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1.
Genetic variation among five elite winter barley cultivars (H. vulgare L.) currently grown in Bulgaria was assessed at the molecular level using restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD) markers. The present study sampled RFLPs in four well characterized multigene families in barley: the seed storage protein loci; the 18S, 5.8S and 26S ribosomal DNA loci; the loci coding for 5S ribosomal RNA and the loci coding subunit α of ATP-A complex in the mitochondrial genome. RFLPs were detected in three out of five investigated chromosomal loci in the barley cultivars studied. RAPD assay using arbitrary 10-base primers was applied to generate amplified length polymorphic markers in barley. Overall a total of 15 polymorphic phenotypes were found among the studied barley cultivars by using 11 out of 25 tested primers. All RAPDs were considered as dominant genetic markers except for two, where PCR and Southern blot analysis indicated the presence of codominant amplification products. Five RAPD polymorphisms in F1 and F2 progenies of the cross between Alpha and Obzor were inherited in Mendelian fashion. The determined values for the genetic variation proved a high genetic similarity among the tested cultivars. Genetic similarity (GS) calculated from RFLP and RAPD data ranged from 0.888 to 0.997 with a mean GS – 0.933. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

2.
Summary Morphological, isozyme and random amplified polymorphic DNA (RAPD) markers were used to estimate genetic variation within and between cultivars of red clover (Trifolium pratense L.), an important temperate forage legume. Two cultivars of red clover, Essi from Europe and Ottawa from Canada, were evaluated. Six monogenic morphological characters were observed for 80 plants from each of these two cultivars. All six morphological loci were polymorphic in the cultivar Essi whereas only four loci were polymorphic in the cultivar Ottawa. Forty plants from each cultivar were assayed for isozyme markers. A total of 21 enzyme-coding loci with 43 alleles was detected using twelve enzyme systems. Thirteen and nine of these loci were polymorphic in Essi and Ottawa, respectively. The mean number of alleles per locus was 1.81 in Essi and 1.67 in Ottawa. Seventeen random 10-mer primers were screened for RAPD markers. Nine primers which gave clear and consistent amplified products were used to assay 20 individuals from each cultivar. Each primer gave from 7 to 20 amplified bands with an average of 14.8 bands per primer. One hundred and eight of 116 putative loci were polymorphic in Essi and 90 of 98 loci were polymorphic in Ottawa. High within-cultivar variation was observed in both cultivars using both isozyme and RAPD markers. This high polymorphism makes these markers useful for germplasm characterization and genetic studies in red clover.  相似文献   

3.
Random amplified polymorphic DNA (RAPD) markers were used to develop genetic fingerprints and analyse genetic relationships among 29 Ipomoea accessions from different geographical locations around the world, including unique wild species, and reproducible profiles were obtained for all accessions using random decamer primers. The primers generated 46 polymorphic markers, one primer alone having 10 products, enabling the discrimination of all 29 accessions. A high level of genetic variability in sweet potato collections was suggested by the degree of polymorphism. Half of the Japanese land races were closely related while accessions from Papua New Guinea and The Philippines were distinct and exhibited the greatest genetic diversity. The wild species Ipomoea gracilis and Ipomoea tiliacea formed a group distinct from the cultivated sweet potato. The wild tetraploid accession K233 and the species Ipomoea trifida were progressively more related genetically to the cultivated sweet potato and are the probable progenitors of Ipomoea batatas, and may be suitable as germplasm for genetic enhancement. RAPDs proved to be useful for sweet potato systematics and should be valuable for germplasm management, gene tagging and efficient choice of parents in breeding programmes.  相似文献   

4.
Summary The use of random amplified polymorphic DNA (RAPD) markers obtained from bulked samples was investigated for cultivar identification in red clover. Pooled samples were examined in order to minimize variation within cultivars. To determine the appropriate number of individuals to include in the bulked samples representing each cultivar, DNA samples from two, three, four, five, ten and twenty individuals were pooled. Twenty was found to be an appropriate number of red clover individuals per bulk in order to amplify only the DNA sequences shared among most individuals in each cultivar. Fourteen 10-mer primers were used to amplify genomic DNA from combined leaf samples of 15 red clover cultivars from European, Japanese and North American origins. A total of 79 amplified products, of which 55 were polymorphic, was obtained. Cultivar-specific bands were observed with 13 primers. The amplification patterns obtained from two primers could distinguish all 15 red clover cultivars. Rogers' genetic distances for all 105 pairwise comparisons were calculated to evaluate relationships among these cultivars. Cluster analysis based on these genetic distances separated these 15 cultivars into three groups, with two of the groups consisting of a single Japanese cultivar each, while the third group included cultivars from European, North American, and Japanese origins.  相似文献   

5.
Random amplified polymorphic DNA (RAPD) was used to estimate genetic variability among 111 different clones of Ensete ventricosum, cultivated at 9 different collection sites in southwestern Ethiopia. PCR conditions were optimized for the amplification of DNA fragments in this crop. Out of 126 oligonucleotide primers initially screened,12 were chosen that together generated 97 reproducible polymorphic bands. Each clone proved to have a unique DNA profile, in spite of 8 duplications among the vernacular names represented in this material. The high level of genetic variability encountered is in good accordance with an outcrossing breeding system, and is also indicative of gene flow from wild enset and possibly from otherEnsete species. Genetic variation within collection sites was relatively high, with values for the Shannon-Weaver diversity index ranging from 0.44 to 0.55. A PCA (principal component analysis) demonstrated some differentiation among sites but also considerable overlapping. Partitioning the total variability at different levels with the Shannon-Weaver index shows that only14% was attributable to differences between sites and 86% to variation within sites. Pairwise comparisons of the 9 sites yielded values for Nei's unbiased genetic distances that ranged from 0.054 to 0.225.Cluster analysis as well as PCO (principal co-ordinate analysis) showed that Bonga and Chencha form a nucleus within a loose cluster, which also comprises Wolkitae, Worka, Shonae and Wondo. The remaining three sites, Answae, Setunae and Seltae, take quite isolated positions. Estimates of genetic distances did not correspond with geographical distances between collection sites. Genetic distances, as well as amount of within-site diversity, may instead be connected with the pattern of distribution for various ethnic groups in the enset-based agricultural system, and their dependency on enset as a staple food. This study is the first of its kind on enset. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

6.
M. Rom    M. Bar    A. Rom    M. Pilowsky  D. Gidoni 《Plant Breeding》1995,114(2):188-190
Randomly amplified polymorphic DNA (RAPD) markers were applied in purity control of hybrid seed production of tomato (Lycopersicon esculentum Mill.). DNA from three commercial F1-hybrid cultivars and their parental lines was subjected to RAPD screening with 50 primers. Two of four primers which detected polymorphism between the parents tested, generated paternal-specific RAPDs, enabling a clear distinction to be made between hybrids and their maternal parents. In addition, combination of the polymorphic DNA products generated by these primers exhibited hybrid-specific patterns, enabling each cultivar to be identified. This result indicates the practical usefulness of RAPD markers in hybrid-tomato-seed purity-control tests and cultivar identification. The approach is advantageous in its rapidity and simplicity, particularly as an alternative for those cultivars for which lengthy and costly phenotypic tests are currently used.  相似文献   

7.
The use of bulked leaf samples from individual plants for amplified fragment length polymorphism (AFLP) analysis was evaluated as a tool for assessment of genetic diversity in white clover (Trifolium repens L.). Bulking of leaf samples produced slightly simpler AFLP profiles compared to the combined profiles of individual plants from the same cultivar. Approximately 90% of bands which were present in individual plants were present in bulked samples of the same cultivar. The majority of those absent were rare bands, shared by less than 25% of individual plants. Replicate bulk samples gave almost identical banding patterns, demonstrating the robustness of the bulked AFLP technique. Cluster analysis of AFLP data derived from individual plants resulted in a phenogram similar to that produced from data derived from bulked samples of the same plants. AFLP analysis of bulked samples detected significant amounts of genetic variability among 52 cultivars and accessions with genetic similarity values ranging from 0.42 to 0.92. However, cluster analysis of AFLP data only partially reflected the geographic origin of cultivars and accessions and was not congruent with cluster analysis based on variation for morphophysiological characters. Bulked AFLP analysis provides a powerful tool for rapid assessment of genetic variability in white clover and may also be used for cultivar identification. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

8.
Understanding the genetic relationships among breeding lines is fundamental in crop improvement programs. The objectives of this study were to apply selected polymorphic single sequence repeat (SSR) DNA markers and cluster medium to late maturing tropical elite maize inbred lines for effective hybrid breeding. Twenty elite inbred lines were genotyped with 20 SSR markers. The analysis detected a total of 108 alleles. The unweighted pair group method with arithmetic mean allocated the inbred lines into five clusters consistent with the known pedigrees. The tested inbred lines that were adapted to mid-altitude, sub-humid agro-ecologies were classified in different clusters, except for a few discrepancies. The greatest genetic distance was identified between the clusters of lines CML-202 and Gibe-1-91-1-1-1-1. The analysis determined the genetic grouping present in the source population, which will assist in effective utilization of the lines in tropical hybrid maize breeding programs to exploit heterosis.  相似文献   

9.
Merja Veteläinen 《Euphytica》1994,79(1-2):127-136
Summary Utilization of exotic germplasm offers an approach to broaden genetic variability in breeding populations. This study was conducted in order to 1) compare germplasm of exotic origin with adapted Swedish barleys with respect to genetic differences and 2) to evaluate how exotic material affected agronomic performance in complex crosses. Allozyme studies showed the following Nei's gene diversities among parents: 0.13 (adapted parents), 0.16 (landraces) and 0.25 (H. spontaneum). Cluster analysis indicated that parental groups were genetically divergent. Earliness, straw length, number of ears per plant and thousand kernel weight (TKW) were studied. Variation in agronomic traits showed the following pattern: landraces > H. spontaneum > adapted lines. The best sources for earliness were adapted parents and landraces. Mean straw length was greatest in H. spontaneum lines. Number of ears per plant was quite similar in all groups. The highest TKW was among landraces and adapted parents. Hybrids from the complex crossing programme exceeded parents in earliness and TKW. An index composed from the four traits showed the most favorable frequency distributions for adapted parents and hybrids. Both genetic and agronomic studies indicate that new valuable variation from exotic germplasm may be introduced into barley breeding material.  相似文献   

10.
Eighteen clones involving Erianthus, as one of the parents, were evaluated in a randomised block design under sub-tropical conditions of Karnal (Haryana, India). Fifteen characters, which contribute towards stalk yield and juice-quality, were studied. The growth of these clones was monitored during peak winter months of December and January. Significant variability existed among the clones for all the traits studied, except for pol % in juice at 10-month crop age, indicating potentiality of the clones to select desirable types. Nine clones showed significant increase in stalk length during winter months over the better standard Co 1148. Whereas 6 clones developed more number of leaves than Co 1148. Both these characters showed high genetic variability, high heritability and hence, high expected genetic gain. Path analysis revealed that these traits contributed about 16%, 5% and 4% to the total genetic variability in juice quality traits (pol % and CCS %), stalk yield and CCS yield, respectively. Growth in winter months has resulted in an increase in stalk yield and CCS yield. This may help in reducing the yield gap between tropical and sub-tropical regions. Majority of clones showed resistance to red rot disease (major disease of sugarcane in sub-tropical region). Hence, hybridization of Erianthus with sugarcane has resulted in introgression of genes for cold tolerance and red rot resistance. As Erianthus is known for its hardiness, resistance, of these clones, to other abiotic and biotic stresses is to be ascertained. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

11.
Red clover cultivars, including diploid and tetraploid, are commonly used in legume‐based pasture mixtures. However, information on nodulation under different starter N regimens is limited. We hypothesized that there is genetic variability among different red clover cultivars for nodulation. A root hair deformation assay was conducted using three diploid (AC Christie, Tapani and CRS15) and three tetraploid (Tempus, CRS18 and CRS39) red clover cultivars by inoculating them with Rhizobium leguminosarum biovar trifolii. Nodulation and morphological characteristics of two selected red clover cultivars, AC Christie and Tempus, were determined under five starter N concentrations (0, 0.2, 0.4, 0.8 and 1.6 mg per plant). Inoculation with rhizobia increased root hair deformation with significant interaction across cultivars. Nodulation was delayed under high starter N concentrations, and genotypic differences were evident for days‐to‐nodule initiation. There was a positive quadratic response to starter N for AC Christie and a negative quadratic response for Tempus for nodulation. Tempus had more active nodules (92 %) than AC Christie (73 %). The genetic variability of red clover cultivars should be considered in N fixation studies and their response to availability of initial N.  相似文献   

12.
Summary Simple sequence repeat (SSR) markers linked to quantitative trait loci (QTL) associated with resistance to sorghum shoot fly, Atherigona soccata resistance were used to characterize the genetic and phenotypic diversity of 12 cytoplasmic male-sterile (CMS) and maintainers, 12 restorer lines, and 144 F1 hybrids. The genetic diversity was quite high among the shoot fly-susceptible parents and the hybrids based on them, as indicated by high polymorphic information content (PIC) values, while limited genetic diversity was observed among shoot fly-resistant lines. The phenotypic and genotypic dissimilarity analysis indicated that the shoot fly-resistant and -susceptible parents were 73.2 and 38.5% distinct from each other, and the morphological and genetic distances of certain resistant and susceptible cross combinations was more than their resistant or susceptible parents. Genetic variability among the groups was low (10.8%), but high within groups (89.2%). The genetic and morphological distances suggested that the F1 hybrids were closer to CMS (5 to 12% dissimilar) than the restorer (11 to 87% dissimilar), suggesting that CMS influences the expression of resistance to sorghum shoot fly. The SSR markers can be used to characterize the homologous traits in sorghum germplasm.  相似文献   

13.
The applicability of random amplified polymorphic DNA (RAPD) markers in the cultivated rubber tree, Hevea, was evaluated using 43 decamer oligonucleotide primers in a set of 24 clones selected in different South-East Asian countries. A total of 220 0.35–3.5 kb DNA fragments were amplified, of which 111 were polymorphic. Of these, 80 fragments (RAPD markers) which were repeatable and clearly scorable across all genotypes were used to estimate genetic distances among the clones tested. The estimated genetic distances ranged from 0.05 (RRII 308 and PB 5/51) to 0.75 (RRIC 100 and SCATC 88–13). A mean genetic distance of 0.5 indicates a rather high genetic variability among the tested clones. As expected, because of the breeding history of Hevea, UPGMA cluster analysis and Principal Coordinate Analysis (PCoA) indicated the absence of a distinct geographical grouping. The possible application of RAPD markers for clone identification and also for analysis of genetic relationships among Hevea clones is discussed.  相似文献   

14.
In order to obtain an overview of the genetic diversity present within the set of pea cultivars released in Germany, 21 cultivars were analysed at the DNA level by random amplified polymorphic DNAs (RAPDs) and amplified fragment length polymorphisms (AFLPs), as well as for agronomic traits. Yield of grain cultivars ranged from 2.95 to 3.87 t/ha. Based on the screening of 60 RAPD primers and 32 Eco RI + 3/Mse I+3 AFLP primer combinations, 20 RAPD primers and 11 Eco RI + 3/MseI+ 3 primer combinations generating polymorphic and distinct fragments were chosen for estimation of genetic diversity. Twenty RAPD primers amplified a total of 314 scorable bands ranging from about 262 bp to 1996 bp. Of these, 175 fragments (55.7%) were polymorphic. Based on these data, genetic similarity (GS) was estimated between 0.80 (‘Lisa’ vs.‘Grapis’) and 0.94 (‘Bohatyr’ vs. ‘Sponsor’; mean GS = 0.88). Eleven AFLP primer combinations led to the amplification of 949 scorable fragments ranging from 43 to 805 bp and of these, 462 (48.7%) were polymorphic. Genetic similarity based on AFLPs was calculated between 0.85 (‘Lisa’ vs.‘Laser’) and 0.94 (‘Bohatyr’ vs. ‘Sponsor’, mean GS = 0.90). Correlation of genetic similarity estimated on RAPDs and AFLPs was estimated at r = 0.79** using Spearman's rank correlation coefficient and at r = 0.84 by the Mantel test, respectively. UPGMA cluster analysis carried out on these data separately for RAPDs and AFLPs and on the combined data reflected, to some extent, pedigree relationships and cophenetic correlations (r = 0.89 for RAPDs, r = 0.88 for AFLPs, and r = 0.93 RAPDs + AFLPs) indicate a good fit of respective clusters to genetic similarity data. The correlation of cluster analyses to pedigree information and the impact on parental genotype selection is discussed.  相似文献   

15.
By federal law in Mexico, A. tequilana Weber var. Azul is the only variety of agave permitted for the production of any tequila. Our objective was to assay levels of genetic variation in field populations of A. tequilana var. Azul using randomly amplified polymorphic DNA (RAPD) markers. Ten plants were collected from each of four different fields, with two fields being located in each of two principal regions of Mexico for the cultivation of A. tequilana var. Azul. The two regions are separated geographically by approximately 100km. Genetic relationships between A. tequilana var. Azul and two other varieties of A. tequilana Weber, ‘Chato’ and ‘Siguin’, were also investigated using RAPDs. Among the three varieties, 19 decamer primers produced 130 markers, of which 20 (15.4%) were polymorphic betweenA. tequilana var. Chato and A. tequilana var. Siguin. The results of RAPD analysis suggest that A. tequilana var. Siguin is more closely related to A. tequilana var. Azul than is A. tequilana var. Chato. Among the 40 field selections of A. tequilana var. Azul, only 1 of124 RAPD products (0.8%) was polymorphic and 39 of 40 plants were completely isogenic. This is one of the lowest levels of polymorphism detected to date for the analysis of a crop species, and is proposed to be the result of the promotion of a single conserved genotype over many years due to an exclusive reliance on vegetative propagation for the production of new planting materials. The significance of these results is discussed in relation to breeding programs focused on the improvement of A. tequilana var. Azul. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

16.
RAPD (randomly amplified polymorphic DNA) analyses were carried out on 21 accessions of Lachenalia bulbifera (Cyrillo) Engl. Five pre-selected primers produced an average of 88% polymorphisms. Fifteen of the 21 accessions could be identified using the five primers. In a pairwise comparison genetic distance values ranging from 0.11 to 1.08 were obtained. These values reveal a high amount of variation within the species. The genetic distance values within the tetraploid and hexaploid groups on the south coast were low, but values were high between the groups on the south coast and those on the west coast. A dendogram was constructed from the RAPD banding profiles, using UPGM cluster analysis. The dendogram clusters certain accessions together. These clusters are supported by their geographical locality and chromosome data. The hexaploid group, tetraploid group and octoploid group on the south coast are respectively clustered together. It is concluded that RAPDs can be used to assess the genetic variation at an intra-specific level in Lachenalia. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

17.
刘传光  张桂权 《作物学报》2010,36(11):1843-1852
利用均匀分布于水稻基因组的300个SSR标记对95个华南地区不同年代常规籼稻主栽品种进行分析,研究该地区常规稻品种的遗传多样性及其变化趋势。检测到236个SSR标记有多态性,共获得776个等位基因,每个位点等位基因2~12个,平均3.29个,共有206个位点的等位基因数介于2~4个,占全部多态性位点的87.3%。多态性标记位点的PIC值平均为0.42,变化范围为0.041~0.790。不同染色体的位点多态性差异显著,其中第10染色体的位点平均等位基因数最多,PIC值最高,而第5染色体的位点平均等位基因数最少,PIC值最低;6个年代中,50~70年代育成品种包含等位基因数呈显著的上升趋势,70年代达最高值2.83,随后逐渐下降。分子方差分析(AMOVA)结果显示不同年代间遗传变异仅占总体变异的3.77%,但仍达极显著水平(P0.001)。不同年代育成品种的遗传距离(GD)呈下降趋势。聚类分析结果显示,在遗传相似系数(GS)为0.685处可将品种区分为5大类,表明华南地区各时期的常规稻品种遗传改良都是围绕少数骨干亲本进行的。试验结果显示,华南地区籼稻品种的遗传多样性狭窄且随年代而变化,70年代以后呈下降趋势,在今后的育种中应扩大亲本选材范围、拓宽育种亲本的遗传基础以提高育成品种的遗传多样性。  相似文献   

18.
A. C. Soh 《Euphytica》1994,76(1-2):13-21
Summary Breeding values obtained from best linear unbiased prediction (BLUP) were used to rank nine pisifera (P) male parents belonging to two different but related genetic groups, utilising highly unbalanced data from three D (Dura) × P progeny-test trials of oil palm. The traits studied were fresh fruit bunch yield (FFB), total number of bunches (BNo), average bunch weight (BW), oil to bunch percentage (OB) and average annual height increment (HINC). Four P's from the AVROS genetic group had higher breeding values for FFB, BNo and OB while five P's from the Dumpy-AVROS group were superior in breeding values for BW and HINC. Selection of parents based on the average of the rankings in breeding value for BNo, OB and HINC for each parent tended to favour AVROS P's. However, selection of parents based on the aggregate genetic worth function involving relative economic values, tended to favour Dumpy-AVROS P's. The latter method is preferred to the average ranking method because of its emphasis on relative economic values and the selection index approach.It is suggested that the BLUP technique may prove to be a very useful tool in oil palm breeding.  相似文献   

19.
Oryza malampuzhaensis, one of the tetraploid taxa of the genusOryza, is geographically restricted to Western Ghats of South India. Its taxonomic status is not well established and is generally treated as a tetraploid race of O. officinalis. Sixty-three morphological traits and 262 random amplified polymorphic DNA (RAPD) markers generated by 23 random decamer primers were used to assess the genetic relationship between O. malampuzhaensis and O. officinalis. Pair wise comparisons based on both RAPDs and morphological traits revealed 60% genetic distance between the two taxa and was significantly higher (p <0.01) than the corresponding intra-specific distances. Cluster and principal component analysis (PCA) of genetic distance estimations based on RAPDs and morphological traits clearly differentiated the two taxa. High frequency of discrete O. malampuzhaensis specific RAPDs (21%) and the significantly higher (p < 0.05) mean number of amplification products per individual in O. malampuzhaensis observed in the study reflect its allopolyploid nature. Low genetic diversity within O. malampuzhaensis revealed by RAPD analysis indicates the recent origin of this taxa. The RAPD analysis further revealed the possibility that the putative ‘C’ genomeprogenitor of O. malampuzhaensis is a close relative of O. officinalis. In addition, amplification products diagnostic to O. malampuzhaensis were identified. The results of the present study clearly demonstrated that the O. malampuzhaensis is a distinct entity, and support the recent conclusion that O. malampuzhaensis has diverged enough to deserve species status. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

20.
Successful prediction of heterosis and performance of F1-hybrids from the genetic similarity of their parents based on molecular markers has been reported in several crops and can be very helpful in hybrid breeding. The relationship between genetic similarities based on amplified fragment length polymorphism (AFLP) of 18 European faba bean lines and their hybrid performance and heterosis was investigated. Parental lines, 62 F1-hybrids and their F2-progenies were evaluated in field trials in four environments in Germany for seed yield, 1,000-seed weight and plant height. Results clearly demonstrated a stable superiority of the hybrids over their inbred parents and elite check cultivars, and showed a marked and varying amount of heterosis. Parental seed yield and F2-hybrid yield were promising as predictors for F1-hybrids. AFLP analysis of the 18 inbred lines using 26 EcoRI/MseI primer combinations resulted in 1202 polymorphic fragments. Cluster analysis based on genetic similarity estimates unambiguously identified pedigree-related inbred lines. No clear separation of the 18 inbred lines into subgroups was detected. Correlation coefficients between genetic similarity estimates and either heterosis or F1-hybrid performance were small and not useful. Also correlations between specific genetic similarity and specific combining ability were too small for all traits to be of predictive value. Results showed that AFLP-based genetic similarities are not useful to predict the performance of hybrids or heterosis within the elite European faba bean gene pool.  相似文献   

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