首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
The methodology of sampling and the selection of a proper marker systemfor the analysis of accessions are major concerns in the evaluation of gene bank material. In our study the RAPD analysis of bulked DNA samples and single seedsDNA was successfully employed to evaluate intra- and inter-population geneticvariability of cultivated and wild tartary buckwheat accessions. The bulkingapproach enabled the distinction of all 40 analysed accessions and theirseparation into geographically well defined clusters. Three wild populations,two from Sichuan and one from Qinghai, formed a group that was geneticallyrelatively distant from wild populations from Tibet and all cultivatedlandraces which, on the other hand, exhibited very close relationships. Thesingle seed study that was used after bulked DNA analysis provided detailedinformation of the genetic variation present within some accessions of specialinterest. A moderate level of genetic variability was detected betweenaccessions and the variability was partitioned into between- andwithin-population components. On average, most of the detected variation ispresent between F. tataricumpopulations. The genetic and geographic distribution of variability is furtherdiscussed. We demonstrated the usefulness of combining bulking and single seedstudy approaches for the effective evaluation of genetic variability inF. tataricum accessions that couldalso have wider applicability in the management of plant genetic resources andphylogenetic studies.  相似文献   

2.
Genetic variation within and among several Sorghum populations from different agroecological zones in Malawi were investigated using random amplified polymorphic markers (RAPDs). DNA samples from individual plants were analyzed using 35 oligonucleotides of random sequence. Twenty five of these primers allowed amplifications of random polymorphic (RAPD) loci. Overall, 52% of the scored loci were polymorphic. Every accession was genetically distinct. The analysis of molecular variance revealed that the within-region (among accessions) variations accounted for 96.43% of the total molecular variance. Observed variations in allelic frequency was not related to agroecological differences. The degree of band sharing was used to evaluate genetic distance between accessions and to construct a phylogenetic tree. Further analysis revealed that the sorghum accessions analyzed were genetically close despite considerable phenotypic diversity within and among them. It is suggested that all the sorghum landraces currently available in Malawi should be conserved both ex situ and in situ to maintain the current level of genetic diversity.  相似文献   

3.
The genetic variation existing in a set of barley (Hordeum vulgare L.) landrace samples recently collected in Morocco was estimated. Two kinds of genetic markers, seed storage proteins (hordeins) and random amplified polymorphic DNA (RAPD), were used. Only six out of 31 landraces were subjected to RAPD analysis. Both kinds of markers, RAPD and storage proteins, yielded similar results, showing that the level of variation observed in Moroccan barley was high: all landraces showed variability; 808 different storage protein patterns (multilocus associations) were observed among 1897 individuals (2.32 seeds per association, on average) with an average of 43 multilocus associations per accession. In general, genetic variation within accessions was higher than between accessions. The 100 polymorphic RAPD bands generated by 21 effective primers were able to generate enough patterns to differentiate between uniform cultivars and even between individuals in variable accessions. One of the aims of this work was to compare the effectiveness of RAPD versus storage protein techniques in assessing the variability of genetic resource collections. On average hordeins were more polymorphic than RAPDs: they showed more alternatives per band on gels and a higher percentage of polymorphic bands, although RAPDs supply a higher number of bands. Although RAPD is an easy and standard technique, storage protein analysis is technically easier, cheaper and needs less sophisticated equipment. Thus, when resources are a limiting factor and considering the cost of consumables and work time, seed storage proteins must be the technique of choice for a first estimation of genetic variation in plant genetic resource collections.  相似文献   

4.
Applications of bulking procedures have played an increasingly important role in molecular characterization of plant germplasm, but little attention has been made to address the effectiveness of detecting genetic variation and inferring genetic relationships via bulking. An analysis was performed here to compare the genetic variation detected and genetic relationships inferred via bulking and single-plant sampling of five oat (Avena sativa L.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.) cultivars with known pedigrees using amplified fragment length polymorphism (AFLP) markers. Three AFLP primer pairs were applied to screen one bulk and eight single-plant samples of each cultivar and up to 140 AFLP bands were scored for each sample. Analyses of these AFLP data showed bulking revealed AFLP variation up to 21.4% less than corresponding single-plant sampling for these crop species and also introduced up to 2.2% upward and 5.1% downward biases in detecting AFLP variations for each cultivar. The genetic relationships inferred by bulking using the Dice's coefficient, the simple matching coefficient, and the Jaccard's coefficient were largely the same, but differed from those in single-plant samples employing average Dice's coefficient, average simple matching coefficient, and AMOVA-based distance method. All of the inferred genetic relationships were not congruent to the known pedigrees. Clearly, substantial biases could exist in detection of AFLP variation and in inference of genetic relationships from bulk samples, even for closely related germplasm, and more efforts to assess the effectiveness of bulking in inferring genetic variation and relationships are needed for more informative molecular characterization of plant germplasm.  相似文献   

5.
This investigation was aimed at exploring the genetic diversity among nine typical accessions of Chinese mustard crops using random amplified polymorphic DNA (RAPD) markers and morphological comparison. Totally, 111 reproducible DNA bands were generated by 16 arbitrary primers, of which 91 bands were proved to be polymorphic. Based on pair-wise comparisons of the amplified bands, genetic similarities were obtained using Nei & Li's similarity coefficients and a dendrogram reflecting their relationships was made using the unweighted pair–group method with arithmetic averages (UPGMA). The result of cluster analysis indicated that the nine accessions were capable of being classified into two primary groups, one including accession 2 with expanded root (root mustard), accession 3 with entirely expanded whole stem (long-stem mustard), accession 6 with edible leaves (leaf mustard), accession 8 with edible seed stalk (seed stalk mustard) and another one including accession 4 with expanded basal stem (short-stem mustard), accession 5 with bulgy petiole (leafy bulgy mustard), and accession 9 with mustard-rich seed (seed mustard). Besides, accession 1 with expanded root (root mustard) and accession 7 with edible leaves and seed stalk (seed stalk mustard) were independent of other accessions in the dendrogram. Additionally, by cluster analysis based on highly reproducible RAPD markers, the accessions with similar edible parts of leaves or roots were not actually in the same phylogenetic groups. This implied that they were probably derived from different geographical origins with dissimilar genetic background and possessed higher genetic diversification. Furthermore, the results indicated that the traditional method for classifying Chinese mustard crops was not much reliable as it was largely dependent on phenotypic behaviors. Meanwhile, the phenotypic differences among individuals did not necessarily mean they must have sharp difference in genetic background as they met in the same group. Undoubtedly, these results aforementioned make this crop quite interesting to researchers for further investigating the molecular evolution of this special AABB group.  相似文献   

6.
Some Arachis species are widely used as commercial plants, e.g. the groundnut A. hypogaea, an important source of good quality protein and oil, and A. pintoi and A. glabrata, that are utilized as forage species. Germplasm of most Arachis species is available in germplasm banks. However, little it is known about the genetic attributes of this germplasm, and mainly about its genetic variability, which is very important for its maintenance. In the present study RAPDs were used to assay the genetic variation within and among 48 accessions of five sections of the genus Arachis and to establish the genetic relationships among these accessions. Ten of 34 primers tested were selected for DNA amplification reactions since they yielded the largest numbers of polymorphic loci. A dendrogram was constructed based on data from the 10 primers selected. Eighty RAPD polymorphic bands were analyzed among the accessions studied. The relationships among species based on RAPDs were similar to those previously reported based on morphological, cytological and crossability data; demonstrating that RAPDs can be used to determine the genetic relationships among species of the different sections of the genus Arachis. In general, wide variation was found among accessions and low variation was found within the accessions that had two or more plants analyzed. However, higher polymorphism was found in the section Trierectoides and in one accession of A. major, indicating that generalizations should be avoided and each species should be analyzed in order to establish collection and maintenance strategies.  相似文献   

7.
Analysis of the extent and distribution of genetic diversity incrop plants is essential for optimizing sampling and breedingstrategies. We used random amplified polymorphic DNA (RAPD)markers to assess genetic diversity and relationships in 22 Canadiancultivars, 29 selected world cultivars and 10 landraces of flax(Linum usitatissimum L.). RAPDvariation was generally low and more variation was detected among,than within, the investigated flax accessions. Based on 53 variableRAPD loci observed for the 61 accessions, the landraces had a lowerproportion of fixed recessive RAPD loci (0.427) (i.e.,more genetic variation) than all of the flax cultivars examined(0.492). The linseed cultivars had a lower proportion ofrecessive loci (0.469) than the fiber flax cultivars(0.529). Canadian linseed cultivars had a lower proportionof recessive loci (0.465) than the selected world flaxcultivars (0.512). A trend was also observed that the rateof loss in genetic variation in Canadian flax breeding programs overthe last fifty years was approximately two variable loci per 100 lociper 10 years. Clustering analyses based on similarity estimatesshowed that the fiber cultivars were more related (or similar toeach other) and were classified as a homogeneous group. All ofthe linseed cultivars were clustered in diverse groups with the ninelandrace accessions. Implications of these findings for flax breedingand germplasm management are discussed.  相似文献   

8.
Randomly amplified polymorphic DNA (RAPD) analysis was employed to assess genetic divergence among 29 neem accessions collected from two agro-ecological regions of India (11 agro-climatic sub-zones), which cover three states, Punjab, Haryana and Rajasthan. Out of 24, 10-mer random primers used for studying genetic divergence, 14 were polymorphic, generating a total of 73 amplification products with an average of 5.21 products per polymorphic primer and estimated gene diversity of 0.49. Genetic relationships among accessions were evaluated by generating a similarity matrix based on Jaccard’s coefficient, ranging from 0.70 to 0.96. The phenetic dendrogram generated by UPGMA analysis grouped accessions into five clusters. RAPD performed within accessions (individual seedlings collected from the same mother plant) showed no variation indicating homogeneous population within accessions. Primers OPA-18, OPC-08 and OPI-03 were found most informative based on their resolving power. The degree of genetic variation detected among the 29 accessions with RAPD analysis suggests that RAPD can be used for studying genetic diversity in neem. The study also demonstrated that neem germplasm collected from northwestern plains of India shows no eco-geographical isolation based on sub-zones because accessions collected from different sub-regions are grouping together in the genetic tree.  相似文献   

9.
Detection of genetic relationships between 19 chickpea cultivars and five accessions of its wild progenitor Cicer reticulatum Ladizinsky were investigated by using RAPD and ISSR markers. On an average, six bands per primer were observed in RAPD analysis and 11 bands per primer in ISSR analysis. In RAPD, the wild accessions shared 77.8% polymorphic bands with chickpea cultivars, whereas they shared 79.6% polymorphic bands in ISSR analysis. In RAPD analysis 51.7% and 50.5% polymorphic bands were observed among wild accessions and chickpea cultivars, respectively. Similarly, 65.63% and 56.25% polymorphic bands were found in ISSR analysis. The dendrogram developed by pooling the data of RAPD and ISSR analysis revealed that the wild accessions and the ICCV lines showed similar pattern with the dendrogram of RAPD analysis. The ISSR analysis clearly indicated that even with six polymorphic primers, reliable estimation of genetic diversity could be obtained, while nearly 30 primers are required for RAPD. Moreover, RAPD can cause genotyping errors due to competition in the amplification of all RAPD fragments. The markers generated by ISSR and RAPD assays can provide practical information for the management of genetic resources. For the selection of good parental material in breeding programs the genetic data produced through ISSR can be used to correlate with the relationship measures based on pedigree data and morphological traits to minimize the individual inaccuracies in chickpea.  相似文献   

10.
About 65 years ago, more than 150 Swiss maize landraces (Zea mays L. ssp. mays) of the flint type were collected and conserved ex situ. Due to the climatically and culturally diverse environment of the Alps, a considerable genetic diversity of this material was assumed. To prove this, an efficient method was required to carry out genetic profiling of all the accessions in the Swiss Gene Bank. Simple sequence repeat marker (SSR) profiling in combination with the visualization of the polymerase chain reaction (PCR) products on agarose gels was chosen. Here a set of 19 different landrace accessions was analyzed to: (i) investigate their genetic diversity, (ii) investigate and display the population structure and (iii) determine whether DNA bulks rather than single plants can be used for such analyses. Four repeated samples of one accession were found to be much closer to one another than to the rest of accessions. Furthermore, specific alleles were identified for several accessions. The PCR products of the bulked DNA samples represented only a small part of the variation revealed by the analysis of individuals. Loci with four base repeat motifs performed better in the analysis of bulks than loci with other repeat motifs. The correlation between genetic distance matrices, based on the analysis of individuals and bulks, respectively, was significant. Thus, the single plant approach allowed for sufficient differentiation of accessions, and DNA bulks visualized on agarose gels led to correlated genetic distances although a limited number of alleles were detected. Although the limited resolution of agarose gels likely causes some bias, profiling of larger sets with the individual plant approach appears feasible and more informative compared to the bulk analysis we conducted.  相似文献   

11.
Total 65 lotus accessions in genus Nelumbo mainly collected from China, were subjected to random amplified polymorphic DNA (RAPD) markers to estimate the genetic diversity and to test the genetic basis of the relationships between morphotypes and molecular markers. Seventeen primers generated a total of 195 highly reproducible and discernible loci, among which 173 were polymorphic. Percent polymorphism varied from 66.7 to 100 with an average of 88.72, and five primers out of them, OPC05, OPG10, OPN20, OPP09 and OPS17, showed 100% polymorphism. A relatively high genetic diversity was detected among all the samples with the similarity coefficient values ranging from 0.45 to 0.85, and Nei’s gene diversity (h) 0.30, and Shannon index (I) 0.46. The UPGMA dendrogram clustered 65 accessions in four clusters and the clustering pattern showed two groups, N. nucifera ssp. nucifera and those accessions related to the American lotus, and some special cultivars, landraces, hybrids and the American lotus. Principal Coordinate Analysis (PCA) further indicated that the genetic diversity of Nelumbo accessions was not evenly distributed, instead, was presented by a clustered distribution pattern. Similar to the results revealed by the dendrogram, two main groups representing the two subspecies of N. nucifera, as well as some special landraces, cultivars of Chinese lotus, the Japanese lotus and hybrids out of the two groups were obtained. Neither the UPGMA dendrogram nor the PCA analysis exhibited strict relationship with geographic distribution and morphotypes among the accessions.  相似文献   

12.
As an oilseed crop, the cultivation of Ethiopian mustard (Brassica carinata) is restricted only to Ethiopia. Even though geographic diversity is a potent source of allelic diversity, the extent of genetic diversity among germplasm material of Ethiopian mustard from different countries has not been assessed. Forty-three accessions, comprising 29 accessions from eight different geographic regions of Ethiopia and 14 exotic accessions from Australia, Pakistan, Spain, and Zambia were analysed for their genetic diversity using random amplified polymorphic DNA (RAPD) technique. A set of 50 primers yielded a total of 275 polymorphic bands allowing an unequivocal separation of every Ethiopian mustard accession. The usefulness of the 50 RAPD primers in measuring heterozygousity and distinguishing accessions was variable such that polymorphic information content (PIC) varied from 0.05 to 0.40, band informativeness (BI) from 0.05 to 0.65 and primer resolving power (RP) from 0.15 to 6.83. Jaccard's similarity coefficients ranged from 0.44 to 0.87 indicating the presence of a high level of genetic diversity. On the average, Australian and Ethiopian accessions were the most similar while, Spanish and Zambian accessions were the most distant ones. Cluster analysis grouped the 43 accessions into four groups, which has quite a high fit (r = 0.80) to the original similarity matrix. With no prior molecular information, the RAPD technique detected large genetic diversity among the 43 accessions from five different countries and their grouping by dendrogram and principal coordinate analysis (PCoA) was inclined towards geographic differentiation of RAPD markers. Conversely, RAPD differentiation along geographic origin was not apparent within the Ethiopian accessions.  相似文献   

13.
The present study, using RAPD analysis, was undertaken to characterize genetic variation in domesticated cowpea and its wild progenitor, as well as their relationships. The materials used consisted of 26 domesticated accessions, including accessions from each of the five cultivar-group, and 30 wild/weedy accessions, including accessions from West, East and southern Africa. A total of 28 primers generated 202 RAPD bands. One hundred and eight bands were polymorphic among the domesticated compared to 181 among wild/weedy cowpea accessions. Wild accessions were more diverse in East Africa, which is the likely area of origin of V. unguiculata var. spontanea. Var. spontanea is supposed to have spread westward and southward, with a loss of variability, loss counterbalanceed in southern Africa by introgressions with local perennial subspecies. Although the variabilty of domesticated cowpea was the highest ever recorded, cultivar-groups were poorly resolved, and several results obtained with isozyme data were not confirmed here. However primitive cultivars were more diverse than evolved cultivars, which still suggests two consecutive bottlenecks within domesticated cowpea evolution. As isozymes and AFLP markers, although with a larger number of markers, RAPD data confirmed the single domestication hypothesis, the gap between wild and domesticated cowpea, and the widespread introgression phenomena between wild and domesticated cowpea.  相似文献   

14.
Genetic diversity among 26 cucumber (Cucumis sativus L. var. sativus) accessions from five African countries [Algeria (1), Egypt (21), Ethiopia (2), Kenya (1), and Libya (1)] present in the U.S. National Plant Germplasm System (NPGS) were examined by assessing variation at 71 polymorphic random amplified polymorphic DNA (RAPD) loci. Genetic distances (GD; simple matching coefficient) were estimated among these African accessions and a reference array (RA) of 21 accessions representative of the genetic variation in cucumber. GD among African accessions ranged between 0.41 and 0.97. GD among accessions in the reference array ranged between 0.36 and 0.88. Multivariate analysis identified three distinct groupings (1–3) of African accessions; Group 1 contained 21 accessions (Egypt, Ethiopia and Libya), Group 2 consisted of two accessions (Kenya, Algeria), and Group 3 possessed three accessions (Egypt). These groupings were distinct from each other (P > 0.001). Accessions in Group 1 differed genetically from all other accessions examined (P > 0.01), and accessions in Groups 2 and 3 were uniquely associated with several RA accessions. While GD among accessions in Group 1 ranged between 0.52 and 0.90, distances among Group 2 accessions varied between 0.93 and 0.97. The GD between the two accessions in Group 3 was 0.65. An accession from Syria (PI 181874) and from one Turkey (PI 199383) were genetically more similar to accessions in Group 1 than to other accessions in the RA. Likewise, accessions in Group 2 were genetically similar to two RA accessions from China and a European glasshouse cucumber line, and Group 3 accessions showed genetic affinities with the U.S. market class cultivar Dasher II. Data suggest that some Egyptian accessions (Group 1) possess unique genetic variation, that this germplasm has potential for broadening the genetic base of commerical cucumber, and that further collection of African germplasm is likely to enhance genetic diversity of cucumber in NPGS.  相似文献   

15.
Andrographis paniculata is a medicinal plant of immense therapeutic value. The present study was aimed to elucidate its genetic diversity based on morphochemical and RAPD markers from 53 accessions belonging to 5 eco-geographic regions. Analysis of variance and D 2 statistics revealed significant differences in all the metric traits and sufficient inter-cluster distances indicating considerable diversity among the accessions. The complementary approach of RAPD was used to evaluate the genetic dissimilarities among all the accessions using 6 highly polymorphic primers. The average proportion of polymorphic loci across primers was 96.28%. The molecular genetic diversity based on Shannon index per primer averaged 5.585 with values ranging from 3.08 to 8.70 indicating towards wide genetic base. RAPD based UPGMA and D 2 cluster analysis also revealed that various accessions available in different eco-geographic regions might have originated from native places of wild abundance. Similarity matrices were generated for molecular markers and morphometric data to determine the degree of congruence between the two. A highly significant but low correlation (r = 0.547, P < 0.001) was obtained thus implying the correspondence between the two. The species is hermaphroditic and a habitual inbreeder. The present study yielded a typical triangular congruence between its breeding system, morphometric traits and RAPD markers thus elucidating the usefulness of complementary approaches to make diversity analysis more explanatory and purposeful for optimum genetic amelioration and effective conservation of its genotypic variability.  相似文献   

16.
Isozyme and restriction fragment length polymorphisms (RFLPs) have been applied to studies of genetic relationships and germplasm management in cucumber (Cucumis sativus L.). However, isozymes identify relatively few polymorphisms, and RFLPs are technically complex, expensive, and not compatible for the high through-put required for rigorous assessment of this narrow-based germplasm. Since random amplified polymorphic DNA (RAPD) markers do not manifest such shortcomings, a study was conducted in cucumber to examine genetic relationships in diverse germplasm, assess the usefulness of RAPD markers in distinguishing elite accessions, and compare the relative effectiveness of RAPD markers to that of isozyme and RFLP markers. One hundred and eighteen C. sativus accessions were analyzed using variation at 71 RAPD loci (44 mapped and 27 unmapped). Genetic distances among accessions were estimated using the simple matching coefficient complement, and analyzed using multi-dimensional scaling. Each accession had a unique marker profile, indicating that RAPD analysis was useful in genotypic differentiation. Germplasm grouping patterns were consistent with individual accession origins, theoretical dispersal routes and discriminating morphological characters (i.e., sex expression and fruit length to diameter ratio). Although elite accessions were discriminated by RAPD profiling, their genetic distances were relatively small (between 0.01 and 0.58), indicating limited genetic diversity in this germplasm array. Assessment of a subset of the germplasm array using RAPDs resulted in genetic distance measurements more similar to published genetic distance estimates by RFLP markers (Spearman rank correlation, rs = 0.7–0.8) than estimates by isozyme markers (rs = 0.4). Data indicate that RAPD markers have utility for analysis of genetic diversity and germplasm management in cucumber.  相似文献   

17.
Germplasm conserved as seeds in genebanks requires regular regeneration. In this process, selection and genetic drift may cause loss of genetic diversity from accessions. In the case of selfing crops, separation of distinct lines into different accessions may be an efficient strategy to avoid these negative effects. In order to evaluate the applicability of this method for collection management, knowledge about the level of intra-accession genetic diversity is required. By means of AFLP analysis intra-accession variation was investigated in two cultivars, two landraces and two wild populations of ex situ conserved barley germplasm. In the total sample of 216 individuals analysed (36 per accession), 22 genotypes were observed based on 104 polymorphic loci. The number of genotypes detected ranged from 1 to 3 per accession, except for a Nepalese landrace that revealed 12 genotypes. An UPGMA cluster analysis grouped the genotypes unambiguously into the accession they belonged to and genotypes within accessions were generally found to be closely related. In order to determine the repeatability of the results obtained, 11 individuals belonging to 4 genotypes from the Nepalese landrace were scored for a second set of AFLP markers. Matrices of genetic distances calculated for the two AFLP datasets were found to be highly correlated (r = 0.9346, P < 0.001). Separation of genotypes into different accessions was considered a relevant option only for the Nepalese landrace. Analysis of molecular variance indicated that this accession could be well divided into 8 distinct lines. Further implications of the results for genebank practices are discussed.  相似文献   

18.
The present study was performed to investigate genetic diversity of Kenyan landraces of the white-flowered gourd (Lagenaria siceraria), which exhibits tremendous morphological variation. RAPD analyses were performed on 53 landraces of the cultivated species L. siceraria and 42 accessions of three wild species (40 L. sphaerica, 1 L. abyssinica, and 1 L. breviflora). A total of 432 polymorphic bands were detected using 54 primers. The four species were clearly differentiated from one another. Intra-specific variations were investigated with L. siceraria and its wild relative L. sphaerica. Landraces of the cultivated species collected from different ethnic communities or regions were differentiated. Morphological variations were not associated with RAPD variations. Bitter landraces collected in Maasai communities showed two specific RAPD bands. In the wild species, accessions collected from the eastern and western sides of the Great Rift Valley were genetically differentiated from each other. In both species, genetic and geographical distance matrices computed among all pairs of accessions were significantly correlated, implying that the observed geographical variation can be explained by the 'Isolation by distance model'. Progeny plants derived from a common mother in L. siceraria showed a low level of segregation in RAPD pattern, suggesting that collected landraces are cultivated, maintaining their inherent traits although they are monoecious and insect-pollinated, whereas the wild relative L. sphaerica showed a higher level of segregation. The morphological diversity observed among landraces of L. siceraria is the result of human selection and their genetic identities are maintained by inbreeding probably resulting from frequent self-pollination.  相似文献   

19.
To collect and exploitRoegneria genetic resources, isozyme variation on 7 different enzymes encoded by 26 presumptive loci were analyzed in leaf extracts ofR. kamoji, R. ciliaris, R. nakaii andTriticum aestivum cv. Chinese Spring (control species) using polyacrylamide gel electrophoresis. No isozyme polymorphism was detected within accession of the threeRoegneria species, all having self-pollinating reproduction. However, extensive variations at isozyme loci were observed among accessions ofR. kamoji — even among accessions distributed at different altitudes within the same collection area. These results suggested that: (1) a select few individuals collected at a collection site may be enough to represent the genetic variability of that population; and (2) collection and maintenance ofR. kamoji materials from different altitudes may be required to increase genetic diversity. Furthermore, the banded phenotypes at EST 1 and EST-2 loci may be used as a biochemical marker associated with a morphological character, pubescences covered at leaf margin inR. kamoji. The banded characters at EST- 1, SOD-1, SOD-2, and SOD-3a loci may be used as biochemical markers to identify theR. kamoji chromosomes carrying these loci in aT. aestivum ×R. kamoji hybridization program.  相似文献   

20.
White clover is one of the most important forage legume species worldwide, playing an important role in Southern Brazil temperate cultivated pastures. This work was aimed to characterize the genetic variability of the USDA white clover core collection formed by 78 accessions representing 50 countries, together with two very well known cultivars (Huia and Ladino Regal), using RAPD (Random Amplified Polymorphic DNA) markers to produce genetic fingerprints. There were used DNA bulks formed by the extraction and mixture of 20 random individuals from each accession. Twenty four primers were used, which revealed from 3 to 29 bands, forming a total of 371 polymorphic bans and only one monomorphic, ranging from 50 to 3098 bp. The results showed a genetic similarity among the accessions, ranging from 0.18 to 0.58 (Jaccard’s index), with an average of 0.24, allowing the identification of each individual accession using just three primers. The results also showed a large genetic variability within the white clover core collection, probably due to its reproduction mode and ploidy level, which could be used in plant breeding program.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号