댕댕이나무(Lonicera caerulea var. edulis) 국내 잔존 집단의 유전적 다양성

Abstrllct Genetic variations in Nibea mitsukurii, N. albijfora and Pennahia argentara from different localities were assayed electrophoretically. The genetic variability in N. mirsukurii was relatively high. According to the chi-square values for heterogeneity between two localities and genetic distance (D) values, N. albijfora from the Ariake Sea and the Inland Sea or the East China Sea (D=O.OO92 in average), and N. misukurii, from Tosa Bay vs, Atsumi Bay (D=~O.OO67) were considered to be independent subpopulations, The D value in N. albifiora from the Inland Sea VS, the East China Sea was quite small (D=O.OOlO), In P. argenrara populations, the D values were also small. Further, the relationship between genetic and geographic distances observed in the three species were discussed, P. argenrata showed a positive relationship between these two factors as compared to N. mirsukurii or N, albifiora. It seemed that the lower level of genetic divergence might be due to the frequent gene flow within the large-scale and wide distributional range of the population. During the past decade the application of gel electrophoresis coupled with selective enzyme stain­ ing has shown that a large amount genetic variation exists in natural populations of many species (Allen­ dorf and Utter, 1979). Phenotypes of allozyme can be scored during most stages of their life cycle and their genetics more easily interpreted than the pro­ portional and meristic characters employed in fish taxonomy. Genetic differences among populations within a defined body of water may conceivably decrease with time, due to gene flow by migration within sub­ populations. Alternatively, genetic differentiation could become· accentuated through time, perhaps because subpopulations become increasingly associ­ ated with discrete breeding areas (Felley and Avise, 1980). The fishes of the family Sciaenidae contribute sub­ stantially to the fisheries of the warm and shallow seas and estuaries of the world. Nibea mitsukurii (Jordan et Snyder) commonly known as nibe croak­ er, extends along the coast of the Pacific Ocean from Sendai Bay in the north to Hyuga Basin (an open bay) in the south. Nibea albiflora (Richardson), commonly known as roncader, occurs in Hong­ kong, the East China Sea and northwards to Port Arthur and southern Japan. Pennahia argentata (Houttuyn), commonly known as white croaker, is widely distributed in Japanese, Korean and Chinese waters (Trewavas, 1977).

Ex situ genetic conservation of endangered Vatica guangxiensis (Dipterocarpaceae) in China

Both Hemibarbus labeo and H. medius (Cypriniformes: Cyprinidae: Gobioninae) are primary freshwater fishes and are widely distributed. As such, they provide an ideal model for phylogeographical studies. However, the similarity in morphological characters between these two species made the description of their distributions and the validation of species quite challenging. Here we employed variations in the DNA sequences of mitochondrial COI and ND5 genes (2151 bp) to solve this challenge and to study the population genetics structure of these two species. Among the 130 specimens belonging to 8 populations of H. labeo and 9 populations of H. medius from 17 drainage systems in southern China,196 variable sites (9.1% in the full sequences) falling into 50 haplotypes were identified. The haplotype diversity (h) and the nucleotide diversity (π) were 0.964 and 0.019, respectively, indicating a high level of genetic diversity and an evolutionary potential in both species. The result of neighbor-joining tree based on composite nucleotide sequences of the mtDNA COI and ND5 genes showed that the H. labeo and H. medius fell into two major clades (clade1and clade2): clade1was composed of some specimens of Oujiang River, all the specimens of Hanjiang River and Jiulongjiang River, whereas all remaining populations fell in clade2. The genetic distance between clade I and clade II was 0.036, while that between H. labeo and H. medius was 0.027. The haplotype network analyses indicated that the populations of Hanjiang River and Jiulongjiang River had relatively high genetic variation with the rest rivers. The po-pulations of Hainan Island migrated northward to Moyangjaing River. Haplotypes of the rivers of Hainan Island and Moyangjang River had relatively higher genetic variation with the Yangtze River than Pearl River. The populations of Xiangjiang River had no genetic variation with the populations of Guijiang River and Liujiang River. Analysis of molecular variance (AMOVA) indicated that the genetic variance mainly presented in individuals between geographical regions. The genetic variation of populations among regions was 71.2%, the genetic variation among populations within regions was 16.6%, and that within populations within the regions was 12.2%, indicating that most of the genetic variations resided in the populations among regions. The results of mismatch distribution and tests of neutrality suggested that in all populations, H. labeo, H. medius, clade1and clade2 were relatively stable.

Genetic Variation of the First Generation of Rodent Tuber (Typhonium flagelliforme Lodd.) Mutants Based on RAPD Molecular Markers

Phalaris minor is a noxious weed that thrives in wet soils and swamps across various habitats in Iran. Inter Simple Sequence Repeat (ISSR) markers are effective tools for assessing both intra- and inter-species genetic variations. The relationship between geographical distribution and ecological adaptation in this genus has long been debated. This study aimed to investigate the genetic diversity of P. minor populations in Iran using ISSR and Start Codon Targeted (SCoT) markers to assess genetic variation within and between populations of this taxon. A total of 11 populations of P. minor were sampled. Genomic DNA was extracted from dried leaf samples using a modified Cetyl Trimethyl-Ammonium Bromide (CTAB) protocol. Seven ISSR and two SCoT primers, selected for their reliability and polymorphism, were employed. Genetic diversity indices, the correlation between genetic and geographical distances, and genetic differentiation within and among populations were analyzed. A high level of genetic diversity was observed in P. minor populations. The highest genetic diversity (61%) was found within populations, while genetic diversity between populations accounted for 39%. Genetic distance increased with geographical distance. The observed genetic diversity in P. minor may result from genetic drift, gene flow, and adaptation to environmental conditions.

To protect the germplasm resources of Schizothorax biddulphi, we developed and used 20 pairs of polymorphic microsatellite primers to analyze the genetic diversity and structure of populations. A total of 126 samples were collected from the Qarqan River (CEC), Kizil River (KZL), and Aksu River (AKS) in Xinjiang, China. The results showed that 380 alleles were detected in 20 pairs of primers and the average number of alleles was 19.0. The effective allele numbers and Nei’s gene diversity ranged from 1.1499 to 1.1630 and 0.0962 to 0.1136, respectively. The Shannon index range suggested low levels of genetic diversity in all populations. The genetic distance between the CEC and AKS populations was the largest, and the genetic similarity was the smallest. There was a significant genetic differentiation between CEC and the other two populations. The UPGMA clustering tree was constructed based on population genetic distance, and the clustering tree constructed by individuals showed that the AKS population and KZL population were clustered together, and the CEC population was clustered separately. Also, the group structure analysis also got the same result. It can be seen that although the three populations of S. biddulphi do not have high genetic diversity, the differentiation between the populations was high and the gene flow was limited, especially the differentiation between the CEC population and the other two populations. This study not only provided genetic markers for the research of S. biddulphi but the results of this study also suggested the need for enhanced management of S. biddulphi populations.

Taenia pisiformis is one of the most important parasites of canines and rabbits. T. pisiformis cysticercus (the larval stage) causes severe damage to rabbit breeding, which results in huge economic losses. In this study, the genetic variation of T. pisiformis was determined in Sichuan Province, China. Fragments of the mitochondrial cytochrome b (cytb) (922 bp) gene were amplified in 53 isolates from 8 regions of T. pisiformis. Overall, 12 haplotypes were found in these 53 cytb sequences. Molecular genetic variations showed 98.4% genetic variation derived from intra-region. FST and Nm values suggested that 53 isolates were not genetically differentiated and had low levels of genetic diversity. Neutrality indices of the cytb sequences showed the evolution of T. pisiformis followed a neutral mode. Phylogenetic analysis revealed no correlation between phylogeny and geographic distribution. These findings indicate that 53 isolates of T. pisiformis keep a low genetic variation, which provide useful knowledge for monitoring changes in parasite populations for future control strategies.

Aim Invasive alien species usually exhibit very high adaptation and rapid evolution in a new environment, but they often have low levels of genetic diversity (invasive species paradox). Genetic variation and population genetic structure of feral American mink, Neovison vison, in Poland was investigated to explain the invasion paradox and to assess current gene flow. Furthermore, the influence of mink farming on adaptation of the feral population was evaluated by comparing the genetic structure of feral and ranch mink.Location Samples from feral mink were collected in 11 study areas in northern and central Poland and from ranch mink at 10 farms distributed throughout the country.Methods A 373‐bp‐long mtDNA control region fragment was amplified from 276 feral and 166 ranch mink.Results Overall, 31 haplotypes, belonging to two groups from genetically diverse sources, were detected: 11 only in feral mink, 12 only in ranch mink and eight in both. The genetic differentiation of feral mink from the trapping sites was high, while that among ranch mink from various farms was moderate. There was no significant relationship between genetic and geographic distance. The number of trapping sites where given haplotypes occurred correlated with the number of farms with these haplotypes. The mink from two sites were the most divergent, both from all other feral mink and from ranch mink. Comparison of mtDNA and microsatellite differentiation suggests male‐biased dispersal in this species.Main conclusions American mink in Poland exhibit high genetic diversity and originate from different source populations of their native range. The process of colonization was triggered by numerous escapees from various farms and by immigrants from Belarus. The genetic structure of local feral mink populations was shaped by the founder effect and multiple introductions. The genomic admixture that occurred during mixing of different populations might have increased the fitness of individuals and accelerated the invasiveness of this species.

High genetic diversity in remnant natural populations of Myricaria laxiflora, a species once considered to be extinct in the wild

The central–marginal hypothesis predicts that geographically peripheral populations should exhibit reduced genetic diversity and increased genetic differentiation than central populations due to smaller effective population size and stronger geographical isolation. We evaluated these predictions in the endangered conifer Taxus wallichiana var. mairei. Eight plastid simple sequence repeats (cpSSRs) were used to investigate plastid genetic variation in 22 populations of Taxus wallichiana var. mairei, encompassing nearly its entire distribution range. Low levels of plastid genetic variation and differentiation were detected in the populations, and the findings were attributed to low mutation rates, small population sizes, habitat fragmentation and isolation, and effective pollen or seed dispersal. Hunan and Hubei were identified as major refugia based on the number of private haplotypes and species distribution modeling. Trends in plastid genetic diversity and genetic differentiation from central to peripheral populations supported the predictions of the central–marginal hypothesis. In scenarios wherein the future climate becomes warmer, we predict that some peripheral populations will disappear and southern and southeastern regions will become significantly less habitable. Factors that include the levels of precipitation during the driest month, annual precipitation level, and annual temperature range will be decisive in shaping the future distribution of these populations. This study provides a theoretical basis for the conservation of T. wallichiana var. mairei.

Genetic diversity of the bacterial wilt pathogen Ralstonia solanacearum using a RAPD marker

The global efforts to restore tropical forests and their productive and ecological functions through plantation forestry largely depend on the available genetic variation in the tree species used to establish the plantations. However, there is limited information on the levels and trends of the genetic variation and variability of different plantation tree species in the tropics. Therefore, this study reviews several marker-based studies that have investigated genetic variation. Most of the top economic species like Eucalyptus tereticornis and Mansonia altissima are attributed to low levels of genetic diversity, while others like Pinus caribaea and Swietenia macrophylla still exhibit high expected heterozygosity across different populations. However, the levels of genetic diversity assessed may depend on the markers used. Microsatellites, i.e., simple sequence repeats (SSRs), mostly give higher estimates when compared to other polymerase chain reaction-based markers. Other factors that typically contribute to the directional pattern of genetic variation in tropical tree species and populations include their distribution, density, seed dispersal, succession, and reproduction. Also, anthropogenic impacts like logging and fragmentation have contributed to the vast genetic base reduction of many tropical species and populations. Having adequate genetic variation within the plantation populations is significant in improving their fitness, resilience, fecundity, productivity, and other ecological functions. It also provides a basis for tree improvement and breeding in plantation forests. Although clonal forestry is becoming widespread and considered highly productive, it is attributed to specific economic, technical, and ecological risks, such as the increased spread of pests and diseases. Therefore, further discussions and recommendations to maximise genetic diversity in tropical (clonal) plantations are provided.

The aquatic beetle Cybister rugosus has experienced ongoing habitat loss, a decline in population numbers and confirmed extinctions among insular populations in Japan. It has recently been classified on the Red List as endangered by the Japanese Ministry of Environment and has been designated a specified class II nationally rare species of wild fauna and flora. To design effective conservation strategies for this species, it is essential to compile data on its genetic variation to ascertain its genetic diversity and population structure. Previous studies found low levels of genetic variation in the COI gene among Japanese insular populations and failed to detect a fine population structure. Thus, we developed ten novel microsatellite markers for C. rugosus, using whole-genome shotgun sequencing. The degree of polymorphism for these markers was characterized using summary statistics describing the genetic variation in 49 individuals from populations in Cambodia and on the islands of the Ryukyu Archipelago. Microsatellite data indicated differentiation among the insular populations in Japan, which could not be clearly shown in the COI data, and some insular populations showed low levels of genetic diversity. The newly developed microsatellite markers will contribute to future ecological and evolutionary studies on this species and to conservation research.

Combining DNA variation data and risk assessment procedures offers important diagnostic and monitoring tools for evaluating the relative success of exotic species invasions. Risk assessment may allow us to understand how the numbers of founding individuals, genetic variants, population sources, and introduction events affect successful establishment and spread. This is particularly important in habitats that are "hotbeds" for invasive species--such as the North American Great Lakes. This study compares genetic variability and its application to risk assessment within and among three Eurasian groups and five species that successfully invaded the Great Lakes during the mid 1980s through early 1990s; including zebra and quagga mussels, round and tubenose gobies, and the ruffe. DNA sequences are compared from exotic and native populations in order to evaluate the role of genetic diversity in invasions. Close relatives are also examined, since they often invade in concert and several are saline tolerant and are likely to spread to North American estuaries. Results show that very high genetic diversity characterizes the invasions of all five species, indicating that they were founded by very large numbers of propagules and underwent no founder effects. Genetic evidence points to multiple invasion sources for both dreissenid and goby species, which appears related to especially rapid spread and widespread colonization success in a variety of habitats. In contrast, results show that the ruffe population in the Great Lakes originated from a single founding population source from the Elbe River drainage. Both the Great Lakes and the Elbe River populations of ruffe have similar genetic diversity levels--showing no founder effect, as in the other invasive species. In conclusion, high genetic variability, large numbers of founders, and multiple founding sources likely significantly contribute to the risk of an exotic species introduction's success and persistence.

Background: Sporadic flowering contributes significantly to genetic diversity and connectivity among populations. Woody bamboos present sporadic or gregarious flowering patterns with long flowering cycles. In this study, we analyze the genetic diversity of three Guadua species distributed along the Gulf of Mexico slope that have different patterns of flowering. Questions: (1) Are the three Guadua species genetically differentiated? (2) Does the vulnerable species G. inermis have low levels of genetic diversity? (3) What is the relative contribution of geographic and environmental factors to the genetic structure of G. inermis ? Species studied: Guadua inermis , G. amplexifolia and G. tuxtlensis Study site and dates: During 2014 and 2015, we collected samples of G. inermis in Puebla and southeastern Mexico, G. amplexifolia in Veracruz and Oaxaca, and G. tuxtlensis in southern Veracruz. Methods: We successfully amplified five of nine SSR markers, and genotyped a total of 155 samples. Results: The three Guadua species were genetically differentiated. For G. inermis , we found high levels of population genetic diversity, which are relatively higher than those of other monocot species. Genetic differentiation was high and three groups were detected: north, central and south. We found a significant association between genetic distances and the maximum temperature of the warmest month, but not with geographic distance. Conclusions: Our study is the first to analyze levels of genetic diversity in Mexican bamboos and confirms their taxonomic identity. G. inermis has a strong genetic structure, even when populations are geographically close.