Genetic and morphological diversity in <Emphasis Type="Italic">Tragopogon graminifolius</Emphasis> DC. (Asteraceae) in Iran

Tragopogon graminifolius DC. is a medicinal plant species of the genus Tragopogon L. (Asteraceae) that grows in different regions of Iran and is extensively used by locals. There is no report on genetic variability and population structure of this important plant species. Therefore, we studied the genetic diversity, population structure and morphological variability of 14 geographical populations of Tragopogon graminifolius in Iran. AMOVA and Gst analyses revealed significant molecular differences among the studied populations. Mantel test showed significant correlation between genetic distance and geographical distance of the studied populations and indicated that the neighboring populations had a higher degree of gene flow. STRUCTURE plot identified three main gene pools for Tragopogon graminifolius in Iran and population assignment test revealed that gene flow occurred mostly among populations of the same gene flow. The studied populations differed significantly in their morphological and genetic features. These results may be of use for future conservation of this important plant species.     

Genetic diversity and population structure in four Cirsium (Asteraceae) species

The present study considers genetic diversity of 38 populations in 4 Cirsium species of the genus Cirsium Mill. (Asteraceae), occurring in different ecological regions and tries to compare degree of genetic variability among the species with wide geographical distribution versus endemic C. pyramidale showing confined geographical distribution. The results showed that the endemic species has similar value of genetic diversity parameters as the species with wider distribution. We also studied the possible admixture nature of these populations and tried to understand the relation between genetic changes, geographical distribution and polyploidy level and chromosome pairing in these species. ISSR analysis showed population difference in allele composition and frequency. Clustering and PcoA ordination produced different groupings in each species, while STRUCTURE and reticulation analyses revealed high degree of genetic admixture and gene exchange among populations as well as allelic rearrangement. No significant correlation was observed between geographical distance and genetic distance of the populations and AMOVA test revealed no significant difference among populations in each species studied. However, high amount of within population variation occurred in all 4 species indicating their cross-pollination nature and high genetic admixture. The populations also varied in chiasma frequency and chromosome pairing as well as the occurrence of heterozygote translocations all creating more variability to be used by plants for local adaptation.     

Morphometric and ISSR-Analysis of Local Populations of <Emphasis Type="Italic">Geranium molle</Emphasis> L. from the Southern Coast of the Caspian Sea

Geranium molle is known as Dovefoot Geranium or Awnless Geranium. Dovefoot Geranium is a low-growing herb with pink flowers and sharply toothed leaves. Dovefoot Geranium is native to Eurasia and has been introduced to many habitats of the world. This species is very similar to G. robertianum but its palmate-like leaves and bilobed petals show differences. This plant is considered to be anodyne, astringent and vulnerary. We have no information on its population genetic structure, genetic diversity, and morphological variability in Iran. Therefore, due to the importance of these plant species, we performed a combination of morphological and molecular data for this species. For this study, we used 132 randomly collected plants from 18 geographical populations in 4 provinces. Genetic diversity parameters were determined in these populations. STRUCTURE analysis and K-Means clustering identified 14 gene pools in the country and revealed isolation by distance among the studied populations. The Mantel test showed correlation between genetic and geographical distance. AMOVA revealed a significant genetic difference among populations and showed that 40% of total genetic variation was due to within-population diversity. The consensus tree of both molecular and morphological data identified divergent populations. These data may be used in future breeding and conservation of this important medicinal plant in the country.     

Genetic diversity and population structure of endangered endemic Paeonia jishanensis in China and conservation implications

Paeonia jishanensis, one of the most important ancestral species of cultivated tree peonies, is an endangered ornamental and medicinal plant endemic to China. A total of 236 individuals of P. jishanensis from 10 extant populations were analysed using 21 EST-SSR markers to assess their genetic diversity and population structure. Moderate genetic diversity levels (H_E = 0.340) and high genetic differentiation among populations (F_ST = 0.335) were revealed. Combining the results of STRUCTURE, PCoA and neighbour-joining analyses, the 10 populations were divided into four genetic groups that were significantly related to their geographical origins, which was further supported by hierarchical AMOVA showing the highest variation of 17.9% among groups. The Mantel test showed a significant positive correlation between genetic distance and geographic distance among populations (r = 0.873, P < 0.0001). The genetic structure of P. jishanensis may be due to limited gene flow hindered by vicariance and its breeding system: facultative vegetative reproduction. This study carries significant implications for the conservation and utilization of this endangered species.     

Genotypic diversity and structure of Satureja mutica revealed by inter-simple sequence repeat markers

Satureja mutica (Lamiaceae) is an herbaceous medicinal plant which grows in Iran. The objective of the study was to obtain an overview of the genetic relatedness among and within seven populations of this species using inter-simple sequence repeat (ISSR). Fourteen ISSR primers amplified a total of 197 DNA fragments of which 176 (88.91%) were polymorphic. All ISSR primers were highly effective in discriminating among the populations. Genetic similarity coefficients ranged from 0.45 to 0.94, indicating considerable distance and diversity in the germplasm and were confirmed by clustering analysis. The dendrogram showed a clear clustering pattern of plants indicating a significant association between genetic similarity and geographical distance. Analysis of molecular variance revealed that a greater proportion of total genetic variation existed within populations (75%) rather than among populations (25%). The study indicated that ISSR markers were effective and reliable for assessing the degree of genetic variation of S. mutica. These findings can support future research on the selection of S. mutica for breeding and medicinal plant development.     

Genetic diversity and genome size variability in Linum austriacum (Lineaceae) populations

Genetic diversity and genome size variability were studied in 16 geographical populations of Linum austriacum (Lineaceae). Genetic diversity parameters were determined in each population based on ISSR molecular markers. AMOVA test, Gst value and Hickory test revealed significant molecular difference among the studied populations. Mantel test showed correlation between genetic distance and geographical distance in these populations. NJ tree and NeighborNet network grouped the studied plant specimens in 3 major clusters. STRUCTURE analysis identified 12 allelic combinations in agreement with K-Means clustering result. These analyses revealed the presence of genetic variability both among and within studied population. The plant specimens of these geographical populations also differed significantly in their genome size.     

Population structure and genetic diversity of Huperzia serrata (Huperziaceae) based on amplified fragment length polymorphism (AFLP) markers

The levels and pattern of the genetic variation within and among natural populations of Huperzia serrata were investigated using amplified fragment length polymorphism markers. Seven primer combinations used in the study amplified 615 discernible bands with 532 (86.5%) being polymorphic, indicating a considerable high level of genetic diversity at the species level. AMOVA analysis revealed a low level of genetic differentiation among the ten populations. The UPGMA cluster of all samples showed that individuals from the same population occasionally failed to cluster in one distinct group. A Mantel test showed no significant correlation between genetic distance and geographical distance (r = 0.278, P = 0.891), suggesting that the gene flow was not restricted geographically. A number of factors that might affect the genetic profiles of H. serrata included clonal growth, selective effect of niche and outcrossing, as well as the effective wind-dispersal of spores.     

Genetic diversity of SSR markers in wild populations of Tapiscia sinensis,an endangered tree species

Tapiscia sinensis is a Tertiary relict and endangered tree species with unique scientific research value and great economic value. In this study, we assessed the genetic diversity of five wild T. sinensis populations from different geographical regions using 10 polymorphic simple sequence repeat (SSR) markers. Our results reveal that the natural populations of T. sinensis have rich genetic diversity (PPL = 100%, He = 0.6904, I = 1.4368), with Shannon's index indicating that the T. sinensis populations are at a relatively stable stage. Of the genetic relationships among populations, the distance between the Hunan Yanling (YL) and Guizhou Xifeng (XF) populations is the smallest (0.4829); the genetic distance between the Shaanxi Ningshan (NS) and the Guizhou Xifeng (XF) populations is the largest (0.9821). A Mantel test shows that there is no correlation among the populations between geographic distance and genetic distance. AMOVA suggest that 33.3% of the genetic variation arose among the populations, while 66.7% of the variation arose within them. The moderate gene flow among populations (Nm = 0.7274) is not sufficient to counteract genetic drift within the populations and result in significant differentiation (Fst = 0.2987). Our results will benefit the conservation and exploitation of T. sinensis and provide a theoretical basis for further study of the evolution and phylogeography of the species.     

Genetic diversity and geographical differentiation of Dipteronia Oliv. (Aceraceae) endemic to China as revealed by AFLP analysis

The genus Dipteronia Oliv. endemic to central and southern China consists of two species, Dipteronia sinensis Oliv. and Dipteronia dyeriana Henry, both of them are rare and endangered. AFLP markers were used to characterize the genetic diversity and geographical differentiation of the genus. Eight out of 32 PstI + 3/MseI + 3 selective primer combinations screened were applied to the analysis on 142 individuals of 17 D. sinensis and 4 D. dyeriana populations, respectively. A total of 324 fragments with 316 polymorphic were amplified. The proportion of polymorphic loci (PPB) was 97.53%. The Nei's gene diversity in D. sinensis and D. dyeriana was 0.3319 and 0.3047, respectively. About 43.6% (G_ST = 0.4356) of the genetic variation occurred among the populations, indicating a relatively high genetic differentiation among the populations. Cluster analysis grouped the 21 populations into two groups according to their species delimitation. The populations of D. sinensis were further divided into three subgroups corresponding to their geographical distributions. Correlation analysis revealed a significant correlation (p < 0.05) between geographical distance and genetic distance of these populations, suggesting that the relatively high genetic differentiation among the populations of D. sinensis might be caused by geographical isolation.     

ISSR analysis of genetic diversity of the Qinghai-Tibet Plateau endemic Rhodiola chrysanthemifolia (Crassulaceae)

Inter-simple sequence repeat markers (ISSR) were used to estimate genetic diversity within and among 10 populations of Rhodiola chrysanthemifolia along Nianqingtangula Mountains and Brahmaputra, a species endemic to the Qinghai-Tibet Plateau and an endangered medicinal plant. Of the 100 primers screened, 13 produced highly polymorphic DNA fragments. Using these primers, 116 discernible DNA fragments were generated of which 104 (89.7%) were polymorphic, indicating substantial genetic diversity at the species level. Genetic diversity measured by the percentage of polymorphic bands (PPB) at the population level ranged from 21.97% to 48.8%. Analysis of molecular variance (AMOVA) showed that the genetic variation was found mainly among populations (77.3%), but no regional differentiation was discernible. Variance within populations was only 22.7%. The main factor responsible for this high level of differentiation among populations is probably the historical geographical and genetic isolation of populations in a harsh mountainous environment. Concerning the management of R. chrysanthemifolia, the high genetic differentiation of populations indicates the necessity of conserving the maximum possible number of populations.     

广东省五节芒遗传多样性的ISSR分析

采用ISSR分子标记技术,对广东省内分布的能源植物五节芒(Miscanthus floridulus)13个野生居群共215个个体的遗传多样性进行了研究.9个ISSR引物共扩增到了81个位点,其中76个是多态性位点.结果表明,广东五节芒的遗传多样性水平很高,物种水平上,多态位点百分率(PPB)为93.83％,Nei's...     

菲律宾蛤仔EST-SSRs标记开发及不同地理群体遗传多样性

利用13对微卫星引物对大连、莆田、青岛3个地理群体蛤仔遗传多样性进行了检测。结果表明:13个基因座共检测到154个等位基因,每个座位检测到的等位基因数在2-7个之间,平均有效等位基因数为2.7657;3个群体平均观测杂合度分别为0.4387、0.4194、0.2383,平均期望杂合度分别为0.6488、0.6484、0.5526;群体间的遗传多样性差异不显著(P＞0.05)。NJ聚类结果显示大连和莆田群体的蛤仔亲缘关系较近,二者与青岛群体关系较远。3个群体均有不同程度的偏离Hardy-Weinberg平衡现象,表明各群体基因频率和基因型频率的稳定性相对较低。本研究所获得的微卫星标记的多态信息含量(PIC)>0.5,说明这些微卫星位点的多样性较高,可为下一步遗传图谱构建研究提供参考。     

Genetic diversity and population structure of the endangered medicinal plant Phellodendron amurense in China revealed by SSR markers

Phellodendron amurense is an endangered tree with important medicinal and economic value in China. In this study, eight nuclear SSR primer pairs were employed to assess the genetic diversity and structure of 22 natural populations, including 516 individuals. A total of 66 alleles were detected with an average of 8.3 alleles per locus ranging from 3 to 17. The expected heterozygosity (He) of each SSR locus varied from 0.347 to 0.877 (average 0.627). Analysis of molecular variance (AMOVA) revealed that the main variation component existed within populations (95.11%) rather than among populations (4.89%). The Wilcoxon's sign-rank tests did not show any recent bottleneck effect in any population. A Mantel test displayed a significant correlation between the geographic distances and genetic distances for all populations (r = 0.566, P = 0.0001), indicating conformity to the isolation by distance model. Bayesian clustering and UPGMA supported grouping the populations into two groups. The present genetic structure of P. amurense may be explained by geographical isolation. The lack of genetic structure and genetic diversity decreased with increasing latitude within the Northeast China group may be due to postglacial northward expansion from a single refugium. Proper conservation measures are proposed for this species.     

Genetic structure and essential oil composition in wild populations of Salvia multicaulis Vahl.

The phytochemical study on ten populations of Salvia multicaulis Vahl. revealed that their essential oil qualitative profiles contained a significant amount of monoterpene hydrocarbons, which were the most abundant compounds. Besides, α-Pinene was the major constituent in all studied populations' essential oils. Significant correlations were observed between edaphic parameters and some major essential oil compounds. According to clustering analyses of the chemical data, the S. multicaulis populations were divided into three chemotypes: β-caryophyllene, camphene and camphor, and limonene. The population genetics study showed significant molecular differences among the populations. The Mantel test indicated a significant positive correlation between the geographical distances and genetic diversity, exhibiting a low amount of gene flow and a considerable genetic differentiation value. We also detected four genotypes based on the Nei's genetic distance and structure analysis. The identified chemical and genetic similarities/differences among these populations were correlated with edaphic parameters and geographic distances, suggesting that environmental factors are the primary drivers of the chemical polymorphism of essential oils in S. multicaulis populations.     

Population Explosion in the Yellow-Spined Bamboo Locust Ceracris kiangsu and Inferences for the Impact of Human Activity

Geographic distance and geographical barriers likely play a considerable role in structuring genetic variation in species, although some migratory species may have less phylogeographic structure on a smaller spatial scale. Here, genetic diversity and the phylogenetic structure among geographical populations of the yellow-spined bamboo locust, Ceracris kiangsu, were examined with 16S rDNA and amplified fragment length polymorphisms (AFLPs). In this study, no conspicuous phylogeographical structure was discovered from either Maximum parsimony (MP) and Neighbor-joining (NJ) phylogenetic analyses. The effect of geographical isolation was not conspicuous on a large spatial scale.At smaller spatial scales local diversity of some populations within mountainous areas were detected using Nei''s genetic distance and AMOVA. There is a high level of genetic diversity and a low genetic differentiation among populations in the C. kiangsu of South and Southeast China. Our analyses indicate that C. kiangsu is a monophyletic group. Our results also support the hypothesis that the C. kiangsu population is in a primary differentiation stage. Given the mismatch distribution, it is likely that a population expansion in C. kiangsu occurred about 0.242 Ma during the Quaternary interglaciation. Based on historical reports, we conjecture that human activities had significant impacts on the C. kiangsu gene flow.     

Genetic Diversity and Structure of Sinopodophyllum hexandrum (Royle) Ying in the Qinling Mountains,China

Sinopodophyllum hexandrum is an important medicinal plant whose genetic diversity must be conserved because it is endangered. The Qinling Mts. are a S. hexandrum distribution area that has unique environmental features that highly affect the evolution of the species. To provide the reference data for evolutionary and conservation studies, the genetic diversity and population structure of S. hexandrum in its overall natural distribution areas in the Qinling Mts. were investigated through inter-simple sequence repeats analysis of 32 natural populations. The 11 selected primers generated a total of 135 polymorphic bands. S. hexandrum genetic diversity was low within populations (average H_e = 0.0621), but higher at the species level (H_e = 0.1434). Clear structure and high genetic differentiation among populations were detected by using the unweighted pair group method for arithmetic averages, principle coordinate analysis and Bayesian clustering. The clustering approaches supported a division of the 32 populations into three major groups, for which analysis of molecular variance confirmed significant variation (63.27%) among populations. The genetic differentiation may have been attributed to the limited gene flow (N_m = 0.3587) in the species. Isolation by distance among populations was determined by comparing genetic distance versus geographic distance by using the Mantel test. Result was insignificant (r = 0.212, P = 0.287) at 0.05, showing that their spatial pattern and geographic locations are not correlated. Given the low within-population genetic diversity, high differentiation among populations and the increasing anthropogenic pressure on the species, in situ conservation measures were recommended to preserve S. hexandrum in Qinling Mts., and other populations must be sampled to retain as much genetic diversity of the species to achieve ex situ preservation as a supplement to in situ conservation.     

Genetic variability and population structure in Sapindus emarginatus Vahl from India

Sapindus emarginatus is an economically important tropical tree species sparsely distributed in different geographical provinces like Gangetic Plains, Western Ghats, and Deccan Plateau in India. In the present paper estimation of genetic variability within and among 41 accessions representing five populations was carried out using 3 single primer amplification reaction (SPAR) methods viz. RAPD, DAMD and ISSR. The cumulative data analysis was carried out for all three SPAR methods, and showed 82.32% polymorphism across all the accessions of S. emarginatus. Jaccard's similarity values among 41 accessions ranged from 0.15 to 0.49 with an average value of 0.37. The intra-population genetic diversity revealed highest values of Nei's genetic diversity (0.19,) Shannon information index (0.29) and polymorphic loci (55.18%), among the accessions of Gujarat (GJ) population, while the corresponding lowest values were (0.10), (0.15) and (26.40%) respectively among the accessions of Rajasthan (RJ) population. The maximum inter-population average genetic distance (0.20) was between Karnataka (KA) and RJ, while the corresponding least genetic distance (0.06) was between Allahabad (AL) and Varanasi (VS) populations. The analysis of molecular variance (AMOVA) revealed maximum percentage of variation among individuals of populations (72%) followed by 16% among regions and 12% among populations. Principal coordinate analysis (PCA) of cumulative data also supported the clustering pattern in the UPGMA dendrogram. These results suggest that genetic diversity is corroborating with the geographical diversity. Mantel's test was performed which revealed a highly significant correlation between cumulative vs RAPD, and showed the maximum (0.93) correlation coefficient, followed by cumulative vs ISSR (0.78) and cumulative vs DAMD (0.91) respectively, and this clearly indicates that the SPAR methods (RAPD, DAMD and ISSR) are sufficiently informative and are suitable to analyze the genetic variability within and among the populations of S. emarginatus.     

琴叶风吹楠资源遗传多样性的AFLP分析

为研究濒危植物琴叶风吹楠(Horsfieldia pandurifolia)的遗传多样性,利用AFLP分子标记技术,对采自云南省西双版纳州、临沧市的8个居群共56份琴叶风吹楠样品进行了分析。结果表明,琴叶风吹楠在物种水平的多态性较高,多态性百分率为75.16%;在居群水平,平均多态性百分率为36.20%;AMOVA分析表明,琴叶风吹楠的遗传变异主要存在于居群内(75.45%),而居群间的变异仅为24.55%;mantel检验结果表明,地理距离和遗传距离存在不显著的正相关(r=0.119 7, P=0.321 0);基于遗传相似性系数,对8个居群进行了UPGMA聚类分析,在遗传相似性系数0.951处可将8个居群聚为3组。这些为琴叶风吹楠的保护和开发利用提供了理论依据,并提出了保护建议。     

Genetic diversity of Stemona parviflora: A threatened myrmecochorous medicinal plant in China

The plant species Stemona parviflora, which is endemically distributed in Hainan and Guangdong Provinces of China, is an important constituent of Chinese traditional medicine “Baibu”. Based on AFLP analysis, at the species level, the percentage of polymorphic bands (PPB), gene diversity H, and Shannon's information index I of S. parviflora are 100%, 0.2826, and 0.4458, respectively. The genetic differentiation among populations is low (G_st = 0.0799), while the gene flow among these populations is high (N_m = 5.754). Actually, no distinguishable genetic structure is inferred according to the AFLP analysis in this study. There was no significant positive correlation between genetic distance and geographic distance either. Based on its medicinal use, seed dispersal pattern (myrmecochory), mating system, fragmentation of the natural habitat by rubber and eucalyptus planting, and the historical formation and transition of Hainan island and Guangdong provinces, we discuss the current threatened condition of the traditional medicinal plant S. parviflora. In/ex situ conservation tactics are recommended to save this important species.     

Genetic relationships among some new cat populations sampled in Europe: A spatial autocorrelation analysis

The allelic frequencies of nine Mendelizing genetic characteristics that control coat colour, tabby and length and some skeletal abnormalities have been studied in four feral domestic cat populations, two in the north of Catalonia (Girona and Roses & L’Estartit, northeastern Spain) and two Adriatic Italian populations (Rimini and Venice). Using different genetic and multivariate analyses (Nei’s and Cavalli-Sforza and Edwards’s genetic distances, phenograms and cladograms using different algorithms, strict consensus trees, canonical population, principal coordinates and nonmetric multidimensional scaling analyses), I show the genetic relationships between these populations and other Western European cat populations previously studied. In the Western European area comprising Catalonia, Italy, France and Great Britain, I found significant spatial structure for thet ^b, l andW alleles and for the average correlogram for the seven alleles studied as a whole using a spatial autocorrelation analysis. The genetic distance matrices between these European cat populations also showed a significant correlation with the geographical distance between these populations using Mantel’s test. These analyses showed that in each of these countries, local cat populations have characteristic genetic profiles which were different to neighbouring populations in nearby countries. At least in this area of Western Europe, the geographical distances between cat populations (although the gene flow can be relatively high) is an important factor which can explain differences in allele frequencies between these populations.