Allozyme Variation of Picea abies in Poland

The aim of this study was to determine the levels and patterns of allozyme variation among 29 populations of Norway spruce [ Picea abies (L.) Karst.] from Poland. Thirteen investigated isoenzyme systems were encoded by 27 gene loci and, on average, 71% of the loci per population were polymorphic. The average and effective numbers of alleles per locus were 2.17 and 1.26, respectively, while the expected heterozygosity was 0.156. A relatively low allozyme differentiation among populations from north-eastern and southern Poland was observed ( F ST = 0.028, mean genetic distance D = 0.005). The results suggest that historical events and extensive gene flow played an important role in the distribution of the observed allozyme differentiation of Norway spruce in Poland.     

Genetic variation among 11 <Emphasis Type="Italic">Abies concolor</Emphasis> populations based on allozyme analysis

In order to obtain information on the genetic structure ofAbies concolor and the genetic variation among 11 populations introduced from America to China, allozyme analysis based on starch gel electrophoresis technology was used. 24 loci of 10 allozyme systems were mensurated, and the genetic structure and genetic diversity of the 11 populations of A. concolor evaluated. The results show that the genetic variation among is significant, and the genetic variation within A. concolor populations is more important. In contrast with other conifers, the variation of A. concolor is above the average level of conifers, and higher than the same level of Abies. The percentage of polymorphic loci (P) was 62.5%, the number of alleles per locus (A) 2.08, the number of effective alleles per locus (Ae) was 1.37, the expected heterozygosity (H) 0.204, and the Shannon information index (/) 0.351 7. There is a short genetic distance (D=0.061) and a low gene flow (Nm=0.839 4) among the 11 introduced populations ofA. concolor with high genetic variation. The genetic differentiation coefficient (Gst) was 0.229 5, which is higher than that of the mean in Abies or Pinus.     

Genetics of red alder (Alnus Rubra Bong.) populations in British Columbia and its implications for gene resources management

The genetic structure of 19 red alder (Alnus rubra Bong.) populations representing the natural range of the species in British Columbia was investigated at 19 allozyme loci. The estimated average number of alleles per locus (1.79), percentage of polymorphic loci (52.6), and total expected genetic diversity (0.113) were all lower than those reported for most long-lived woody species but comparable to early successional species. About 8% of the total genetic variation was attributable to among-population differentiation, the majority being detected at the Aat-2 locus between the Mainland and the Islands regions. Phylogenetic analysis grouped the 19 populations into two distinct clusters that perfectly coincided with their geographical arrangement. Genetic differentiation between populations within both the Mainland and the Islands regions was very weak, accounting for about 3% of the total genetic variation within each region. Red alder is predominantly an outcrossing species with an average outcrossing rate of 0.85. The rate of outcrossing also varied widely among populations, ranging from 0.56 to 0.98. Practical implications of these findings with respect to tree improvement and in situ gene conservation are discussed.     

白皮松天然群体遗传多样性的等位酶分析

采用8种等位酶对白皮松4个天然群体的遗传多样性和遗传分化进行了研究.在4个群体中共检测到10个基因位点,15个等位基因,其中6个位点为多态位点;群体总体水平多态位点比率P=60%,平均有效基因数A=1.92,平均期望杂合度He=0.106,种群平均遗传距离为0.006 8.南漳白皮松群落平均等位基因数A=1.9,平均有...     

Genetic diversity of sea buckthorn (Hippophae rhamnoides) populations in northeastern and northwestern China as revealed by ISSR markers

As a N₂-fixing tree species, sea buckthorn (Hippophae rhamnoides) is well adapted to arid regions and is utilized for multiple purposes in China. Current knowledge of genetic variability of H. rhamnoides is limited in terms of rangewide distributions. Eleven natural populations of sea buckthorn in northeastern and northwestern China were analyzed to detect genetic variation among and within populations, by use of ISSR (inter-simple sequence repeats) markers. Using eight primers, 207 polymorphic loci were observed, ranging in size from 250 to 2500 bp. The coefficient of gene differentiation (Gst = 0.0679) showed that the total molecular variance of 11 populations was mainly existed within populations. The genetic variation within and among the 11 populations was 93.21 and 6.79%, respectively. No significant correlation between genetic and geographic distances of the populations was found using ISSR markers. Our study provides a population-level genetic profile for further investigation and conservation of genetic diversity of sea buckthorn.     

Analysis of genetic relationship in 12 species of Section Strobus with ISSR markers

Genetic relationship of 12 species of Section Strobus was analyzed with ISSR markers. 117 loci were detected with 12 ISSR primers. Percentage of polymorphic bands （PPB） varied from 5.93% to 19.92%. P. pumila had the highest levels of genetic differentiation and P. flexilis had lowest. Total genetic diversity （Hr） of 12 species in Section Strobus was 26.21%, of which intraspecific genetic diversity （Hs） was 7.66%, and interspecific genetic diversity （DST） was 18.55%, and the genetic variation in interspecies accounted for 70.78% of the total genetic diversity. According to the cluster results of genetic distance, the 12 species were classified into two groups. The first group included P. griffithii, P.armandi, P. fenzeliana, P. kwangtungensis, P. strobus, P. monticola and P. wangii. The second group included P. albicaulis, P pumila, P. flexilis, P. sibirica and P koraiensis.     

Genetic diversity and differentiation of fall webworm (Hyphantria cunea Drury) populations

The molecular variation and genetic relationships among five populations of the fall webworm (Hyphantria cunea Drury) in China were assessed using microsatellite technology. Ten microsatellite primers, producing polymorphic bands, were used across 300 samples. The percentage of polymorphic loci (PPB) was 98.36%; the percentage of polymorphic loci in five populations ranged from high to low in the following order: Cangzhou population, Yantai population, Qinhuangdao population, Dandong population, and Shijiazhuang population. The results showed that 34.38% of the total genetic variation of the fall webworm (GST) occurs among populations, while most variation (65.62%) exists within populations. Nei’s genetic distances ranged from 0.1386 to 0.3224. Using the unweighted pair group method with arithmetic mean (UPGMA), Nei’s genetic distances were analyzed by a clustering technique and the dendrogram shows that population differentiation is closely related to the time and geographic origin of the invasion. The major factors impacting genetic diversity of fall webworm populations are longitude, the plain area ratio, annual precipitation, latitude and time of invasion. The formation of genetic structure is correlated with characteristics of the life history and invasion ecology of the species.     

Genetic variation of Taxus baccata L. populations in the Eastern Alps and its implications for conservation management

Abstract

The English yew (Taxus baccata L.) is an endangered rare tree species in Austria. More than 600 bud samples were collected from seven populations in three regions of the Eastern Alpine mountains for estimating their genetic structures by using isozyme gene markers. Nine gene loci encoding for seven enzyme systems were investigated. The revealed 32 alleles indicate a higher multiplicity of the east alpine gene pool compared with other European regions. English yew showed a high level of genetic variation, with a mean number of alleles per locus (A/L) of 2.7. A total of 76.4% of the loci were polymorphic, the average expected heterozygosity was (H _e) 0.274 and the mean observed heterozygosity (H _o) was 0.238. The relative proportion of genetic differentiation among the regions was found to be 6.2%, the level of gene flow was high (Nm=3.78) and the level of inbreeding (0.130) among the regions was medium. The obligatory out crossing (dioecious plant), the long generation time, the ability to regenerate from stump and the seed dispersal by birds and rodents might contribute to the high level of genetic variation found within the population. The conservation propositions are discussed with respect to the genetic structure and the poor recruitment of this species.     

Genetic Variation among 11 Abies concolor Populations Based on Allozyme Analysis

In order to obtain information on the genetic structure of Abies concolor and the genetic variation among 11 popula- tions introduced from America to China, allozyme analysis based on starch gel electrophoresis technology was used. 24 loci of 10 allozyme systems were mensurated, and the genetic structure and genetic diversity of the 11 populations of A. concolor evaluated. The results show that the genetic variation among is significant, and the genetic variation within A. concolor populations is more important. In contrast with other conifers, the variation of A. concolor is above the average level of conifers, and higher than the same level of Abies. The percentage of polymorphic loci (P) was 62.5%, the number of alleles per locus (A) 2.08, the number of ef- fective alleles per locus (Ae) was 1.37, the expected heterozygosity (H) 0.204, and the Shannon information index (I) 0.351 7. There is a short genetic distance (D=0.061) and a low gene flow (Nm=0.839 4) among the 11 introduced populations of A. concolor with high genetic variation. The genetic differentiation coefficient (Gst) was 0.229 5, which is higher than that of the mean in Abies or Pinus.     

An analysis of the pattern of genetic variation in Vitellaria paradoxa using RAPD markers

Vitellaria paradoxa C.F.Gaertn. is one of the most economically and socially important tree species in the Sudano-Sahelian region. Little is known of the pattern of variation within its natural range. Eight populations covering most of the natural range from Senegal to Uganda were sampled and leaves of 118 individual trees were collected. An analysis of molecular diversity was carried out using random amplified polymorphic DNA (RAPD) markers. Fifteen random primers generated 67 polymorphic and 15 monomorphic RAPD loci ranging from size 1670 bp to 280 bp. Shannon's diversity index varied from Central Africa/Ndele (0.374) to Uganda/Amoya (0.350) but the differences between populations were smaller than the population standard errors. Correspondence analysis of unrooted neighbour-joining trees suggested that genetic distances between populations were correlated with geographic distances. This trend was confirmed by a Mantel test giving a coefficient of correlation between genetic and geographic distances of R = 0.88 (P = 0.0001). Result of AMOVA (analyses of molecular variance) showed that 14.8% (P = 0.002) of the RAPD variation was distributed among populations. Nested analysis of variance indicated that variance between the western and eastern groups of population represented 8.7% (P = 0.001) of the total variation and the variation amongst populations within group was 9.5% (P = 0.001). Eighty two percent of the variation was explained by variation amongst individuals within populations. The origin of genetic structure and level of diversity may be explained by the glacial refugia, the biological traits of Vitellaria paradoxa and by the impact of semi-domestication. Based on these results, sampling options of the natural populations are suggested for in or ex situ conservation. For the development of Vitellaria paradoxa breeding population, the sampling should consist of many individual trees selected within a few populations to capture a large proportion of variation.This revised version was published online in November 2005 with corrections to the Cover Date.     

红豆树优树子代遗传多样性及与生长相关性分析

[目的]研究红豆树优树自由授粉子代遗传多样性及其对生长的影响,比较天然居群子代和孤立木子代遗传多样性差异,揭示子代遗传多样性的变化规律及天然居群在子代遗传多样性维持中的作用,为红豆树遗传保育和优异种质挖掘提供科学依据。[方法]以来自浙、闽、赣、川等26个红豆树优树自由授粉家系为研究对象,利用11对SSR引物对765个子代群体进行遗传多样性评价,同时分析子代遗传多样性参数与种子、生长性状的相关性。[结果](1)红豆树优树子代群体具有较高的遗传多样性,有效等位基因数为7.766个,观测杂合度(H_O)和期望杂合度(H_E)分别为0.469和0.865。(2)除SSR8外,其余位点的观测杂合度均小于期望杂合度,表明子代群体绝大多数位点处于杂合子缺失状态。(3)红豆树不同家系的遗传多样性存在明显差异,12号家系的遗传多样性水平最高,8号家系则最低。(4)比较发现,天然居群子代的遗传多样性显著或极显著地高于孤立木子代。(5)F统计量和分子方差分析(AMOVA)均表明,红豆树优树子代群体的遗传变异主要存在于家系内,家系间的遗传分化相对较小。(6)相关性分析发现,子代遗传多样性参数与种子性状、子代年高生长量呈显著正相关(r=0.378~0.527)。[结论]较大的红豆树天然居群在维持其子代较高遗传多样性中发挥了重要作用,子代遗传多样性显著影响苗木生长,这为红豆树遗传保育和优良家系选择提供了理论依据。     

Genetic diversity of Castanopsis acuminatissima (Bl.) A. DC. in northern Thailand and the selection of seed trees for forest restoration

Castanopsis acuminatissima (Bl.) A. DC. is one of a number of framework species which are being planted to restore seasonally dry tropical forests in northern Thailand. This study describes the level of microsatellite variation within and among three populations of this species in three National Parks in northern Thailand: Doi Suthep-Pui, Doi Inthanon and Jae Sawn, using published primers developed for Castanopsis cuspidata var. sieboldii Nakai. The five microsatellite loci employed in this study detected a total of 54 alleles (n = 72). The informativeness of the microsatellite loci varied from six to 18 alleles, with an average of 10.8 alleles found over all loci. The mean observed heterozygosities in the three populations showed no significant deviations from Hardy-Weinberg expectations. The vast majority of genetic diversity was contained within the populations, with no significant differentiation between them (F_ST = 0.006). Algorithms were designed to capture microsatellite diversity, and the rationale for using microsatellite markers to inform genetic conservation is discussed. The implications for seed collection of C. acuminatissima for forest restoration are also discussed.     

Genetic variation in natural populations of Abies nephrolepis Max. in South Korea

Abies nephrolepis Max. is a fir species occurring in Northeast China, the extreme southeast of Russia and Korea. In Korea, A. nephrolepis is one of only three native fir species growing in high, mountainous areas with a disjunct distribution. We investigated genetic variation in A. nephrolepis by examining 24 ISSR polymorphic loci in 248 individuals representing eight natural populations in Korea. The level of intra-population genetic diversity (H _e = 0.240) was similar to or slightly lower than that of plants with similar ecological traits and life history. Most of the genetic diversity was allocated among individuals within populations (G _ST = 0.082, Φ_ST = 0.041) and the number of migrants per generation (N _m ) was 5.56. Nei’s genetic distances were small (D = 0.027) and unrelated to geographic distances between populations. Implications for the conservation of genetic variation in A. nephrolepis in South Korea were discussed.     

花吊丝竹居群遗传多样性的ISSR分析

[目的]研究花吊丝竹居群遗传多样性和遗传结构,为种质资源有效利用和良种选育提供理论指导。[方法]利用12条ISSR引物对48份种质(共3个居群)花吊丝竹居群进行遗传多样性和遗传距离分析。[结果]共检测到124个位点,其中,多态性位点为102个,种质和居群水平上的多态位点百分比(PPB)分别为82. 26%和50. 27%,Ne’基因多样性指数(He)分别为0. 220 4和0. 206 6,Shannon’s信息指数(I)分别为0. 349 4和0. 300 5,表明花吊丝竹居群间存在中等水平的遗传变异。根据Nei’s遗传多样性计算出不同居群间分化水平(Gst)=0. 163 3,表明16. 33%的遗传变异存在于居群间,居群内的遗传变异为83. 67%。居群间的基因流Nm为2. 562 1,表明花吊丝竹居群间存在较大基因流,很大程度减少居群间遗传差异。基于遗传距离的UPGMA聚类结果表明,48份种质可分为3组,3个居群可分为2组,居群间地理距离与亲缘关系无显著相关性。[结论]虽然花吊丝竹主要靠营养生殖来繁衍后代,其居群遗传多样性较丰富,且居群内遗传多样性大于居群间。此外,福建居群遗传多样性明显高于广西和广东地区居群。     

Small-scale genetic diversity in oneseed hawthorn (<Emphasis Type="Italic">Crataegus monogyna</Emphasis> Jacq.)

We have examined the pattern of random amplified polymorphic DNA (RAPD) variation among six populations of Crataegus monogyna from northern Italy, extending over an area of about 20,000 km². The aim was to evaluate local differentiation in relation to geographical distance. Of the 73 loci analysed, 65 were polymorphic, and there were no bands at complete fixation at the population level. The mean genetic diversity was 0.291, with the values for individual populations ranging between 0.252 and 0.333. According to the analysis of molecular variance most of the genetic variation was found within populations (about 80%), with a significant proportion being attributable to genetic differences between populations. No evidence for isolation by distance was found in the set of populations sampled. The efficacy of RAPD markers in analysing genetic variation, and the contribution of the results in terms of the preservation of biodiversity and defining the most appropriate strategies for collecting forest reproductive material, are discussed.     

Genetic variation and division of Pinus sylvestris provenances by ISSR markers

Inter Simple Sequence Repeat (ISSR) was used to detect genetic variation among nine provenances, including 135 individuals. A total of 108 loci were amplified using 10 random primers. The differentiation of the percentage of polymorphic bands (PPB) among different provenances was evident, ranging from 27% to 54%, of which Honghuaerji provenance had the highest PPB and Kalunshan provenance had the lowest PPB. Shannon's Information index (I) at species level was 0.1581 and Nei's gene diversity (h) was 0.2393. Coefficient of gene differentiation (G_ST) calculated by Popgene was 0.3965, these results indicated that majority of genetic variation (60.35%) was found within provenances. According to dendrogram amongpinus sylvestriv provenances, nine provenances were divided into two provenance areas, namely Daxing's and Xiaoxing'an Mountains provenance area and Hulunbeier provenance area. Foundation item: This study was supported by National Scientific and Technological Brainstorm Project. Biography: LI Hui-yu (1978-), female, Ph.D. candidate, Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Song Funan     

Genetic variation and gene flow among Prunus cerasoides D. Don populations in northern Thailand: analysis of a rehabilitated site and adjacent intact forest

This study describes the level of genetic variation and gene flow within and among populations of Prunus cerasoides in rehabilitated sites and adjacent intact forest. The seven microsatellite loci employed detected a total of 75 alleles (n = 401). Polymorphic information content (PIC) varied from 0.34 to 0.83. Between the adult populations there was moderate genetic differentiation with an F _ST value of 0.0575, which suggests that the restoration plots had a similar genetic composition to that of the natural population. The gene flow assessment provides some interesting insights into the genetic diversity of P. cerasoides. In the 16 naturally occurring trees over 83% of the genotyped seed were fathered by unidentified trees whereas in restoration plot A only about 32% of the pollen came from an unidentified father. This proportion was even less in Plot C where 25% of the pollen parents were unidentified. The naturally occurring trees within Doi Suthep were surrounded by planted trees, which were contributing to the paternity of the seed crop. This result demonstrates that ‘‘fill in’’ planting should consist of locally sourced material if it is considered important to conserve the genetic integrity of the local populations.     

Allozyme variation and recent evolutionary history of eastern hemlock (<Emphasis Type="Italic">Tsuga canadensis</Emphasis>) in the southeastern United States

Eastern hemlock (Tsuga canadensis [L.] Carr.) is a widespread and ecologically important conifer species of eastern North America that is threatened by the hemlock woolly adelgid (Adelges tsugae Annand), a pest introduced into the United States from Asia in the 1920s. Information about the genetic composition of eastern hemlock is necessary to guide ex situ conservation efforts in the southeastern United States, where the species is expected to harbor relatively high amounts of genetic variation in areas of Pleistocene glacial refuge. Nineteen allozyme markers were used to quantify the genetic variation present in 20 eastern hemlock populations in the southeastern United States. Results indicate that the species has low levels of genetic diversity in the region compared to most other conifers, but greater population differentiation (F _ST = 0.126). Populations along the eastern periphery and in the Appalachian interior exhibited higher levels of diversity than those along the western periphery of its geographic range. The results suggest that the glacial refuge area for eastern hemlock was likely located east of the southern Appalachian Mountains, and indicate that ex situ conservation seed collections should be concentrated in these areas of higher diversity.     

Genetic diversity and genetic differentiation of natural Pinus koraiensis population

Genetic diversities and genetic differentiations of the four Pinus koraiensis populations （Gaofeng Forestry Farm at Tangwanghe in Yichun City, Erdaobaihe Town in the Changbai Mountains, Shcngshan Forestry Farm in Heihe City, in China, and the suburb of Vladivostok City in Russia） were analyzed by using ISSR PCR technique. The results of 15 primers amplification showed that the ratio of polymorphic site of P koralensis population was 60.7%. Euch primer had 3.6 polymorphic sites, The diversity levels of the four P. koraiensis populations were rather higher compared with those of other Pinaceae species. The genetic diversity levels of t： koraiensis populations grown in the center region were higher than those grown in the edge zone. The genetic diversity of r3 koraiensis mainly came from the interiot of the population, accounting for 73% of total genetic diversity. There were no positive correlation between genetic distances and geographical distances for the four P koraiensis populations. The gradual decrease of natural distribution region of P. koraiensis was due to anthropic destroy and environmental factors （i.e. fire and wind throw）, rather than the lower genetic diversity.     

Genetic diversity of Quercus glandulifera var. brevipetiolata populations in three forest communities with different succession stages

In order to understand the relationship between population succession and its genetic behavior, random amplified polymorphic DNA (RAPD) technique was used to analyze the genetic diversity of Quercu glandulifera var. brevipetiolata populations in three forest communities with different succession stages (coniferous forest, coniferous and broad-leaved mixed forest, evergreen broad-leaved forest). The results showed that 145 repetitive loci were produced in 60 individuals of Q. glandulifera using 11 primers, among which 120 loci were polymorphic, and the total percentage of polymorphic loci was 82.76% with an average of 64.14%. Estimated by the Shannon information index, the total genetic diversity of the three populations was 0.4747, with an average of 0.3642, while it was 0.3234, with an average of 0.2484, judged from the Nei index. Judged from percentage of polymorphic loci, Shannon inform at ion index and Nei index, the genetic diversity followed a decreasing order: coniferous forest > broad-leaved mixed forest > evergreen broad-leaved forest. Analysis of molecular variance (AMOVA) showed that 69.73% of the genetic variance existed within populations and 30.27% of the genetic variance existed among populations. The coefficient of gene differentiation (GST) was 0.2319 and the gene flow (N _m) was 1.6539. The mean of genetic identity among populations of Q. glandulifera was 0.8501 and the mean of genetic distance was 0.1626. The genetic identity between the Q. glandulifera population in the coniferous forest and that in the coniferous and broadleaved mixed forest was the highest. UPGMA cluster analysis based on Nei’s genetic distance showed that the population in the coniferous forest gathered with that in the coniferous and broad-leaved mixed forest firstly, then with that in the evergreen broad-leaved forest. The genetic structure of Q. glandulifera was not only characteristic of the biological characteristics of this species, but was also influenced by the microenvironment in different communities. __________ Translated from Journal of Northwest Forestry University, 2008, 23(1): 18–22 [译自: 西北林学院学报]