Colonization of plant rhizosphere by actinomycetes of different genera

The survival of environmental isolates of actinomycetes introduced with the seeds of agricultural plants in root-free soil and in the rhizosphere and rhizoplane was studied. Different strategies of colonization of the rhizosphere were revealed for the representatives of the genera Streptomyces, Micromonospora, and Streptosporangium, organisms typical for the moderate climate rhizosphere. The plants of winter rye (Secale cereale L.) inoculated with actinomycetes were shown to have growth advantages, while the cow clover plants (Trifolium pratense L.) had no growth advantages compared to uninoculated plants. The role of the plant component in the interaction with mycelial prokaryotes is discussed.     

Importance of <Emphasis Type="Italic">Rhus verniciflua</Emphasis> Stokes (lacquer tree) in prehistoric periods in Japan,deduced from identification of its fossil woods

In Japan, lacquered artifacts and remains of lacquer processing became common items in the early Jomon period beginning at ca. 6300 b.p. (ca. 5300 cal b.c.). However, there was no archaeobotanical evidence that Rhus verniciflua (lacquer tree), which is thought to be a prehistoric introduction from China on botanical grounds, grew in Japan until its distinction in wood structure from those of native Rhus species was clarified in 2004. Based on this new refinement in identification, 573 Rhus fossil woods so far reported from various archaeological sites in Japan were re-identified. The results showed that R. verniciflua commonly grew in middle to northern Honshu since the early Jomon period and that it may have been introduced from China with other cultivated plants before that time. During the Jomon period, R. verniciflua trees were used not just for lacquer collection, but also for building in the lowland which exploited their durability in waterlogged conditions.     

Influences on the transport and establishment of exotic bird species: an analysis of the parrots (Psittaciformes) of the world

Most studies of exotic species invasions only consider the factors that affect the establishment of populations following release, yet this is only one step on the invasion pathway. Different factors are likely to influence which species are transported and released. Here, we examine the influence of species traits on the successful transition of species through several stages in the introduction pathway (transport, release, and establishment), using parrots (Aves: Psittaciformes) as a model system. We use a species‐level supertree of parrots to test for phylogenetic auto‐correlation in the introduction process. Our analyses find that different sets of variables are related to the probability that a species enters each stage on the invasion pathway. The availability of individuals for transport and release seems to be most important for passage through these stages, but has no obvious effect on establishment following release. Rather, establishment success is higher for sedentary species, and species with broad diets.     

Gene flow in Trinidadian guppies

In 1957, guppies Poecilia reticulata from the Caroni drainage were introduced into habitat suitable for (but devoid of) guppies upstream of a waterfall in the Turure River of the Oropuche drainage. Previous allozyme studies, describing gene flow due to both sexes, showed that guppies downstream of the waterfall barrier represent an admixture of native and introduced genotypes. Using a polymerase chain reaction-restriction fragment length polymorphism assay of the highly divergent mitochondrial NADH2 gene only 12% of genotypes in the downstream population were shown here to correspond to the native matriline. The prevalence of introduced genotypes is discussed in the context of sexual conflict theory.     

Biogeographic anomaly or human introduction: a cryptogenic population of tree skink (Reptilia: Squamata) from the Cook Islands,Oceania

Archaeological and molecular data have revealed that the present day faunas of many island groups in Melanesia, Polynesia, and Micronesia are not representative of the biodiversity generated within this region on an evolutionary timescale. Erroneous inferences regarding the mechanisms of speciation and the significance of long distance dispersal in shaping the present diversity of these island systems have resulted from this incomplete diversity and distributional data. The lizard fauna east of Samoa has been suggested to derive entirely from human‐mediated introductions, a distribution congruent with biogeographic patterns for other Pacific species. Distinguishing between introduced populations and those that result from natural colonization events is difficult, although molecular data provide a useful means for elucidating population history and identifying the likely sources of introductions. We use molecular data (1726 bp of mitochondrial DNA and 286 bp of nuclear DNA) to evaluate a population of arboreal lizards from the Cook Islands and to determine whether this arboreal skink population is the sole endemic component of the lizard fauna east of Samoa or the result of human‐mediated introduction. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 318–328.     

Tri-oceanic connectivity of the supposedly cosmopolitan polychaete,Harmothoe imbricata (Annelida: Polynoidae): insights from the COI marker

ABSTRACT

In this study, we investigated the global population genetic structure of the polychaete, Harmothoe imbricata, to determine connectivity patterns within the species. We sequenced the mtDNA marker, cytochrome c oxidase I (COI) from 29 specimens sampled across three sites from the New England coast of the United States. These were supplemented with 145 archived sequences from GenBank and the Barcode of Life Database, representing 16 global populations, which encompassed three broadly defined marine biogeographic regions: the Atlantic, Pacific and Arctic. The resulting haplotype network and pairwise AMOVA results showed marked structure across all the major biogeographic regions and also provides evidence for cryptic diversity in the species. Haplotypes from Arctic populations were more closely related to each other than those from the northwestern and northeastern Atlantic. Two evolutionary divergent lineages were recovered from Los Angeles, California and Manitoba, Canada. The highest genetic diversity was observed in the Arctic populations, providing evidence for an Arctic origin for H. imbricata. While human-mediated introductions may have likely contributed to some of the genetic patterns observed in this study, future work should incorporate a nuclear DNA component which could shed more light on contemporary movement of this species across large spatial scales.     

Multiple introduction events and artificial long-distance dispersal of the exotic slug Ambigolimax valentianus in Japan

ABSTRACT

The three-band garden slug Ambigolimax valentianus, native to the Iberian Peninsula, is an exotic species distributed worldwide and was introduced to Japan into the 1950s. For control of this slug, it is necessary to elucidate its introduction sources and dispersal patterns since the introduction event occurred. However, knowledge about this slug in Japan remains poor. Thus, we attempted to estimate the origin and dispersal patterns of this slug using genetic approaches. We investigated the genetic diversity of the mitochondrial cytochrome c oxidase subunit I gene across 11 populations of A. valentianus in three prefectures in central Japan. Ten haplotypes were found in the Japanese populations, five of which were haplotypes found in foreign individuals. The same haplotypes were found in all three prefectures, whereas the average haplotype diversity was high across all populations. Significant genetic differentiation was detected among 22 of 55 population pairs, but there was no isolation by distance. These molecular results suggest that multiple introductions to Japan may have occurred in the past such that the founder effect in the early stage of introduction was diluted. Furthermore, long-distance dispersal of A. valentianus would have occurred after introduction into Japan because of human activities rather than natural dispersal.     

Translocation of the Eastern Bristlebird 1: radio‐tracking of post‐release movements

Summary Translocating birds to a new area of habitat to restore or supplement depleted populations may pose a significant threat to the translocated individuals. While for many species, translocated individuals appear to move larger distances than resident animals, species with poor dispersal capacity may be restricted in movements and translocation methods may need to accommodate differences in movements to ensure success. In this study, designed to provide insights to inform our broader programme of translocations in New South Wales, Australia, we investigated post‐release movements in the endangered, semi‐flightless Eastern Bristlebird (Dasyornis brachypterus). We predicted that movements would be minimal, with few differences between males and females, similar to published information for a resident un‐manipulated population. Following the release of 45 birds at a host location at Jervis Bay, NSW, over a 3‐year programme, we followed individuals for up to 2 weeks using radio‐tracking. The translocated birds had larger maximum movements and moved through much larger home ranges than non‐translocated individuals from the resident population. Translocated birds moved 300 m further after release when conspecifics were present. Males moved further than females and tended to have larger home ranges, although average daily displacement did not differ. We concluded that the semi‐flightlessness of the species does not result in minimal movements. Release at a small number of locations in the new habitat was considered appropriate for the species, as animals seem to move enough to find new unoccupied areas in a relatively short period. This work provided us with increasing confidence to continue with further translocations.     

植物种质资源引进风险分析方法概述

种质资源作为生物资源的重要组成部分,是培育作物优质、高产、抗病（虫）、抗逆新品种的物质基础。近年来,为满足我国种业飞速发展的需要,我国不断从国外引入大量的种质资源,种质资源相比其他植物产品携带有害生物的风险更高。种质资源引进过程中不可避免地携带有害生物,可能会带来严重危害。目前,美国、澳大利亚等国家已制定了关于种质资源的风险分析方法,但我国缺少针对种质资源有害生物统一的风险分析方法。本文分析了国际植物检疫措施标准、主要的贸易国家及我国有害生物风险分析标准方法的主要内容,针对引进种质资源过程中亟需解决的有害生物风险分析问题开展讨论,并对种质资源有害生物风险分析系统其未来展开工作提出以下建议：设置符合种质资源风险分析特性的指标;采用半定量风险评估方法对种质资源进行风险分析;根据不断的学习和实际工作的需要,对风险评估指标体系进行验证和适当修改。