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1.
M. Yamamori 《Euphytica》2009,165(3):607-614
In common and durum wheats (Triticum aestivum L. and T. durum Desf.), variant waxy (Wx) alleles have been reported for three Wx proteins (Wx-A1, -B1 and -D1), responsible for amylose synthesis in flour starch. Five variant alleles, Wx-A1c, -A1e, -B1c, -B1d and -D1c, were examined to elucidate their effects on amylose content in flour starch. Common wheat lines carrying a Wx protein produced by one variant (e.g., Wx-A1c) and one control (e.g., Wx-A1a) allele were bred and their starches were compared. Results showed that Wx-A1e did not produce amylose (waxy phenotype), whereas three alleles (Wx-A1c, -B1c and -B1d) reduced amylose, and -D1c might have increased it slightly. Most data on blue value, swelling power and starch paste clarity in water and dimethyl sulphoxide also suggested the variant Wx alleles either reduced or increased amylose content.  相似文献   

2.
The present work was conducted to identify microsatellite markers linked to the rice blast resistance gene Pi-1(t) for a marker-assisted selection program. Twenty-four primer pairs corresponding to 19 microsatellite loci were selected from the Gramene database (www. gramene.org) considering their relative proximity to Pi-1(t) gene in the current rice genetic map. Progenitors and DNA bulks of resistant and susceptible families from F3 segregating populations of a cross between the near-isogenic lines C101LAC (resistant) and C101A51 (susceptible) were used to identify polymorphic microsatellite markers associated to this gene through bulked segregant analysis. Putative molecular markers linked to the blast resistance gene Pi-1(t) were then used on the whole progeny for linkage analysis. Additionally, the diagnostic potential of the microsatellite markers associated to the resistance gene was also evaluated on 17 rice varieties planted in Latin America by amplification of the specific resistant alleles for the gene in each genotype. Comparing with greenhouse phenotypic evaluations for blast resistance, the usefulness of the highly linked microsatellite markers to identify resistant rice genotypes was evaluated. As expected, the phenotypic segregation in the F3 generation agreed to the expected segregation ratio for a single gene model. Of the 24 microsatellite sequences tested, six resulted polymorphic and linked to the gene. Two markers (RM1233*I and RM224) mapped in the same position (0.0 cM) with the Pi-1(t) gene. Other three markers corresponding to the same genetic locus were located at 18.5 cM above the resistance gene, while another marker was positioned at 23.8 cM below the gene. Microsatellite analysis on elite rice varieties with different genetic background showed that all known sources of blast resistance included in this study carry the specific Pi-1(t) allele. Results are discussed considering the potential utility of the microsatellite markers found, for MAS in rice breeding programs aiming at developing rice varieties with durable blast resistance based on a combination of resistance genes. Centro Internactional de Agricultura Tropical (CIAT) institute where the research was carried out  相似文献   

3.
Grain protein content is an important analysis target to determine grain quality in rice. This study analyzed quantitative trait loci (QTLs) for the content of grain protein and amylose using the chromosomal segment substitution lines developed from ‘Koshihikari’ and ‘Nona Bokra’. It also evaluated the effects of target QTL on eating and cooking quality through the physical properties of cooked rice and its gel consistency. QTL analysis over 3 years detected the QTL on chromosome 12, TGP12, which consistently decreased total grain protein content via the ‘Nona Bokra’ allele. Selected CSSL with TGP12, CSSL-TGP12, showed a lower content of total grain protein in brown and milled rice, and had similar amylose content, grain size, and weight of brown rice, compared with ‘Koshihikari’. Based on the results of sodium dodecyl sulfate polyacrylamide gel electrophoresis, brown rice with CSSL-TGP12 had no remarkable decrease or loss in any specific protein. Regarding eating and cooking quality, CSSL-TGP12 did not show stable effects on physical properties, hardness, stickiness, or adherability of cooked rice or its gel consistency. These results suggest that TGP12 could be one of the key genetic factors for the alteration of grain protein content without an effect on eating or cooking quality.  相似文献   

4.
Peach powdery mildew is one of the major diseases of the peach. Various sources of resistance to PPM have thus been identified, including the single dominant locus Vr2 carried by the peach rootstock ‘Pamirskij 5’. To map Vr2, a linkage map based on microsatellite markers was constructed from the F2 progeny (WP2) derived from the cross ‘Weeping Flower Peach’ × ‘Pamirskij 5’. Self-pollinations of the parents were also performed. Under greenhouse conditions, all progenies were scored after artificial inoculations in two classes of reactions to PPM (resistant/susceptible). In addition to Vr2, WP2 segregated for three other traits from ‘Weeping Flower Peach’: Rm1 for green peach aphid resistance, Di2 for double-flower and pl for weeping-growth habit. With their genomic locations unknown or underdocumented, all were phenotyped as Mendelian characters and mapped: Vr2 mapped at the top of LG8, at 3.3 cM, close to the CPSCT018 marker; Rm1 mapped at the bottom of LG1, at a position of 116.5 cM, cosegregating with the UDAp-467 marker and in the same region as Rm2 from ‘Rubira’®; Di2 mapped at 28.8 cM on LG6, close to the MA027a marker; and pl mapped at 44.1 cM on LG3 between the MA039a and SSRLG3_16m46 markers. Furthermore, this study revealed, for the first time, a pseudo-linkage between two traits of the peach: Vr2 and the Gr locus, which controls the red/green color of foliage. The present work therefore constitutes a significant preliminary step for implementing marker-assisted selection for the four major traits targeted in this study.  相似文献   

5.
The recessive mutation of the XANTHA gene (XNT) transforms seedlings and plants into a yellow color, visually distinguishable from normal (green) rice. Thus, it has been introduced into male sterile lines as a distinct marker for rapidly testing and efficiently increasing varietal purity in seed and paddy production of hybrid rice. To identify closely linked markers and eventually isolate the XNT gene, two mapping populations were developed by crossing the xantha mutant line Huangyu B (indica) with two wild type japonica varieties; a total of 1,720 mutant type F2 individuals were analyzed for fine mapping using polymorphic InDel markers and high dense microsatellite markers. The XNT gene was mapped on chromosome 11, within in a fragment of ~100 kb, where 13 genes are annotated. The NP_001067671.1 gene within the delimited region is likely to be a candidate XNT gene, since it encodes ATP-dependent chloroplast protease ATP-binding subunit clp A. However, no sequence differences were observed between the mutant and its parent. Bioinformatics analysis demonstrated that four chlorophyll deficient mutations that were previously mapped on the same chromosome are located outside the XNT region, indicating XNT is a new gene. The results provide useful DNA markers not only for marker assisted selection of the xantha trait but also its eventual cloning.  相似文献   

6.
Intergeneric hybrid plants between Colchicaceous ornamental plants, Sandersonia aurantiaca and Gloriosa rothschildiana, have successfully been produced via ovule culture. After 5 days of reciprocal cross-pollination, a few pollen tubes were observed in the ovary. Although seeds were obtained in both reciprocal cross-combinations, they did not germinate under ex vitro conditions. Ovules with placental tissues isolated 14 days after cross-pollination of S. aurantiaca × G. rothschildiana were cultured on a medium containing 0.01 mg l–1 each of -naphthaleneacetic acid (NAA) and 6-benzyladenine (BA), on which 41.5% of ovules swollen and produced callus-like structures within 10 weeks. When such swollen ovules were transferred to a medium containing 0.1 mg l–1 each of NAA and BA, 7.5% of the initially cultured ovules produced rhizome-like structures within 6 weeks. Among the rhizome-like structures, those derived from two independent ovules (3.7% of the initially cultured ovules) produced multiple shoots following transfer to a medium containing 0.25 mg l–1 NAA and 2.5 mg l–1 BA. Multiple shoot-derived plantlets were established on a plant growth regulator-free medium, and they were successfully transplanted to pots. Early verification of their hybridity was accomplished by flow cytometry (FCM) analysis, chromosome observation and rDNA analysis.  相似文献   

7.
Using three varieties of Brassica rapa, cv. Hauarad (accession 708), cv. Maoshan-3 (714) and cv. Youbai (715), as the maternal plants and one variety of B. oleracea cv. Jingfeng-1 (6012) as the paternal plant, crosses were made to produce interspecific hybrids through ovary culture techniques. A better response of seed formation was observed when ovaries were cultured in vitro at 9–12 days after pollination on the basal MS and B5 media supplemented with 6-benzylaminopurine (BA) and naphthylacetic acid (NAA). The best response was observed for cross 714×6012 with the rate of seeds per ovary reaching 43.0%. Seeds for cross 715×6012 showed the best germination response (66.7%) on the regeneration medium (MS+1.0 mg l–1 BA+0.05 mg l–1 NAA). In all three cross combinations, good response in terms of root number and length of plants was observed on the root induction medium (MS+1.0 mg l–1 BA+0.1 mg l–1 NAA). A better response was observed for the regenerated plants cultured for 14 days than for 7 days. The ovary-derived plants with well-developed root system were hardened for 8 days and their survival rate reached over 80%. Cytological studies showed that the chromosome number of all plants tested was 19 (the sum of both parents), indicating that these regenerated plants were all true hybrids of B. rapa (n = 10) × B. oleracea (n = 9). The regenerated plants were doubled with colchicine treatment, and the best response in the crosses 708×6012, 714×6012 and 715×6012 was observed when treated with 170 mg l–1 colchicine for up to 30 h and their doubling frequency reached 52, 56 and 62%, respectively.  相似文献   

8.
The rice FRIZZY PANICLE (FZP) locus on chromosome 7, in which an ERF and acidic domain are present, is concerned with the regulation of spikelet meristem identity and the determination of panicle architecture. Many fzp mutants drastically alter panicle morphology with higher-order rachis-branches developing successively instead of the development of floral organs in these mutants. A new mutant showing the same fzp phenotype was induced by γ-ray irradiation of seeds of a rice cultivar “Gimbozu”. Examination of this fzp-like mutant for its allelism to a known allele of fzp-1, nucleotide sequence, and panicle and agronomic characteristics clearly indicated that the allele of this fzp-like mutant is located in FZP. Because there is a previously identified allele called fzp-9, we designated this new allele as fzp-10. fzp-10 has a single nucleotide (cytosine) deletion between the ERF domain and the acidic domain, which results in a frameshift mutation and a premature stop codon, thereby altering the C-terminus of the encoded protein. The degree of higher-order branching in the panicles was significantly reduced in the fzp-10 mutant compared with that of fzp-1. Moreover, the fzp-10 mutant showed highly depressed culm and panicle lengths and panicle number, as well as delayed heading dates compared with its wild type and also with fzp-1. fzp-10 has several new characteristics, its altered nucleotide position and severity of phenotype alteration, and, therefore, could be a new gene resource to examine the function of FZP and the determination of rice panicle architecture.  相似文献   

9.
Rice blast resistance gene ‘Pi-z’ present in rice genotypes, Zenith and Fukunishiki, represents a potential source of blast resistance for the north-western Himalayan region of India. We tested the reliability of microsatellite markers linked to Pi-z for assessing blast resistance phenotype in crosses of commercial importance. A new set of microsatellite markers linked to Pi-z was also developed by exploiting the publicly available marker and genomic resources of rice. Of the three previously reported markers for Pi-z, only MRG5836 was suitable for the marker assisted selection of Pi-z. Among the 17 microsatellites selected from the putative region of Pi-z locus, two, RM8225 and RM8226 cosegregated with MRG5836 and were located at distance of 1.2–4.5 cM from the gene. A new microsatellite marker ‘SSR236’ was developed from the (CT)16 repeat of PAC clone P0502B12, which exhibited closer linkage (0.6–1.2 cM) to Pi-z. Survey of the allelic diversity at the loci of the Pi-z linked microsatellite markers revealed that the Fukunishiki and Zenith type alleles were not present in majority of the local indica rice genotypes. As these markers are polymorphic between the Pi-z donors and a great majority of local indica rices tested, they can be used as a selection tool in rice breeding programs aimed at improving the blast resistance of local rices.  相似文献   

10.
The genetics of resistance to Cucumber mosaic virus (CMV) in Cucumis sativus var. hardwickii R. Alef, the wild progenitor of cultivated cucumber was assessed by challenge inoculation and by natural infection of CMV. Among the 31 genotypes of C. sativus var. hardwickii collected from 21 locations in India the lowest mean percent disease intensity (PDI) was recorded in IC-277048 (6.33%) while the highest PDI was observed in IC-331631 (75.33%). All the four cultivated varieties (DC-1, DC-2, CHC-1 and CHC-2) showed very high PDI and susceptible disease reaction. Based on mean PDI, 8 genotypes were categorized as resistant, 13 as moderately resistant, 9 as moderately susceptible and one as susceptible. A chi-square test of frequency distribution based on mean PDI in F2 progenies of six resistant × susceptible crosses revealed monogenic recessive Mendelian ratio 1(R):3(S) to be the best fit. This monogenic recessive model was further confirmed by 1(R):1(S) ratio as the best fit for back cross with resistant parent and no fit for either 3:1 or 1:1 in the back cross with the susceptible parent. The results revealed that CMV resistance in C. sativus var. hardwickii was controlled by a single recessive gene. Considering the cross compatibility between C. sativus var. hardwickii and cultivated cucumber, the resistance trait can be easily transferred to cultivated species through simple backcross breeding.  相似文献   

11.
Embryogenic calli derived from anther cultures of the two-rowed winter barley cultivar Igri were plated on solid L3 medium containing the proline analogue hydroxyproline (Hyp), 10–20 mmol l–1. Exposure to Hyp caused severe degeneration of most of the calli. Hyp resistant calli, distinguishable by their lighter colour and higher growth rate, and control calli not exposed to Hyp were plated on L3 regeneration medium. From 22,500 anthers exposed to Hyp 46 Hyp resistant regenerates were obtained, which were transferred to soil. After cultivation for 5–10 weeks at normal growth conditions they were cold hardened at 2 C under short day conditions together with control regenerates. Frost tolerance assays with segments of fully grown leaves of unhardened and cold hardened plants revealed that Hyp resistant regenerants were significantly more frost tolerant than the control regenerants. Improved frost tolerance was found also in the progenies R1 to R9, and genotypic segregation in the R1 generation in a 1:2:1 ratio was indicated. Increased proline content was observed in the R2 generation and in subsequent generations and was significantly (P 0.001) correlated with increased frost tolerance in the Hyp lines. Comparative studies of R9 progenies from homozygous R2 plants with the wild type Igri under field conditions in winter at three locations in Europe as well as crossing experiments confirmed the heritable improvement of frost tolerance and winter survival, respectively, in the Hyp lines. The results support the hypothesis that proline accumulation in cold acclimated winter barley plants is causally related to the acquisition of frost tolerance. Moreover, the described biotechnological procedure may be applicable in breeding programs for improved winter hardiness and possibly also for other stress tolerances.  相似文献   

12.
Quantitative trait loci (QTL) associated with four milling recovery properties, two chemical properties, six paste properties of grain, and six textural parameters of cooked rice were identified using an introgression line (IL) population of rice developed from an interspecific cross over two years. The IL population consisted of 121 lines from a cross between wild rice (O. rufipogon Griff.) and a japonica cultivar. A total of 28 QTLs were identified for the 14 traits using inter mapping. Of these, 10 were significant over two years indicating that these QTLs are stable across years and environments. For eight (21%) of the QTLs identified, the O. rufipogonderived alleles contributed a desirable effect on amylose content, protein content, minimum viscosity, final viscosity, and consistency. Among these, pc3 for protein content and ac7 for amylose content were significant in both years and showed an R2 value of 25.5 and 30.9%, respectively. The markers closely associated with these useful alleles can be used to trace the inheritance of specific chromosome segments in the IL population and also offer a starting point for map-based cloning of genes underlying these traits.  相似文献   

13.
The potential of microsatellite markers for use in genetic studies has been evaluated in Allium cultivated species (Allium cepa, A. fistulosum) and its allied species (A. altaicum, A. galanthum, A. roylei, A. vavilovii). A total of 77 polymerase chain reaction (PCR) primer pairs were employed, 76 of which amplified a single product or several products in either of the species. The 29 AMS primer pairs derived from A. cepa and 46 microsatellites primer pairs from A. fistulosum revealed a lot of polymorphic amplicons between seven Allium species. Some of the microsatellite markers were effective not only for identifying an intraspecific F1 hybrid between shallot and bulb onion but also for applying to segregation analyses in its F2 population. All of the microsatellite markers can be used for interspecific taxonomic analyses among two cultivated and four wild species of sections Cepa and Phyllodolon in Allium. Generally, our data support the results obtained from recently performed analyses using molecular and morphological markers. However, the phylogeny of A. roylei, a threatened species with several favorable genes, was still ambiguous due to its different positions in each dendrogram generated from the two primer sets originated from A. cepa and A. fistulosum.  相似文献   

14.
To clarify the polyploid origin of the sweetpotato, we analyzed retentions of three distinctive types of Waxy intron 2 (Wx-In2) variants among 27 sweetpotato lines and 24 selected relatives and their phylogenetic relationships with Wx-In2 from 11 closest relatives. The three types of Wx-In2 effectively distinguish three diploid constituent genomes of very close homeology in the sweetpotato: Type I is characteristic of some loci in Genome I and III, and Types II and III are specific to loci in Genome II and III. The Type I Wx-In2 variation was found to be retained in 19 sweetpotato lines, Ipomoea littoralis Blume (4×), I. tabascana (4×), and I. tenuissima (2×); Type II to be retained in all 27 sweetpotato lines, I. littoralis Blume, and two I. trifida accessions; Type III to be retained in 13 sweetpotato lines, I. tenuissima, and four distantly related species. Because of the nature of independent random divergence of orthologous intronic sequences, these highly selective retentions of genome-specific or characteristic sweetpotato Wx-In2 variations among four diploid or tetraploid sweetpotato relatives are consistent only with separate lineages of diploid genomes of the sweetpotato. Such an allohexaploid origin of the sweetpotato probably occurred via hybridization between I. tenuissima and I. littoralis Blume, derived earlier from I. trifida and an unidentified species sibling to I. tenuissima. However, neither the involvement of I. tabascana nor a multiple origin of the sweetpotato can be ruled out. The inference is supported by maximal likelihood relationships between the three types of Wx-In2 from the sweetpotato and Wx-In2 from its 11 closest relatives.  相似文献   

15.
Gluten protein determines the processing quality of both durum wheat and bread wheat. The glutenin subunits compositions and associated quality traits of 20 Ethiopian durum wheat varieties were systematically analyzed using SDS-PAGE and Payne numbers. A total of 16 glutenin patterns were identified. At the Glu-A1 locus, all varieties scored the null allele. The predominant glutenin alleles at the Glu-B1 locus were Glu-B1b (7+8) and Glu-B1e (20). In Glu-3, the most abundant glutenin subunits were Glu-A3a and Glu-B3c. Based on the Payne scores, the varieties Yerer, Ginchi, Candate, and Foka were identified to have allelic composition suitable for pasta making. The cluster analysis using agglomerative hierarchical clustering (AHC) method classified the varieties into four similarity classes. Based on the findings of this experiment, suggestions were made for allelic composition improvement through introgression of superior alleles from known Glu-1 and Glu-3 sources.  相似文献   

16.
A genetic factor that blocks the cannabinoid biosynthesis in Cannabis sativa has been investigated. Crosses between cannabinoid-free material and high content, pharmaceutical clones were performed. F1s were uniform and had cannabinoid contents much lower than the mean parental value. Inbred F2 progenies segregated into discrete groups: a cannabinoid-free chemotype, a chemotype with relatively low cannabinoid content and one with relatively high content, in a monogenic 1:2:1 ratio. In our model the cannabinoid knockout factor is indicated as a recessive allele o, situated at locus O, which segregates independently from previously presented chemotype loci. The genotype o/o underlies the cannabinoid-free chemotype, O/o is expressed as an intermediate, low content chemotype, and O/O is the genotype of the high content chemotype. The data suggests that locus O governs a reaction in the pathway towards the phenolic cannabinoid precursors. The composition of terpenoids and various other compound classes of cannabinoid-free segregants remains unaffected. Backcrossing produced cannabinoid-free homologues of pharmaceutical production clones with potential applications in pharmacological research. A new variant of the previously presented allele ‘B 0’, that almost completely obstructs the conversion of CBG into CBD, was also selected from the source population of the cannabinoid knockout factor.  相似文献   

17.
Cytoplasmic-nuclear male-sterility is an important biological tool, which has been used by plant breeders to increase yields in cross-pollinated cereals and vegetables by commercial exploitation of the phenomenon of hybrid vigor. In legumes, no such example exists due to the absence of an economic way of mass pollen transfer from male to female parent. Pigeonpea [Cajanus cajan (L.) Millsp.], however, is a different legume where a moderate level of insect-aided natural out-crossing (25–70%) exists and it can be used to produce commercial hybrid cultivars, if an efficient and stable cytoplasmic-nuclear male-sterility (CMS) system is available. This paper reports the development of a stable CMS system (ICP 2039A), derived from an inter-specific hybrid of Cajanus cajanifolius, a wild relative of pigeonpea, with a cultivar ICP 11501. Using this genetic material, designated as the A4 cytoplasm, a number of fertility restorers and maintainers have been developed. The best short-duration experimental pigeonpea hybrid ICPH 2470 produced 3205 kg ha−1 grain yield in 125 days, exhibiting 77.5% advantage over the control cultivar UPAS 120. At present, all the important biological systems necessary for a successful commercial hybrid breeding program are available in pigeonpea and the package of this technology has been adopted by private seed sector in India for the production and marketing of hybrid varieties.  相似文献   

18.
We have previously reported that expression of salt-responsive genes, including Bruguiera gymnorhiza ankyrin repeat protein 1 (BgARP1), enhances salt tolerance in both Agrobacterium tumefaciens and Arabidopsis. In this report, we further characterized BgARP1-expressing Arabidopsis to elucidate the role of BgARP1 in salt tolerance. BgARP1-expressing plants exhibited more vigorous growth than wild-type plants on MS plates containing 125–175 mM NaCl. Real-time PCR analysis showed enhanced induction of osmotin34 in the 2-week-old transformants under 125 mM NaCl. It was also showed that induction of typical salt-responsive genes, including RD29A, RD29B, and RD22, was blunted and delayed in the 4-week-old transformants during 24 h after 200 mM NaCl treatment. Ion content analysis showed that transgenic plants contained more K+, Ca2+, and NO3 , and less NH4 +, than wild-type plants grown in 200 mM NaCl. Our results suggest that BgARP1-expressing plants may reduce salt stress by up-regulating osmotin34 gene expression and maintaining K+ homeostasis and regulating Ca2+ content. These results indicate that BgARP1 is functional on a heterogeneous background.  相似文献   

19.
Submergence is a major stress causing yield losses particularly in the direct-seeded rice cultivation system and necessitates the development of a simple, rapid and reliable bioassay for a large scale screening of rice germplasms with tolerance against submergence stress. We developed two new bioassay methods that were based primarily on the seedling vigor evaluated by the ability of fast shoot elongation under submerged conditions, and compared their effectiveness with two other available methods. All four bioassay methods using cultivars of 7 indica and 6 japonica types revealed significant and consistent cultivar differences in seedling vigor under submergence and/or submergence tolerance. Japonica cultivars were more vigorous than indica cultivars, with Nipponbare being the most vigorous. The simplest test tube method showed the highest correlations to all other methods. Our results suggest that seedling vigor serves as a submergence avoidance mechanism and confers tolerance on rice seedlings to flooding during early crop establishment. A possible relationship is discussed between seedling vigor based on fast shoot elongation and submergence tolerance defined by recovery from submergence stress.  相似文献   

20.
Compact growth is an important quality criterion in horticulture. Many Campanula species and cultivars exhibit elongated growth which is suppressed by chemical retardation and cultural practice during production to accommodate to the consumer’s desire. The production of compact plants via transformation with wild type Agrobacterium rhizogenes is an approach with great potential to produce plants that are non-GMO. Efficient transformation and regeneration procedures vary widely among both plant genera and species. Here we present a transformation protocol for Campanula. Hairy roots were produced on 26–90% of the petioles that were used for transformation of C. portenschlagiana (Cp), a C. takesimana × C. punctata hybrid (Chybr) and C. glomerata (Cg). Isolated hairy roots grew autonomously and vigorously without added hormones. The Cg hairy roots produced chlorophyll and generated plantlets in response to treatments with cytokinin (42 µM 2iP) and auxin (0.67 µM NAA). In contrast, regeneration attempts of transformed Cp and Chybr roots lead neither to the production of chlorophyll nor to the regeneration of shoots. Agropine A. rhizogenes strains integrate split T-DNA in TL- and TR-DNA fragments into the plant genome. In this study, regenerated plants of Cg did not contain TR-DNA, indicating that a selective pressure against this T-DNA fragment may exist in Campanula.  相似文献   

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