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51.
长春净月潭地区土壤跳虫的生态分布   总被引:9,自引:1,他引:8  
陈鹏  田中真悟 《昆虫学报》1990,33(2):219-226
土壤动物直接参与土壤形成,它与土壤微生物的相互配合,对植物凋落物的分解起着十分重要的作用。土壤跳虫是土壤动物中最重要的类群之一。关于它的生态分布,目前国内报道不多。东北师范大学和日本九州大学合作,对长春净月潭地区的土壤跳虫进行了初步调查。  相似文献   
52.
The global distribution, abundance, and diversity of microscopic freshwater algae demonstrate an ability to overcome significant barriers such as dry land and oceans by exploiting a range of biotic and abiotic colonization vectors. If these vectors are considered unlimited and colonization occurs in proportion to population size, then globally ubiquitous distributions are predicted to arise. This model contrasts with observations that many freshwater microalgal taxa possess true biogeographies. Here, using a concatenated multigene data set, we study the phylogeography of the freshwater heterokont alga Synura petersenii sensu lato. Our results suggest that this Synura morphotaxon contains both cosmopolitan and regionally endemic cryptic species, co‐occurring in some cases, and masked by a common ultrastructural morphology. Phylogenies based on both proteins (seven protein‐coding plastid and mitochondrial genes) and DNA (nine genes including ITS and 18S rDNA) reveal pronounced biogeographic delineations within phylotypes of this cryptic species complex while retaining one clade that is globally distributed. Relaxed molecular clock calculations, constrained by fossil records, suggest that the genus Synura is considerably older than currently proposed. The availability of tectonically relevant geological time (107–108 years) has enabled the development of the observed, complex biogeographic patterns. Our comprehensive analysis of freshwater algal biogeography suggests that neither ubiquity nor endemism wholly explains global patterns of microbial eukaryote distribution and that processes of dispersal remain poorly understood.  相似文献   
53.
Microsatellites have been applied in a variety of fields, including conservation genetics. Species‐specific microsatellites are considered as more powerful genetic markers to generate an accurate genetic composition of a species itself. Accordingly, we characterized 15 polymorphic microsatellite loci from Korean goral, Nemorhaedus caudatus, one of the most endangered species in South Korea. The new markers should benefit future studies of the endangered species of other Asian gorals and their relatives for the study of genetic diversity and potential conservation management.  相似文献   
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Using the magnetic particles method, we isolated six polymorphic microsatellite loci from an apterous grasshopper, Podisma kanoi Strozhenko, which shows conspicuous structural variation in chromosomes. The isolated loci were polymorphic, with three to 10 alleles among 20 individuals. Expected heterozygosities ranged from 0.23 to 0.90. These loci can be used to examine the history of population fragmentation and the establishment of chromosomal variation.  相似文献   
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Aphids of the tribe Eriosomatini are typically associated with the tree genera Ulmus and Zelkova as the primary host, on which they induce several types of leaf gall. To elucidate evolutionary changes in the aphid–host associations and gall morphology, phylogenetic relationships were inferred using 36 species (28 in the ingroup) and based on 52 morphological characters. Phylogenetic analysis with equal character weighting led to hundreds of most‐parsimonious trees, and the strict consensus of these was poorly resolved. However, the successive weighting of characters yielded three most‐parsimonious trees. The strict consensus of these supported the monophyly of the Eriosomatini and the monophyly of most genera. Reconstruction of the aphid–host associations on the consensus tree indicated that the ancestral Eriosomatini were associated with Zelkova and that the association with Ulmus evolved twice independently. Ancestral reconstruction suggests that galls of the leaf‐roll type are ancestral to those of the completely and incompletely closed pouch type, and that each type of pouch galls evolved independently. It is suggested that despite early diversification of the Eriosomatini on Zelkova species, Zelkova‐associated eriosomatines had become extinct or survived as relict parthenogens on the secondary host due to the elimination of Zelkova in most regions since the late Tertiary. In contrast, two large genera in the Eriosomatini, Eriosoma and Tetraneura, are associated with the largest elm section Ulmus whose elements are distributed widely in Eurasia, including boreal regions. Therefore, the available evidence suggests that the present species diversity and distribution patterns of the eriosomatines have been largely affected by the diversification and extinction of their host plants during the late Tertiary and Quaternary.  相似文献   
57.
1. Natural selection favours females who can correctly assess the predation risk and hence avoid high‐risk oviposition sites and reduce the mortality rate of their offspring. In spite of the potential significance of such behaviour, relatively few studies have assessed the relationship between oviposition behaviour and predation risk. 2. The present study aimed to determine the sublethal effects of predators on oviposition site selection by gravid females, the foraging activity of larvae, and the life history traits of two mosquito species that breed in different habitats, Aedes albopictus Skuse (container breeder) and Culex tritaeniorhynchus Giles (wetland breeder). 3. Female C. tritaeniorhynchus avoided laying eggs at oviposition sites in the presence of a predator cue. In contrast, female A. albopictus laid eggs in both the absence and presence of the predator cue. 4. To examine the effects of predator cues on larval behaviour, experiments were conducted in the absence and presence of a predator cue. Although larval activity was lower in the presence of the predator cue than that in its absence in both species, C. tritaeniorhynchus responded to the predator cue more strongly than A. albopictus. Female A. albopictus that had been reared with caged predators exhibited an extended larval development period, whereas the adult C. tritaeniorhynchus reared in the presence of predators were smaller than those reared in their absence. 5. This finding might explain why C. tritaeniorhynchus avoid laying eggs in predator‐conditioned water, for example to increase the fitness of their offspring, but A. albopictus either cannot detect predator cues or are not sensitive to them.  相似文献   
58.
This study assessed the knowledge and perception of human biological materials (HBM) and biorepositories among three study groups in South Korea. The relationship between the knowledge and the perception among different groups was also examined by using factor and regression analyses. In a self‐reporting survey of 440 respondents, the expert group was found more likely to be knowledgeable and positively perceived than the others. Four factors emerged: Sale and Consent, Flexible Use, Self‐Confidence, and Korean Bioethics and Biosafety Action restriction perception. The results indicate that those who are well aware of the existence of biobanks were more positively inclined to receive the Sale and Consent perception. As a result of the need for high quality HBMs and the use of appropriate sampling procedures for every aspect of the collection and use process, the biorepository community should pay attention to ethical, legal, and policy issues.  相似文献   
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The susceptibility of members of the Anopheles sinensis Group in Korea to insecticides was evaluated under laboratory conditions using 15 insecticides currently used by local public health centers in Korea. The insecticides included eight pyrethroids, six organophosphates and a pyrazol analogue. Based on their LC50 values, the order of susceptibility of An. sinensis larvae to the insecticides was bifenthrin, chlorfenapyr, α-cypermethrin and λ-cyhalothrin, with values of 0.009, 0.04, 0.06 and 0.08 p.p.m., respectively. The least susceptibility was obtained with fenitrothion, with an LC50 of 7.7 p.p.m. In the comparative resistance test, the resistance ratios (RR) of 14 insecticides were compared to each other using two strains of members of the An. sinensis Group collected in the locality in 2001 and 2008. Anopheles spp. demonstrated higher RR to organophosphates such as fenthion, and low RR for the pyrethroids. Among the organophosphates, fenthion had the highest RR of 33.3 and 270.0 fold differences for LC50 and LC90 values, respectively. Among the pyrethroids, permethrin was observed to have the highest RR of 3.8 and 1.8 fold differences for LC50 and LC90 values, respectively. However, there were no significant differences in susceptibility to chlorfenapyr, chlorpyrifos, deltamethrin and fenitrothion. An. sinensis s. l. was more susceptible to the six insecticides bifenthrin, λ-cyhalothrin, α-cypermethrin, cypermethrin, cyfluthrin and pyridafenthion, showing 0.03, 0.06, 0.3, 0.3, 0.4 and 0.4 fold differences in resistance rates (RR LC50), respectively.  相似文献   
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