Patterns of morphological diversity in tetraploid wheat (Triticum turgidum L.) landraces from Ethiopia

Thirty‐four tetraploid (2n = 4x = 28) wheat (Triticum turgidum L.) landrace populations collected from four regions in Ethiopia, and consisting of 4099 entries were characterized for glume colour, glume pubescence, beak awn, seed colour and spike density. The main objective was to analyse the diversity and distribution of these traits on the basis of administrative regions and altitudinal gradients. The Shannon‐Weaver Diversity Index (H') was used to estimate the magnitude of diversity. With the exception of spike density, all characters were polymorphic in all regions and most altitude groups. However, clinal patterns were observed in only a few cases. At the population level, the mean H’ varied from completely monomorphic (H’ = 0.00) to highly polymorphic (H’ = 0.80 ± 0.07). The highest diversity was found in regions with relatively better climatic conditions and in optimal altitude ranges. On country basis, seed colour (H’ = 0.98) and spike density (H’ = 0.43) displayed the highest and the lowest diversity indices, respectively. Spike density was the only character that exhibited significant differences (P<0.01) both “between regions”; and “between altitude groups”;. Across characters, most of the variance was due to the lowest hierarchy, the “within‐population”; component. The “between region”; and “between altitude group”; variances were significant, but spike density alone was responsible for the differences. The overall mean H’ for Ethiopia was 0.77 + 0.09 and did not seem to have reduced appreciably within the past 25 years or so, when compared to previous estimates.     

Isozyme Polymorphism and Genetic Differentiation in Natural Populations of a New Tetraploid Species <Emphasis Type="Italic">Avena agadiriana</Emphasis>, from Morocco

A new wild tetraploid oat Avena agadiriana Baum et Fedak was collected from the five populations along the Atlantic coast in Morocco. Variations in six enzyme systems were surveyed and allele frequency, percentage of polymorphic loci, number of alleles per locus, observed and expected heterozygosities, and unbiased genetic distance were calculated. Phenotypic frequencies were scored representing 11 polymorphic loci. The mean percentage of polymorphic loci was 46.25, the mean number of alleles per locus was 1.502, and the mean expected heterozygosity was 0.1526. Two heterozygotes resulting from outcrosses were found in the progeny from M60 and M71. The population of M71 had peculiar alleles Est-4A not present in the other populations. Most of the genetic diversity of this species was between populations with little existing within populations. Geographic and genetic distances between populations were positively correlated with each other and the correlation coefficient was 0.7031. Cluster analysis showed two strongly differentiated groups were apparent, M71 and M74, and the remainder. The former group appears to be adapted to man-made habitat, such as road side or eucalyptus plantation, and the latter to a distinct dry, sandy habitat. To make wide intra-specific variation in this species, the modified mating system would be indispensable.     

紫茎泽兰群体遗传多样性及遗传结构的AFLP分析

紫茎泽兰是我国最为严重的入侵物种之一。本研究以中国境内的紫茎泽兰为材料，用AFLP方法研究了其群体遗传多样性及遗传分化。用筛选出的3对荧光引物，对5个地区62个群体进行AFLP分析，共扩增出490条带，其中多态性带328条，群体的遗传多样性较高(P = 66.9%，H = 0.171，I = 0.268)，主要存在于群体内，群体间的遗传分化系数Fst为0.287。AMOVA分析表明，在地区水平紫茎泽兰的遗传分化主要存地区内，群体内遗传分化占 70.25%，群体间遗传分化占21.71%，地区间的遗传分化仅占8.04%。UPGMA聚类分析结果表明，62个地理群体主要分为四大类群，并且有明显的地缘关系。Sigmaplot分析表明海拔是影响紫茎泽兰遗传多样性主要地理因子。Mantel检验表明遗传距离与地理距离成正相关(r = 0.34)，但也有例外。由此推断风媒传播可能是紫茎泽兰的主要传播方式，水媒传播可能是紫茎泽兰的另一主要传播途径；随着紫茎泽向东、向北扩散，新入侵地区的遗传多样性逐步降低。     

Isozyme polymorphism and genetic differentiation in natural populations of an endemic tetraploid species <Emphasis Type="Italic">Avena maroccana</Emphasis> in Morocco

A wild tetraploid oat Avena maroccana Gdgr. was collected from the 11 populations in the periphery of Rommani and Casablanca geographic groups of Morocco. Genetic diversity of the species was investigated using six allozyme systems. Allelic frequencies were scored representing eight polymorphic and five monomorphic loci. Coefficient of gene differentiation (Gst) was 0.3019, which indicated great genetic differentiation. The number of alleles per locus was 2.6154, the percentage of polymorphic loci was 61.54, and the expected heterozygosity was 0.2462 in all populations. Genetic diversity in A. maroccana was high in comparison to self-pollinated species. In total, nine heterozygotes resulting from outcrossing were found in the progeny from M1, M3, M4, M22 and M26. The population of M7 had peculiar alleles Pgd–2SS and Pgd-1SS in high frequency. M9 had the lowest level of diversity out of the 11 populations. Geographic and genetic distances between all the populations were not significantly correlated with each other (r = 0.0996). Cluster analysis showed that two groups, (M1, M22, M2 and M4) and (M3, M23, M8, M5 and M26) were apparently differentiated. Two populations of the Casablanca group, M7 and M9 were independent from each other, and were separated distinctly from the other populations. Genetic diversity of the Rommani and Casablanca groups was almost the same in all the parameters. This was due to the similar man-made habitat such as roadside or rich fertile soil and brown clay soils. The population size of A. maroccana was small and restricted to the narrow central Morocco with great genetic differentiation so that genetic diversity may be reflected from the results of genetic drift and outcrossing heterozygote segregation.     

桂林地区蜈蚣蕨群体遗传多样性及与南宁地区群体的对比分析

采用等位酶电泳技术,研究了桂林地区的桂林市、雁山镇、永福县的野生蜈蚣蕨群体的遗传多样性,并与南宁地区群体进行比较。所测定的酶系统包括：氨基肽酶（AMP）、还原型辅酶Ⅰ心肌黄酶（DIA）、异柠檬酸脱氧酶（IDH）、苹果酸脱氨酶（MDH）、6-磷酸葡萄糖酸脱氢酶（PGD）、磷酸葡萄糖异构酶（PGI）、磷酸葡萄糖变位酶（PGM）和莽草酸脱氧酶（SKD共8个酶系统,15个酶位点。分析结果表明：桂林地区蜈蚣蕨群体内遗传多样性水平中等偏上,每个位点的等位基因平均为1．7,多态位点百分数为60％,平均期望杂合度为0．251,略高于南宁地区。     

Genetic diversity in wild Tunisian populations of Mentha pulegium L. (Lamiaceae)

The allozyme variation of 15 Tunisian wild populations of Mentha pulegium L. threatened by human activities (clearing, hard-grazing, ploughing, traditional uses) was surveyed by the analysis of 14 isozyme loci using horizontal gel starch electrophoresis. The species exhibited a high level of genetic variation within populations (the mean Ap = 2.20, P = 72%, Ho = 0.349 and He = 0.229), which indicates a predominately outcrossing mating system and the recruitment of new genotypes via dispersal seeds. The genetic structure analysis of the populations using F statistics indicates no inbreeding, and showed an excess of heterozygosity for few loci. The moderate differentiation of populations (F_ST = 0.110) and the low rate of gene flow between them (Nm = 2.02) might been caused by recent isolation of the populations through biotope disturbances. The value of Nei's genetic identity varied from 0.839 to 0.999 reflecting a relatively low genetic divergence between populations. Cluster analysis using UPGMA method and Nei's genetic identity values, showed that populations geographically close didn't always cluster together. However, populations within the same bioclimatic stage generally subclustered together indicating that differentiation between bioclimatic regions occurred.     

江西野生毛花猕猴桃群体SSR遗传多样性研究

为分析江西野生毛花猕猴桃群体遗传多样性,以江西省境内的5个野生毛花猕猴桃雄性群体(72个个体)为试验材料,采用SSR分子标记技术,选取15对多态性引物,利用聚丙烯酰胺电泳对PCR产物进行检测。结果表明,15对SSR引物共检测到86个位点,多态性位点百分率为100.0%;观察到的平均等位基因数为5.733,有效等位基因数为3.002,Shannon信息指数为1.046。表观杂合度介于0.111~0.819之间,预期杂合度介于0.041~0.876之间,遗传分化系数为2.01,野生毛花猕猴桃雄性群体间存在较大的遗传分化。5个毛花猕猴桃雄性群体遗传距离范围为0.102~0.409,遗传相似度范围为0.665~0.903,群体间遗传距离与地理距离无相关性。群体的遗传多样性丰富度依次为庐山>井冈山>南源山>武功山>麻姑山,江西地区供试的野生毛花猕猴桃雄性群体在分子水平上具有丰富的多态性。本研究结果为毛花猕猴桃雄性品种选育、种质创新与利用提供了一定的理论基础。     

江西青岚湖五种淡水蚌遗传多样性的微卫星DNA分析

利用北美Epioblasma capsaeformis（蚌科）和中欧Margaritifera margaritifera L.（珍珠蚌科）两种淡水双壳类的20对微卫星引物对江西青岚湖五种淡水蚌群体进行了PCR扩增，筛选出8对多态性较高的引物，并用这8个微卫星座位分别对三角帆蚌、褶纹冠蚌、洞穴丽蚌、射线裂脊蚌和中国尖嵴蚌五种蚌类群体进行了遗传多样性分析。结果表明：不同蚌类群体的平均等位基因数为2.8750～4.000，平均观测杂合度（HO）为0.4417～0.6333，平均期望杂合度（HE）为0.4430～0.5706，平均多态信息含量（PIC）为0.368～0.498，五个群体表现出较高的遗传多样性。有多个座位在不同蚌类群体中偏离哈代－温伯格平衡。五种蚌类群体间的遗传距离在0.6228与1.4724之间，三角帆蚌和褶纹冠蚌之间的遗传距离最大，射线裂脊蚌和洞穴丽蚌之间的遗传距离最小。     

Genetic diversity and population structure of Guinea yams and their wild relatives in South and South West Ethiopia as revealed by microsatellite markers

Genetic diversity and population structure of Guinea yams and their wild relatives collected from south and south west Ethiopia were assessed using microsatellite markers. The total number of alleles amplified for the 7 loci studied was found to be 60, with an average of 8.6 alleles per locus. The average expected heterozygosity for the entire population was found to be 64 % indicating that Guinea yams and their wild relatives in the study area display a high level of genetic diversity. Using allelic richness as a measure of genetic diversity the wild forms exhibited greater allelic diversity than the cultigens. Contrary to what is expected in vegetatively propagated crops, none of the seven loci studied showed a significant excess of heterozygotes. In all the comparisons made, a low mean F_ST (but significant) has been observed, indicating that the majority of microsatellite diversity in the populations under study was found within rather than between populations.     

Genetic variation in the endangered Rutaceae species <Emphasis Type="Italic">Citrus hongheensis</Emphasis> based on ISSR fingerprinting

Citrus hongheensis is a critically endangered species endemic to the Honghe river region in southeastern Yunnan, China. Its genetic diversity and differentiation were investigated using Inter-Simple Sequence Repeat (ISSR) markers. One hundred primers were screened, and a total of 245 loci were amplified from seven natural populations by 13 informative and reliable primers. Of these 245 ISSR loci, 233 were polymorphic and the detected variations revealed a relatively high level of intraspecific genetic diversity. At the population level, the mean percentage of polymorphic loci (PPB) was 36.50%, while the average expected heterozygosity (He) and Shannon diversity index (Ho) were 0.1327 and 0.1972, respectively. At the species level (across all populations), PPB was 95.10%, while He and Ho were 0.3520 and 0.5195, respectively. A high Gst value (0.6247) indicated that there is significant differentiation among populations, which was confirmed by AMOVA analysis (Φst = 0.6420). Pairwise genetic identity (I) values among populations ranged from 0.6341 to 0.7675, with a mean of 0.7008. We propose that the high level of genetic differentiation may be the result of habitat fragmentation and limited gene flow (Nm = 0.1502). For effective in situ conservation and population restoration of C. hongheensis it will be important to maintain historical processes, including high outbreeding rates, sufficient gene flow, and large effective population sizes.     

Isozyme diversity and analysis of the mating system of the wild rice Oryza latifolia Desv. in Costa Rica

Oryza latifolia is the most abundant and widespread wild relative of rice in the lowlands of Costa Rica. It also has the most diverse morphology. However, little is known about the genetic diversity and mating system of this allotetraploid species. Genetic analyses of nine populations from different life zones from the Pacific and Atlantic slopes were performed using six isozyme loci. Differences in genetic variability were observed among populations, of which Palo Verde and Santa Rosa were the most diverse. Most Atlantic populations clustered together, and a similar result was obtained with the Pacific populations. High levels of interpopulation diversity were observed while most populations were monomorphic for at least one genotype, suggesting little genetic flow within populations. Even in polymorphic populations no variation was observed within progeny groups, combined with Hardy-Weinberg disequilibria in most populations, commonly observed in autogamous species or in species with clonal reproduction. However, the high frequency of heterozygous-like patterns may suggest that the reproductive system of O. latifolia might be more complex. Future research may explain the genetic patterns as well as the reproductive biology of this species. The knowledge of the genetic diversity and mating system of O. latifolia could contribute to the implementation of genetic resource conservation strategies and gene flow analyses, as well as of breeding programs for rice improvement.     

Diversity in natural populations of wild Brassica oleracea as estimated by isozyme and RAPD analysis

Naturally occurring populations of wild Brassica oleracea were collected in Spain, France, and Great Britain. Allele frequencies at four isozyme loci were determined for 18 populations, while five populations were screened using five random primers to generate RAPDs. Levels of homozygosity and gene diversity, H, were computed for each population using isozyme data and RAPD data when applicable. Homozygosity levels tended to be higher in smaller populations, which could also be observed as increased numbers of homozygous loci in smaller populations. Gene diversity values based on isozymes indicated considerable within population variation regardless of population size. The RAPID based gene diversities were significantly higher and the two exceptional populations displayed diversity levels more in keeping with the rest. The coefficient of gene differentiation, G _ST , for populations in each region showed that the Spanish populations were more homogenous than the French or British. When the G _ST for all populations was calculated using isozymes vs. RAPD data, the RAPD data gave a significantly lower value, a plausible result of the higher within population variation detected using RAPDs. Genetic distances between populations from different regions were also calculated from both data sets and used to produce phenograms. Clustering according to geographic region was not evident using either isozyme or RAPD data.     

Genetic diversity in populations of wild diploid wheat Triticum urartu Tum. ex. Gandil. revealed by isozyme markers

Genetic variation and its distribution within and among 23 populations of Triticum urartu collected from Syria, Lebanon, Turkey, Armenia, and Iran was estimated using isozyme markers at eight polymorphic loci. The number of alleles per locus (A= 1.21), percentage polymorphic loci (P= 20.1%), and mean gene diversity (H_e= 0.024) were relatively low. In a population from Lebanon, a high number of alleles per locus (A= 2.13) and percentage polymorphic loci (P= 87.5%) was found. On average, genetic variation among populations (G_ST= 0.407) was smaller than within-population variation (0.593). However, different patterns of genetic structure were found among various geographic regions. Interpopulation variation was highest for the Iranian populations (0.89) followed by the Turkish populations (0.66). A reverse pattern was observed for the Syrian (0.11) and for the Lebanese (0.13) populations. The Armenian populations exhibited similar interpopulation and within-population variation. Principal component and cluster analyses resulted in distinct grouping of the geographically proximal populations, with the exception of the two Iranian populations. The Turkish populations were different from the neighboring Armenian populations compared to other countries. The populations from southern Syria and those from Lebanon also exhibited a high degree of genetic diversity. The two most heterozygous loci, Mdh-2 and Pgi-2, separated the populations along the first and second principal components, respectively. Most of the rare alleles were scattered sporadically throughout the geographic regions. Rare alleles with high frequencies were found in the Turkish and Armenian populations. These results indicated that different geographic regions require specific sampling procedures in order to capture the range of genetic variation observed in T. urartu populations.     

Genetic diversity and local population structure of fragmented populations of Trillium camschatcense (Trilliaceae)

Trillium camschatcense, a long-lived common woodland herb, has been experiencing intensive habitat fragmentation over the last century in eastern Hokkaido, Japan. We examined the genetic diversity and population genetic structure of 12 fragmented populations with different population sizes using allozyme electrophoresis. The percentage of polymorphic loci and mean number of alleles per locus were positively related to population size, probably due to the stochastic loss of rare alleles (frequency of q<0.1) in small populations. Populations with 350 flowering plants or fewer had lost almost all of their rare alleles. While the heterozygosity and inbreeding coefficient were not related to population size, some small populations showed relatively high inbreeding coefficients. In spite of the low genetic differentiation among overall populations (F_ST=0.130), local population structuring was recognized between the two geographically discontinuous population groups. Within groups, sufficient historical gene flow was inferred, whereas a low dispersal ability of this species and geographical separation could produce apparent differentiation between groups.     

Genetic Diversity in Tunisian Ceratonia siliqua L. (Caesalpinioideae) Natural Populations

The last two centuries witnessed the human-caused fragmentation of Tunisian Ceratonia siliqua L. (Caesalpinoideae) populations which were often represented by scattered individuals. Seventeen populations growing in four bioclimatic zones: sub-humid, upper semi-arid, mean semi-arid and lower semi-arid zones, were sampled for allozyme diversity to assess their genetic diversity and structuration using eight isozymes revealed by starch gel electrophoresis. The species showed high diversity within populations. The average number of alleles per polymorphic locus was 1.98, the percentage of polymorphic loci was 83.4% and the mean observed heterozygosity (Ho) and expected heterozygosity (He) under Hardy–Weinberg equilibrium were respectively 0.247 and 0.316. A substantial level of inbreeding within populations induced by Wahlund effect, was observed (F_IS = 0.231). High diversity resulted from the great number of genotypes in the ancestral population before fragmentation, favoured by the outbreeding of the species. High differentiation and low gene flow were detected among populations (F_ST = 0.200) and among pairs of ecological zones (0.113< F_ST <0.198). However, the differentiation coefficient of the four zones was low (F_ST = 0.085) and similar to the average F_ST for forest trees. Population structuration depends on geographic distance between sites rather than bioclimate, indicating that structuration has occurred slowly and that climatic conditions have had little effect. Nei's genetic distances (D) between populations were low and ranged from 0.004 to 0.201. Mean D value for all population was 0.087. The UPGMA clustering established for all populations through Nei's genetic distances did not clearly show that, for the majority of populations, grouping had resulted from ecological factors or geographic location. The substantial differentiation and the high genetic similarities between populations indicate that populations have been recently isolated as a result of anthropic pressure. In-situ conservation strategies must first focus on populations with a high level of genetic diversity and rare alleles. Appropriate conservation action should take account of bioclimatic zones. Ex-situ preservation should be based on a maximum number of individuals collected within populations in each ecological group and their propagation in different bioclimates by means of cuttings.     

Phenotypic diversity of Ethiopian grass pea (Lathyrus sativus L.) in relation to geographical regions and altitudinal range

Fifty grass pea (Lathyrus sativus L.) populations collected from different administrative regions and altitude classes in Ethiopia, were evaluated for variations of five morphological traits. Shannon-Weaver diversity index was calculated for traits, populations and altitude classes. Monomorphism was recorded in flower color (blue) for most of the populations. Olive seed colour was dominantly distributed in all regions with mean frequency of 50% while black seed colour is rare with mean frequency of 4% in Ethiopia. Much variability was observed within populations. High diversity values for pattern of testa colour and leaflet size were recorded in populations of highland origin (>2550 m.a.s.l.). Shannon's diversity index is highest in Gondar (H = 0.65) followed by Tigray region (H = 0.64) even though there was no significant variation in H values between regions. These regions with high diversity are recommended for immediate in situ and ex situ conservation.     

Genetic diversity in European accessions of the Barley Core Collection as detected by isozyme electrophoresis

Genetic diversity in 79 European accessions of the Barley Core Collections was surveyed using isozyme electrophoresis. A total of 26 alleles were observed at the ten isozyme loci. All loci were polymorphic except Pgd-1 which was monomorphic. The comparison of the results with those of previous studies indicates that most of the alleles occurring in the European Barley are also observed in this set of the European Barley Core Collections. Only five alleles (Est-1 Al; Est-5 Ag, Te; Pgi-1 C and Ndh-2 B) were absent. Nine of 26 alleles were rare alleles, which were detected only in one or two accessions. Moreover, most of rare alleles were detected in 6-rowed winter barley. It is very important to include rare alleles for maximising the genetic variations in core collections. In the set of European Barley Core Collection, 6-rowed barley contained larger diversity than 2-rowed barley; winter type contained larger diversity than spring type. The cluster analysis separated 79 accessions into three major groups. Group I is more complex and comprised 2-rowed spring, 2-rowed winter and 6-rowed winter barley. In this group, 18 accessions in the cluster A and 14 accessions in the cluster B possessed identical genotypes as judged from the ten isozyme data. Principal coordinate analysis could not clearly separate the spring cultivars from the winter barley lines, as well as not separate 2-rowed from 6-rowed barley.     

Genetic Diversity and Structure of Wild Tunisian Myrtus communis L. (Myrtaceae) Populations

Myrtus communis L. (Myrtaceae), in Tunisia, is closely associated with Quercus suber L. forest which stretched continuously from the North to parts of Cap Bon and Tunisian Dorsal. The destruction of the primary oak forests associated to an over-exploitation of Myrtus for its essential oil quality had led to discontinuous populations exhibiting various levels of degradation. Using starch gel electrophoresis, we analyzed the polymorphism of nine isozymes in order to assess genetic diversity and structuring of 17 natural populations prospected in the three geographical regions and coinciding with subhumid, humid inferior and semi-arid superior bioclimates. The analysis of the level and the distribution of the genetic diversity in this species might help in its conservation. Out of the 18 loci detected for all populations and isozymes analyzed, 12 loci were polymorphic. Allelic frequencies differed according to populations and particular alleles characterized ecological groups. A high level of genetic variation within populations was observed. The mean number of alleles per polymorphic locus was Ap = 1.67, the percentage of polymorphic loci was P = 60.3% and the observed (Ho) and the expected (He) heterozygosities were respectively 0.144 and 0.215. Populations belonging to subhumid (Cap Bon) and semi-arid superior (Tunisian Dorsal) climates, located in degraded sites exhibited the highest level of inbreeding (0.425 < F_IS < 0.450). A high level of differentiation (F_ST = 0.396) and a low gene flow (Nm = 0.337) among populations, as a result of habitat intermediate destruction, were revealed. The differentiation of populations within the same bioclimate (or geographic) group was substantial and relatively higher for semi-arid superior populations (F_ST = 0.262), which were more distant. The three ecological groups exhibited a high level of structuring (F_ST = 0.401). These differentiations might be due to geographic distances and to the variations of ecological factors between sites, including human activities and environmental factors. Nei’s (1972) genetic distances calculated between pairs of populations were globally low (0.006 < D < 0.367) with a mean of 0.15. They indicate a high level of similarity between populations. UPGMA clustering, established through Nei’s genetic distances, showed three population aggregates according to their geographic/bioclimatic appartenances. The high differentiation between populations and the low level of their genetic divergence indicated their recent isolation under anthropic pressures. The species conservation (in situ or ex situ) strategies should take into account the genetic diversity level within populations and its variation between geographic groups.     

Geographic differentiation of morphological traits and isozymes in the Mediterranean island endemic Anchusa crispa: implications for the conservation of a protected species

Understanding population differentiation and genetic diversity within population is critical to the development of conservation programmes for threatened species. The protected species, Anchusa crispa Viv. occurs on coastal sand dunes in three disjunct geographical groups of populations: two populations on the east coast of Corsica, several populations around a single estuary on the west coast of Corsica and at a number of sites in north-west Sardinia, where two different subspecies occur. In this study we quantify differentiation of reproductive traits and isozymes among regions and populations on Corsica and between subspecies on Sardinia. No isozyme variation was detected within any of the studied populations nor among populations from a given geographic region. Two loci showed geographic differentiation between regions on Corsica. On Sardinia, the two subspecies showed no isozyme differentiation, and, depending on the loci examined, are similar to one or other of the two regions on Corsica. Reproductive traits show significant differentiation between geographic regions on Corsica, but little variation among populations within a region. In populations on the west coast of Corsica, flowers are small and have a stigma situated at the same level as the apex of the anthers whereas on the east coast, flowers are larger and have the stigma below the anthers. On Sardinia, A. crispa subsp. crispa has a floral morphology similar to the Corsican plants, whereas subspecies maritima has larger flowers with the stigma positioned above the anthers (approach-herkogamy). Quantitative variation in floral morphology thus agrees with the separation of two taxonomic entities on Sardinia and geographic variation in reproductive traits and isozymes has important ramifications for the sampling of populations for conservation programmes.     

鳜原种群体和养殖群体遗传多样性的微卫星分析

本研究利用20对微卫星引物对鳜（Sinipelrca chuatsi）原种群体和养殖群体进行遗传多样性分析。结果表明,在鳜原种群体中检测到多态性位点14个,养殖群体11个。在两个群体中共检测到等位基因数96个,其中原种群体检测到等位基因数53个,每个位点的等位基因数在1～7之间,平均有效等位基因数为2．7390;养殖群体检测到等位基因数43个,每个位点的等位基因数在1-6之间,平均有效等位基因数为2．1284。原种群体的平均观察杂合度0．5708,Nei氏期望杂合度0．5295,平均多态信息含量PIC0．5353;养殖群体的平均观察杂合度0．3839,Nei氏期望杂合度0．4011,平均多态信息含量PIC0．5043。因此,与养殖群体相比,鳜原种群体仍有丰富的遗传多样性。本研究可为鳜种质资源的保护、监测和遗传育种提供分子水平上的数据。