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1.
Genetic variability of yellow potato cyst nematode G. rostochiensis from three Russian populations (Karelia, Vladimir oblast, and Moscow oblast) was investigated using two types of nuclear markers. Using RAPD markers identified with the help of six random primers (P-29, OPA-10, OPT-14, OPA-11, OPB-11, and OPH-20), it was possible to distinguish Karelian population from the group consisting of the populations from two adjacent regions (Moscow oblast and Vladimir oblast). Based on the combined matrix, containing 294 RAPD fragments, dendrogram of genetic differences was constructed, and the indices of genetic divergence and partition (P, H, and G(st)), as well as the gene flow indices N(m) between the nematode samples examined, were calculated. The dendrogram structure, genetic diversity indices, and variations of genetic distances between single individuals in each population from Karelia and Central Russia pointed to genetic isolation and higher genetic diversity of the nematodes from Karelia. Based on polymorphism of rDNA first intergenic spacer ITS1, attribution of all populations examined to the species G. rostochiensis was proved. Small variations of the ITS1 sequence in different geographic populations of nematodes from different regions of the species world range did not allow isolation of separate groups within the species. Possible factors (including interregional transportations of seed potato) affecting nematode population structure in Russia are discussed.  相似文献   

2.
The Grp1 locus confers broad-spectrum resistance to the potato cyst nematode species Globodera pallida and Globodera rostochiensis and is located in the GP21-GP179 interval on the short arm of chromosome V of potato. A high-resolution map has been developed using the diploid mapping population RHAM026, comprising 1,536 genotypes. The flanking markers GP21 and GP179 have been used to screen the 1,536 genotypes for recombination events. Interval mapping of the resistances to G. pallida Pa2 and G. rostochiensis Ro5 resulted in two nearly identical LOD graphs with the highest LOD score just north of marker TG432. Detailed analysis of the 44 recombinant genotypes showed that G. pallida and G. rostochiensis resistance could not be separated and map to the same location between marker SPUD838 and TG432. It is suggested that the quantitative resistance to both nematode species at the Grp1 locus is mediated by one or more tightly linked R genes that might belong to the NBS-LRR class. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. A. Finkers-Tomczak and S. Danan contributed equally to this research.  相似文献   

3.
Genetic variability in random amplified polymorphic DNA (RAPD) was studied in 90 individuals of Caragana microphylla, an outcrossing perennial shrub species, from five natural populations sampled in Inner Mongolia steppe of China on a small scale. Nineteen selected primers were used to amplify DNA samples, and totally 225 bands were detected. The percentage of polymorphic bands within populations ranged form 58.22% to 63.56%, with an average of 60% at the population level and 71.11% at the species level, indicating relatively high genetic variations in C. microphylla species. Shannon’s information index (l) and Nei’s gene diversity (h) showed the similar trend with each other. According to the analysis of Nei’s gene diversity, the percentage of genetic variation among populations was 7.13%, indicating a low level of genetic differentiation among populations. There existed a strong gene flow (N m = 3.26) among populations. Although AMOVA analysis also revealed most variation was within populations (ΦST = 4.1%), a significant proportion was observed among populations (P < 0.001) in the present study, suggesting genetic differentiation occurred among populations at a certain extent. Based on Mantel’s tests and the results of previous studies, the genetic structure pattern of C. microphylla accorded with the isolation-by-distance model on a very large scale, however, on a small scale, the significant genetic differentiation among populations might be enhanced by the micro-environmental divergence among the sampling sites, rather than by geographic factors. Analysis of the genetic variations of C. microphylla populations provided useful information for the adaptive strategy of Caragana species.  相似文献   

4.
Marek Renčo 《Biologia》2007,62(2):195-200
The life cycle of Globodera rostochiensis pathotype Ro1 was studied under experimental conditions on selected potato cultivars (Korela, Albina, Vivaldi, Veronika, Vera, Monalisa, Victoria, Maranca, Désirée) in Slovakia during two growing seasons. Two peaks of second stage juveniles (J2) were found in the soil; the first peak three and four weeks after planting in the first and second year, respectively. The last J2 were found on 23 September. The number of J2 found in the second peak was much higher. First J2 associated with roots were observed 18 days, on middle early and seritonous cultivars 34 days after planting, but fourth stage juveniles (J4) were observed 40 days after planting in both cultivar groups. First adult males were found in soil 43 and 46 days after planting, respectively, and the last males two weeks later. White females filled with eggs were observed on roots 61 days after planting. The cycle from hatching of J2 in the soil to the hatching of J2 from brown cysts required 68 days in the first year and 60 days in the second year.  相似文献   

5.
Ninety-one potato genotypes (cultivars and breeding lines) selected as resistant or susceptible to pathotype Ro1 of Globodera rostochiensis were screened for the presence of two PCR markers, 0.14 and 0.76 kb in length. Both PCR markers were linked with the H1 gene, located at the distal end of the long arm of chromosome V, and were present in 88 to 100% of the resistant cultivars and breeding lines. The 0.76 kb PCR marker was detected in all resistant genotypes and in approximately 86% of susceptible breeding lines as well as in all susceptible cultivars. The 0.14 kb marker was detected in 88% of resistant breeding lines and in 94% of resistant cultivars. Most of the susceptible genotypes tested (91% of cultivars, but only 50% of breeding lines) did not show the presence of the 0.14 kb marker. We conclude that the 0.14 kb H1 marker is likely to be useful for the proper selection of potato genotypes resistant to the Ro1 pathotype of G. rostochiensis.  相似文献   

6.
The gastropod Hexaplex trunculus is widely distributed in a relatively large range of habitats, but has no dispersal stage. We investigated its genetic structure across its distribution range, from Mediterranean Sea to adjacent Atlantic coasts, by sequencing mitochondrial DNA portions of the NADH dehydrogenase gene ND2 (420 pb) and the internal transcribed spacer ITS2 (450 pb). Our results suggested a significant genetic variability of ND2 (π = 0.009 and Hd = 0.629) and low variability of the ITS2 sequences. A strong phylogeographic break, separated the Aegean populations from those of Western/Eastern Mediterranean and the Atlantic ones, was founded. The tow lineages may have been separated by vicariance events due to the Peloponnese break that separates the Aegean populations from other populations and was maintained until now by the quasi-circular anticyclonic front associated to the straits of Cretan Arc of the Peloponnesian Peninsula. Tunisian coasts appear particularly diverse since the two divergent lineages co-occured. These results may have management consequences since H. trunculus is a high commercial value harvested species.  相似文献   

7.
A set of 30 accessions of five Curcuma species-C. latifolia, C. malabarica, C. manga and C. raktakanta and 13 morphotypes (identified on the basis of morphological markers) of C. longa conserved in the In Vitro Genebank at National Bureau of Plant Genetic Resources, New Delhi, were subjected to RAPD analysis. Of the 200 RAPD primers screened, 21 polymorphic primers were selected for further study. Mean genetic similarities based on Jaccard’s similarity coefficient ranged from 0.18 to 0.86 in accessions of cultivated species, i.e., C. longa and from 0.25 to 0.86 in wild species. The dendrogram derived from the RAPD data corroborated the morphological classification of the morphotypes. The efficiency of individual RAPD primers was also compared; primers OPC-20, OPO-06, OPC-01 and OPL-03 were adjudged highly informative in discriminating the germplasm of Curcuma.  相似文献   

8.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.  相似文献   

9.
Allothrombium pulvinum Ewing is a common natural enemy of aphids and some other arthropods. So far, there are no studies that have addressed genetic variation of this predatory mite. We investigated genetic variation of A. pulvinum across its whole known range in Iran. A 410 bp portion of the mitochondrial cytochrome c oxidase subunit I gene (coxI) and 797–802 bp portion of the internal transcribed spacer 2 of rDNA (ITS2) were sequenced for 55 individuals from 11 populations, resulting in 12 and 26 haplotypes, respectively. In the coxI region, haplotype and nucleotide diversities varied among populations from 0.00 to 0.90 and from 0.0000 to 0.0110, respectively. In the ITS2 region they varied from 0.20 to 0.91 and from 0.0006 to 0.0023, respectively. For both gene regions the highest haplotype and nucleotide diversities were detected in population Mahmoud Abad from northern Iran. Statistically significant population differentiation (F ST) was detected in most pair-wise population comparisons. The results of population differentiation for both gene regions were generally congruent indicating that A. pulvinum from Iran consists of genetically different populations. This suggests that A. pulvinum comprises at least two geographically distinct populations or even more than one species. This study is an initial step towards understanding genetic variation of A. pulvinum, a taxon for which little molecular information is available. More intensive sampling and analysis of additional DNA regions are necessary for more detailed classification of this taxon.  相似文献   

10.
Nine resistance gene homologues (RGHs) were identified in two diploid potato clones (SH and RH), with a specific primer pair based on conserved motifs in the LRR domain of the potato cyst nematode resistance gene Gpa2 and the potato virus X resistance gene Rx1. A modified AFLP method was used to facilitate the genetic mapping of the RGHs in the four haplotypes under investigation. All nine RGHs appeared to be located in the Gpa2/ Rx1 cluster on chromosome XII. Construction of a physical map using bacterial artificial chromosome (BAC) clones for both the Solanum tuberosum ssp. tuberosum and the S. tuberosum ssp. andigena haplotype of SH showed that the RGHs are located within a stretch of less than 200 kb. Sequence analysis of the RGHs revealed that they are highly similar (93 to 95%) to Gpa2 and Rx1. The sequence identities among all RGHs range from 85 to 100%. Two pairs of RGHs are identical, or nearly so (100 and 99.9%), with each member located in a different genotype. Southern-blot analysis on genomic DNA revealed no evidence for additional homologues outside the Gpa2/ Rx1 cluster on chromosome XII.  相似文献   

11.
A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.  相似文献   

12.
Although Sequence-Characterized Amplified Region (SCAR) markers linked to the potato H1 locus, which confers resistance to pathotypes Ro1 and Ro4 of the potato cyst nematode (PCN) Globodera rostochiensis, have been reported, robust markers that enable estimation of allele dosage would improve the quality of information obtained from genotyping parental accessions (cultivars/breeding lines) and progeny populations within breeding programmes. With this in mind, we have developed single nucleotide polymorphism (SNP)-based molecular markers flanking the H1 resistance gene, using genomic re-sequence data from five elite tetraploid accessions. The published TG689 and 57R primer sequences were used in a Basic Local Alignment Search Tool (BLAST) examination of the reference potato genome, and SNPs within the vicinity of these primer regions were identified and targeted for designing probe-based High Resolution Melting (HRM) SNP assays. Evaluation of the subsequently developed HRM markers, TG689_1P and 57R_1P, against the publicly available SCAR markers, TG689 and 57R, indicated that the HRM markers enabled more reliable marker-trait association than the SCARs. Additionally, allelic dosage estimates for the H1 locus were also derived using the TG689_1P marker, providing a tool to optimise parental and progeny selections in PCN resistance breeding.  相似文献   

13.
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.  相似文献   

14.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.  相似文献   

15.
Mexico is one of the five largest producers of papaya worldwide, but losses caused by pathogens, mainly fungus, at the pre- and post-harvest stages are often more than 50% of the crop. Papaya anthracnose, caused by three different species of the Colletotrichum genus in Mexico, occupies a preponderant place in this problem. Although two of these species, C. gloeosporiodes and C. truncatum, have been characterized morphologically and genotypically, this has not occurred with C. magnum, the third species involved, about which there is very little information. Because of this, it is vital to know its genetic characterization, much more so considering that the studies carried out on the other two species reveal a wide genetic diversity, differences in pathogenicity and in the response to fungicides of the different strains characterized. In this work, Colletotrichum spp. isolates were collected at different papaya orchards in the south-southeast of Mexico. C. magnum isolates identified by species-specific primers were characterized by morphological and molecular approaches. Differences in colony characteristics resulted in five morphological groups. AP-PCR, DAMD and ISSR markers were found to be very efficient for revealing the interspecific variability of this species. The high genetic variability found in the accessions of C. magnum was linked to the geographical area where they were collected. Isolates from Chiapas State were the most variable, showing point mutations in the ITS1-ITS2 region. These results will enable a better phytosanitary management of anthracnose in papaya in this region of Mexico.  相似文献   

16.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.  相似文献   

17.
Sunflower (Helianthus annuus) stem canker caused by Diaporthe helianthi is one of the most important sunflower diseases in Croatia. Until recently, sunflower was the only known host for D. helianthi. In our research carried out in the area of Eastern Croatia, isolates of Diaporthe/Phomospis were collected from Xanthium italicum, X. strumarium and Arctium lappa. Using morphological, cultural and molecular ITS rDNA data, isolates from these weeds were identified as D. helianthi. The following isolates were used in the pathogenicity test: one isolate originated from sunflower (Su5/04), three from X. italicum (Xa2, Xa3 and Xa5), two from X. strumarium (Xa9 and Xa12), one from Xanthium sp. (Xa13) and one from A. lappa (Ar3). According to the results, it was determined that isolate Xa5 (originated from X. italicum) was the most pathogenic to sunflower stems. The average length of the lesion was 11.3 cm. The lowest level of pathogenicity was found in Xa9 (isolated from X. strumarium). The length of the lesion was 0.1 cm.  相似文献   

18.
A complex study on the adaptation of cn and vn mutants and the allozymes of alcoholdehydrogenase (ADH) was carried out in initially pure lines, and their panmixia populations during exchange of the mutant genotype with that of wild-type flies (C-S) and D) through saturating crossings. The relative adaptation of the genotypes was estimated by their effect on reproductive efficiency in the experimentally obtained population. Fecundity, lifespan, and the resistance of the studied genotypes to hyperthermia were investigated individually. It was shown that the high level of adaptation of the cn mutants and the low level of adaptation of the vg mutants was correlated with the presence of different ADH allozymes. In the studied population, the F-allozyme of ADH accompanied the vg mutation, while the S-allozyme of the enzyme was detected in cn mutants. Saturating crossings of C-S(Adh Svg(Adh F) and D(Adh F) × cn(Adh S), along with the parallel determination of the allele composition of the Adh locus, demonstrated that the complete substitution of the F-allozyme of ADH in the vg mutants by the S-allozyme in D flies, as well as the substitution of the S-allozyme of ADH in the cn mutants by the F-allozyme in D flies was realized only after the 15th–20th backcrosses. These results favor the coadaptation of cn and vg marker genes with alleles of the Adh locus and indicate the important role of the latter in the adaptation of genotypes. In the studied population, selection acted primarily against the vg mutants, which were inferior to the cn mutants, and heterozygote genotypes in indices of the main adaptation components.  相似文献   

19.
Seol E  Jung Y  Lee J  Cho C  Kim T  Rhee Y  Lee S 《Plant cell reports》2008,27(7):1197-1206
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species.  相似文献   

20.
Expressed sequence tag-derived microsatellite markers (EST-SSR) were generated and characterized in Laminaria japonica using data mining from updated public EST databases and polymorphism testing. Fifty-eight of 578 ESTs (10.0%) containing various repeat motifs were used to design polymerase chain reaction (PCR) amplification primers. A total of 12 pairs of primer were generated and used in the PCR amplification. Alleles per locus ranged from two to ten (average of 5.7). The observed heterozygosities and expected heterozygosities were from 0.045 to 0.543 and from 0.056 to 0.814, respectively. All loci were in Hardy–Weinberg equilibrium and no linkage disequilibrium was detected. These robust, informative, and potentially transferable polymorphic markers appear suitable for population, genetic, parentage, and mapping studies of L. japonica.  相似文献   

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