The random amplified polymorphic DNA （RAPD） marker was assessed to detect the genetic relationships among 48 hybrid Cymbidium cultivars from Japan, Korea, China, and USA, and 2 species of native Cymbidium. Twenty pr...The random amplified polymorphic DNA （RAPD） marker was assessed to detect the genetic relationships among 48 hybrid Cymbidium cultivars from Japan, Korea, China, and USA, and 2 species of native Cymbidium. Twenty primers were screened from 100 random decamer primers, and a total of 258 DNA bands were amplified, 253 of which （98.1%） were polymorphic. The average number of polymorphic DNA bands amplified by each primer was 12.6. All cultivars were distinguishable when a number of primers were considered. Genetic similarities among the cultivars and species were estimated based on the amount of band sharing ranging from 0.364-0.817 with an average of 0.581. According to the data, a dendrogram of genetic relationship, which was constructed using the UPGMA method, showed that all the tested cultivars and native species were classified into five cluster groups with the similarity coefficient of 0.592. It revealed that the genetic relationships among tested accessions were to some extent related with their origin, flower colour, branch type, and genealogy. It further indicated that the RAPD technique is a useful tool for studying the genetic relationships among hybrid Cymbidium cultivars.展开更多
The genetic relationships among oakleaf loquat （Eriobotrya prinoides）, Daduhe loquat （Eriobotrya prinoides var. dadunensis） and common loquat （Eriobotrya japonica） were studied by RAPD and ISSR markers. The resu...The genetic relationships among oakleaf loquat （Eriobotrya prinoides）, Daduhe loquat （Eriobotrya prinoides var. dadunensis） and common loquat （Eriobotrya japonica） were studied by RAPD and ISSR markers. The results showed that the similarity coefficient between oakleaf loquat and common loquat was minimal （0.6996 and 0.7219, respectively） and the similarity coefficient between oakleaf loquat and Daduhe loquat was maximal （0.8403 and 0.8211, respectively）, while the similarity coefficient between Daduhe loquat and common loquat was always intermediate （0.7195 and 0.7219, respectively）. The highest additivity was obtained when Daduhe loquat was regarded as the undetermined hybrid （44.9% and 45.8%, respectively）. The specific bands of oakleaf loquat and common loquat were present in Daduhe loquat. Thus, it could be concluded that Daduhe loquat was a hybrid of oakleaf loquat and common loquat.展开更多
Orchidaceae has known as an attractive flower and immense species. We have found a large species of Orchidaceae grow naturally in Papua’s jungle, Indonesia territorial. This study aims to reveal genetic variation and...Orchidaceae has known as an attractive flower and immense species. We have found a large species of Orchidaceae grow naturally in Papua’s jungle, Indonesia territorial. This study aims to reveal genetic variation and genetic relationships among endemic orchids in Papua based on RAPD markers. The study included 26 accessions of Papua’s endemic orchids used for genomic DNA extraction. Genomic DNAs were extracted by usingDNAextraction kit from Qiagen and genomic DNA amplification by using 10 decamer RAPD primers. DNA fragments that were amplified by Polymerase Change Reaction (PCR) were visualized and documented by using UV illumination apparatus. Genetically, endemic Orchids in Papua were described high variation. Fragments amplification by using ten RAPD primers and performed in the PCR tools resulted in 54 numbers of polymorphic fragments and no monomorphic band. The number of polymorphic bands per primer ranged from 4 to 7 with averaged 5.4 bands per assay unit. The genetic dissimilarities (GDs) among examined orchids ranged from 0.10 to 0.94 based on Nei’s unbiased coefficients. Dendrogram construction showed that Papua’s endemic orchid (PEO) samples different from another and separated to form group by their own at the 0.40 coefficient value and at the 0.6 coefficient value indicate that PEO sample is divided into nine groups i.e. samples at the genera level were separated into their own groups.展开更多
In this study, forty celery cultivars introduced from different regions of China were used as experimental materials to verify and analyze the practicability of RAPD technology in the identification of celery cuhivars...In this study, forty celery cultivars introduced from different regions of China were used as experimental materials to verify and analyze the practicability of RAPD technology in the identification of celery cuhivars. The results showed that RAPD technology could distinguish accurately the genetic relationship among various celery cultivars as a simple and ideal DNA molecular marker technology suitable for genetic relationship analysis. To be specific, 13 RAPD primers with clear amplified bands and significantly different number of amplified bands were screened, which provided basis for the identification of genetic relationship among different celery cultivars.展开更多
Genetic relationship of 12 ramie varieties with different drought resistance was analysed by using RAPD.Twenty-five 10-mer random primers were used to amplify the total DMA of these varieties.The results showed that t...Genetic relationship of 12 ramie varieties with different drought resistance was analysed by using RAPD.Twenty-five 10-mer random primers were used to amplify the total DMA of these varieties.The results showed that the amplified products of 12 ramie varieties could be obtained with 12 primers.The length of amplified products was 0.6-5.15 kb.Ninety bands were identified in total,of which 11 bands were common in all 12 varieties and 79 bands were polymorphic.The polymorphic bands were 87.78% of the total amplified bands.According to the result of cluster analysis,12 ramie varieties could be divided into two classes and three groups.It was found that high drought resistant varieties were clustered into different groups or subgroups in the same class,which shows near relationship among them.展开更多
The genetic relationships among twenty-five accessions of Garcinia kola using six Random Amplified Polymorphic (RAPD) primers were evaluated in this study. The highest volume of total genomic DNA (2218/μl) was record...The genetic relationships among twenty-five accessions of Garcinia kola using six Random Amplified Polymorphic (RAPD) primers were evaluated in this study. The highest volume of total genomic DNA (2218/μl) was recorded in ON4 from Ikare, while the highest DNA concentration of 1.93 gl was found in OS3 from Ilesa. The highest Polymorphic Information Content (PIC) and gene diversity of 93.77% and 0.94 respectively were revealed by primer OPO2 compared to other primers. The dendogram generated from Unweighted Pair Group with Mean Average (UPGMA) clustering delineated two groups, A and B, consisting of 21 and 4 accessions respectively. This study clearly showed the level of molecular diversity in the accessions and the information provided could be utilized for genetic improvement and conservation of Garcinia kola.展开更多
Objective： To identify the plants in Vitex including Vitex negundo L. , V. negundo var. cannabifolia （Sieb. et Zuee. ） Hand. -Mazz. , V. trifolia L. and V. trifolia L. var. simplicifolia Cham.. Methods： Both intra...Objective： To identify the plants in Vitex including Vitex negundo L. , V. negundo var. cannabifolia （Sieb. et Zuee. ） Hand. -Mazz. , V. trifolia L. and V. trifolia L. var. simplicifolia Cham.. Methods： Both intra- and inter-species relationships among these plants were analyzed by RAPD marker. Twenty-one samples collected from different locations in China were tested using 25 RAPD arbitrary 10- mer primers which were screened from 32 primers. Cluster analysis was conducted by Ward＇s minimumvariance method of SAS software. Results： A total of 224 bands were produced and 128 bands showed polymorphism among 21 samples. The level of polymorphism within species was 51.7%. The dendrogram constructed based on RAPD analysis showed that 21 samples can be placed in 2 groups at the level of SPRS value of 0. 3636. The first group included V. trifolia var. simplicifolia and V. trifolia. The other consisted of V. negundo and V. negundo var. cannabifolia.. At the level of SPRS value of 0. 1, 21 samples can be obviously divided into 3 groups. V. trifolia and V. trifolia var. simplicifolia were clustered into one group, V. negundo and V. negundo var. cannabifolia were separately clustered to 2 groups. Conclusion： RAPD analysis is in good agreement with the traditional plant taxonomic classification, and fundamentally identical with their origins and morphologie characteristics, which indicates that the genetic relationship among samples is related to their center of origin. These medicinal species in Vitex have their specific bands which are available to identify. These specific bands can be used as species-specific molecular markers of Fruetus Vitieis for the application of germplasm identification and classification.展开更多
Genetic diversity of 50 cucumber (Cucumis sativus L.) accessions from American, Holland, Japan and China was detected and evaluated using RAPD markers. 25 selected primers produced 215 scorable polymorphic RAPD bands ...Genetic diversity of 50 cucumber (Cucumis sativus L.) accessions from American, Holland, Japan and China was detected and evaluated using RAPD markers. 25 selected primers produced 215 scorable polymorphic RAPD bands and the ratio of polymorphism is 86.98%. Four main groups of cucumber accessions could be distinguished from UPGMA analysis: Occidental cucumber, South-China cucumber, North-China cucumber and Xishuangbanna cucumber. Our result confirmed that cucumber is a narrow-based germplasm, nevertheless RAPD analysis was stili useful in cucumber genotypic differentiation. More significantly, Xishuangbanna cucumber (Cucumis sativus L. Var Xishuangbannanesis Qi et Yuan), a mutation of cucumber, was clustered together to a special group in the study, which implied its special status in cucumber germplasm.展开更多
A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA （RAPD）, amplified frag...A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA （RAPD）, amplified fragment length polymorphism （AFLP） and simple sequence repeat （SSR） markers in establishing genetic relationships among 29 almond cultivars and three related wild species. SSRs presented a high level of polymorphism and greater information content, as assessed by the expected hetrozygosity, compared to AFLPs and RAPDs. The lowest values of expected hetrozygosity were obtained for AFLPs; however AFLPs showed the highest efficiency, owing to their capacity to reveal large numbers of bands per reaction, which led to high values for various types of indices of diversity. All the three techniques discriminated almond genotypes very effectively, except that SSRs failed to discriminate between ＇Monagha＇ and ＇Sefied＇ almond genotypes. The correlation coefficients of similarity were statistically significant for all the three marker systems, but were lower for the SSR data than for RAPDs and AFLPs. For all the markers, high similarity in dendrogram topologies was obtained, although some differences were observed. All the dendrograms, including that obtained by the combined use of all the marker data, reflect relationships for most of cultivars according to their geographic diffusion. AMOVA detected more variation among cultivated and related wild species of almond within each geographic group. Bootstrap analysis revealed that the number of markers used was sufficient for reliable estimation of genetic similarity and for meaningful comparisons of marker types.展开更多
A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA (RAPD), amplified fragme...A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers in establishing genetic relationships among 29 almond cultivars and three related wild species. SSRs presented a high level of polymorphism and greater information content, as assessed by the expected hetrozygosity, compared to AFLPs and RAPDs. The lowest values of expected hetrozygosity were obtained for AFLPs; however AFLPs showed the highest efficiency, owing to their capacity to reveal large numbers of bands per reaction, which led to high values for various types of indices of diversity. All the three techniques discriminated almond genotypes very effectively, except that SSRs failed to discriminate between ‘Monagha’ and ‘Sefied’ almond genotypes. The correlation coefficients of similarity were statistically significant for all the three marker systems, but were lower for the SSR data than for RAPDs and AFLPs. For all the markers, high similarity in dendrogram topologies was obtained, although some differences were observed. All the dendrograms, including that obtained by the combined use of all the marker data, reflect relationships for most of cultivars according to their geographic diffusion. AMOVA detected more variation among cultivated and related wild species of almond within each geographic group. Bootstrap analysis revealed that the number of markers used was sufficient for reliable estimation of genetic similarity and for meaningful comparisons of marker types.展开更多
Genetic relationships between Ziziphus jujuba and Ziziphus spinosa populations were studied using RAPD data in population genetics. 275 loci were gained among which 249 loci were polymorphic by 22 primers. The polymor...Genetic relationships between Ziziphus jujuba and Ziziphus spinosa populations were studied using RAPD data in population genetics. 275 loci were gained among which 249 loci were polymorphic by 22 primers. The polymorphic loci percentage was 89% among Z.spinosa population while that of Z.jujuba population was 56%. 31 specific RAPD markers were detected on 3 Z.jujuba varieties and 15 Z.spinosa forms. Cluster analysis showed: when λ=12, the forms tested were divided into 2 groups. One included Z. jujuba cv. Zanhuangdazao, Yudichuangan, Yuanshichuangan, Xiaochuangan, Qiantai No.1, Luzhuangchuangan; the other included Z. jujuba cv. Zilingdan and 26 Z. spinosa forms. All above indicated that Z. jujuba and Z.spinosa should be regarded as two separate species.展开更多
RAPD technique was used to detect the genetic relationship among seven Betula species.233 loci in total were amplified by using 14 random primers.The percentage of polymorphic loci varied from 12.02% to 36.91%,in whic...RAPD technique was used to detect the genetic relationship among seven Betula species.233 loci in total were amplified by using 14 random primers.The percentage of polymorphic loci varied from 12.02% to 36.91%,in which B.costata had the highest variation level.The dendrogram of genetic relationship was constructed on the basis of the genetic distances among species.According to genetic distance in more than 1.22,six species were clustered into two groups,where B.fruticosal was one group and others,including B.davurica,B.pendula,B.platyphylla,B.schmidtii and B.costata, were grouped together.It indicated that the result of genetic relationship obtained by RAPD technique was closely consistent with that classified by traditional morphological classification.The analysis of genetic relationship among Betula species would validly guide the parental selection and interspecies crossing for Betula species.展开更多
文摘The random amplified polymorphic DNA （RAPD） marker was assessed to detect the genetic relationships among 48 hybrid Cymbidium cultivars from Japan, Korea, China, and USA, and 2 species of native Cymbidium. Twenty primers were screened from 100 random decamer primers, and a total of 258 DNA bands were amplified, 253 of which （98.1%） were polymorphic. The average number of polymorphic DNA bands amplified by each primer was 12.6. All cultivars were distinguishable when a number of primers were considered. Genetic similarities among the cultivars and species were estimated based on the amount of band sharing ranging from 0.364-0.817 with an average of 0.581. According to the data, a dendrogram of genetic relationship, which was constructed using the UPGMA method, showed that all the tested cultivars and native species were classified into five cluster groups with the similarity coefficient of 0.592. It revealed that the genetic relationships among tested accessions were to some extent related with their origin, flower colour, branch type, and genealogy. It further indicated that the RAPD technique is a useful tool for studying the genetic relationships among hybrid Cymbidium cultivars.
文摘The genetic relationships among oakleaf loquat （Eriobotrya prinoides）, Daduhe loquat （Eriobotrya prinoides var. dadunensis） and common loquat （Eriobotrya japonica） were studied by RAPD and ISSR markers. The results showed that the similarity coefficient between oakleaf loquat and common loquat was minimal （0.6996 and 0.7219, respectively） and the similarity coefficient between oakleaf loquat and Daduhe loquat was maximal （0.8403 and 0.8211, respectively）, while the similarity coefficient between Daduhe loquat and common loquat was always intermediate （0.7195 and 0.7219, respectively）. The highest additivity was obtained when Daduhe loquat was regarded as the undetermined hybrid （44.9% and 45.8%, respectively）. The specific bands of oakleaf loquat and common loquat were present in Daduhe loquat. Thus, it could be concluded that Daduhe loquat was a hybrid of oakleaf loquat and common loquat.
文摘Orchidaceae has known as an attractive flower and immense species. We have found a large species of Orchidaceae grow naturally in Papua’s jungle, Indonesia territorial. This study aims to reveal genetic variation and genetic relationships among endemic orchids in Papua based on RAPD markers. The study included 26 accessions of Papua’s endemic orchids used for genomic DNA extraction. Genomic DNAs were extracted by usingDNAextraction kit from Qiagen and genomic DNA amplification by using 10 decamer RAPD primers. DNA fragments that were amplified by Polymerase Change Reaction (PCR) were visualized and documented by using UV illumination apparatus. Genetically, endemic Orchids in Papua were described high variation. Fragments amplification by using ten RAPD primers and performed in the PCR tools resulted in 54 numbers of polymorphic fragments and no monomorphic band. The number of polymorphic bands per primer ranged from 4 to 7 with averaged 5.4 bands per assay unit. The genetic dissimilarities (GDs) among examined orchids ranged from 0.10 to 0.94 based on Nei’s unbiased coefficients. Dendrogram construction showed that Papua’s endemic orchid (PEO) samples different from another and separated to form group by their own at the 0.40 coefficient value and at the 0.6 coefficient value indicate that PEO sample is divided into nine groups i.e. samples at the genera level were separated into their own groups.
文摘In this study, forty celery cultivars introduced from different regions of China were used as experimental materials to verify and analyze the practicability of RAPD technology in the identification of celery cuhivars. The results showed that RAPD technology could distinguish accurately the genetic relationship among various celery cultivars as a simple and ideal DNA molecular marker technology suitable for genetic relationship analysis. To be specific, 13 RAPD primers with clear amplified bands and significantly different number of amplified bands were screened, which provided basis for the identification of genetic relationship among different celery cultivars.
文摘Genetic relationship of 12 ramie varieties with different drought resistance was analysed by using RAPD.Twenty-five 10-mer random primers were used to amplify the total DMA of these varieties.The results showed that the amplified products of 12 ramie varieties could be obtained with 12 primers.The length of amplified products was 0.6-5.15 kb.Ninety bands were identified in total,of which 11 bands were common in all 12 varieties and 79 bands were polymorphic.The polymorphic bands were 87.78% of the total amplified bands.According to the result of cluster analysis,12 ramie varieties could be divided into two classes and three groups.It was found that high drought resistant varieties were clustered into different groups or subgroups in the same class,which shows near relationship among them.
文摘The genetic relationships among twenty-five accessions of Garcinia kola using six Random Amplified Polymorphic (RAPD) primers were evaluated in this study. The highest volume of total genomic DNA (2218/μl) was recorded in ON4 from Ikare, while the highest DNA concentration of 1.93 gl was found in OS3 from Ilesa. The highest Polymorphic Information Content (PIC) and gene diversity of 93.77% and 0.94 respectively were revealed by primer OPO2 compared to other primers. The dendogram generated from Unweighted Pair Group with Mean Average (UPGMA) clustering delineated two groups, A and B, consisting of 21 and 4 accessions respectively. This study clearly showed the level of molecular diversity in the accessions and the information provided could be utilized for genetic improvement and conservation of Garcinia kola.
基金Supported by specific TCM modernization fund.Shanghai Commission of Sci &.Tech (No.04D19810)
文摘Objective： To identify the plants in Vitex including Vitex negundo L. , V. negundo var. cannabifolia （Sieb. et Zuee. ） Hand. -Mazz. , V. trifolia L. and V. trifolia L. var. simplicifolia Cham.. Methods： Both intra- and inter-species relationships among these plants were analyzed by RAPD marker. Twenty-one samples collected from different locations in China were tested using 25 RAPD arbitrary 10- mer primers which were screened from 32 primers. Cluster analysis was conducted by Ward＇s minimumvariance method of SAS software. Results： A total of 224 bands were produced and 128 bands showed polymorphism among 21 samples. The level of polymorphism within species was 51.7%. The dendrogram constructed based on RAPD analysis showed that 21 samples can be placed in 2 groups at the level of SPRS value of 0. 3636. The first group included V. trifolia var. simplicifolia and V. trifolia. The other consisted of V. negundo and V. negundo var. cannabifolia.. At the level of SPRS value of 0. 1, 21 samples can be obviously divided into 3 groups. V. trifolia and V. trifolia var. simplicifolia were clustered into one group, V. negundo and V. negundo var. cannabifolia were separately clustered to 2 groups. Conclusion： RAPD analysis is in good agreement with the traditional plant taxonomic classification, and fundamentally identical with their origins and morphologie characteristics, which indicates that the genetic relationship among samples is related to their center of origin. These medicinal species in Vitex have their specific bands which are available to identify. These specific bands can be used as species-specific molecular markers of Fruetus Vitieis for the application of germplasm identification and classification.
基金This work was supported by Beijing Natural Science Funds
文摘Genetic diversity of 50 cucumber (Cucumis sativus L.) accessions from American, Holland, Japan and China was detected and evaluated using RAPD markers. 25 selected primers produced 215 scorable polymorphic RAPD bands and the ratio of polymorphism is 86.98%. Four main groups of cucumber accessions could be distinguished from UPGMA analysis: Occidental cucumber, South-China cucumber, North-China cucumber and Xishuangbanna cucumber. Our result confirmed that cucumber is a narrow-based germplasm, nevertheless RAPD analysis was stili useful in cucumber genotypic differentiation. More significantly, Xishuangbanna cucumber (Cucumis sativus L. Var Xishuangbannanesis Qi et Yuan), a mutation of cucumber, was clustered together to a special group in the study, which implied its special status in cucumber germplasm.
文摘A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA （RAPD）, amplified fragment length polymorphism （AFLP） and simple sequence repeat （SSR） markers in establishing genetic relationships among 29 almond cultivars and three related wild species. SSRs presented a high level of polymorphism and greater information content, as assessed by the expected hetrozygosity, compared to AFLPs and RAPDs. The lowest values of expected hetrozygosity were obtained for AFLPs; however AFLPs showed the highest efficiency, owing to their capacity to reveal large numbers of bands per reaction, which led to high values for various types of indices of diversity. All the three techniques discriminated almond genotypes very effectively, except that SSRs failed to discriminate between ＇Monagha＇ and ＇Sefied＇ almond genotypes. The correlation coefficients of similarity were statistically significant for all the three marker systems, but were lower for the SSR data than for RAPDs and AFLPs. For all the markers, high similarity in dendrogram topologies was obtained, although some differences were observed. All the dendrograms, including that obtained by the combined use of all the marker data, reflect relationships for most of cultivars according to their geographic diffusion. AMOVA detected more variation among cultivated and related wild species of almond within each geographic group. Bootstrap analysis revealed that the number of markers used was sufficient for reliable estimation of genetic similarity and for meaningful comparisons of marker types.
文摘A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers in establishing genetic relationships among 29 almond cultivars and three related wild species. SSRs presented a high level of polymorphism and greater information content, as assessed by the expected hetrozygosity, compared to AFLPs and RAPDs. The lowest values of expected hetrozygosity were obtained for AFLPs; however AFLPs showed the highest efficiency, owing to their capacity to reveal large numbers of bands per reaction, which led to high values for various types of indices of diversity. All the three techniques discriminated almond genotypes very effectively, except that SSRs failed to discriminate between ‘Monagha’ and ‘Sefied’ almond genotypes. The correlation coefficients of similarity were statistically significant for all the three marker systems, but were lower for the SSR data than for RAPDs and AFLPs. For all the markers, high similarity in dendrogram topologies was obtained, although some differences were observed. All the dendrograms, including that obtained by the combined use of all the marker data, reflect relationships for most of cultivars according to their geographic diffusion. AMOVA detected more variation among cultivated and related wild species of almond within each geographic group. Bootstrap analysis revealed that the number of markers used was sufficient for reliable estimation of genetic similarity and for meaningful comparisons of marker types.
文摘Genetic relationships between Ziziphus jujuba and Ziziphus spinosa populations were studied using RAPD data in population genetics. 275 loci were gained among which 249 loci were polymorphic by 22 primers. The polymorphic loci percentage was 89% among Z.spinosa population while that of Z.jujuba population was 56%. 31 specific RAPD markers were detected on 3 Z.jujuba varieties and 15 Z.spinosa forms. Cluster analysis showed: when λ=12, the forms tested were divided into 2 groups. One included Z. jujuba cv. Zanhuangdazao, Yudichuangan, Yuanshichuangan, Xiaochuangan, Qiantai No.1, Luzhuangchuangan; the other included Z. jujuba cv. Zilingdan and 26 Z. spinosa forms. All above indicated that Z. jujuba and Z.spinosa should be regarded as two separate species.
文摘RAPD technique was used to detect the genetic relationship among seven Betula species.233 loci in total were amplified by using 14 random primers.The percentage of polymorphic loci varied from 12.02% to 36.91%,in which B.costata had the highest variation level.The dendrogram of genetic relationship was constructed on the basis of the genetic distances among species.According to genetic distance in more than 1.22,six species were clustered into two groups,where B.fruticosal was one group and others,including B.davurica,B.pendula,B.platyphylla,B.schmidtii and B.costata, were grouped together.It indicated that the result of genetic relationship obtained by RAPD technique was closely consistent with that classified by traditional morphological classification.The analysis of genetic relationship among Betula species would validly guide the parental selection and interspecies crossing for Betula species.
