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1.
Molecular tools opened a new vista to understand natures bio-diversity and its relevance and the same approach was availed of to build-up the foundation work on the bio-diversity of silkworm spp in India. It is well established that the heritage of usage of silk for dress materials in India, Russia, and China dates back to pre-medieval period and in spite of industrial development resulting to de-forestation, India still can claim as the owner of wide bio-diversity, espicially in northern India for silkworm spp. The molecular diversity was assessedamong Antheraea mylitta, A. assama, A. pernyi, A. proylei, A. roylei and Philcosomia cynthia wiht 11 ISSR and 8 non-random primers on agarose gel. Neis statistics as also Euclidean distance matrix was applied to find the genetic diversity between the six species, wherein the closest relationship between A. pernyi and A. proylei is established. With the help of POPGEN statistics, the average genetic heterozygosity appeared as 0.271 while Shanons index is 0.4312 and alleles with segregation ratios of 3:1, 2:1, 1:1, 9:1 (generated with ISSR primers) were identified which can be utilized for future molecular breeding program. Further, and attempt was made to isolate a number of bands generated with 3 ISSR and six non-random primers, specific for different species and 22 such markers have been characterized through sequencing which will be made available through international public domain database.From Genetika, Vol. 40, No. 12, 2004, pp. 1618–1627.Original English Text Copyright © 2004 by Chatterjee, Tanushree.This article was submitted by the authors in English.  相似文献   

2.
Amplified inter simple sequence repeats (ISSR) markers were used to determine genetic relationships among mutant silkworm strains of Bombyx mori. Fifteen ISSR primers containing simple sequence repeat (SSR) motifs were used in this study. A total of 113 markers were produced among 20 mutant swains, of which 73.45% were found to be polymorphic. In selected mutant genetic stocks, the average number of observed allele was (1.7080±0.4567), effective alleles (1.5194±0.3950) and genetic diversity (Ht) (0.2901±0.0415). The dendrogram produced using the unweighted pair group method with arithmetic means (UPGMA) and cluster analysis made using Nei's genetic distance resulted in the formation of one major group containing 6 groups separated 20 mutant silkworm strains. Therefore, ISSR amplification is a valuable method for determining the genetic variability among mutant silkworm swains. This efficient molecular marker would be useful for characterizing a considerable number of silkworm swains maintained at the germplasm center.  相似文献   

3.
Liu YQ  Qin L  Li YP  Wang H  Xia RX  Qi YH  Li XS  Lu C  Xiang ZH 《Neotropical Entomology》2010,39(6):967-976
The genetic diversity and genetic structure of three Chinese silkworm species Bombyx mori L., Antheraea pernyi Guérin-Meneville and Samia cynthia ricini Donovan were comparatively assessed based on RAPD markers. At the species level, A. pernyi and B. mori showed high levels of genetic diversity, whereas S. cynthia ricini showed low level of genetic diversity. However, at the strain level, A. pernyi had relatively highest genetic diversity and B. mori had lowest genetic diversity. Analysis of molecular variance (AMOVA) suggested that 60% and 72% of genetic variation resided within strains in A. pernyi and S. cynthia ricini, respectively, whereas only 16% of genetic variation occurred within strains in B. mori. In UPGMA dendrogram, individuals of A. pernyi and B. mori formed the strain-specific genetic clades, whereas those of S. cynthia ricini were distributed in a mixed way. The implications of these results for the conservation and utilization in breeding programs of three silkworm species are discussed.  相似文献   

4.
Understanding of fish genetic characterization plays a vital role in the conservation and utilization of fish genetic resources of grouper species. The present study was carried out to assess the genetic diversity and phylogenetic relationships in five grouper species, Epinephelus spp. from eastern Saudi Arabian coast using two molecular marker systems, inter simple sequence repeat (ISSR) and microsatellite (SSR) markers. In total, 219 individuals grouper specimens (Epinephelus tauvina, E. coioides, E. bleekeri, E. malabaricus, and E. areolatus) were genotyped with 10 ISSR and 11 SSR selected primers. The ISSR produced 94 DNA fragments, of which 44 were polymorphic with an average of 2.13 fragment per primer. While SSR primers generated 107 alleles, all of them were polymorphic with an average 9.72 per primer. ISSR and SSR techniques demonstrated a high level of gene diversity and genetic distances illustrated by UPGMA dendrograms among the grouper species. The results proved that the SSR markers were highly informative and efficient in detecting genetic variability and relationships of the Epinephelus spp.  相似文献   

5.
Intersimple sequence repeat (ISSR) amplification was used to analyze genetic relationships among silkworm, Bombyx mori L., strains. Nineteen primers containing simple sequence repeat (SSR) motifs were tested for amplification on a panel of 42 strains, representative of the diversity of silkworm germplasm; 12 of the primers amplified distinct, reproducible bands. The primers amplified a total of 108 bands, of which 85 (78.7%) were polymorphic. The ISSR results suggested that within the dinucleotide class, the poly(CA) motif was more common than the poly(CT) motif. The ISSR amplification pattern was used to group the silkworm strains into seven subclusters based on their origin in an unweighted pair-group method with arithmetic average cluster analysis by using Nei's genetic distance. Seven major ecotypic silkworm groups were analyzed. Principal component analysis of the ISSR data supported the unweighted pair-group method with arithmetic average clustering. Therefore, ISSR amplification is a valuable method for determining genetic variability among silkworm varieties. This efficient genetic fingerprinting technique should be useful for characterizing the large numbers of silkworm strains held in national and international germplasm centers.  相似文献   

6.
利用RAPD和ISSR分子标记分析怀地黄种质遗传多样性   总被引:42,自引:0,他引:42  
用RAPD与ISSR技术对怀地黄的8个品种和2个脱毒品系进行了种质遗传多样性分析。分别从80条RAPD引物和44条ISSR引物中筛选出适合怀地黄种质分析的17条RAPD引物和10条ISSR引物,用于RAPD和ISSR分析。17条RAPD引物共扩增出177条带, 多态性位点数为109; 多态性位点比率为61.58%;平均多样性指数(I)为0.3135;每个位点的有效等位基因数(Ne)是1.3641; 10条ISSR引物共扩增出110条带. 多态性位点数为79; 多态性位点比率为71.58%;平均多样性指数(I)为0.3577;每个位点的有效等位基因数(Ne)是1.4037。 基于扩增条带数据库建立了各自的Jaccard遗传相关系数矩阵,构建了相似的分子树状图,将10个供试材料分为2类:一类群含组培85.5、大田85.5、组培9302、大田9302、金状元和金白6个材料;另一类群含北京1号、大红袍、地黄9104和野生地黄4个材料。两种分子标记的分析结果呈极显著正相关(r=0.649)。结果表明,RAPD与ISSR标记适合于怀地黄种质遗传多样性分析,ISSR标记技术是一种多态性和重复性优于RAPD技术的实用技术。  相似文献   

7.
Genetic diversity analysis was undertaken in 42 geographically distant genotypes accessions of bottle gourd (Lagenaria siceraria) from India northeastern (14) and northern region (28) using inter-simple sequence repeat (ISSR) markers. A total of 209 amplified bands were obtained from 20 ISSR primers used in this study, of which 186 were polymorphic with 89.00 % band polymorphism. Various parameters namely, observed number of alleles, effective number of alleles, Nei’s gene diversity/heterozygosity, resolving power, Shannon’s information index and gene flow were estimated under experiment. Jaccard’s similarity coefficient matrix was generated for pairwise comparisons between individual ISSR profiles and UPGMA cluster analysis based on this matrix showed clustering into six groups. Jaccard’s coefficient of similarity values ranged from 0.409 to 0.847, with a mean of 0.628 revealing a moderate level of genetic diversity. The Bayesian model-based approach to infer hidden genetic population structures using the multilocus ISSR markers revealed two populations among the 42 genotypes. This is the first report on the assessment of genetic variation using ISSR markers in this medicinal vegetable plant, and this study of diversity analysis will be helpful in analyzing future hybrid breeding strategy and devising effective germplasm exploration and conservation strategy.  相似文献   

8.
Inter simple sequence repeat (ISSR) markers were used to analyse genetic diversity of Swertia chirayita genotypes collected from the temperate Himalayas of India. Allied species of Swertia chirayita were used in the study as outliers. Nineteen UBC primers generated a total of 315 ISSR bands, revealing 98.7 % polymorphism among the genotypes assayed. This was reduced to 42.5 % when the outliers were excluded. The results revealed a high genetic diversity within the genotypes.  相似文献   

9.
Mulberry (Morus spp.), a deciduous tree, originated at the foothills of the Himalayas and is used in sericulture for its leaf to feed the silkworm Bombyx mori L. Species differentiation among the genotypes of the genus Morus has never been out of debate as inter-specific hybridization events are often fertile. In the present study attempts were made to elucidate the genetic relationships among 18 mulberry genotypes collected from India and Japan using 15 Inter Simple Sequence Repeat (ISSR) and 15 Random Amplified Polymorphic DNA (RAPD) primers. The ISSR primers generated 81.13% polymorphism while the RAPDs generated 71.78% polymorphism. The polymorphic index of the primers identified UBC-812, UBC-826, UBC827, UBC-881, OPA-01, OPA-02, OPA-04 and OPH-17 as informative primers in mulberry. The genetic similarity coefficients and the dendrograms showed considerable genetic similarity among the genotypes. However, using the DNA markers, these genotypes were discriminated into two major groups in accordance with their geographic origin and species status. Distribution of the genotypes on a two-dimensional figure on the basis of the ALSCAL algorithm using Euclidean distance further confirmed the genetic divergence between these two groups. From the study it can be concluded that though morphologically Japanese and Indian mulberry genotypes show little divergence, genetic analysis using DNA markers could unravel significant genetic variation between these two groups. Similarly, while the species status of Japanese mulberry genotypes agrees with the genetic analysis, the same does not apply to Indian genotypes, in agreement with many earlier reports. The information generated in this study is of much use for taxonomical grouping and also for utilization in breeding and conservation programs.  相似文献   

10.
Sugarcane is susceptible to red rot disease caused by phytopathogenic fungus Colletotrichum falcatum Went which ultimately affect the economy of farmers as well as sugar based industry. One of the various ways to control this devastating disease is to develop disease resistance sugarcane cultivar and this requires the complete understanding of genetic makeup of pathogen. Although South Gujarat is well known sugarcane cultivating area, less published data can be found about PCR-based genetic diversity in prevalent C. falcatum accessions. So, present investigation aims at finding molecular variation among the ten accessions of C. falcatum using RAPD and ISSR molecular markers. A total of 35 RAPD and 39 ISSR primers were screened across 10 C. falcatum accessions, of which 15 RAPD and 21 ISSR primers have showed consistent amplification. Statistics related to genetic variation were estimated using NTSYS-PC by means of Dice’s coefficient. The results revealed 80.6% and 68.07% polymorphism and similarity coefficient ranged from 0.43 to 0.91 and 0.73 to 0.93 in RPAD and ISSR analysis respectively. The dendrogram generated using RAPD, ISSR and combined RAPD-ISSR grouped accessions into different clusters which reveal considerable level molecular variation among the C. falcatum accessions. It is also evident from PCA plots that accessions are rather dispersed with tested marker systems indicating good genetic base. So, in nut shell, we found considerable genetic variation and relatedness within C. falcatum accessions collected from different areas of south Gujarat, India using RAPD and ISSR markers.  相似文献   

11.
The objective of this study was to quantify the molecular diversity and to determine the genetic relationships among Secale spp. and among cultivars of Secale cereale using RAPDs, ISSRs and sequence analysis of six exons of ScMATE1 gene. Thirteen ryes (cultivated and wild) were genotyped using 21 RAPD and 16 ISSR primers. A total of 435 markers (242 RAPDs and 193 ISSRs) were obtained, with 293 being polymorphic (146 RAPDs and 147 ISSRs). Two RAPD and nine ISSR primers generated more than 80% of polymorphism. The ISSR markers were more polymorphic and informative than RAPDs. Further, 69% of the ISSR primers selected achieved at least 70% of DNA polymorphism. The study of six exons of the ScMATE1 gene also demonstrated a high genetic variability that subsists in Secale genus. One difference observed in exon 1 sequences from S. vavilovii seems to be correlated with Al sensitivity in this species. The genetic relationships obtained using RAPDs, ISSRs and exons of ScMATE1 gene were similar. S. ancestrale, S. kuprijanovii and S. cereale were grouped in the same cluster and S. segetale was in another cluster. S. vavilovii showed evidences of not being clearly an isolate species and having great intraspecific differences.  相似文献   

12.
The silkworm B. mori is a multicellular organism revealing genetic resources which makes an ideal model for lepidoptera for the present investigation. With the objective of targeting distinctive markers for utilization in future breeding programmes, Bivoltine and Polyvoltine silkworm strains were used by inter-simple sequence repeats (ISSR) and random amplified polymorphic-DNA (RAPD) fingerprinting to detect their genetic versatility and volatility. Six ISSR primers generated 99 markers, of which 76.76% were found to be polymorphic with an average number of observed alleles (N a) (1.86 ± 0.40), an effective number of alleles (N e) (1.43 ± 0.30) as well as six RAPD primers that produced a total of 95 bands, developing 61.05% polymorphism with N a (1.93 ± 0.51) and N e (1.18 ± 0.30). The dendrogram produced by UPGMA analysis, based on Dice’s coefficient, clustered four races into two major groups which accurately segregated them according to their inheritance of voltinism. In this research, the ISSR markers were more accurate than the RAPD markers and ISSR also displayed better polymorphism. The outcome showed that the bivoltine strains exhibited higher allelic expressions with ISSR primers when compared to the polyvoltine strains. Despite exhibiting their unique race by certain DNA markers, most of the primers represented voltinism-specificity. Hence molecular marker amplification is a beneficial approach to reveal genetic divergence among closely related strains, and molecular characterization of phylogenetic relationships in addressing evolutionary evidences of individuals.  相似文献   

13.
BACKGROUND AND AIMS: There are more than 80 species of Leucadendron and most are used as cut flowers. Currently, more than 100 cultivars are used by industry and many of them are interspecific hybrids. The origin of most cultivars is unclear and their genetic diversity and relationships have not been studied. This investigation was carried out to evaluate the genetic variation and relationships among 30 Leucadendron cultivars. METHODS: ISSR markers were applied to determine the genetic variation and to discriminate Leucadendron cultivars. Sixty-four ISSR primers were screened and 25 primers were selected for their ability to produce clear and reproducible patterns of multiple bands. KEY RESULTS: A total of 584 bands of 305-2400 bp were amplified, of which 97 % were polymorphic. A dendrogram generated using the Unweighted Pair Group Method with Arithmetic Average based on a distance measure of total character difference showed that the Leucadendron cultivars clustered into two main groups. Twenty-four of the 30 cultivars can be unequivocally differentiated, but identical profiles were observed for three cultivar pairs, 'Katie's Blush' and 'Silvan Red', 'Highlights' and 'Maui Sunset', and 'Yellow Crest' and 'Yellow Devil'. CONCLUSIONS: ISSR profiling is a powerful method for the identification and molecular classification of Leucadendron cultivars. A fingerprinting key was generated based on the banding patterns produced using two ISSR primers (UBC856 and UBC857). In addition cultivar-specific ISSR bands were obtained for 17 of the 30 Leucadendron cultivars tested.  相似文献   

14.
通过建立和优化枳椇Hovenia acerba的ISSR反应体系,并利用ISSR分子标记方法,对福建省12个种源地35份枳椇材料进行遗传多样性及亲缘关系研究。枳椇遗传多样性分析的ISSR最佳反应体系为反应总体积25 μL,10×Ex Taq Buffer(Mg2+ plus) 2.5 μL,dNTP Mixture 375 μmol·L-1,引物0.4 μmol·L-1,DNA模板75 ng,Ex Taq酶1 U,ddH2O 14.55 μL。程序:预变性94 ℃ 5 min;变性 94 ℃ 30 s,退火50 ℃ 1 min,延伸72 ℃ 90 s,共 35 个循环;最后延伸72 ℃ 7 min。利用筛选出的10个ISSR引物共检测了基因组DNA中175个位点,其中多态性位点155个,占总位点数的88.57%。供试材料观测等位基因数(Na) 1.8857、有效等位基因数(Ne) 1.4300,Nei’s基因多样性指数(H) 0.2572,Shannon多样性指数(I) 0.3959。UPGMA聚类分析表明,以遗传相似系数0.74为阈值,可将35份枳椇分成四大组。ISSR标记有效地揭示福建省枳椇种质资源丰富的遗传多样性,具较大开发利用价值。  相似文献   

15.
The determination of genetic differences among crop genotypes has become the primary need to grant patent and the protection of Plant Breeder Rights (PBR). In the present study RAPD and ISSR markers were employed for the characterization of 16 sesame genotypes. Twenty six RAPD and 17 ISSR primers that generated clear and reproducible banding patterns amplified 194 and 163 bands, respectively among 16 sesame genotypes. Both RAPD and ISSR primers showed maximum discrimination power, and produced putative variety specific bands, which could be used for the identification of all the sesame genotypes, individually. However, only AG and CA based ISSR primers were found effective in the discrimination of genotypes. A poor correlation was observed between the matrices produced by RAPD and ISSR primers, which might be due to the array of different sites of the genome. Though, there was greater similarity among sesame genotypes (0.78 for RAPD and 0.71 for ISSR), the observed genetic diversity (0.22 for RAPD and 0.29 for ISSR), was found effective for the characterization of sesame genotypes. It is suggested that putative variety specific RAPD and ISSR markers could be converted to Codominant sequence characterized amplified region/sequence tagged site (SCAR /STS) markers to develop robust variety specific markers.  相似文献   

16.
To find out the genetic diversity of Indian Foc isolates of banana, a total of 107 isolates of Fusarium which includes 98 Foc isolates obtained from different banana growing regions of India and seven Foc isolates belong to all known VCGs obtained from Australia and two non-pathogenic Fusarium oxysporum (npFo) isolates were subjected to ISSR analysis. In the initial screening of ISSR primers, out of 34, 10 primers which generated more polymorphic bands were selected for further analysis. The Phylogenetic analysis carried out based on the fingerprints obtained through ISSR analysis indicated the presence of wide genetic diversity among the Foc isolates of India and also its polyphyletic nature. Totally, seven different clusters were obtained and these clusters differentiated the Foc isolates of India based on the races/VCGs. Besides, the cluster analysis clearly distinguished the freshly emerged Foc strain obtained from cv. Grand Naine (Cavendish-AAA) and Poovan (Mysore-AAB) from the other Foc isolates. The non-pathogenic F. oxysporum isolates which have been included for comparison purpose also clustered separately. All these above said findings indicates for the first time the discriminatory power of ISSR to clearly distinguish and separate the Foc isolates according to its race/VCGs and also its virulence. This study would be useful not only to design and develop effective management strategies but also useful for quarantine purposes.  相似文献   

17.
Auricularia auricula-judae is an edible and medicinal jelly mushroom, and it is widely cultivated in China. In the present study, inter-simple sequence repeat (ISSR) molecular marker was employed to assess the genetic diversity of 22 wild strains and two cultivars of A. auricula-judae obtained from many ecological regions of China. With the use of 11 ISSR primers, a total of 368 (99.7%) and 81 (71.7%) polymorphic loci in wild and cultivated strains were detected, respectively. The mean genetic similarity of A. auricula-judae was 0.75, based on the dendrogram generated via similarity coefficient, all the tested strains were classified into six groups at a similarity level of 76%, and the two cultivated strains consisted of one group alone. The results of principal coordinate analysis were in accordance with UPGMA clustering, and the first most informative coordinate accounted for 75.9% of the variations, indicated a high level of genetic diversity among wild A. auricula-judae strains. In general, ISSR marker was an effective method to discriminate the A. auricula-judae stains and to evaluate their genetic diversity.  相似文献   

18.
As a popular flowering species with many cultivars, Cymbidium ensifolium (L.) is commercially important in horticulture. However, so far little has been known about genetic diversity and conservation genetics of this species. Understanding of the genetic variation and relationships in cultivars of C.?ensifolium is a prerequisite for development of future germplasm conservation and cultivar improvement. Here we report assessment of genetic variations in C.?ensifolium cultivars using the DNA fingerprinting technique of inter-simple sequence repeats (ISSR). A total of 239 ISSR loci were identified and used for evaluation of genetic variation with a selection of 19 ISSR primers. Among these ISSR loci, 99.16% were polymorphic with wide genetic variation as shown by Nei??s gene diversity (H?=?0.2431) among 85 tested cultivars. ISSR fingerprinting profiles showed that each cultivar had its characteristic DNA pattern, indicating unequivocal cultivar identification at molecular level. Eighteen cultivar-specific ISSR markers were identified in seven cultivars. The cultivar Sijiwenhan was confirmed as hybrid by four ISSR primers. Several cultivars with same name but different geographical origins were distinguished based on their ISSR profiles. A dendrogram generated with ISSR markers could group 73 of 85 cultivars into four major clusters. Further analysis of ISSR variation revealed that about 69% of total genetic variation in this species is due to genetic divergence inside geographical groups. Our results suggest that both germplasm collection and in?situ conservation are important for future planning of C.?ensifolium species conservation.  相似文献   

19.
Bombyx mori L., commonly recognised around the world as the mulberry silkworm, is characterized by a wide variability in yield and developmental traits, which have been proven through conventional genetic analysis to be of polygenic nature. A large number of morpho-biochemical traits and RFLP and RAPD markers are mapped on different linkage groups, but to this point very little attention has been given to unravelling the genetics of yield traits. To address this issue, polymorphic profiles of 147 markers generated with 12 ISSR primers on the genomic DNA of 20 silkworm stocks of diverse yield status were subjected to multiple regression and discriminant function analyses (DFA). This led to the identification of eight markers generated by six primers, which demonstrated high beta-coefficient indices of -0.451 to -0.940. Furthermore, a significant difference between the yield traits for stocks with and without the specific marker could also be established. The inheritance pattern of one marker, L13800bp, identified at the first step of selection of markers through stepwise regression analyses for five yield parameters is discussed in the context of applying multiple regression analysis for establishing association, if not linkage, between a group of DNA markers and a particular yield trait of polygenic nature and using such markers in molecular marker-assisted breeding programs.  相似文献   

20.
Assefa K  Merker A  Tefera H 《Hereditas》2003,139(3):174-183
The DNA polymorphism among 92 selected tef genotypes belonging to eight origin groups was assessed using eight inter simple sequence repeat (ISSR) primers. The objectives were to examine the possibility of using ISSR markers for unravelling genetic diversity in tef, and to assess the extent and pattern of genetic diversity in the test germplasm with respect to origin groups. The eight primers were able to separate or distinguish all of the 92 tef genotypes based on a total of 110 polymorphic bands among the test lines. The Jaccard similarity coefficient among the test genotypes ranged from 0.26 to 0.86, and at about 60 % similarity level the clustering of this matrix using the unweighted pair-group method based on arithmetic average (UPGMA) resulted in the formation of six major clusters of 2 to 37 lines with further eight lines remaining ungrouped. The standardized Nei genetic distance among the eight groups of origin ranged between 0.03 and 0.32. The UPGMA clustering using the standardized genetic distance matrix resulted in the identification of three clusters of the eight groups of origin with bootstrap values ranging from 56 to 97. The overall mean Shannon Weaver diversity index of the test lines was 0.73, indicating better resolution of genetic diversity in tef with ISSR markers than with phenotypic (morphological) traits used in previous studies. This can be attributed mainly to the larger number of loci generated for evaluation with ISSR analysis as compared to the few number of phenotypic traits amenable for assessment and which are further greatly affected by environment and genotype x environment interaction. Analysis of variance of mean Shannon Weaver diversity indices revealed substantial (P < or = 0.05) variation in the level of diversity among the eight groups of origin. In conclusion, our results indicate that ISSR can be useful as DNA-based molecular markers for studying genetic diversity and phylogenetic relationships, DNA fingerprinting for the identification of varieties or cultivars, and also for genome mapping in tef.  相似文献   

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