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1.
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   

2.
An introgression line derived from an interspecific cross between Oryzasativa and Oryza officinalis, IR54741-3-21-22 was found to beresistant to an Indian biotype of brown planthopper (BPH). Genetic analysisof 95 F3 progeny rows of a cross between the resistant lineIR54741-3-21-22 and a BPH susceptible line revealed that resistance wascontrolled by a single dominant gene. A comprehensive RAPD analysisusing 275 decamer primers revealed a low level of (7.1%) polymorphismbetween the parents.RAPD polymorphisms were either co-dominant (6.9%), dominant forresistant parental fragments (9.1%) or dominant for susceptible parentalfragments (11.6%). Of the 19 co-dominant markers, one primer,OPA16, amplified a resistant parental band in the resistant bulk and asusceptible parental band in the susceptible bulk by bulked segregantanalysis. RAPD analysis of individual F2 plants with the primerOPA16 showed marker-phenotype co-segregation for all, with only onerecombinant being identified. The linkage between the RAPD markerOPA16938 and the BPH resistance gene was 0.52 cM in couplingphase. The 938 bp RAPD amplicon was cloned and used as a probe on122 Cla I digested doubled haploid (DH) plants from aIR64xAzucena mapping population for RFLP inheritance analysis and wasmapped onto rice chromosome 11. The OPA16938 RAPD markercould be used in a cost effective way for marker-assisted selection of BPHresistant rice genotypes in rice breeding programs.  相似文献   

3.
The availability of an array of molecular marker systems allowed comparing the efficiency of two of these marker systems to estimate the relationships among various taxa. The objective of this study was to assess the genetic diversity among 40 cultivated varieties and five wild relatives of rice, Oryza sativa L. involving simple sequence repeat (SSR) randomly amplified polymorphic DNA (RAPD) markers. The accessions were evaluated for polymorphisms after amplification with 36 decamer primers and 38 SSR primer pairs. A total of 499 RAPD markers were produced among the 40 cultivated varieties and five wild relatives with a polymorphism percentage of 90.0. Out of 38 SSR primer pairs used, only one locus viz., RM115 was monomorphic. The average Polymorphism Information Content (PIC) value was 0.578 and it ranged from a low of zero (RM 115) to a high of 0.890 (RM 202). The Mantel matrix correspondence test was used to compare the similarity matrices and the correlation coefficient was 0. 582. The test indicated that clusters produced based on RAPD and SSR markers were not conserved since matrix correlation value was 0.582 as against the minimum required value of 0.800. The two marker systems contrasted most notably in pair-by-pair comparisons of relationships. SSR analysis resulted in a more definitive separation of clusters of genotypes indicating a higher level of efficiency of SSR markers for the accurate determination of relationships between accessions that are too close to be accurately differentiated by RAPD markers. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

4.
Summary Thirty-five rice (Oryza sativa L.) varieties, including 18 japonica, 5 javanica and 12 indica subspecies and 12 lettuce (Lactuca sativa L.) varieties were identified taxonomically, using PCR with originally designed 21 RAPD (Random Amplified Polymorphic DNA) primers and 8 sequence-specific primers, used for amplifying four specific DNA fragments. Use of these primers revealed polymorphisms among varieties in rice and lettuce and facilitates DNA fingerprinting. Dendrograms of both species based on polymorphisms were constructed and genetical relationships were established. In rice, half the number of amplified bands were polymorphic and almost all varieties differentiated. However, differentiation of minor genetic alterations among somaclonal variants or mutants and their mother varieties was not feasible. In L. sativa, 47% of the amplified fragments were polymorphic and all 12 varieties were differentiated. Some of the PCR fragments were variety or type specific, which could be used for indicators for type-selection. The dendrogram obtained showed differentiated clusters of crisphead, leaf and butterhead type, findings in good accord with the classification based on the genetic background.  相似文献   

5.
A. A. Levy  M. Feldman 《Euphytica》1989,40(3):275-281
Summary The mode of inheritance, linkage groups, and chromosomal location of 23 morphological and 4 biochemical traits were characterized in the wild tetraploid emmer wheat,Triticum turgidum var.dicoccoides. These traits were described and their mode of inheritance was determined by their segregation in four F2 populations derived from crosses between four var.dicoccoides accessions and a tetraploiddurum cultivar. Linkage groups among the genes encoding for these traits were determined or postulated, and their chromosomal location was deduced by linkage to previously located genes. The genetic control of the following traits was characterized and is first reported here: black keel; hairy leaf sheath; hairy auricles; hairy rachilla; hairy kernel brush; obtuse flag leaf; and curved neck/peduncle. The linkage data indicated that developmentally-related genes tended to occur in clusters.  相似文献   

6.
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   

7.
For the first time in the history of black pepper cultivation, a partly fertile interspecific hybrid having partial resistance to the dreaded disease Phytophthora foot rot was developed through hybridizing Piper nigrum with the wild species Piper colubrinnum. Hybridity of interspecific progenies was established through morphology, anatomy, cytology, and molecular studies. The hybrid, whose chromosome number is 2n = 39, is a triploid hybrid between a tetraploid and diploid species. The hybrid designated as Culture P5PC-1 exhibited distinct anatomical and morphological feature with a large number of long spikes with reduced setting percentage. The RAPD primers OPE 07 and OPG 08 were identified as hybrid specific molecular markers. Functional evaluation revealed partial introgression of genes—responsible for Phytophthora foot rot resistance—into the hybrid. This hybrid is considered as a successful breakthrough for introgression of resistance to the cultivated species Piper nigrum from the wild species Piper colubrinnum.  相似文献   

8.
The African rice Oryza glaberrima, traditionally cultivated since more than 3.500 years, is of poor agronomic performance but resistant/tolerant to various stresses and diseases. The introduction of these characters into O. sativa cultivars is difficult since crossing barriers cause spikelet sterility in F1. Backcrossing can restore fertility and recently facilitated the development of fertile O. glaberrima × O. sativa ssp. japonica hybrid progenies for rain fed systems. With the objective to gain access to African rice germplasm for improvement of irrigated rice, crosses were performed with eighteen O. glaberrima and twenty O. sativa ssp. indica accessions. In total about one hundred F1-hybrid grains were obtained. The F1 plants were all completely sterile and backcrossing (BC) to O. sativa was performed in order to restore spikelet fertility. Monitoring of Tog5681 × IR64 hybrid progenies under field conditions revealed a broad genetic diversity within the BC1 and BC2 populations. Some BC1 and BC2 progeny plants outperformed the O. sativa parent, indicating that the heterozygocity level and complementary gene action after two backcrosses are still sufficient to positively influence plant vigor. Spikelet fertility of progenies was highly variable, but almost complete fertility was already observed within the BC1F2 population. High spikelet fertility was preserved in one out of two analyzed BC1F3 families and inmost of the BC2F3 families. The ability to restore spikelet fertility within few generations and the potential of the genetic diversity present in interspecific progenies facilitates the development of plant types specifically designed for the African irrigated and lowland environment. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

9.
Summary Symmetric somatic hybrids were produced by electrofusion of protoplasts of two dihaploid tuber-bearing potato (Solanum tuberosum L.) lines and Solanum brevidens Phil., a diploid non-tuber-bearing wild potato species. A total of 985 plants was obtained. Verification of nuclear hybridity of putative hybrids was based on additive RAPD patterns, general morphological characteristics and chromosome counts. 53 (90%) calli regenerated into plants which were identified as somatic hybrids. Most of the hybrids were aneuploids at the tetraploid (4×) or hexaploid (6×) level. The 20 hybrids tested expressed a high level of resistance to potato virus Y (PVY N ) characteristic of the S. brevidens parent. Resistance to late blight (Phytophthora infestans (Mont.) de Bary) varied between hybrids, but was on average better than that of the fusion parents. Resistance of hybrids to bacterial stem rot (Erwinia carotovora subsp. atroseptica (van Hall) Dye) was not superior to that of commercial potato cultivars.  相似文献   

10.
Two species in genus Oryza, O. glaberrima and O. glumaepatula, are valuable and potential sources of useful genes of interest for rice improvement. However, the hybrid sterility between O. sativa and these two species is a main reproduction barrier when transferring the favorable traits/genes to mbox{O. sativa.} To overcome it, the nature of hybrid sterility should be understood further. The objective in the report is to map a new hybrid sterility gene as a Mendelian factor from O. glaberrima and analyze the co-linear of hybrid sterility S loci mbox{between} mbox{O. glaberrima} and mbox{O. glumaepatula} via comparative mapping approach. A BC2F2 population, derived from a single semi-sterility plant of BC2F1 of WAB56-104/ WAB450-11-1-2-P41-HB (WAB450-6) //WAB56-104///WAB56-104 was employed to map this pollen killer in O. glaberrima since WAB450-6 is a progeny of interspecific hybrid between O. sativa and O. glaberrima. A new pollen killer locus, S29(t) in O. glaberrima, was identified and mapped to interval between SSR marker RM7033 (1.1 cM) and RM7562 (1.3 cM) on rice chromosome 2. Comparative mapping indicated that S29(t) closely corresponded to S22 which is also a pollen killer gene in O. glumaepatula and is tightly linked with RFLP marker S910 on the short arm of rice chromosome 2. The good co-linear between S29(t) and S22 implied that there might exist common (orthologous) hybrid sterility loci controlled the reproduction barrier among AA genome species of genus Oryza, which will contribute significantly to our understanding of speciation and operation of hybrid sterility between O. sativa and its AA genome relatives.  相似文献   

11.
To further understand the nature of hybrid sterility between Oryza sativa and Oryza glaberrima, quantitative trait loci (QTL) controlling hybrid sterility between the two cultivated rice species were detected in BC1F1 and advanced backcross populations. A genetic map was constructed using the BC1F1 population derived from a cross between WAB450-16, an O. sativa cultivar, and CG14, an O. glaberrima cultivar. Seven main-effect QTLs for pollen and spikelet sterility were detected in the BC1F1. Forty-four sterility NILs (BC6F1) were developed via successive backcrosses using pollen sterility plants as female and WAB450-16 as the recurrent parent. Seven NILs, in which the target QTL regions were heterozygous while the other QTL regions as well as most of the reminder of the genome were homozygous for the WAB450-16 allele, were selected as the QTL identification materials. BC7F1 for the seven NILs showed a continuous variation in pollen and spikelet fertility. The four identified pollen sterility QTLs were located one each on chromosomes 1, 3, 7 and 7. Pollen sterility loci qSS-3 and qSS-7a were on chromosomes 3 and 7, respectively, which coincides with the previously identified S19, and S20, while loci qSS-1 and qSS-7b on chromosomes 1 and 7L appear distinct from all previously reported loci. An epistatic interaction controlling the hybrid sterility was detected between qSS-1 and qSS-7a.  相似文献   

12.
Summary Most of the commercial hybrids of indica rice are based on wild abortive (WA) source of cytoplasmic-genetic male sterility (CMS). Such cytoplasmic uniformity may lead to genetic vulnerability to disease and insect pests. To overcome this problem, diversification of CMS sources is essential. Crosses of 46 accessions of O. perennis and two accessions of O. rufipogon as female parents were made with two restorers (IR54, IR64) of WA cytosterility. Sterile hybrids were backcrossed with the respective recurrent parents. Of all the backcross derivatives, one line having the cytoplasm of O. perennis Acc 104823 and the nuclear background of IR64 was found to be stable for male sterility. The newly developed CMS line has been designated as IR66707A. This line is completely sterile (0% seed set) under selfed conditions. Crosses of IR66707A with 10 restorers of WA cytoplasm showed almost complete (93–100%) pollen sterility, indicating that the male sterility source of IR66707A is different from WA sterility. Southern hybridization of IR66707A, O. perennis (cytoplasmic donor), IR66707B (maintainer) and V20A (WA cytoplasm) using mitochondrial DNA specific probes (5 endonucleases × 8 probes) showed identical banding patterns between IR66707A and O. perennis. However, in more than half of the combinations, different banding patterns were observed between IR66707A and IR66707B and between IR66707A and V20A. The results suggest that IR66707A has the same cytoplasm as the donor (O. perennis), and CMS may not be caused by any major rearrangement or modification of mtDNA. The new CMS source identified will be useful in cytoplasmic diversification in hybrid rice breeding.  相似文献   

13.
Summary Random amplified polymorphic DNA (RAPD) analysis was carried out to evaluate polymorphism and genetic similarity between 39 Mediterranean mandarin genotypes. One hundred eleven amplification products were identified using 21 random primers. An average of 2.2 RAPD markers was obtained for each primer, corresponding to 42% of the amplification products. Genotype-specific RAPD markers were also found, mainly in known hybrids. UPGMA cluster analysis revealed the low level of genetic variation between accessions of Mediterranean mandarins, whereas their hybrids with other Citrus species showed greater genetic dissimilarity. Twenty accessions yielded very similar patterns, suggesting either that they could be a single clone, or that the technique was not able to detect genomic variation. However, for the other specimens genetic polymorphism can easily be detected by RAPD, although the genetic variation between accessions was quite low. The large number of hybrids and the low polymorphism between accessions support the hypothesis that Mediterranean mandarins are all true hybrid of Common mandarins (Citrus reticulata Blanco).  相似文献   

14.
蓝伟侦  柳哲胜  李刚  覃瑞 《作物学报》2007,33(4):560-565
用覆盖抗褐飞虱基因Bph15的两个BAC克隆，即20M14 (27 kb)和64O9 (36 kb)作为探针，对非洲栽培稻、药用野生稻和宽叶野生稻体细胞染色体进行荧光原位杂交(FISH)。两个BAC克隆均被定位于非洲栽培稻和药用野生稻第4染色体的短臂上，杂交信号的百分距离分别为37.03±4.11和81.22±3.62，相应的信号检出率为41.18%和38.22%。在宽叶野生稻中，有两对同源染色体同时检出信号，分别定位于染色体的短臂和着丝粒区，信号距着丝粒平均百分距离分别为87.78±5.23和0，信号检出率为52.58%。由此推知，这两个BAC克隆在非洲栽培稻和药用野生稻的第4染色体分布同线且同区，并且在宽叶野生稻的DD基因组也存在Bph15基因的同源序列。在未封阻的情况下，BAC克隆在非洲栽培稻的多条染色体上有杂交信号，表明它和栽培稻C0t-1 DNA在一定程度上具有同源性。上述结果初步显示Bph15在3个稻种染色体中的相对位置。文章讨论了Bph15在3个种间的关系，为有效分离和利用Bph15基因提供了有益的依据，对不同基因组及二倍体和四倍体中功能基因可能进化机制的分析提供了线索。  相似文献   

15.
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   

16.
Variation in 39 polymorphic RAPD markerswas studied for 18 populations of Solanum anguivi, S. aethiopicum Gilogroup and S. aethiopicum Shum groupin Uganda. UPGMA and PCO analyses of thedata revealed no clear groupingscorresponding to the species and groups. AnAMOVA analysis of the genetic variationshowed that the variation among species andgroups was less than 10%, whereas thevariation within species and groups wasmore than 90%. A Mantel test showed nocorrelation between genetic distance andgeographic distance. The data gives onlyvery weak support for the separation of themore morphologically distinct S.aethiopicum and S. anguivi. TheGilo- and Shum-groups of S.aethiopicum, which were previouslyregarded as two separate species can not beseparated on the basis of RAPD data, and itis most likely that they are keptmorphologically distinct by a strongman-made selection pressure.  相似文献   

17.
Genetic diversity of wheat wild relatives in the Near East detected by AFLP   总被引：3，自引：0，他引：3  
In order to reveal the molecular genetic diversity of wheat wild relatives, an AFLP analysis was conducted with 16 accessions of five Triticum andAegilops species originating from the Near East. Variation within population was studied with at least seven individuals per accession. Four primer combinations were used for selective amplification. Based on the scored bands, we estimated percentage of polymorphic bands, 1 – proportion of shared bands (1-psb) and nucleotide diversity (π). Of the five species used in this study, Ae. speltoides had the highest level of `within population' variation. This species had also the highest value of the variation among populations. As for Triticum species, the level of variation within population was low in diploid species (T. urartu and T. boeoticum),whereas two tetraploid species (T. dicoccoides and T. araraticum) had relatively high levels of variation within population. While the two diploid Triticum indicated a clear interspecific divergence, the two tetraploid wild wheats were not clearly divergent in this study. The variance portioning analysis indicated that the variation detected for diploid Triticum species was mainly composed of `between species' variation, on the other hand that for tetraploid Triticum was mostly composed of `within population' variation. In conclusion, AFLP analysis reveals molecular variation in all accessions used in this study, suggesting a potential genetic diversity of the wheat wild relatives in natural populations. These results have implications for the design of strategies to maintain genetic diversity within genebank collections. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

18.
Summary Recurrent backcrossing has been carried out with a view to transfer a gene for non-glutinous endosperm from two strains of O. glaberrima (Wx g /Wx g ) to glutinous japonica and indica varieties (wx/wx) of Oryza sativa. In the course of backcrosses Wx g /wx segregants were crossed with each of the two glutinous varieties of sativa as the respective recurrent male parent. The wx/wx and Wx g /wx segregants in the successive generations were consistently fully fertile and semi-sterile, respectively. The semi-sterility of Wx g /wx plants was attributable to abortion of most of the pollen grains carrying the gene wx. The nucleus but not cytoplasm was related to the semi-sterility. The Wx g /Wx plants having the gene for non-glutinous endosperm of a glaberrima strain and a japonica variety of sativa were also semi-sterile. Both wx- and Wx-megaspores in the plants heterozygous for the gene Wx g were deleteriously affected. The results could be explained by assuming that a factor tightly linked with the gene Wx g of glaberrima sterilizes gametes not carrying it in the heterozygotes and that the gametocidal action is exerted when combined with the sativa nucleus by the recurrent backcross method.  相似文献   

19.
Summary The genetic dissection of morphological traits can helpful to evaluate their potential values as markers for rice genetic improvement. In this study, a RI population derived from a cross from Zhenshan97 and IRAT109 was used to dissect the genetic bases of seven morphological traits such as leaf sheath color (LSC), grain apiculus color (GAC), grain hairiness density (GHD), grain awn length (GAL), ratio of leaf length to width (RLW), leaf erectness (LER) and natural leaf rolling status (NLR). Totally, 26 main-effect QTLs and 22 epistatic QTLs were detected. Of them, 11 main-effect and 3 epistatic QTLs expressed environmental interactions. GAC controlled by a single gene could be regarded as the most useful marker. LSC controlled by two major interacted main-effect QTLs, but with no environmental interaction, is suitable to become morphological marker. LSC will be a very efficient morphological marker for identification of hybrid plants at rice seedling stage when the two major QTLs are introduced into male sterile line and restorer line separately. GHD controlled by a major QTL and a few minor QTLs with comparative low QEIs could also be used as marker. The traits GAL, NLR, RLW and LER, which were controlled by a number of minor effect QTLs and affected by environmental conditions could not be used as marker. But the QTLs with large effects, such as nrl8, can be targeted for corresponding trait improvement through marker-aided selection in rice breeding.  相似文献   

20.
Dasypyrum villosum (L.) P. Candargy is discussed as a species commonly used in wheat improvement. Chromosomal localization of the potentially useful traits and chromosomal position of some morphological and isozyme markes are shown. The investigations using molecular RAPD, AFLP, SSR, RFLP markers and in situ (GISH, FISH) hybridization experiments on D. villosum itself and in wide hybrids with Triticum are summarized. The article also presents the information about designation of D. villosum chromosomes and the current knowledge on the phenomenon of two-coloured D. villosum caryopses.  相似文献   

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