RAPD analysis of genetic diversity and population genetic structure of Stipa krylovii Reshov. in Inner Mongolia steppe

Random amplified polymorphic DNA (RAPD) analysis was used to characterize the genetic diversity and population genetic structure of Stipa krylovii populations in Inner Mongolia steppe of North China. Thirteen 10 bp oligonucleotide primers, which generated 237 RAPD bands, were used to analyze 90 plants of five populations from three regions, meadow steppe, typical steppe and desert steppe, from the east to the west. The genetic diversity of Stipa krylovii that was revealed by observed number of alleles (na), expected number of alleles (ne), Nei's diversity index (h), Shannon's diversity index (H), amplificated loci, polymorphic loci and the percentage of polymorphic loci (PPB) increased from the east to the west. The Pearson's correlation analysis between genetic diversity parameters and ecological parameters indicated that the genetic diversity of Stipa krylovii was associated with precipitation and cumulative temperature variations along the longitude (humidity were calculated by precipitation and cumulative temperature). Dendrogram based on Jaccard's genetic distance showed that the individuals from the same population formed a single sub-group. Although most variation (56.85%) was within populations, there was high genetic differentiation among populations of Stipa krylovii, high differentiation within and between regions by AMOVA analysis. Either Nei's unbiased genetic distance (G(ST)) or gene flow (Nm) among pairwise populations was not correlated with geographical distance by Mantel's test (P > 0.05), suggesting that there was no consistency with the isolation by distance model in these populations. Natural selection may have played a role in affecting the genetic diversity and population structure, but habitat destruction and degradation in northern grassland in China may be the main factor responsible for high genetic differentiation among populations, within and among regions.     

Genetic analysis of two Portuguese populations of <Emphasis Type="Italic">Ruditapes decussatus</Emphasis> by RAPD profiling

The clam Ruditapes decussatus is commercially important in the south of Portugal. The random amplified polymorphic DNA (RAPD) technique was applied to assess the genetic diversity and population structure of two Portuguese populations occurring in the Ria Formosa (Faro) and the Ria de Alvor, respectively. Twenty-five individuals of each population were investigated by RAPD profiles. Genetic diversity within populations, measured by the percentage of polymorphic loci (%P), varied between 68.57% (Alvor) and 73.88% (Faro). Shannon’s information index (H) and Nei’s gene diversity (h) were 0.281 and 0.176, respectively, for the Alvor population and 0.356 and 0.234 for the Faro population. Overall, genetic variation within R. decussatus populations was high. The total genetic diversity (H _T) was explained by a low variation between populations (G _ST = 0.145), which is consistent with high gene flow (N _m = 2.9). The analysis of molecular variance (AMOVA) showed that 65% of variability is within populations and 35% between populations (Φ_PT = 0.345; P ≥ 0.001). The value of Nei’s genetic distance was 0.0881, showing a low degree of population genetic distance, despite the different geographic origin. This is the first study on the population genetics of R. decussatus by RAPD technique. The results may be useful for restocking programs and aquaculture.     

Genetic variability and differentiation of <Emphasis Type="Italic">Caragana microphylla</Emphasis> populations as revealed by RAPD markers

Genetic variability in random amplified polymorphic DNA (RAPD) was studied in 90 individuals of Caragana microphylla, an outcrossing perennial shrub species, from five natural populations sampled in Inner Mongolia steppe of China on a small scale. Nineteen selected primers were used to amplify DNA samples, and totally 225 bands were detected. The percentage of polymorphic bands within populations ranged form 58.22% to 63.56%, with an average of 60% at the population level and 71.11% at the species level, indicating relatively high genetic variations in C. microphylla species. Shannon’s information index (l) and Nei’s gene diversity (h) showed the similar trend with each other. According to the analysis of Nei’s gene diversity, the percentage of genetic variation among populations was 7.13%, indicating a low level of genetic differentiation among populations. There existed a strong gene flow (N _m = 3.26) among populations. Although AMOVA analysis also revealed most variation was within populations (Φ_ST = 4.1%), a significant proportion was observed among populations (P < 0.001) in the present study, suggesting genetic differentiation occurred among populations at a certain extent. Based on Mantel’s tests and the results of previous studies, the genetic structure pattern of C. microphylla accorded with the isolation-by-distance model on a very large scale, however, on a small scale, the significant genetic differentiation among populations might be enhanced by the micro-environmental divergence among the sampling sites, rather than by geographic factors. Analysis of the genetic variations of C. microphylla populations provided useful information for the adaptive strategy of Caragana species.     

Genetic variation,population structure and identification of yellow catfish, <Emphasis Type="Italic">Mystus nemurus</Emphasis> (C&;V) in Thailand using RAPD,ISSR and SCAR marker

Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were used to investigate the genetic structure of four subpopulations of Mystus nemurus in Thailand. The 7 RAPD and 7 ISSR primers were selected. Of 83 total RAPD fragments, 80 (96.39%) were polymorphic loci, and of 81 total ISSR fragments, 75 (92.59%) were polymorphic loci. Genetic variation and genetic differentiation obtained from RAPD fragments or ISSR fragments showed similar results. Percentage of polymorphic loci (%P), observed number of alleles, effective number of alleles, Nei’s gene diversity (H) and Shannon’s information index revealed moderate to high level of genetic variations within each M. nemurus subpopulation and overall population. High levels of genetic differentiations were received from pairwise unbiased genetic distance (D) and coefficient of differentiation. Mantel test between D or gene flow and geographical distance showed a low to moderate correlation. Analysis of molecular variance indicated that variations among subpopulations were higher than those within subpopulations. The UPGMA dendrograms, based on RAPD and ISSR, showing the genetic relationship among subpopulations are grouped into three clusters; Songkhla (SK) subpopulation was separated from the other subpopulations. The candidate species-specific and subpopulation-specific RAPD fragments were sequenced and used to design sequence-characterized amplified region primers which distinguished M. nemurus from other species and divided SK subpopulation from the other subpopulations. The markers used in this study should be useful for breeding programs and future aquacultural development of this species in Thailand.     

Allozyme variations in six natural populations of scots pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis>) in Turkey

Genetic variation in six natural populations of Scots pine (Pinus sylvestris L.) was determined with isoenzyme analyses. For this purpose, haploid female gametophytes of seeds and horizontal starch gel electrophoresis technique were used. A total of 17 loci and 58 alleles were observed in studying 10 enzyme systems. The average proportion of polymorphic loci for populations ranged from 58.8% to 70.6%. The average number of alleles per locus per population was 2.65. The mean estimated expected heterozygosity (He) of populations was 0.294. A rather high proportion of genetic diversity (96.4%) was due to within-population variation and the remaining (3.6%) was due to variation among populations. The level of gene flow (N_em) was found to be 6.69 per generation. Nei’s genetic distance coefficient ranged from 0.006 to 0.027 (mean 0.017) among all possible population pairs. The mean value of Nei’s genetic distance is similar to the values reported for other European Scots pine populations. The low mean value of Nei’s genetic distance among populations is enough to explain low interpopulation variation. According to genetic variation parameters, three out of six populations (Akdagmadeni-Yozgat, Refahiye-Erzincan and Vezirkopru-Samsun) appear to be preferable populations for genetic conservation and forest tree breeding programs.     

Genetic Variation and Population Structure of Oriental Migratory Locust, Locusta migratoria manilensis, in China by Allozyme, SSRP-PCR, and AFLP Markers

Allozyme analysis, microsatellite primer PCR (SSRP-PCR), and amplified fragment length polymorphism (AFLP) techniques were used to assess genetic diversity and population structure of the Chinese oriental migratory locust, Locusta migratoria manilensis. A total of 299 PCR markers (67 SSRPs and 232 AFLPs) were detected in eight populations, of which 98.7% were polymorphic markers. The proportion of polymorphic loci (95.5–98.8%) by SSRP+AFLP markers indicated no significant differences between populations, and all populations exhibited a similar level of variability; results of the allozyme analysis demonstrated that 19 loci gave rise to a lower level of polymorphism (55.6–66.7%). The genetic distances between the populations were relatively low. Shannon’s index and Nei’s gene diversity showed low differentiation among the populations. Allozyme analysis, however, reflected greater similarity and smaller differentiation between the populations than those shown by SSRP and AFLP markers. Neighbor-joining dendrograms derived from both the allozyme and SSRP+AFLP markers showed that the genetic distances among Chinese oriental migratory locust populations were not greatly influenced by geographic distance and breeding habitats.     

The genetic structure of red raspberry (<Emphasis Type="Italic">Rubus idaeus</Emphasis> L.) populations in Lithuania

The red raspberry (Rubus idaeus L.) is widely distributed in Lithuania and occupies a range of habitats. The presence of coadapted gene pools in local populations of R. idaeus is a question of interest not only to plant scientists, but also to plant breeders. In this study, we investigated the genetic structure of R. idaeus and the influence of local habitats on the genetic diversity within and among populations. Nineteen populations of R. idaeus were sampled from different habitats in various agroclimatic subregions of Lithuania, and analyzed using RAPD markers. 113 RAPD bands were identified among 315 individuals; 84.31% of these were polymorphic. The mean values of Shannon’s information index for different populations ranged from 0.341 to 0.455. Nei’s gene diversity established within populations averaged 0.266. An AMOVA revealed 74% of genetic variation among individuals within populations of R. idaeus, and 23% among populations. The remaining genetic variation was distributed among populations from different agroclimatic subregions (3%). The results of this study suggest that the genetic structure of R. idaeus populations in Lithuania may be influenced partially by isolation by distance as well as by local environmental conditions.     

Genetic variation and phylogeographic history of <Emphasis Type="Italic">Picea likiangensis</Emphasis> revealed by RAPD markers

Repeated cycles of retreat and recolonization during the Quaternary ice ages are thought to have greatly influenced current species distributions and their genetic diversity. It remains unclear how this climatic oscillation has affected the distribution of genetic diversity between populations of wind-pollinated conifers in the Qinghai-Tibetan region. In this study, we investigated the within-species genetic diversity and phylogenetic relationships of Picea likiangensis, a dominant forest species in this region using polymorphic DNA (RAPD) markers. Our results suggest that this species has high overall genetic diversity, with 85.42% of loci being polymorphic and an average expected heterozygosity (H _E) of 0.239. However, there were relatively low levels of polymorphism at population levels and the differences between populations were not significant, with percentages of polymorphic bands (PPB) ranging from 46.88 to 69.76%, Nei’s gene diversity (H _E) from 0.179 to 0.289 and Shannon’s indices (Hpop) from 0.267 to 0.421. In accordance with our proposed hypothesis, a high level of genetic differentiation among populations was detected based on Nei’s genetic diversity (G _ST = 0.256) and AMOVA analysis (Phi _st = 0.236). Gene flow between populations was found to be limited (Nm = 1.4532) and far lower than reported for other conifer species with wide distribution ranges from other regions. No clusters corresponding to three morphological varieties found in the south, north and west, respectively, were detected in either UPGMA or PCO analyses. Our results suggest that this species may have had different refugia during the glacial stages in the southern region and that the northern variety may have multiple origins from these different refugia.     

Genetic diversity of Stipa grandis P.Smirn populations across the species’ range in the Inner Mongolia Plateau of China

In order to investigate the genetic diversity of dominant species under the background of climate change and grassland utilization in the Inner Mongolia Plateau of China, we sampled seven Stipa grandis populations along an increasing aridity gradient in the present study. The Nei’s gene diversity of populations (He) was estimated to be 0.15 and the percentage of polymorphic loci (PPL) was 49.28%. The genetic differentiation among populations (Φ_ST) was 0.2431. There was a significant relationship between genetic distance and geographic distance among the S. grandis populations by Mantel's test. The genetic diversity was significantly correlated with longitude and annual mean precipitation, which suggested that a combination of climatic factors affected the genetic diversity. The populations in the marginal habitat should be paid more attention because of their low genetic diversity and its significance for conservation of the whole species.     

Population genetic structure of <Emphasis Type="Italic">Sargassum thunbergii</Emphasis> (Fucales,Phaeophyta) detected by RAPD and ISSR markers

Genetic variation of four populations of Sargassum thunbergii (Mert.) O. Kuntze and one outgroup of S. fusiforme (Harv.) Setchell from Shandong peninsula of China was studied with random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. A total of 28 RAPD primers and 19 ISSR primers were amplified, showing 174 loci and 125 loci, respectively. Calculation of genetic diversity with different indicators (P%, percentage of polymorphic loci; H, the expected heterozygosity; I, Shannon’s information index) revealed low or moderate levels of genetic variations within each S. thunbergii population. High genetic differentiations were determined with pairwise Nei’s unbiased genetic distance (D) and fixation index (F _ST ) between the populations. The Mantel test showed that two types of matrices of D and F _ST were highly correlated, whether from RAPD or ISSR data, r = 0.9310 (P  = 0.008) and 0.9313 (P = 0.009) respectively. Analysis of molecular variance (AMOVA) was used to apportion the variations between and within the S. thunbergii populations. It indicated that the variations among populations were higher than those within populations, being 57.57% versus 42.43% by RAPD and 59.52% versus 40.08% by ISSR, respectively. Furthermore, the Mantel test suggested that the genetic differentiations between the four populations were related to the geographical distances (r > 0.5), i.e., they conformed to the IBD (isolation by distance) model, as expected from UPGMA (unweighted pair group method with arithmetic averages) cluster analysis. As a whole, the high genetic structuring between the four S. thunbergii populations along distant locations was clearly indicated in the RAPD and ISSR analyses (r > 0.8) in our study.     

Genetic differences between wild and hatchery populations ofDiplodus sargus andD. vulgaris inferred from RAPD markers: implications for production and restocking programs design

Restocking and stock enhancement programs are now recognized as an important tool for the management of fishery resources. It is important, however, to have an adequate knowledge on the genetic population structure of both the released stock and the wild population before carrying out such programs. In this study, random amplified polymorphic DNA (RAPD) markers were applied to assess genetic diversity and population structure of wild and hatchery populations of the white seabreamDiplodus sargus and the common two-banded seabreamD. vulgaris (Sparidae). The estimated values for intrapopulation genetic variation, measured using the percentage of polymorphic loci (%P), Shannon indexH’, and Nei’s gene diversity (h), showed high values for all populations. The percentage of genetic variation withinD. sargus andD. vulgaris populations, based on coefficient of gene differentiation, reached 82.5% and 90% of the total genetic variation, respectively. An undeniable decrease in genetic variation was found in both hatchery populations, particularly inD. sargus, compared to the wild ones. However, the high values of variation within all populations and the low levels of genetic variation among populations did not indicate inbreeding or depression effects, thus indicating a fairly proper hatchery management. Nevertheless, the results of this study highlight the importance of monitoring the genetic variation of hatchery populations, particularly those to be used in restocking programs. The creation of a genetic baseline database will contribute to a more efficient conservation management and to the design of genetically sustainable restocking programs.     

Population genetic structure of <Emphasis Type="Italic">Tamarix chinensis</Emphasis> in the Yellow River Delta,China

Tamarix chinensis, with its important ecological significance, is a vital dominant plant in the Yellow River Delta of China. To understand its genetic structure and population dynamics, five populations of T. chinensis, consisting of 140 individuals, were analyzed in this study using inter simple sequence repeat markers. Seventy-eight polymerase chain reaction fragments were scored, of which 62 were polymorphic. The mean percentage of polymorphic loci (P), the mean Nei’s gene diversity (h), and the mean Shannon’s information index (I) were 79.5%, 0.239, and 0.363, respectively. These indexes indicated that a moderate level of genetic diversity existed in T. chinensis populations of the Yellow River Delta. Both analysis of molecular variance (AMOVA) (Φ _st = 0.169) and Popgene (G _st = 0.159) analyses revealed the low level of genetic differences among the five populations of T. chinensis. The results implied that relatively frequent gene flow existed among populations. However, slightly uneven genetic diversity was also found among populations. Unweighted pair group method with arithmetic mean and principal component analysis showed that populations with similar soil salinity had a close relationship, rather than populations with closer geographical distance. A significant negative correlation between genetic diversity and soil salinity of the five populations (r = −0.958, p < 0.01) showed that soil salinity played an important role in shaping the population genetic structure of T. chinensis in the Yellow River Delta, China.     

Genetic diversify among Balkan trout populations based on RAPD analysis

Random amplified polymorphic DNA (RAPD) markers were used to estimate the population structure and phylogenetic relationships among samples of the Salmo trutta complex that inhabit the Balkan Peninsula. Five random oligodecamers were selected to amplify DNA from 140 fish from seven populations. Using these primers, 55 discernible DNA fragments were generated, of which 50 (90.91%) were polymorphic. The statistical results indicated that there was low genetic diversity within populations (with an average percentage of polymorphic bands (P) of 11.69% and a Nei’s genetic diversity index (h) of 0.035), but at the same time high genetic differentiation among populations (F _ST = 0.89). The distribution of genetic diversity among Balkan trout may result from their evolutionary history and reflects genetic drift coupled with bottleneck phenomena. Overall, RAPDs proved valuable tools for quick and reliable stock discrimination and provided information that might be useful regarding conservation and management of trout.     

Genetic comparisons between seed bank and <Emphasis Type="Italic">Stipa krylovii</Emphasis> plant populations

The soil seed bank represents the potential plant population since it is the source for population replacement. The genetic structure of a Stipa kryiovii (Roshev.) plant population and its soil seed bank was investigated in the Xilinguole Steppe of Inner Mongolia using random amplified polymorphic DNA (RAPD) analyses. The population was sampled at two sites that were in close proximity to each other (0.5 km apart). Thirty plants and 18 seed bank samples were taken from each site to determine the genetic diversity between sites and between sources (plant or seed). The material was analyzed using 13 primers to produce 92 loci. Eighty-six were multi-loci, of which 23 loci (26.74%) of allele frequencies showed significant differences (P ≤ 0.05). The genetic similarity between two seed bank sites was 0.9843 while the genetic similarity between two plant sites was 0.9619. Their similarities were all greater than that between the seed bank and plant populations. An analysis of their genetic structure showed that 87.86% of total variation was derived by two-loci. Genetic structures between plant and soil seed bank populations in S. krylovii were different due to the variance of mean gametic disequilibria and mean gene diversity. AMOVA results showed that the majority of variance (88.62%) occurred within sites, 12.75% was from between-groups. Further research is needed to investigate the selective function in maintaining the genetic diversity of Stipa krylovii plant populations.     

Genetic variability of Chalara fraxinea, dieback cause of European ash (Fraxinus excelsior L.)

A total of 159 colonies of Chalara fraxinea were isolated between 2005 and 2006 from dying trees of European ash (Fraxinus excelsior L.) aged between 3 and 10 years. They derived from five regions of Poland differing by geographic location and climatic conditions. On the basis of 90 RAMS markers, pathogen intra- and inter-population variability, as well as its dependency on geographic distance and climatic conditions in the regions of strain origin, was analysed. The applied measures of intrapopulation genetic variability (genetic distance, Nei’s unbiased diversity, Shannon’s Information Index and percentage of polymorphic loci) allowed for differentiation of two strain groups: the first deriving from lowlands and the second from uplands and mountainous areas. Strains in lowlands were characterised by smaller number of markers, smaller number of polymorphic loci and smaller intrapopulation genetic variability. Positive and statistically significant correlation was shown between variability of isolates and elevation of regions above sea level. Pair-wise genetic distances between groups of isolates (Nei’s unbiased genetic distance) from particular regions were not significantly correlated with the corresponding geographic distances. On the basis of AMOVA, it was shown that 85% of variability was within-region differences and 2% between-region differences, whereas differences between lowlands and uplands were 13%. Principal Components Analysis (PCA) for the investigated regions confirmed the results from Nei’s genetic distance matrix.     

草履蚧不同寄主和地理种群遗传分化的RAPD分析

应用随机扩增多态性DNA(RAPD)技术对草履蚧保定、石家庄、邯郸16个不同寄主地理种群遗传多样性和种群分化进行研究,结果显示4个RAPD引物共扩增出41个多态性位点,多态位点比率为100%。遗传距离指数在0.701—0.4360,平均为0.2395。其中以邯郸枫杨和邯郸垂丝海棠为寄主的草履蚧种群遗传距离最小(0.0701);以石家庄紫叶李和邯郸木槿为寄主的种群遗传距离最大(0.4360)。遗传一致度系数在0.6466—0.9290。说明草履蚧不同种群遗传多样性丰富并存在遗传差异。聚类分析结果表明草履蚧种群遗传多样性同时受到寄主和地理因素的双重影响,且不同寄主草履蚧种群已产生明显的遗传分化。     

Genetic Diversity of <Emphasis Type="Italic">Hevea</Emphasis> IRRDB’81 Collection Assessed by RAPD Markers

The majority of Hevea (Hevea brasiliensis Muell. Arg.) genetic resource in Vietnam derived from the IRRDB’81 germplasm collected in the Amazonian habitats of the genus. Random amplified polymorphic DNA (RAPD) analysis was used to examine the genetic diversity and structure of the IRRDB’81 germplasm. A total of 59 accessions from 13 different districts of the Brazilian states namely Acre, Rondonia, and Mato Grosso were brought into the study using six arbitrarily preselected primers. Sixty-five RAPD band patterns ranging in size from 0.2 to 3.0 kbp were scored for analysis. Differences in the level of DNA polymorphism among the districts and states were revealed. The percentage of the polymorphic DNA fragments calculated for 13 individual districts varied from 15.38 to 70.77%. The mean values of heterozygosity within the district varied from 0.064 to 0.264. Pairwise district Nei’s genetic distance values ranged from 0.046 for Catriquacu and Itanba of Mato Grosso to 0.304 for Tarauaca of Acre and Aracatuba of Mato Grosso. The estimated values of Shannon’s diversity index ranged from 0.093 for the Assis-Brasil district of Acre to 0.389 for the Jiparana district of Rondonia. The analysis of molecular variance (AMOVA) indicated that most of the genetic variations were found among accessions within the districts, while interdistrict variance component accounted for 14.1% only. The low interdistrict differentiation probably implied an extensive gene flow among them. Both the principal coordinate analysis and UPGMA cluster analysis based on genetic distance values revealed a varying degree of separation among the districts and that conformed to geographical origins of Hevea IRRDB’81 collection.     

Contrasting patterns of spatial genetic structure of diploid and triploid populations of the clonal aquatic species,<Emphasis Type="Italic">Butomus umbellatus (Butomaceae)</Emphasis>, in Central Europe

Genetic diversity in a sample of an aquatic plantButomus umbellatus from 37 localities in Czechia and Slovakia was studied by analyzing six polymorphic loci in three enzymatic systems (SKDH, PGD and AAT). Diversity among ramets was low in eight populations with relatively extensive sampling (only one population possessed more than one multilocus genotype), suggesting high clonality of reproduction in these populations. However, among-population diversity was high: G = 0.782 and 0.881 for the samples of diploid and triploid populations, respectively. Heterozygosity of individual plants averaged over variable loci was also high: H = 0.554 for diploids and 0.453 for triploids. Genetic differentiation among populations was additionally studied using cluster analysis. Several populations of diploids clustered separately from all other populations, whereas another group of diploid populations clustered with some triploid populations, indicating the possibility of relatively recent, probably multiple origin of these triploid populations from their diploid progenitors. Association between matrices of Nei’s genetic distances among populations from different localities and matrices of geographic distances among these localities revealed highly significant correlation for the sample of diploid populations (r = 0.60,P < 0.001) but no significant correlation for the sample of triploid populations (r = 0.02,P = 0.593). These results indicate a spatial structure of diploid populations in accordance with the isolation by distance model, and a random distribution of genotypes among triploid populations ofB. umbellatus.     

A Study of Conservation Genetics in Cupressus chengiana,an Endangered Endemic of China,Using ISSR Markers

ISSR markers were used to analyze the genetic diversity and genetic structure of eight natural populations of Cupressus chengiana in China. ISSR analysis using 10 primers was carried out on 92 different samples. At the species level, 136 polymorphic loci were detected. The percentage of polymorphic bands (PPB) was 99%. Genetic diversity (H _e) was 0.3120, effective number of alleles (A _e) was 1.5236, and Shannon’s information index (I) was 0.4740. At the population level, PPB = 48%, A _e=1.2774, H _e=0.1631, and I=0.2452. Genetic differentiation (G _st) detected by Nei’s genetic diversity analysis suggested 48% occurred among populations. The partitioning of molecular variance by AMOVA analysis indicated significant genetic differentiation within populations (54%) and among populations (46%; P < 0.0003). The average number of individuals exchanged between populations per generation (N _m ) was 0.5436. Samples from the same population clustered in the same population-specific cluster, and two groups of Sichuan and Gansu populations were distinguishable. A significantly positive correlation between genetic and geographic distance was detected (r=0.6701). Human impacts were considered one of the main factors to cause the rarity of C. chengiana, and conservation strategies are suggested based on the genetic characters and field investigation, e.g., protection of wild populations, reestablishment of germplasm bank, and reintroduction of more genetic diversity.     

ISSR primer screening and preliminary evaluation of genetic diversity in wild populations of Gycyrrhiza uralensis

Fourteen efficient inter-simple sequence repeat (ISSR) primers were screened and optimized for detecting the genetic diversity in wild populations of Glycyrrhiza uralensis Fisch. By using these primers, 249 polymorphic bands out of a total of 270 (92.2 %) were generated from 70 individuals of 4 wild G. uralensis populations sampled from Inner Mongolia Province of China. Nei’s gene diversity (h) and Shannon index (I) calculated from the data matrix of the ISSR phenotypes revealed a high level of genetic diversity with h = 0.268 and I = 0.415 within this plant. Analysis of molecular variation (AMOVA) showed that most of the genetic variation (81 %) occurred within the populations, whereas the variance among populations was only 19 %. The UPGMA tree based on Nei’s unbiased genetic diversity illustrated that populations from Bulage and Bayanwusu were genetically close related, while the population from Shanghaimiao was found to be the most diverse from the other three. The high genetic diversity implies that the wild resources of this species could be restored soon if an appropriate and efficient protection strategy was employed. Our results also provided an optimized method for evaluating genetic diversity of G. uralensis using ISSR markers which was useful for further investigation.