend on the null model used. Contrasting estimated costs of tolerating close inbreeding with those of avoiding it (by dispersal to other plots), however, suggests that the costs of avoiding close inbreeding are substantially greater than those of tolerating it. Therefore, although inbreeding avoidance cannot be rejected as a cause of dispersal of this species, it is not the primary cause, and particularly not for sex-biased dispersal. The general problems of investigating inbreeding avoidance are discussed. It is argued that all previous null models based on random mating in finite populations produce expected frequencies of close inbreeding that in fact include inbreeding avoidance, since they implicitly assume random dispersal within a finite population. Thus, comparisons between observed and expected frequencies of close inbreeding based on random mating are inadequate. The most promising method of investigating inbreeding avoidance is to experimentally study individual movements and mating preferences in the presence and absence of close kin.     

Two sorediate crustose lichens assigned to Lecanora

Nordin, A., Sundin, R. & Thor, G. 1995. Two sorediate crustose lichens assigned to Lecanora. — Nord. J. Bot. 15: 553–556. Copenhagen. ISSN 0107–055X.
Lecanora viridissima is described and L. navarrensis is reported from Sweden (Dals-land, Sodermanland, Gotland, Oland, Smiland) and Estonia (Laanema, Saarema). The latter species is reported with apothecia from one locality in Sweden. Lecanora viridissima has not been found with apothecia or pycnidia but is placed in Lecanora due to its general habit and the presence of atranorin. It is distinguished by its morphology, chemistry and habitat. Lecanora viridissima has so far only been found on the island of Gotland in Sweden.     

Silurian (Ludlow) acastid trilobites from Gotland and Scania,Sweden

Acastid trilobites from Ludlow strata on Gotland include three stratigraphically non-overlapping species ofAcastella Reed:Acastella madidipes n. sp. (Hemse Marl and Eke Beds),A. breviceps (Angelin 1851) (Burgsvik Beds), andA. amatrix n. sp. (Hamra Beds, and probably Burgsvik Beds). Type and other material ofA. breviceps (Angelin) from the Klinta Formation, Scania, is revised. Meraspid and early holaspid material ofAcastella is described. Some characters supportAcaste and allied taxa of mostly Wenlock age as a monophyletic subfamily Acastinae.Acastella as widely recognized is a grade with Devonian species more closely related to Asteropyginae than to the Ludlow type species. Baltic Ludlow-P?00ED;dolí species previously placed inScotiella Delo form a distinct group,Ewacaste n. gen., that includes a species from the uppermost Eke Beds on Gotland.     

Synchronisation of adult activity of the archaic moth, <Emphasis Type="Italic">Micropterix calthella</Emphasis> L. (Lepidoptera,Micropterigidae), with anthesis of sedges (<Emphasis Type="Italic">Carex</Emphasis> spp., Cyperaceae) in an ancient wood

Micropterix calthella L. (Micropterigidae) is a small, day-flying moth from the basal-most extant lineage of the Lepidoptera. The species name reflects its conspicuous presence on Caltha palustris L. (Ranunculaceae). However, adults also favour sedges (Carex spp., Cyperaceae), on which they gather gregariously to feed on pollen and find mates. In a UK ancient wood, the phenology of eight sedge species together with individual moth and mating pair densities were monitored from 15th April to 8th June 2009. 4841 moth sightings were recorded. Moths on Carex spikes at various developmental stages were compared with null models to test for preference patterns. Approximately 99% of individuals selected Carex spikes where dehiscing anthers were present. The sedge phenology data suggest three distinct periods of pollen production. Overlaying this with the moth data reveals moth phenology strongly linked to a suite of early and mid-season woodland sedges. Of the twenty-eight other angiosperm species (seventeen families) in flower, only Ranunculus ficaria L. (Ranunculaceae) and R. repens L. attracted moths. Adult moths kept in captivity on potted Carex flacca Schreb. for 10 days laid eggs at the plant-soil interface. When C. flacca pollen production ceased, surviving adults were moved onto freshly dehiscing anthers of potted C. pallescens L., where they survived a further 14 days. Soil-dwelling first instar larvae were observed to consume C. sylvatica Huds leaves. In a choice experiment, larvae were significantly more likely to consume C. sylvatica than Stellaria media (L.) Vill. (Caryophyllaceae) leaf material (previously noted to be favoured by larvae). Synchrony between adult moths and Carex spp., and the use of Carex by both adults and larvae, suggests sedges may be host plants for M. calthella in lowland ancient woodlands.     

Hominins, sedges, and termites: new carbon isotope data from the Sterkfontein valley and Kruger National Park

Stable carbon isotope analyses have shown that South African australopiths did not have exclusively frugivorous diets, but also consumed significant quantities of C4 foods such as grasses, sedges, or animals that ate these foods. Yet, these studies have had significant limitations. For example, hominin sample sizes were relatively small, leading some to question the veracity of the claim for australopith C4 consumption. In addition, it has been difficult to determine which C4 resources were actually utilized, which is at least partially due to a lack of stable isotope data on some purported australopith foods. Here we begin to address these lacunae by presenting carbon isotope data for 14 new hominin specimens, as well as for two potential C4 foods (termites and sedges). The new data confirm that non-C3 foods were heavily utilized by australopiths, making up about 40% and 35% of Australopithecus and Paranthropus diets respectively. Most termites in the savanna-woodland biome of the Kruger National Park, South Africa, have intermediate carbon isotope compositions indicating mixed C3/C4 diets. Only 28% of the sedges in Kruger were C4, and few if any had well-developed rhizomes and tubers that make some sedges attractive foods. We conclude that although termites and sedges might have contributed to the C4 signal in South African australopiths, other C4 foods were also important. Lastly, we suggest that the consumption of C4 foods is a fundamental hominin trait that, along with bipedalism, allowed australopiths to pioneer increasingly open and seasonal environments.     

Status of Eldana saccharina (Lepidoptera: Pyralidae), its host plants and natural enemies in Ethiopia

Surveys for sugarcane stem borers were undertaken in Ethiopia to determine the prevalence and distribution of these and their natural enemies in crops and indigenous host plants. Eldana saccharina Walker was not recovered from sugarcane, but was present in three indigenous wetland sedges, Cyperus papyrus, C. fastigiatus and C. dives in the southern, central and northern part of the country. The latter indigenous host plant was present in waterways adjacent to sugarcane on the commercial sugar estates. The tachinids Schembria eldanae Barraclough and Actia sp. were common parasitoids of E. saccharina larvae in these indigenous sedges. The braconid Dolichogenidea sp. was recovered from E. saccharina larvae in C. dives. Pathogens comprising Beauveria bassiana, Bacillus thuringiensis and Entomophthora sp., were found to be important mortality factors of E. saccharina larvae in the indigenous sedges. The occurrence of E. saccharina in Ethiopia is reported for the first time, and the host plant preferences of the borer and its indigenous natural enemies found during the surveys are recorded. In addition, its potential threat to sugarcane production in Ethiopia is discussed.     

Starting from scratch: Evolution of the lichen thallus in the basidiolichen Dictyonema (Agaricales: Hygrophoraceae)

Phylogenetic studies indicate that the basidiolichen genus Dictyonema s.lat., often thought to represent only a single genus with few species, includes several well-supported genus-level clades, all of which form associations with a unique lineage of obligately lichenized cyanobacteria (Rhizonema). In an attempt to elucidate the evolution and genus- and species-level diversification in Dictyonema s.lat., we generated 68 new sequences of the nuclear large subunit rDNA (nuLSU), the internal transcribed spacer (ITS), and the RNA polymerase II subunit (RPB2), for 29 species-level lineages representing all major clades of Dictyonema s.lat. and most of the species currently known. The multilocus phylogeny obtained via maximum likelihood and Bayesian approaches indicates the presence of five genus-level groups: a basal clade, Cyphellostereum, that is sister to the rest of the species, a paraphyletic grade representing Dictyonema s.str., and three clades representing the genera Acantholichen, Cora, and Corella. To determine the evolutionary transformations of the lichenized thallus in the group, ancestral character state reconstruction was done using six characters (lichenisation, thallus type, cortex type, hyphal sheath and haustorial type, photobiont morphology, and basidiocarp type). Our analysis indicates a progressive development of the lichenized thallus from loosely organized filamentous crusts with separate, cyphelloid basidiocarps in Cyphellostereum, to filamentous crusts with derived hyphal sheath and cyphelloid–stereoid basidiocarps partially incorporated into the lichen thallus in Dictyonema, to squamulose–foliose thalli with corticioid basidiocarps entirely supported by the lichen thallus in Cora. These results indicate a remarkable evolutionary integration of lichenized and reproductive tissues in Dictyonema s.lat., supporting the hypothesis that, at least in this case, lichenized thalli may have evolved from reproductive structures in their nonlichenized ancestors.     

Africa's wild C4 plant foods and possible early hominid diets

A small minority of Africa's wild plant foods are C4. These are primarily the seeds of some of the C4 grasses, the rootstocks and stem/leaf bases of some of the C4 sedges (especially papyrus), and the leaves of some of the C4 herbaceous dicots (forbs). These wild food plants are commonly found in disturbed ground and wetlands (particularly the grasses and sedges). Multiple lines of evidence indicate that C4 grasses were present in Africa by at least the late Miocene. It is a reasonable hypothesis that the prehistory of the C4 sedges parallels that of the C4 grasses, but the C4 forbs may not have become common until the late Pleistocene. CAM plants may have a more ancient history, but offer few opportunities for an additional C4-like dietary signal. The environmental reconstructions available for the early South African hominid sites do not indicate the presence of large wetlands, and therefore probably the absence of a strong potential for a C4 plant food diet. However, carbon isotope analyses of tooth enamel from three species of early South African hominids have shown that there was a significant but not dominant contribution of C4 biomass in their diets. Since it appears unlikely that this C4 component could have come predominantly from C4 plant foods, a broad range of potential animal contributors is briefly considered, namely invertebrates, reptiles, birds, and small mammals. It is concluded that the similar average C4 dietary intake seen in the three South African hominid species could have been acquired by differing contributions from the various sources, without the need to assume scavenging or hunting of medium to large grazing ungulates. Effectively similar dominantly dryland paleo-environments may also be part of the explanation. Theoretically, elsewhere in southern and eastern Africa, large wetlands would have offered early hominids greater opportunities for a C4 plant diet.     

猕猴肝门静脉系统和肝静脉系统的观察

以铸型方法及实体解剖观察了猕猴(Macaca mulatta) 肝的门静脉分支和肝静脉分支。猕猴肝门静脉与人、猪、兔、牛、羊等相似, 同样可将全肝分成二叶四段, 即左叶、右叶; 左外侧段、左内侧段、右内侧段、右外侧段。尾状叶的左、右部可分别隶属于左叶和右叶。猕猴肝大静脉有左外侧叶肝静脉、左内侧叶肝静脉、肝中静脉、肝右静脉及尾状叶肝静脉。此外, 作者对哺乳动物门静脉分支的规律性, 猕猴肝大静脉的命名及吻合作了讨论。