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1.
Summary Hordeum spontaneum is the progenitor of cultivated barley (H. vulgare) and is an important source of genetic variation for barley breeding programs. The genetic diversity ofH. spontaneum in the Australian germplasm collection was investigated using the polymerase chain reaction with random and semi-random primers. This approach was found to be robust in respect of reaction conditions. Genetic dissimilarity values between genotypes were used to produce a phenogram of the relationships among the accessions using the unweighted pair group method with arithmetic mean. The largest divergence was observed among Israeli accessions, whereas the Turkish and Iranian samples clustered as distinct subsets, each apparently related to portion of the Israeli material. The results indicate that the genetic diversity of the wild barleys is broadly correlated with geographic distribution.  相似文献   

2.
Genetic variability in RAPDs (Randomly Amplified Polymorphic DNA) was studied in 104 genotypes of wild barley, Hordeum spontaneum from 21 populations sampled in Israel, Turkey and Iran, seven population from each country. The band (= loci) frequencies were calculated for each population and correlated with ecogeographical variables. In general, high RAPD genetic diversity indices were associated with stressful environments, either with hot or cold steppes and deserts. Interpopulational genetic distances showed no association with the geographic distance between the populations' provenance. Significant Spearman rank correlations between RAPD band frequencies and ecogeographical parameters of provenance occured. Frequencies of RAPD bands were significantly correlated with the principal component factors of allozymes. The correlation data indirectly suggest that natural selection appears to be the major determinant of both RAPD and allozyme diversities both being correlated with environmental stress.  相似文献   

3.
Genetic diversity in 12 landraces of bambara groundnut (Vigna subterranea), an indigenous African legume, was evaluated using Random Amplified Polymorphic DNA (RAPD) markers. DNA from individuals of each landrace was also analysed to determine the level of heterogeneity within landraces. RAPDs revealed high levels of polymorphism among landraces. The percentage polymorphism ranged from 63.2% to 88.2% with an average of 73.1% for the 16 RAPD primers evaluated. The construction of genetic relationships using cluster analysis groups the 12 landraces in two clusters. RAPDs are useful for the genetic diversity studies in V. subterranea and can identify variation within landraces.  相似文献   

4.
A quantitative trait locus analysis was carried out to unravel the genetic basis of dormancy in wild barley (Hordeum spontaneum) from Israel. Two accessions, Ashkelon and Mehola, from divergent environments were crossed to produce a mapping population. A linkage map was produced from the F2 population, and F4 seeds were used for germination experiments. Five quantitative trait loci (QTL) were detected for dormancy across the different germination experiments. These QTL were found on chromosomes 1, 2, 5, 6 and 7. The variation explained by each QTL varied between 8 and 25%. Ashkelon alleles increased the germination except for the QTL on chromosome 5. Three out of these five QTL co-locate with QTL found earlier in cultivated barley crosses, although this does not necessarily imply that they would be the same loci. The level of dormancy is much higher in wild barley than in cultivated barley and wild barley may have alleles that have not yet been utilised in breeding for optimally dormant barley.  相似文献   

5.
Development of crop cultivars with high yield under low nitrogen (N) supply is a basic approach for the enhancement of agricultural sustainability. The previous studies showed that Tibetan wild barley shows wider genetic diversity in abiotic stress and poor fertility tolerance. In this study, four barley genotypes (two Tibetan wild and two cultivated), differing in N use efficiency (NUE), were characterized for their growth and physiological responses to low N stress. The genotypes ZD9 (cultivated) and XZ149 (wild) with high NUE performed better in terms of shoot dry weight (DW) and photosynthetic parameters under both low and normal N levels and had higher antioxidative enzyme activities, N concentration, and accumulation in both shoots and roots under low N stress. The current results showed the substantial difference among barley genotypes in low N tolerance and verified the significance of Tibetan wild barley in the genetic improvement of cultivated barley in NUE.  相似文献   

6.
Inter-Simple Sequence Repeat (ISSR) and Randomly Amplified Polymorphic DNA (RAPD) markers were used to analyze genetic distance among H. vulgare subsp. spontaneum populations from west Turkey. Fifty-five RAPD and 10 ISSR primers were used to detect variation among sample. A total of 55 polymorphic loci were found using 65 primers. Two distinct cluster groups were clearly established among populations. The minimum variation was detected between Pinarbasi and Bornova (GD = 0.192) populations and the maximum was found between Icmeler and Aydin populations (GD = 0.926). As two dominant markers, RAPD and ISSRs are effective and promising marker systems for detecting genetic variation.  相似文献   

7.
Boerhavia diffusa is extensively used in herbal medicines as well as in the Ayurvedic system, because it contains a set of clinically important compounds. In the present study, the genetic variability in Boerhavia diffusa between accessions of different geographical origin within the Indian territory is assessed through random amplified polymorphic DNA (RAPD) markers. Twenty-eight accessions of Boerhavia were screened with eighteen primers of which nine were found to be the most informative. The degree of polymorphism was found to be high in accessions collected from different places of Uttar Pradesh (Set II) in comparison to other states of India (Set I). A relatively lower level of polymorphism was recorded in accessions collected from diverse locations around Lucknow (Set III). Accessions from neighbouring geographical regions exhibited more similarity than those from distant regions (as revealed by the set I analysis). Certain diagnostic markers may be correlated with morphological character(s) such as plant type. BDL appeared most distinct and divergent from the rest of the accessions and the BDJ plant in set II also showed least similarity estimate. Fragments of 5.62 Kb and 4.47 Kb with primer GN59 was found to be unique for BDP and BD2 having ovate leaf character, whereas ovoid leaf genotype exhibited 0.79 Kb (GN34 primer) fragment. Similarly a unique band type (0.35 Kb) with primer GN83 was present in BDL and BD1 that share light pink flower. Jaccard's, and Nei and Li similarity coefficient values amongst the accessions were in the range of 0.22 to 0.89 and 0.33 to 0.93, respectively. Association of RAPD markers with the leaf characteristics, flower colour as well as with geographical locations has been made. This shows that RAPD markers are also useful for the study of genetic structure of Boerhavia populations.  相似文献   

8.
To examine changes in the level of and pattern in variability in 197 Nordic and Baltic spring barley cultivars over time we used 21 mapped barley simple sequence repeats (SSRs). A total number of 191 alleles were found from 22 SSR loci. The number of alleles per locus ranged from 2 to 23, with average of 8.63 107 alleles were rare (frequency <0.05) among the cultivars and only one allele was frequently observed (frequency >0.95). The gene diversity between loci in Nordic and Baltic material varied between 0.033 and 0.891. Average gene diversity was 0.623. The SSR data separated two-rowed and six-rowed cultivars. According to analysis of molecular variance (AMOVA) differentiation in two-rowed vs six-rowed accounted for 23.6% of the total variation. Overall no significant decrease of average gene diversity over time could be found. However, differences were observed when spring barleys from northern (north of ∼58°) and southern (south of ∼58°) parts of the Nordic and Baltic area were compared. For the southern ecogeographical region significant decrease of genetic diversity was observed in the middle of the 20th century, whereas no significant changes in the northern part were found. We found larger differentiation between modern and old cultivars in the South compared to the ones in North parts of the region. The magnitude of changes in genetic diversity differed also with the country of origin. Danish cultivars had a significant decrease in diversity in the middle of century, whereas changes in Finland, Norway and Sweden were not significant.  相似文献   

9.
Twenty-two accessions of H. agriocrithon from Tibet were investigated for morphological and physiological characters, and genotypes combined alleles at the tightly linked Est1, Est2 and Est4 complex locus encoding esterase isozymes. H. agriocrithon was similar in plant type to Tibetan cultivated barley, but different from H. spontaneum. The accessions of H. agriocrithon were classified by their spike-awn types into vars. eu-agriocrithon, dawoense and paradoxon, with one exceptional accession of the awnless naked type similar to var. nuditonsum of cultivated barley. They were characterized by spring growth habit, susceptibility to Japanese race I of powdery mildew, and either of the same three esterase genotypes as those of cultivated barley from Tibet, Bhutan and Ladakh. The similarity suggested that the esterase complex locus on chromosome 3H is closely linked with some QTL for adaptation to Tibetan conditions. On the origin of H. agriocrithon, it might be concluded that natural hybridization between H. spontaneum and six-rowed barley occurred in northern parts of Afghanistan, Pakistan or India, and seeds of their segregants mixed into barley or wheat were brought up to Tibet, resulting six-rowed barley with brittle rachis.  相似文献   

10.
Naked barley, due to its favorable attributes such as high feed value, good human nutrition and easy processing, increasingly attracts people’s attention. Qinghai–Tibet Plateau is very rich in naked barley resources and has a long growing history. Genetic diversity of these cultivated naked barley is, however, poorly documented. This study analyzed the genetic diversity of monomeric prolamins (protein fraction corresponding to wheat gliadins) using the Acid -PAGE technique in eighty-six cultivated naked barley cultivars from Qinghai–Tibet Plateau. Extensive diversity was observed. A total of 43 different bands and 76 distinct patterns were found. Jaccard’s coefficient of similarity was calculated, and the accessions were divided into five main groups by cluster analysis using UPGMA. Differentiation among the populations from different collecting regions was investigated, based on the polymorphism of monomeric prolamins. The genetic diversity within the accessions from Tibet was slightly higher with an average diversity index of 0.29 than those from Sichuan. This study supports Tibetan Plateau is the diversity center of the cultivated naked barley and suggests that cultivated naked barley from Qinghai–Tibet Plateau is an important pool of variability that could be used in cereal breeding.  相似文献   

11.
To assess the genetic diversity of the most important olive cultivars used in Portugal, a base collection was established with two hundred and one accessions of eleven cultivars from the different agro-ecological-regions (AER) of olive oil production. Inter-cultivar diversity was evaluated using seven RAPD primers producing fifty-nine polymorphic markers that enable cultivar distinction. Discriminant analysis according to fruit use and AER revealed a genetic structure associated with local selection both for fruit exploitation and agro-ecological adaptation. Intra-cultivar diversity of the ancient cultivar Galega was also investigated. Three RAPD and five ISSR primers produced ninety-three polymorphic markers upon seventy-seven accessions from five AERs. Total accession discrimination was achieved. UPGMA clustering and discriminant analysis revealed that the genetic diversity was predominantly structured according to accessions origin. The within and among AER variation revealed by AMOVA supported this genetic structure and showed a high proportion of intra-AER variability. These evidences suggest that Galega is composed by a mixture of different genotypes adapted to local conditions, indicating that this cultivar is in an early stage of domestication and should be treated as a landrace instead of a uniform cultivar. The assessment of Galega genetic diversity within each of the five AERs indicated the highest significant level (Hg = 6.23 at p< 0.001) in Ribatejo-Santarém. This finding associated with the distinctiveness of Galega in relation to other Portuguese cultivars and with the recent insights of olive tree domestication allowed us to hypothesize that Ribatejo-Santarém was the ecological region of origin and dispersion of this ancient cultivar.  相似文献   

12.
Taro [Colocasia esculenta (L.) Schott] germplasm accessions collected from different parts of India were subjected to RAPD (Random Amplified Polymorphic DNA) analysis to assess the genetic diversity prevalent and also to test the genetic basis of morphotypic classification. Thirteen random decamer primers out of the 22 tested were used to analyse 32 taro accessions belonging to 28 morphotypes. Three out of these thirteen primers analysed showed 100 per cent polymorphism. Per cent polymorphism varied from 60 to 100 among the polymorphic primers. High genetic diversity was revealed as the similarity coefficient values ranged from 0.50 to 0.98. No two accessions analysed in the present study showed a similarity coefficient value of one thereby indicating their distinctness and presence of high genetic diversity in Indian taro germplasm. Dendrogram obtained from UPGMA analysis grouped 32 accessions in four clusters and three accessions were placed as outliers. Clustering pattern did not show any strict relationship with geographical distribution, morphotype classification and genotypic diversity. Further, accessions classified, as belonging to the same morphotypic group did not always cluster together. Presence of a very close genepool of the wild, weedy and cultivated forms with extreme levels of phenotypic and genotypic variation is suggested as the reason for high genetic diversity reported. Usefulness of DNA markers such as RAPD in characterising and assessing the genetic diversity in Indian taro germplasm is hereby demonstrated.  相似文献   

13.
The allozyme variation of 15 Tunisian wild populations of Mentha pulegium L. threatened by human activities (clearing, hard-grazing, ploughing, traditional uses) was surveyed by the analysis of 14 isozyme loci using horizontal gel starch electrophoresis. The species exhibited a high level of genetic variation within populations (the mean Ap = 2.20, P = 72%, Ho = 0.349 and He = 0.229), which indicates a predominately outcrossing mating system and the recruitment of new genotypes via dispersal seeds. The genetic structure analysis of the populations using F statistics indicates no inbreeding, and showed an excess of heterozygosity for few loci. The moderate differentiation of populations (FST = 0.110) and the low rate of gene flow between them (Nm = 2.02) might been caused by recent isolation of the populations through biotope disturbances. The value of Nei's genetic identity varied from 0.839 to 0.999 reflecting a relatively low genetic divergence between populations. Cluster analysis using UPGMA method and Nei's genetic identity values, showed that populations geographically close didn't always cluster together. However, populations within the same bioclimatic stage generally subclustered together indicating that differentiation between bioclimatic regions occurred.  相似文献   

14.
Colonial bentgrass (Agrostis capillaris L.) is a cool-season grass, native to temperate Asia and Europe. It has good tolerance to low temperatures and partial shade and is well suited to golf course fairways and tees. Little information is available regarding levels and patterns of genetic variation among populations of colonial bentgrass, which would be useful for breeding programs. To study the genetic relationships among 27 colonial bentgrass accessions obtained from the US National Plant Germplasm System (NPGS), randomly amplified polymorphic DNA (RAPD) markers were scored and analyzed. Out of 80 primers screened, 16 were selected for further analysis, which yielded a total of 120 polymorphic bands used to differentiate the accessions. Dice's similarity coefficients for pair-wise comparisons ranged from 0.23 to 0.84 based on the RAPD data. Since there was no similarity coefficient value close to 1 between any two accessions, there was no apparent duplication among the sampled accessions. A dendrogram constructed on the basis of the Unweighted Pair Group Method with Arithmetic average (UPGMA) clustering algorithm clearly separated 26 of the accessions into three clusters with one accession distinct from the rest. The least similar pair of accessions was PI 204397 from Turkey and PI 628720 from Bulgaria, and the most similar pair was PI 509437 from Romania and PI 491264 from Finland. Clustering patterns based on principal components analysis (PCA) corresponded well with the dendrogram. A high cophenetic correlation (r = 0.82) was found between the RAPD data matrix and cophenetic matrix. The accession PI 628720, from Bulgaria, did not cluster with any other accessions.  相似文献   

15.
A comparative characterization of 10 field populations of the maize (Zea mays var. indurata) landrace Nostrano di Storo was carried out using different types of PCR-based markers. The inbred line B73 and three synthetics (VA143, VA154 and VA157) selected from as many landraces were also used. Genetic diversity and relatedness were evaluated over 84 SSR and 53 I-SSR marker alleles using a total of 253 individual DNAs. Up to 23 alleles per SSR locus were scored while the average effective number of alleles per population was 6.99. Nei's total genetic diversity as assessed with SSR markers was HT = 0.851 while the average diversity within populations was HS = 0.795. The overall Wright's fixation index FST was as low as 0.066. Thus, more than 93% of the total variation was within population. Unique alleles over all SSR loci were found for six populations. An average of 17.7 marker alleles per I-SSR primer were scored with an effective number of marker alleles per locus of 1.34. The Shannon's diversity information index over all populations and I-SSR loci was 0.332, varying from 0.286 to 0.391. The extent of differentiation between populations was as low as GST = 0.091. Dice's genetic similarity matrices were estimated for both SSR and I-SSR markers. The mean genetic similarity coefficients within and between populations were respectively 0.269 and 0.217, for SSR markers, and 0.591 and 0.564, for I-SSR markers. UPGMA dendrograms displayed all field populations but one clustered into a distinct group, in which the synthetic VA154, selected from the Marano Vicentino landrace, was also included. One field population and the other two synthetics were clustered separately as well B73. The matrix correlation assayed by the Mantel's correspondence test was as high as 0.908. Findings suggest that, although a high variability can be found among plants, most plant genotypes belong to the same landrace called Nostrano di Storo. Although gene flow from commercial hybrids might have occurred, the large number of polymorphisms and the presence of both unique alleles and alleles unshared with B73 and synthetics are the main factors underlying the value of this flint maize landrace as a source of genetic variation and peculiar germplasm traits. Because of its exclusive utilization for human consumption, such a molecular marker characterization will be a key step for obtaining the IGP mark and so promote the in situ conservation and protection of the landrace Nostrano di Storo.  相似文献   

16.
Wild barley, Hordeum vulgare L. ssp. spontaneum (C. Koch) Thell., is the progenitor of cultivated barley. Almost unanimously the center of diversity is considered to be in the Fertile Crescent of the Near East, where wild barley grows under a wide range of environmental and climatic conditions. Jordanian wild barley is expected to harbor genes useful for the improvement of cultivated barley, particularly those associated with tolerance to drought. This study evaluated 103 wild barley accessions collected from different areas of Jordan along with 29 cultivated barley genotypes for several morphological and agronomical traits. The Hordeum vulgare ssp. spontaneum C. Koch accessions were grouped into six populations according to the longitude, latitude, altitude, and rainfall zone of the collection site, and the cultivated barley in one population. The evaluation was conducted during the 2004–2005 growing season under field conditions in three locations in Jordan; namely, Khanasri, Ramtha, and Maru with 123.0, 222.9, and 429.2 mm annual rainfall, respectively. We used an unreplicated design with two systematic checks (the cultivars Rum and Mu’ta) each repeated 15 times. The results showed the existence of high variability among the Hordeum vulgare ssp. spontaneum C. Koch accessions for most of the traits, especially for plant height, tiller number, days to heading, days to anthesis, peduncle length, and peduncle extrusion. Plant height, earliness, peduncle length, and peduncle extrusion were found to be adaptive traits under drought conditions and several superior genotypes for each trait were identified. Genetic variation within population was much higher than between populations. Clustering of populations was according to their ecological geographical pattern.  相似文献   

17.
Thirty Portuguese and eight foreign olive (Olea europaea L.) cultivars were screened using Random Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeat (ISSR) markers. Twenty RAPD primers amplified 301 reproducible bands of which 262 were polymorphic; and 17 ISSR primers amplified 204 bands of which 180 were polymorphic. The percentage of polymorphic bands detected by ISSR and RAPD was similar (88 and 87%, respectively). The genetic variability observed was similar in the Portuguese and foreign olive cultivars. Seven ISSR and 12 RAPD primers were able to distinguish individually all 38 olive cultivars. Twenty specific molecular markers are now available to be converted into Sequence Characterised Amplified Region (SCAR) markers. Relationships among Portuguese and foreign cultivars is discussed.  相似文献   

18.
Genetic diversity of 70 populations of niger (Guizotia abyssinica) representing all its growing regions in Ethiopia was investigated using random amplified polymorphic DNA (RAPD) to reveal the extent of its populations genetic diversity. Ninety-seven percent of the loci studied was revealed to be polymorphic for the whole data set. The within population diversity estimated by Shannon diversity index and Nei gene diversity estimates was revealed to be 0.395 and 0.158, respectively. The extent of genetic variation of populations from major niger producing regions was significantly lower than that of populations from other regions; however, it is distributed regardless of altitude of growth. Genetic differentiation between populations was estimated with Shannon index as G ST (0.432), Nei’s G ST (0.242) and AMOVA based F ST (0.350) and appears to be equivalent to the average values calculated from various RAPD based studies on outcrossing species. Higher proportion of the variation detected by AMOVA resided within populations (64.58%) relative to the amount of variation among populations (35.42%). UPGMA cluster analysis showed that most of the populations were clustered according to their region of origin. However, some populations were genetically distant from the majority and seem to have unique genetic properties. It is concluded that the crop has a wide genetic basis that may be used for the improvement of the species through conventional breeding and/or marker assisted selection. Collection of germplasm from areas not yet covered and/or underrepresented is the opportunity to broaden the genetic basis of genebank collection.  相似文献   

19.
Wild banana Musa balbisiana Colla is one of the progenitors of cultivated bananas and plantains. It is native to Southeast Asia and the western Pacific. South China represents the northern limit of its distribution range. The genetic diversity of Musa balbisiana was assessed by the amplified fragment length polymorphism (AFLP) fingerprinting in 15 populations of China. Four primer pairs produced 199 discernible loci. High levels of genetic diversity were detected, with P = 78.5%, H E = 0.241, and H pop = 0.3684 at population level, and P = 100%, H T = 0.3362 and H sp = 0.5048 at species level. Significant genetic differentiation among populations was detected based on Hickory’s analysis (27.6%), Shannon’s diversity index (27.0%) and AMOVA (27.1%). The AFLP results are discussed and compared with data obtained by microsatellites method. The estimates of genetic diversity and differentiation between each pair of populations computed with microsatellites and AFLP markers were not significantly correlated. Conservation strategies for Musa balbisiana in China are proposed.  相似文献   

20.
The strong hunting pressure on the red-legged partridge, Alectoris rufa, warranted its inclusion into the list of species of European conservation concern. During the last decades, restocking plans with farmed specimens have counterbalanced the hunting drawings from wild populations. Our concern was the study of A. rufa in the easternmost part of its range, the central Italy, to gain insights into the effects of this compensation practice on the genetic structure of its populations. Partridges from both a geographically isolated, long-time protected, wild population (Pianosa island, Tuscan Archipelago National Park) and two Tuscan farms (Bieri and Scarlino) were investigated. All the specimens were very similar in outward appearance, looking much like to A. rufa. Ninety-six sequences of both Cytochrome b and D-loop Control Region of mitochondrial DNA (mtDNA) were analysed to get evidence of ancestry at the population level, whereas, the Random Amplified Polymorphic DNA (RAPD) technique was employed to get fingerprinting at the individual level. Pianosa and Bieri populations showed both the A. rufa and Alectoris chukar mtDNA lineages, whereas the Scarlino one only the A. rufa-mtDNA line. However, a spread overall pattern of A. rufa × A. chukar hybridisation among specimens, whatever their mtDNA lineage could result to be, was disclosed by means of RAPD species-specific markers. This is the first genetically documented record of the A. rufa × A. chukar hybrids. The occurrence of the pure, native A. rufa genome in the easternmost part of the species’ geographical range may be guessed to be virtual.  相似文献   

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