Genetic diversity of Mexican brook lamprey <Emphasis Type="Italic">Lampetra (Tetrapleurodon) geminis</Emphasis> (Alvarez del Villar, 1966)

Lampreys are the only surviving representatives of the oldest known vertebrates. The Mexican lamprey L. geminis (nonparasitic), is particularly interesting, because it is an endemic, biogeographical relict, and a threatened species. RAPD markers were used to describe genetic diversity in L. geminis A total of 77 specimens were collected from five populations, three in the R'o Grande de Morelia-Cuitzeo basin and two in the R'o Duero-Lerma-Chapala basin, Mexico. Eighty-eight RAPD markers were obtained from eight primers. Genetic diversity within each population was estimated using Shannon's index (S), heterozygosity (H) and gene diversity (h). These estimates revealed significant variation within populations, although a variance homogeneity test (HOMOVA) showed no significant differences among populations or between basins. Nei genetic distance values indicate a low genetic differentiation among populations. Analysis of molecular variance (AMOVA) indicates that most of the genetic diversity occurs within populations (91.4%), but that a statistically significant amount is found among populations (P0.001). Principal coordinates and cluster analyses of RAPD phenotypes show that specimens are not grouped by geographical origin. The genetic diversity found within L. geminispopulations may be explained by its breeding system and an overlapping of generations. The scarce genetic differentiation among populations is likely to the low rate of DNA change that characterizes the lamprey group.     

Population Analysis of Licuala glabra Griff. var. glabra (Palmae) using RAPD Profiling

Random amplified polymorphic DNA (RAPD) profiling revealed geneticdiversity among three populations ofLicuala glabra var. glabra,an understorey palm growing in the dipterocarp forests of Terengganu,Malaysia. The Bukit Bauk population had individuals withoutaerial stems. The Bukit Besi individuals had stem heights to30 cm, while those of the Rasau Kerteh population had stemsup to 4 m in height. Southern blot analysis confirmed that anapparent monomorphic band generated by the primer OPU-17 amongthe three different populations corresponds to the same locus.Six primers were used to generate 87 RAPD bands that formed2-state character raw data for estimating genetic distancesusing the simple matching coefficient of similarity. The phenogramgenerated by UPGMA of the RAPD data grouped the individualsfrom the three populations under three clusters. This was inagreement with the morphological grouping. The infraspecificL. glabra var.selangorensis Becc. was grouped closer to theL. glabra var. glabra individuals than to the outgroupL. scortechiniiBecc. Principal component analysis supported the observationfrom the phenogram. The results show discrete genetic structuringin the populations studied and provide useful information forfuture conservation measures. Copyright 1999 Annals of BotanyCompany Licuala glabra Griff. var. glabra, RAPD, palm, AMOVA, population, genetic diversity, conservation.     

Genetic Diversity inBrassica oleraceaL. (Cruciferae) and Wild Relatives (2n=18) using RAPD Markers

This paper presents the evaluation of genetic diversity in 29populations of wild taxa of theBrassica oleraceaL. group (2n=18)and two cultivars, using RAPDs as molecular markers. In a previouspaper (Lázaro and Aguinagalde,Annals of Botany82: 000–000,1998), 11 isozymes were used for the same purpose. Results obtainedwith the two molecular markers (isozymes and RAPDs) are compared.DNA from ten individuals per population was analysed using sixdifferent primers; the 151 detected bands were polymorphic,11 were common to all species, six to all taxa, only one toevery population; and no bands were shared by every individual.The dendrogram obtained using genetic distances clustersB. oleraceapopulationswithB. bourgeaui, B. alboglabra, B. montanaandB. incana. B.insularis, B. macrocarpa, B. villosaandB. rupestrispopulationsform another cluster. Populations ofB. creticaandB. hilarionisformthe third cluster. Genetic diversity inB. oleraceapopulations,theB. rupestriscomplex andB. creticasubspecies was estimatedusing the AMOVA programme; the latter was the most diverse.Copyright1998 Annals of Botany Company. Brassica oleraceaL., wild relatives, genetic diversity, genetic resources, RAPD markers, AMOVA.     

大猿叶虫四地理种群遗传多样性的RAPD分析

以大猿叶虫Colaphellus bowringi Baly 4个地理种群的基因组DNA为材料, 进行RAPD分析。从80条引物中筛选出11条稳定性好、多态性高的引物进行扩增, 共得到65个扩增位点, 53个多态位点, Nei氏遗传多样性指数为0.1049~0.2061, Shannon多样性指数为0.1641~0.3167。结果表明所分析的大猿叶虫遗传变异很高, 其中江西龙南种群遗传变异最小, 山东泰安种群遗传变异最高。种群间的遗传距离范围为0.0636~0.3200, 其中江西龙南种群和江西修水种群间的遗传距离最小, 哈尔滨种群与江西龙南种群间的遗传距离最大, 种群遗传距离的大小与其相对地理距离的远近吻合。结果提示种群遗传距离的大小与它们生物学上的相似性有关联。     

Genetic diversity of the narrow endemic Allium aaseae (Alliaceae)

Low levels of genetic variability are common for a number of geographically restricted plants: these data are consistent with theoretical expectations that small populations should be genetically depauperate. However, in some species, high levels of variability have been found in rare species. Allium aaseae is a rare, narrow endemic in the foothills of the Boise Front of southwestern Idaho. Genetic variation in the rare endemic A. aaseae, and nearby populations of the more common species, A. simillimum, was examined with randomly amplified polymorphic DNA (RAPD) data. Eight populations of A. aaseae and six populations of A. simillimum (three near the range of A. aaseae, and three distant populations) of 25 individuals each were examined for this analysis. Genetic diversity as determined with RAPD markers of both species examined in this study is largely found within and not among populations. Levels of genetic diversity are high, especially for a narrow endemic species such as A. aaseae. Proportion of RAPD loci polymorphic was high in both species, although slightly higher in the more common A. simillimum. Because these higher levels of genetic variability run counter to theory, alternative explanations beyond population size must be invoked to explain the levels of genetic diversity found in this study. Possible explanations are (1) A. aaseae is only recently derived from A. simillimum, (2) hybridization between A. aaseae and A. simillimum is occurring, (3) multiple origins of A. aaseae, (4) populations of A. simillimum included in the analysis are all A. aaseae, (5) A. aaseae and A. simillimum are conspecific, and (6) an artifact of RAPD data.     

Inter and intraspecific genetic diversity (RAPD) among three most frequent species of macrofungi (Ganoderma lucidum,Leucoagricus sp. and Lentinus sp.) of Tropical forest of Central India

In present study seven RAPD primers were used to access the diversity within and among twelve populations of three mushroom species Ganoderma lucidum, leucoagaricus sp. and Lentinus sp. Total of 111 bands were scored by 7 RAPD primers in 30 accessions of three mushroom species collected from different sampling sites of central India. Total 111 bands were generated using seven primers which were F-1, OPG-06, OPC-07, OPD-08, OPA-02, OPD-02, OPB-10. All 111 bands were polymorphic in nature (100%). Therefore, it revealed that the used primers had sufficient potency for population studies and 30 accessions had higher genetic differences among each other. In best of the knowledge, this is the first report, which accesses the genetic diversity between three mushroom species (Gd Ganoderma lucidum, Lg Leucoagaricus sp., Ls Lentinus). The polymorphic percentage ranged from 3.60 to 23% within twelve populations, while polymorphic percentage among group was 40.56, among population within groups was 41.12 and within population was 18.32. This indicated that the genetic diversity within the population was very low, but slightly higher in the populations of three species. Among three groups representing Gd., Lg and Ls, Among populations within groups shown highest percentage of variation (Pv?=?41.12) while within populations, the lowest percentage of variation (18.32) was observed. This result also support that the highest genetic variation was present among groups in comparison to among the population within a species and lowest genetic variation was observed within the population.     

RAPD Profiling in Detecting Genetic Variation in Endemic Coelonema (Brassicaceae) of Qinghai-Tibet Plateau of China

Random amplified polymorphic DNA (RAPD) markers were used to measure genetic diversity of Coelonema draboides (Brassicaceae), a genus endemic to the Qilian Mountains of the Qinghai-Tibet Plateau. We sampled 90 individuals in 30 populations of Coelonema draboides from Datong and Huzhu counties of Qinghai Province in P.R. China. A total of 186 amplified bands were scored from the 14 RAPD primers, with a mean of 13.3 amplified bands per primer, and 87% (161 bands) polymorphic bands (PPB) was found. Analysis of molecular variance (AMOVA) shows that a large proportion of genetic variation (84.2%) resides among individuals within populations, while only 15.8% resides among populations. The species shows higher genetic diversity between individuals than other endemic and endangered plants. The RAPDs provide a useful tool for assessing genetic diversity of rare, endemic species and for resolving relationships among populations. The results show that the genetic diversity of this species is high, possibly allowing it to adapt more easily to environmental variations. The main factor responsible for the high level of differentiation within populations and the low level of diversity among populations is probably the outcrossing and long-lived nature of this species. Some long-distance dispersal, even among far separated populations, is also a crucial determinant for the pattern of genetic variation in the species. This distributive pattern of genetic variation of C. draboides populations provides important baseline data for conservation and collection strategies for the species. It is suggested that only populations in different habitats should be studied and protected, not all populations, so as to retain as much genetic diversity as possible.     

Genetic diversity analysis of Rhododendron aureum Georgi (Ericaceae) located on Changbai Mountain using ISSR and RAPD markers

Rhododendron aureum Georgi (Ericaceae) is a perennial alpine shrub endemic to Changbai Mountain in China. We used ISSR and RAPD markers to describe the diversity and genetic structure within and among four natural populations located at different altitudes. DNA from 66 individuals was amplified with ten ISSR markers and seven RAPD markers. High genetic diversity was observed by these two techniques at the species level. The genetic diversity of populations increased with altitudinal gradients from low to high. The coefficient of gene differentiation (G_ST 0.3652 in ISSR and 0.2511 in RAPD) and AMOVA analysis revealed that most genetic diversity was distributed within populations (61.96% in ISSR and 70.23% in RAPD). The estimate of gene flow based on G_ST was 0.8690 in ISSR and 1.4910 in RAPD. The UPGMA clustering results using ISSR and RAPD showed that all individuals from the same altitude were gathered together, and the two populations (TYD2a and YHLa) from middle altitudes always clustered together. Compared with populations from different altitudes, similar genetic diversity and low genetic differentiation were obtained from populations at the same altitudes, as revealed by ISSR markers. In addition to the reproductive strategy of R. aureum, these data highlight that local environmental conditions may play an important role in shaping the diversity and genetic structure of this species.     

High RAPD but no cpDNA sequence variation in the endemic and endangered plant, Heptacodium miconioides Rehd. (Caprifoliaceae)

Heptacodium miconioides Rehd. is an endangered species endemic to China and has suffered rapid decrease of distribution range and population size. This species has been disappeared in central China where the modal specimen was collected. We analyzed the genetic variation of the remaining populations to reveal whether the genetic diversity also suffered decrease and to provide some suggestions for conservation. All the nine known remaining populations were sampled. Genetic variation was analyzed based on RAPD markers and two fragments of cpDNA sequence, intergenic spacers of petG-trnP and trnS-trnG. No variation was observed in the two fragments of cpDNA sequence. However, the species exhibited high level of RAPD variation compared to other threatened or rare plants. Measures of genetic diversity within populations were strongly related to the log of estimated population size, indicating that large populations usually have more genetic diversity than that of small ones. About 25% of the variation was partitioned among populations. Significant relationship was observed between differentiation and geographical distance, indicating a pattern of isolation-by-distance. Given for few populations remaining, all the populations should be protected and urgent efforts be paid on the small populations to avoid their local extinction.     

Random Amplified Polymorphic DNA Variation among and within Selected Ixora (Rubiaceae) Populations and Mutants

Random amplified polymorphic DNA (RAPD) analysis was used tostudy variation among and within selectedIxora (Rubiaceae) populationsand mutants. Six populations of I. congesta yielded identicalbanding patterns suggesting genetic uniformity of this species.However, six populations of I. coccinea varieties (three red-flowered,two yellow-flowered and one red-flowered wild-type) exhibitedinfraspecific differences in RAPD profiles. Small and largeleaves of an atavistic mutant cultivar of I. coccinea were alsosubjected to RAPD analysis. An extra band was amplified in thelarge leaves that was absent in small leaves, suggesting thatthe phenotypic alteration in this taxon is due to genetic mutationrather than epigenetic changes. Similarly, an extra band wasdetected in the white sectors of I. Variegated compared to thegreen sectors, suggesting that the shoot apical meristems ofthis cultivar exist as a genetic chimera. DNA gel blot hybridizationwas performed to confirm the specificities of selected bands.Our study indicates that differences among individuals of variouspopulations and mutants may be detected using RAPD markers.Copyright 1999 Annals of Botany Company Ixora L., variegated variety, RAPD fingerprinting, DNA gel blot, intraspecific genetic similarity, atavistic mutant.     

Conservation genetics of endangeredBrasenia schreberi based on RAPD and AFLP markers

Brasenia schreberi J.F. Gmelin is a declared endangered species found in the lakes and ponds of South Korea. For planning its conservation strategy, we examined the genetic diversity within and among six populations, using randomly amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP). Polymorphisms were more frequently detected per loci with AFLP (69.3%) than RAPD (36.8%). High genetic diversity was recognized within populations: polymorphic loci (PPL) values ranged from 36.3% in the CJM population to 74.5% in the GGT population, with a mean value of 47.8% based on AFLP markers. Great genetic differentiation (θ^B) was detected among the six populations (0.670 on RAPD and 0.196 on AFLP), and we calculated a low rate of gene flow (N_em), i.e., 0.116 on RAPD and 0.977 on AFLP. Furthermore, a Mantel test revealed that no correlation existed between genetic distances and geographical distances among the six local populations, based on RAPD or AFLP markers. These results are attributed to a number of factors, including an insufficient length of time for genetic diversity to be reduced following a natural decline in population size and isolation, adaptation of the genetic system to small population conditions, and a restricted gene flow rate. Based on both its genetic diversity and population structure, we suggest that a strategy for conserving and restoringB. schreberi must focus on maintaining historical processes, such as high levels of outbreeding, while monitoring increased gene flow among populations. This is because a reduction in genetic diversity as a result of genetic drift is undesirable.     

Population genetic study in the Balearic endemic plant species Digitalis minor (Scrophulariaceae) using RAPD markers

Digitalis minor (Scrophulariaceae) is a cardenolide-producing plant endemic to the eastern Balearic Islands (Mallorca, Menorca, and Cabrera) that occurs in two morphologically distinct varieties: D. minor var. minor (pubescent) and D. minor var. palaui (glabrous). Levels and patterns of genetic diversity in 162 individuals from 17 D. minor populations across the entire geographic range were assessed using random amplified polymorphic DNA (RAPD) markers. Comigrating RAPD fragments tested were found to be homologous by Southern hybridization in both var. minor and var. palaui. To avoid bias in parameter estimation, analyses of population genetic structure were restricted to those RAPD bands that fulfilled the 3/N criterion (observed frequencies were less than 1 - [3/N] in each population) either among or within each island. Analyses of molecular variance (AMOVAs) with distances among individuals corrected for the dominant nature of RAPD (genotypic analysis) showed low values (1.57-17.55%) of between-population variability, indicating a relatively restricted population differentiation as expected for an outcrossing species such as D. minor. Nested AMOVAs demonstrated, however, a not significant partitioning of genetic diversity among Mallorca, Menorca, and Cabrera islands. Estimates of the Wright, Weir, and Cockerham and the Lynch and Milligan F(ST) from null allele frequencies corroborated AMOVA partitioning and provided evidence for population differentiation in D. minor. Our RAPD data did not show significant differences between pubescent and glabrous populations of D. minor, suggesting a failure to find a correlation between the RAPD loci and this morphological trait.     

祁连山区特有物种黑虎耳草的居群遗传多样性研究

利用叶绿体基因(rbcL和trnS-G)及核糖体DNA内转录间隔区(ITS),对祁连山区狭域分布的特有物种黑虎耳草8个居群(115个个体)进行遗传多样性研究,旨在揭示黑虎耳草的居群遗传结构及其历史进化过程。结果表明:(1)所有取样个体共检测到4个cpDNA单倍型和9个ITS单倍型,其中祁连山东南部的居群固定较多的单倍型和特有单倍型,而西北部居群只固定少数几个广泛分布的单倍型,且遗传多样性普遍较低。(2)基于cpDNA数据和ITS数据的分子变异分析(AMOVA)显示,遗传变异主要来源于居群内。(3)基于cpDNA数据的中性检验表明,Tajima’s D(-1.012 30,P 0.05)和FuLi’s D*(-2.066 77,P 0.05)均为负值,均不显著;歧点分布分析结果显示,黑虎耳草居群经历过近期的扩张事件。根据物种现有遗传分布格局推测,黑虎耳草在第四纪冰期时退缩到祁连山东南部的边缘避难所,间冰期或冰期后回迁到祁连山西北部地区,在回迁过程中由于奠基者效应导致祁连山西北部的居群仅固定少数广泛分布的单倍型,并呈现出较低的遗传多样性;由于居群较小且相互隔离,该物种经历了严重的瓶颈效应和遗传漂变,导致该物种总遗传多样性(H_T)和居群平均遗传多样性(H_S)远低于虎耳草属其他青藏高原-喜马拉雅广域分布的物种。     

AN EVALUATION OF RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) FOR THE IDENTIFICATION AND PHYLOGENY OF FRESHWATER SNAILS OF THE GENUS BULINUS (GASTROPODA: PLANORBIDAE)

The Random Amplified Polymorphic DNA (RAPD) assay was used tostudy genetic variation within and between 9 species of thegenus Bulinus and to determine whether RAPD profiles could beused as markers for identification purposes. RAPDs were generatedwith 8 primers of two different sizes (l0mers & 15mers)and were visualised using both polyacrylamide gel electrophoresis(PAGE) with silver staining and agarose gel electrophoresiswith ethidium bromide staining. The species groups of Bulinushad few similarities in their RAPD profiles and there was interspecificvariation within groups. Intrapopulation variation was observed,with all primers, for B globosus collected from a single sitein Zimbabwe PAGE/silver staining methods visualised a greaternumber of RAPDs in comparison with agarose/ethidium bromidemethods. Phenetic analysis indicated that distance estimatesbetween taxa were sometimes non-additive and the phylo-geneticanalysis of such non-metnc data is discussed. The resultantphenograms, constructed using a least squares method, were constrainedalmost into a polytomy with topologies often differing betweendata sets. It was concluded that this phenomenon was most likelyattributable to large nucleotide divergences between the speciesgroups which go beyond the phylogenetic scope of RAPD analysis.RAPD profiles, when used in conjunction with other taxonomicmethods, may contribute to the identification of species ofBulnus on a regional basis, but the observed variability ina natural population suggests that a diagnostic RAPD profilefor each species throughout its geographic range is unlikely. (Received 19 April 1995; accepted 1 September 1995)     

Population genetics of drifting (Calanus spp.) and resident (Acartia clausi) plankton in Norwegian fjords

Kaartvedt distinguished between drifting and resident planktonand hypothesized that the latter were distinguished by theirability to maintain their horizontal position in desired habitats(Kaartvedt, 1993). In this study, we examined the populationgenetic consequences of these two lifestyles for copepods infour fjords of western Norway (Lurefjorden, Masfjorden, Sognefjordenand Sørfjorden) and one fjord in eastern Norway (Oslofjorden).Based on DNA sequence variation of a region of mitochondrial16S rRNA, we contrasted population genetic diversity and structurein drifting populations of Calanus spp. with that of residentpopulations of Acartia clausi. With the exception of Sørfjorden(where Calanus spp. were rare), two or three species of Calanusco-occurred in significantly different proportions in the fjords.Based on a 350 base-pair region of mitochondrial 16S rRNA, Calanusspp. varied in molecular genetic diversity, with the highestvalues for C.helgolandicus. There was no evidence of significantgenetic structure of fjord populations for either C.finmarchicusor C.helgolandicus; the population structure of C.glacialiscould not be evaluated as the species was only abundant in Lurefjorden.Acartia clausi was abundant in all five fjords sampled for thisstudy. Molecular genetic diversity of A.clausi, based on a 220bp region of mt 16S rRNA, was within the range of Calanus spp.values. Populations of A.clausi showed significant genetic structure(i.e. haplotype frequencies differed markedly) among the fjords.The results of this study indicated that little exchange (geneflow) occurs between populations of A.clausi in different fjords,and suggested that the populations are long-term residents ofa fjord. In contrast, most Calanus spp. fjord populations maybe replaced periodically, as they drift with currents flowingto and from coastal and fjord environments.     

Genetic variability of an endangered Bromeliaceae species (Pitcairnia albiflos) from the Brazilian Atlantic rainforest

Pitcairnia albiflos is a Bromeliaceae species endemic to Brazil that has been included as data-deficient in the extinction risk list of Brazilian flora. We analyzed genetic variability in P. albiflos populations using RAPD markers to investigate population structure and reproductive mechanisms and also to evaluate the actual extinction risk level of this species. Leaves of 56 individuals of P. albiflos from three populations were collected: Urca Hill (UH, 20 individuals), Chacrinha State Park (CSP, 24 individuals) and Tijuca National Park (TNP, 12 individuals). The RAPD technique was effective in characterizing the genetic diversity in the P. albiflos populations since it was possible to differentiate the populations and to identify exclusive bands for at least two of them. Even if there is low genetic diversity among them (CSP-UH = 0.463; CSP-TNP = 0.440; UH-TNP = 0.524), the populations seem to be isolated according to the low genetic diversity observed within them (H(pop) CSP = 0.060; H(pop) UH = 0.042; H(pop) TNP = 0.130). This fact might be the result of clonal and self-reproduction predominance and also from environmental degradation around the collection areas. Consequently, it would be important to protect all populations both in situ and ex situ to prevent the decrease of genetic variability. The low genetic variability among individuals of the same population confirms the inclusion of this species as critically endangered in the risk list for Brazilian flora.     

Population genetic structure of Titanotrichum oldhamii (Gesneriaceae), a subtropical bulbiliferous plant with mixed sexual and asexual reproduction

• Background and Aims Titanotrichum oldhamii is a monotypicgenus distributed in Taiwan, adjacent regions of China and theRyukyu Isands of Japan. Its conservation status is vulnerableas most populations are small and widely scattered. Titanotrichumhas a mixed system of reproduction with vegetative bulbils andseeds. The aim of this study was to understand the populationgenetic structure of Titanotrichum in relation to its specificreproductive behaviour and to determine possible implicationsfor conservation strategies. • Methods After an extensive inventory of most wild populationsof Titanotrichum in East Asia, samples from 25 populations withinits major distribution were carried out utilizing RAPD and inter-SSRmolecular fingerprinting analysis. • Key Results The findings support the conclusion thatmany populations reproduce predominantly asexually but thatsome genetic variation still exists within populations. However,significant amounts of variation exist between populations,perhaps reflecting population differentiation by drift. Thispartitioning of genetic diversity indicates that the level ofinter-population gene exchange is extremely low. These findingsare consistent with field observations of very limited seedproduction. The Chinese populations are similar to those ofNorthern Taiwan, while the Ryukyu populations fall within therange of variation of the north-central Taiwan populations.The Taiwanese populations are relatively variable and differentiationbetween north, east and south Taiwan is evident. • Conclusions The distribution of Titanotrichum seems tobe consistent with a former land connection between China, Taiwanand the Ryukyu Islands at a glacial maximum during the Quaternary,followed by progressive fragmentation of the populations. North-centralTaiwan is the centre of genetic diversity, possibly due to theproximity of the former land bridge between the regions, togetherwith the variety of suitable habitats in north Taiwan. The significanceof these findings for conservation is discussed.     

Randomly amplified polymorphic DNA analysis of four different populations of the Indian major carp, Labeo rohita (Hamilton)

The level of genetic variation provides the raw material for selective improvement of a stock. Random amplified polymorphic DNA (RAPD) assay was used to assess the genetic variation in three rivers: the Halda, the Jamuna and the Padma as well as in one hatchery population of the commercially important Indian major carp, Labeo rohita. RAPD markers were amplified from DNA samples of 35 fish from each of the four populations using six decamer random primers. The polymorphic loci proportions were 0.33, 0.28, 0.28 and 0.26 and Nei's gene diversity values were 0.06, 0.07, 0.06 and 0.05 for the Halda, the Jamuna, the Padma and the hatchery populations, respectively. The pairwise population differentiation (F_ST) values indicated a low level of genetic differentiation between the population pairs. From the unweighted pair group method of arithmetic mean (UPGMA) dendrogram based on Nei's genetic distances a correlation between genetic affinities and geographical area was found. The populations were segregated into two groups: the Halda in one group and the Jamuna, the Padma and the hatchery in another group. Overall, the RAPD technique can be introduced as a tool in the population genetics of the rohu fish to provide information on their genetic stock structure.     

Intra-specific genetic diversity in wild olives (Olea europaea ssp cuspidata) in Hormozgan Province, Iran

Wild olive (O. europaea ssp cuspidata) plants grow in various regions of Iran and are expected to have considerable genetic diversity due to adaptation to the various environmental conditions. We examined the genetic diversity of four populations of wild olive growing in Hormozgan Province located in southern Iran by using 30 RAPDs and 10 ISSR markers. The mean value of polymorphism for RAPD loci was 73.71%, while the value for ISSR loci was 81.74%. The Keshar population had the highest value of intra-population polymorphism for both RAPD and ISSR loci (66.86 and 62.71%, respectively), while the Tudar population had the lowest values (20.35 and 28.81%, respectively). Similarly, the highest and lowest number of effective alleles, Shannon index and Nei's genetic diversity were also found for these two populations. The highest value of H(pop)/H(sp) within population genetic diversity for RAPD and ISSR loci was found for the Keshar population (H(pop) = 0.85 and H(sp) = 0.90). OPA04-750, OPA13-650 and OPA02-350 RAPD bands were specific for Tudar, Bondon and Keshar populations, respectively, while no specific ISSR bands were observed. Analysis of molecular variance as well as the pairwise F(ST) test showed significant differences for RAPD and ISSR markers among the populations. The NJ and UPGMA trees also separated the wild olive populations from each other, indicating their genetic distinctness. UPGMA clustering of the four wild olive populations placed the Tudar population far from the other populations; Keshar and Bokhoon population samples revealed more similarity and were grouped together. We conclude that there is high genetic diversity among O. europaea ssp cuspidata populations located in southern Iran. We also found RAPD and ISSR markers to be useful molecular tools to discriminate and evaluate genetic variations in wild olive trees.     

不同地理种群银杏大蚕蛾COI基因序列变异与遗传分化

银杏大蚕蛾Caligula japonica是亚洲东部的特有种, 既是一种重要的林业害虫, 也是一种珍贵的野生蚕类资源。为了揭示银杏大蚕蛾地理种群间的内在联系, 测定了我国分布的12个地理种群的线粒体细胞色素氧化酶C亚基I（COI）基因部分序列（GenBank登录号: FJ358506-FJ358517）, 对地理种群间的序列变异和遗传分化进行了分析。结果表明: 银杏大蚕蛾地理种群间的COI序列同源性高达99%~100%, 显示出比较小的遗传差异。序列对准后从供试COI序列中仅鉴定出9个变异位点和6个单元型, 其中3种是共享单元型。系统发育分析结果表明种群间已经按地理位置形成了一定的地理格局, AMOVA分析显示北方组和南方组之间已经具有明显的遗传分化（FST=0.478, P<0.001）。综合分析, 我们认为北方组和南方组之间的遗传分化可能与差异巨大的生态条件有关。研究结果为银杏大蚕蛾的种群遗传学和生态学研究提供了一个基本的分子生物学线索。