草酸钙结晶在几种凤仙花属植物中的特征及其分类学意义

首次研究了7种凤仙花属(ImpatiensL.)植物茎的解剖学及细胞组织中草酸钙结晶的特征.结果表明,7种凤仙花属植物茎的解剖学结构非常近似,而茎中草酸钙结晶特征则差异显著,7种凤仙花属植物茎中均有草酸钙针晶,根据草酸钙结晶形态特征的不同,将针晶分为3种类型,即针晶束、针晶簇和散针晶.其中,黄金凤、长角凤仙花、锐齿凤仙花和红纹凤仙花有针晶束分布,而湖北凤仙花、紫花黄金凤和窄萼凤仙花则无针晶束分布,只有针晶簇或散针晶分布;此外,针晶的形态、长度、排列方式及丰富程度等在不同的物种中亦有差异.草酸钙结晶特征对凤仙花属植物的分类具有一定的科学意义.     

Comparisons of genetic diversity in a narrow endemic, Impatiens hypophylla, and in its widespread congener, I. textori (Balsaminaceae)

Genetic diversity in two species of Impatiens in Korea was investigated using starch gel electrophoresis. Impatiens hypophylla is a rare species endemic to southwestern Japan and southeastern Korea, whereas I. rextori is widespread in East Asia. Impatiens textori has considerably higher genetic diversity than I. hypophylla . For example, mean values of genetic diversity within populations (He) of I. textori and I. hypophylla were 0.206 and 0.102, respectively. The high outcrossing rate (mean 1 = 0.89), abundance and widespread distribution, and large population size may be factors responsible for the maintenance of high levels of genetic variation in I. textori . Analyss of fixation indices indicated that considerable population substructuring within populations of I. hypophylla , partly resulting from inbreeding and/or genetic drift in small populations coupled with limited gene flow (mean F_IS= 0.699). However, the degree of population divergence observed in I. hypophylla (mean G_ST= 0.059) was considerably lower than that in other plants with similar life history traits. It is supposed that similar selection at populations of I. hypophylla examined might maintain similar gene frequencies in isolated populations.     

Pastoralism, plant conservation, and conflicts on proliferation of Himalayan knotweed in high altitude protected areas of the Western Himalaya, India

The conservation policy of banning pastoral grazing, and subsequently emerging conflicts between conservationists and pastoral communities regarding the proliferation of Himalayan knotweed (Polygonum polystachyum), was studied in the Valley of Flowers National Park, a high altitude protected area of the Western Himalaya, India. A total of 10 habitat types identified in the study area were sampled using quadrats along an altitudinal gradient between 3000 and 4500 m. Plant species richness decreases with altitude and also varies across habitat types. The highest density of P. polystachyum and its associated species, Impatiens sulcata, was found between 3300 and 3500 m in the disturbed habitat types, viz., bouldery areas, fragmented treeline zone, avalanche-prone areas and eroded slopes. Eradication of P. polystachyum from the national park by managers is not going to serve any meaningful purpose to the long-term conservation; rather it initiates soil erosion and instability, hindering the establishment of natural plant communities.     

Hybridization and speciation in the carabid beetles of the subgenusOhomopterus (Coleoptera, Carabidae, genusCarabus)

Natural hybridization among wingless carabid beetles of the subgenusOhomopterus (Carabidae, genusCarabus) is reviewed, and its significance in the evolution of this subgenus discussed. Natural hybridization occurs between parapatric species of similar size. Two case studies of natural hybridization suggest that natural hybridization could have affected the evolution of this subgenus in different ways. When there is a large difference in genital morphology between hybridizing species, interspecific copulation often results in genital injuries that causes mortality of copulating individuals, and hence reduces the fitness of hybridizing individuals greatly. In such a case, hybridization may be effective in maintaining the parapatric distribution of the two species, and in the long term, may promote reinforcement selection for traits which are effective in prezygotic reproductive isolation. When the morphological difference in genitalia is not so large as to cause genital injury, a hybrid population may be established at the intermediate zone between two parental species, provided that the immigration rates of the two species into the intermediate zone are small. Thus, natural hybridization may have contributed to both divergence and reticulate evolution in this subgenus.     

云南凤仙花属一新种及一新记录种

报道了在云南西南部发现的凤仙花属一新种——滇红凤仙花（Impatiens quintadecimacopii G.W.Hu&Q.F.Wang）和一新记录种——伸展凤仙花（I.porrecta Wall.ex Hook.f.&Thomson）。这两个种在形态上很相似,但在花色、侧萼片形状、旗瓣形状和蒴果颜色上明显有别。根据形态特征,这两个种应属于凤仙花亚属（I. subg.Impatiens）单花组（I. sect.Uniflora）。结合核糖体DNA内转录间隔区序列（ITS）与叶绿体atpB-rbcL间隔区序列开展系统发育分析,结果进一步确认了这两个种关系紧密,以及它们在单花组内的系统位置。     

Seed Morphology of Impatiens L. (Balsaminaceae) and Its Taxonomic Significance

The seed surface of 12 species of Impatiens L. from Mt. Omei was observed under SEM for the first time. The important characters used in the paper include cell specialization on seed surface, arrangement pattern of the cells, the degree of the cell elevation, chalazal zone morphology and appendix at the tail of the seed. According to these characters, the seed surface morphology of 12 species can be divided into two types: 1. the seed without conspicuous differentiation of surface cells, laevigate on the surface, represented by I. wilsoni; the seeds of species indicated by 3-colpate pollen grains are expected to belong to the type. 2. the seed with the large cell elevation at different levels, surface scabrous, represented by the other 11 species; most species with 4-colpate pollen have this kind of seeds. The results verify that the seed morphology of the genus can supply characters significant to taxonomy of the genus at species level. The evolution of seed surface of Impatiens has close correlation with that ofthe flower and pollen morphology.     

云南省凤仙花属(凤仙花科)2新记录种

报道了云南省凤仙花科(Balsaminaceae)凤仙花属(Impatiens L.)植物2新记录,即睫毛萼凤仙花(I.blepharosepala Pritz.ex Diels)和红雉凤仙花(I.oxyanthera Hook.f.),并提供了形态描述及其图片,凭证标本保存于重庆三峡学院生命科学与工程学院植物标本馆。该报道的睫毛萼凤仙花花色为白色,红雉凤仙花植株茎、叶皆被微柔毛,茎有分枝,小枝细,丰富了2个物种的形态描述。     

Study of two species of mussels, Mytilus trossulus and Mytilus galloprovincialis (Bivalvia, Mytilidae) and their hybrids, using PCR markers, in Peter the Great Bay of the Sea of Japan]

Bivalve mollusks of the genus Mytilus (M. trossulus and M. galloprovincialis) occurring in Peter the Great Bay of the Sea of Japan were first studied in Russia. A region of nonrepetitive sequences of the gene encoding the polyphenolic adhesive protein bissus was used as a species-specific genetic marker. After amplification using specific primers, a 126-bp fragment was found to amplify in all representatives of M. galloprovincialis collected from driftwood in the gulf Posset (the southwestern part of Peter the Great Bay). M. trossulus specimens from the same region were shown to have a 168-bp fragment. In Vostok Gulf (the eastern part of Peter the Great Bay), both artificially grown mussels and those from natural habitats contained a 168-bp fragment or two fragments (126- and 168-bp) that corresponded to a hybrid form between the above species. The possibility of using this genetic marker to identify closely related Mytilus strains and their hybrids in similar habitats, near the Primorye coast in particular, was demonstrated. The presence of approximately 9% of hybrid specimens confirms that a zone of hybridization between M. trossulus and M. galloprovincialis may exist in this region.     

Impatiens brittoi (Balsaminaceae) sp. nov. from the southern Western Ghats,India

The new species Impatiens brittoi (Balsaminaceae) allied to I. herbicola Hook. f., is described from the Idukki biodiversity zone of the Western Ghats of India. Detailed notes on morphology, key diagnostic characters, distribution, pollen morphology, conservation status and colour photographs are provided for the identification of the new species.     

Gene flow across a climatic barrier between hybridizing avian species, California and Gambel's quail (Callipepla californica and C. gambelii)

Allopatric species commonly interbreed in a restricted margin between their ranges. The particular factors that permit interbreeding between species determine the extent of hybridization and its significance for evolution and conservation. Using California quail and Gambel's quail (Callipepla californica and C. gambelii) that naturally hybridize in a narrow region between relatively mesic and xeric environments, I assessed the exchange of genetic and phenotypic traits in relation to vegetative and climatic features (temperature and precipitation) that characterize the area of range overlap, and I examined genetic and phenotypic traits within the hybrid zone over a five-year period in relation to variation in precipitation. Using microsatellite markers, this study reveals that genetic, plumage, and morphometric traits are tightly associated with vegetation, rainfall, and temperature profiles through the abrupt transition from one parental species to the other across the hybrid zone. Results show that the hybrid zone has remained clinal, stationary, and bounded over the five-year study period. There was no evidence of introgression outside the narrow hybrid zone. Interannual climatic fluctuations are associated with internal hybrid zone dynamics but did not alter the shape and position of the zone. A transect through the hybrid zone revealed rapid and episodic genetic mixing within the zone. Possible long-term consequences of this restricted hybridization for the evolution of the two parental species are discussed in the light of changing environments.     

Spread of alien invasive Impatiens balfourii in Europe and its temperature,light and soil moisture demands

Impatiens balfourii was introduced in the beginning of the 20th century from the Himalayas to Southern Europe where it was able to establish. In recent years an increasing number of more northern situated occurrences were recorded. An overview about the current distribution of Impatiens balfourii in Europe is given and new records for Germany are presented. To explore the range of potential habitat conditions, vegetation relevés and autecological experiments were conducted. Gas exchange measurements showed an optimum of net photosynthesis at 24–32 °C and light saturation above 700 μmol m⁻¹ s⁻¹ PPFD without any signs of photoinhibition. A moisture gradient experiment showed that Impatiens balfourii prefers fresh soils of moderate dampness. In contrast to the native I. noli-tangere and to the alien species I. glandulifera and I. capensis, which prefer moister or even wet habitats, Impatiens balfourii resembles in its soil moisture demands the alien Impatiens parviflora which originates also in Central Asia and which is invasive in Europe. But in contrast to I. parviflora and to all other established Impatiens species in Europe, I. balfourii is able to colonize even open habitats with high light intensities. Against this background, a further expansion of Impatiens balfourii in Europe appears to be likely.     

Conflicts between a fungal entomopathogen, Zoophthora radicans, and two larval parasitoids of the diamondback moth

Zoophthora radicans (Zygomycetes: Entomophthorales), Diadegma semiclausum (Hymenoptera: Ichneumonidae), and Cotesia plutellae (Hymenoptera: Braconidae) are all natural enemies of the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae). Adult C. plutellae are not susceptible to Z. radicans infection but the pathogen can infect and kill adult D. semiclausum. Infection of adult D. semiclausum prior to exposure to P. xylostella host larvae significantly reduced the number of parasitoid cocoons subsequently developing from the host larvae. Although Z. radicans infection of P. xylostella larvae prior to parasitism by D. semiclausum or C. plutellae always resulted in the death of the immature parasitoids, neither species discriminated between healthy and Z. radicans-infected host larvae in an oviposition choice experiment. However, host larvae recently killed by Z. radicans were always rejected by D. semiclausum but sometimes accepted by C. plutellae. At 20 degrees C, egg to pupa development took 6.7 and 7.8 days for D. semiclausum and C. plutellae, respectively. C. plutellae parasitism significantly increased host instar duration but D. semiclausum parasitism did not. Cadavers of P. xylostella larvae parasitized 1 day prior to fungal infection showed no reduction in Z. radicans conidia yield. However, cadavers of larvae parasitized 3 days prior to fungal infection demonstrated a marked decrease in Z. radicans conidia yield. Z. radicans infection of P. xylostella larvae < or = 4 days after parasitism resulted in 100% parasitoid mortality; thereafter, the reduction in parasitoid cocoon yield decreased as the time between parasitism and initiation of fungal infection increased. The extended duration of the host larval stage induced by C. plutellae parasitism increased the availability of the parasitoid to the pathogen. Estimates of interspecific competition indicated a similar pattern for the interaction between Z. radicans and each species of parasitoid.     

Long tandem arrays of complex repeat units in Chironomus telomeres.

A cloned 340-bp DNA fragment excised by EcoRI from the Chironomus pallividittatus genome has been localized to the telomeres by in situ hybridization as well as to connectives between telomeres. No hybridization was observed in other regions of the chromosomes. Another cloned EcoRI fragment, 525 bp long has also been studied. This represents a partial duplication of the 340-bp sequence. Genomic blot hybridization experiments show that the 340-bp sequence is a representative monomeric unit of tandemly repeated arrays which account for 1.2% of the Chironomus genome, on average 300 kb per telomere. The repeat unit contains two types of subrepeats each present twice per repeat unit. Northern blot hybridization experiments show that the telomere-associated sequences are transcribed into a discrete RNA species approximately 20 kb in size. The evolution of this telomere-associated DNA is discussed.     

Inter-species hybridization among Neotropical cats of the genus Leopardus, and evidence for an introgressive hybrid zone between L. geoffroyi and L. tigrinus in southern Brazil

Natural hybrid zones between distinct species have been reported for many taxa, but so far, few examples involve carnivores or Neotropical mammals in general. In this study, we employed mitochondrial DNA (mtDNA) sequences and nine microsatellite loci to identify and characterize a hybrid zone between two Neotropical felids, Leopardus geoffroyi and L. tigrinus, both of which are well-established species having diverged from each other c. 1 million years ago. These two felids are mostly allopatric throughout their ranges in South America, with a narrow contact zone that includes southern Brazil. We present strong evidence for the occurrence of hybridization between these species and identify at least 14 individuals (most of them originating from the geographical contact zone) exhibiting signs of interspecific genomic introgression. The genetic structure of Brazilian L. tigrinus populations seems to be affected by this introgression process, showing a gradient of differentiation from L. geoffroyi correlated with distance from the contact zone. We also corroborate and extend previous findings of hybridization between L. tigrinus and a third related felid, L. colocolo, leading to an unusual situation for a mammal, in which the former species contains introgressed mtDNA lineages from two distinct taxa in addition to its own.     

Effect of Temperature on Germination in Northernmost Populations of Culcita macrocarpa and Woodwardia radicans

Abstract: Spore germination of Culcita macrocarpa C. Presl and Woodwardia radicans (L.) Sm. from nine populations at the northern limit of their distribution, in the northwest Iberian Peninsula, was investigated. In a first experiment, population type and temperature (10, 15, 20, and 25 °C) were both found to affect germination percentage and germination time significantly in both species. There were also significant interactions between the two factors with respect to the percentage germination of C. macrocarpa and the germination time of W. radicans. In C. macrocarpa there was an outstanding increase in germination time at 15 °C and, above all, at 10 °C, whereas in W. radicans the most remarkable result was the existence of two populations with especially low germination percentages. In a second experiment, germination of 20 individuals from each population of W. radicans was compared with similar inter-population differentiation. Although its variability possibly has a genetic basis, these species are able to germinate successfully, and it seems probable that the season in which it occurs depends more on spore release than on thermal conditions in the populations. The effect of temperature on germination in both species does not explain their coastal distribution. Temperature is probably more important in limiting other stages of the life cycle.     

Rodent species diversity in relation to altitudinal gradient in Northern Serengeti,Tanzania

Rodents are among the successful small mammals in the world. In species richness, rodents outnumber other mammalian orders owing partly to their capability to exploit many different habitats. Their diversities have been influenced by many factors including the altitude. This study assessed rodent diversity across the two altitudinal zones, that is, lowland western zone and highland eastern zone, in the Serengeti ecosystem, Tanzania. Capture‐Mark‐Recapture studies were undertaken in November 2009 and April 2010 using live traps in the ecosystem to compare variations in species diversity of rodents in the two zones of the ecosystem. Eight (8) rodent species were recorded in each zone area. However, species richness was higher in crop land and woodland areas than in grasslands in each zone. The two zones comprised of different species diversities for which Rényi Diversity profiles indicated the higher diversity in the eastern zone than the western zone although the difference was not significant (P > 0.05). Differences between the eastern and western zones could be attributed to the altitudinal gradient whereby the east was at a higher elevation than the west. Maintenance and management of wildlife corridors will assist migration of rodents between the two zones and enhance continuous gene flow.     

十四种凤仙花属植物种皮微形态特征及其分类学意义

通过扫描电镜对凤仙花属(Impatiens)14种植物的种子表皮微形态特征进行了观察。根据种皮表面纹饰及衍生物的特点,将该属植物的种皮微形态特征划分为4种类型,即光滑型、颗粒型、网状型和隆起型,后两者又可细分为若干亚型,其中负网状亚型和网状-丘状隆起亚型为首次报导。研究表明,14种凤仙花属植物种子表皮微形态特征差异显著,它们作为属内种的分类鉴别特征具有重要价值;种子表皮的微形态学特征与其植物体的部分表型特征具有相关性,在一定程度上反映了属内类群的分化。     

Distribution, hybridization and variation in the Israeli landsnail Levantina (Pulmonata: Helicidae)

The rock-dwelling landsnail Leuantinu is represented in Israel by two species, caesareana and hierosolyma . They are both found abundantly in Mediterranean, steppe, semi-arid and extremely arid habitats, and are probably ancient elements in the Israeli fauna. Their common borderline shows no association with altitude, rainfall, temperature, climatic zones, lithology, phytogeography, or the distribution of predators. The possiblity that one species is actively displacing the other, and that the position of the borderline is temporary, is rejected on grounds both of previous research and of fossil finds.
A narrow hybrid zone occurs in most places along the borderline. Laboratory experiments show that these hybrids are inferior to the parent species in viability and fecundity, and that assortative mating of the two parent species occurs in a mixed population. Hybridization may perhaps be maintained because selection favours the individual that will mate with its own species whenever it can tind one, but is capable of mating with other species when it cannot. In these conditions, hybridization is not a waste of reproductive energy.
Certain morphological changes occur in the vicinity of the hybrid zone. Far from the zone, caesareana resembles hierosolyma in shell-height, shell shape and genitalia; approaching the hybrid zone it diverges from hierosolyma in these characteristics and develops a distinct variant, caesareana var. werneri . This divergence may represent an accumulation of isolating mechanisms in the proximity of the hybrid zone, and thus be a case of reproductive character displacement. If indeed it is, then it differs from most described cases of character displacement in that the species are parapatric, not sympatric, and the displaced character is found not only at the common frontier but also from 2–12 km into the allopatric zone.     

New Plants from the Hengduan Mountains

Two new species of Impatiens (Balsaminaceae) and two new species of Compositae from the Hengduan Mountains of China are described and illustrated.They are I. muliensis, I. hengduanensis, Aster zayuensis and Anaphalis batangensis.     

Testing Bergmann's rule in the presence of potentially confounding factors: a case study with three species of Galerida larks in Morocco

Aim  To test Bergmann's rule (which predicts a larger body size in colder areas within warm-blooded vertebrate species) in three partially sympatric species of larks ( Galerida theklae , Galerida cristata and Galerida randonii ) that occur in Morocco.
Location  Morocco.
Methods  Restriction fragment length polymorphism techniques applied on cytochrome b haplotypes were used to discriminate G. cristata and G. randonii , and to investigate the effects of interspecific hybridization in their contact zone. A comprehensive statistical framework was then designed to test Bergmann's rule in our three Galerida species (using altitude as a proxy for cold temperatures), while controlling for the possible influence of interspecific hybridization and competition and accounting for spatial autocorrelation. The method we propose is conservative in the sense that potentially confounding factors are adjusted so as to maximize their influence on the variable of interest.
Results  Bergmann's rule was strongly supported in G. theklae and G. randonii . However, body size did not respond to altitude in G. cristata , a result that was not simply explained by species-specific differences in geographical ranges and altitudinal span. In G. cristata , we detected a tendency for body size to increase with aridity, in agreement with an alternative definition of Bergmann's rule. However, since G. cristata also hybridizes with G. randonii in a contact zone located in the most arid part of the range of G. cristata , we could not tease apart the relative contribution of selection and hybridization in driving this pattern.
Main conclusions  This study highlights the need for careful statistical designs that allow meaningful variables to be picked out from large sets of potential factors. When taking these factors into account, we found that Bergmann's rule was still strongly supported in two out of the three species examined.