共查询到20条相似文献,搜索用时 31 毫秒
1.
Liangming Chen Zhigang Zhao Xi Liu Linglong Liu Ling Jiang Shijia Liu Wenwei Zhang Yihua Wang Yuqiang Liu Jianmin Wan 《Molecular breeding : new strategies in plant improvement》2011,27(2):247-258
The incomplete fertility of japonica × indica rice hybrids has inhibited breeders’ access to the substantial heterotic potential of these hybrids. As hybrid sterility
is caused by an allelic interaction at a small number of loci, it is possible to overcome it by simple introgression at the
major sterility loci. Here we report the use of marker-assisted backcrossing to transfer into the elite japonica cv. Zhendao88 a photoperiod-sensitive male sterility gene from cv. Lunhui422S (indica) and the yellow leaf gene from line Yellow249 (indica). The microsatellite markers RM276, RM455, RM141 and RM185 were used to tag the fertility genes S5, S8, S7 and S9, respectively. Line 509S is a true-breeding photoperiod-sensitive male sterile plant, which morphologically closely resembles
the japonica type. Genotypic analysis showed that the genome of line 509S comprises about 92% japonica DNA. Nevertheless, hybrids between line 509S and japonica varieties suffer from a level of hybrid sterility, although the line is highly cross-compatible with indica types, with the resulting hybrids expressing a significant degree of heterosis. Together, these results suggest that segment
substitution on fertility loci based on known information and marker-assisted selection are an effective approach for utilizing
the heterosis of rice inter-subspecies. 相似文献
2.
Haploid sporophytes of Osmunda claytoniana (2n = x = 22) were apogamously produced from calli when cultivated on a hormone-free medium. Flow cytometric analysis showed that
ploidy chimeras were spontaneously produced in a haploid sporophyte of O. claytoniana and those of O. japonica that were obtained in the previous study. In the haploid sporophyte of O. claytoniana, a diploid pinnule and a partially diploid terminal segment were produced in a haploid pinna. In O. japonica, a haploid sporophyte yielded a diploid pinna in a haploid frond, and another haploid sporophyte yielded a diploid pinnule
in a haploid pinna. Diploid chimeras were large in size and could be readily distinguished from other haploid parts of the
fronds. It is likely that the chimeras were produced clonally from a single diploid cell that established chromosome doubling. 相似文献
3.
By applying polyethylene glycol (PEG)-mediated protoplast fusion, the first somatic hybrids were obtained between Cyclamen persicum (2n = 2x = 48) and C. coum (2n = 2x = 30)—two species that cannot be combined by cross breeding. Heterofusion was detected by double fluorescent staining with
fluorescein diacetate and scopoletin. The highest heterofusion frequencies (of about 5%) resulted from a protocol using a
protoplast density of 1 × 106/mL and 40% PEG. The DNA content of C. coum was estimated for the first time by propidium iodide staining to be 14.7 pg/2C and was 4.6 times higher than that of C. persicum. Among 200 in vitro plantlets regenerated from fusion experiments, most resembled the C. coum parent, whereas only 5 plants showed typical C. persicum phenotypes and 46 had a deviating morphology. By flow cytometry, six putative somatic hybrids were identified. A species-specific
DNA marker was developed based on the sequence of the 5.8S gene in the ribosomal nuclear DNA and its flanking internal transcribed
spacers ITS1 and ITS2. The hybrid status of only one plant could be verified by the species-specific DNA marker as well as
sequencing of the amplification product. RAPD markers turned out to be less informative and applicable for hybrid identification,
as no clear additivity of the parental marker bands was observed. Chromosome counting in root tips of four hybrids revealed
the presence of the 30 C. coum chromosomes and 2–41 additional ones indicating elimination of C. persicum chromosomes. 相似文献
4.
The tribe Forsythieae comprises 2 genera (Forsythia and Abeliophyllum) and 14 species distributed mostly in the Far East. Although Forsythieae is considered monophyletic, with many symplesiomorphic
characters, the phylogenetic status of Abeliophyllum remains controversial. We assessed the phylogenetic relationships of Forsythieae, based on a 3.3-kb plastid fragment (trnL-F region and matK gene) and nuclear internal transcribed spacer (ITS) region DNA sequences. We obtained a highly resolved and strongly supported topology with possible outgroups. The topology
of the combined tree was congruent with those of the ITS region and matK gene. Maximum parsimony, maximum likelihood, and Bayesian inference tree analyses for the combined data also yielded identical
relationships. Combined sequence data strongly supported the monophyly of Forsythieae and the close relationship between Fontanesia and Jasminum. Oleaceae, not Fontanesia, was found to be a sister group to Forsythieae. Moreover, the genus Abeliophyllum was distinctly independent of Forsythia. Three Forsythia lineages were suggested: (a) ONJ (ovata-nakaii-japonica clade), (b) VGE (viridissima-giraldiana-europaea), and (c) KISS (koreana-intermedia-saxatilis-suspensa). Our results indicated that F. × intermedia is not a hybrid between F. suspensa and F. viridissima, but further studies are needed to determine its taxonomic identity. Furthermore, the diverse fruit shapes in Oleaceae are
assumed to be the result of parallelism or convergence. 相似文献
5.
Although ferns have been developed by hybridization and chromosome doubling, no natural polyploidy has yet been recorded in
Osmundaceae. So, we produced hybrids artificially by crosses between Osmunda banksiifolia (2n = 2x = 44) and Osmunda lancea (2n = 2x = 44), and investigated their sporogenesis. From the O. banksiifolia × O.
lancea hybrid with 44 univalent chromosomes, allotetraploids with 44 bivalent chromosomes were produced by chromosome doubling,
and allotriploids with 22 univalent chromosomes and 22 bivalent chromosomes were then produced by back crosses. The results
show when and how chromosome doubling occurs in hybrids. The success of artificial hybridization between O. banksiifolia and O. lancea, did not, however, reflect any product of natural hybridization between the two species. 相似文献
6.
Zhou HF Zheng XM Wei RX Second G Vaughan DA Ge S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,117(7):1181-1189
The cross compatible wild relatives of crops have furnished valuable genes for crop improvement. Understanding the genetics
of these wild species may enhance their further use in breeding. In this study, sequence variation of the nuclear Lhs1 gene was used to investigate the population genetic structure and gene flow of Oryza rufipogon and O. nivara, two wild species most closely related to O. sativa. The two species diverge markedly in life history and mating system, with O. rufipogon being perennial and outcrossing and O. nivara being annual and predominantly inbreeding. Based on sequence data from 105 plants representing 11 wild populations covering
the entire geographic range of these wild species, we detected significantly higher nucleotide variation in O. rufipogon than in O. nivara at both the population and species levels. At the population level the diversity in O. rufipogon (Hd = 0.712; θ
sil = 0.0017) is 2–3 folds higher than that in O. nivara (Hd = 0.306; θ
sil = 0.0005). AMOVA partitioning indicated that genetic differentiation among O. nivara populations (78.2%) was much higher than that among O. rufipogon populations (52.3%). The different level of genetic diversity and contrasting population genetic structure between O. rufipogon and O. nivara might be explained by their distinct life histories and mating systems. Our simulation using IM models demonstrated significant
gene flow from O. nivara to O. rufipogon, indicating a directional introgression from the annual and selfing species into the perennial and outcrossing species. The
ongoing introgression has played an important role in shaping current patterns of genetic diversity of these two wild species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
7.
Karin Sonntag Brigitte Ruge-Wehling Peter Wehling 《Plant Cell, Tissue and Organ Culture》2009,96(3):297-305
A method for isolation and shoot regeneration from electrofused protoplasts of L. angustifolius and L. subcarnosus was developed. Viable protoplasts were isolated from leaves of in-vitro grown seedlings at an average yield of 6 × 105 protoplasts g−1 fresh weight. Liquid and agarose solidified B5 media were used for protoplast culture. In the liquid-culture system, all
tested media, VKM, P1 and KM8p, were applicable for inducing cell division (84% of all tested petri dishes at four weeks)
and colony formation. Media containing additional carbohydrates were suitable to produce compact calli with green and brown
pigmentations in different combinations. Analysis of callus with molecular markers allowed to identify six somatic hybrids.
However, none of the parental-protoplast derived cell colonies could develop shoots. This is the first report on protoplast
fusion of L. angustifolius and L. subcarnosus with subsequent shoot regeneration. 相似文献
8.
Zhao ZG Jiang L Zhang WW Yu CY Zhu SS Xie K Tian H Liu LL Ikehashi H Wan JM 《Planta》2007,226(5):1087-1096
Partial abortion of female gametes and the resulting semi-sterility of indica × japonica inter-subspecific rice hybrids have been ascribed to an allelic interaction, which can be avoided by the use of wide compatibility
varieties. To further understand the genetic mechanism of hybrid sterility, we have constructed two sets of hybrids, using
as male parent either the typical japonica variety Asominori, or the wide compatibility variety 02428; and as female, a set of 66 chromosome segment substitution lines
in which various chromosomal segments from the indica variety IR24 have been introduced into a common genetic background of Asominori. Spikelet semi-sterility was observed in
hybrid between CSSL34 and Asominori, which is known to carry the sterility gene S31 (Zhao et al. in Euphytica 151:331–337, 2006). Cytological analysis revealed that the semi-sterility of the CSSL34 × Asominori hybrid was caused primarily by partial
abortion of the embryo sac at the stage of the mitosis of the functional megaspore. A population of 1,630 progeny of the three-way
cross (CSSL34 × 02428) × Asominori was developed to map S31. Based on the physical location of linked molecular markers, S31 was thereby delimited to a 54-kb region on rice chromsome 5. This fragment contains eight predicted open reading frames,
four of which encode known proteins and four putative proteins. These results are relevant to the map-based cloning of S31, and the development of marker-assisted transfer of non-sterility allele inducing alleles to breeding germplasm, to allow
for a more efficient exploitation of heterosis in hybrid rice. 相似文献
9.
10.
Reticulate hybridization is a complicated and creative mechanism in plant evolution that can cause interference in phylogenetic
studies. Based on observations of intermediate morphology, low pollen fertility, and overlapping distributions of putative
parent species, Yang and Wang (Proceedings of the cross-strait symposium on floristic diversity and conservation. National
Museum of Natural Science, Taichung, Taiwan, pp 183–197, 1998) first proposed reticulate hybridization of Alpinia in Taiwan. In the present study, molecular tools were used to explore relationships between four parental species and their
homoploidy hybrids, and the impact of hybridization on phylogeny reconstruction. Based on DNA markers, maternal heritance
of the chloroplast genome, and additivity of nuclear ribosomal internal transcribed spacer, the present results provide strong
support for the hybridization hypothesis. Co-existence of parental ribotypes within hybrids revealed that these hybridization
events were current, while reciprocal and introgressive hybridization were inferred from chloroplast DNA data. Furthermore,
iterative hybridizations involving more than two parental species may occur in notorious hybrid zones. Ecological, phenological,
and physiological evidence provides insight into why such frequent hybridization occurs in Taiwanese Alpinia. In the phylogenetic tree of the Zerumbet clade reconstructed in this study, the chloroplast sequences from one hybrid species
were not grouped into a subclade, implying instability caused by hybridization. Failure to find morphological apomorphies
and biogeographical patterns in this clade was likely partially due to reticulate hybridization.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
In our early experiments, a variety of Bupleurum scorzonerifolium-like somatic hybrid plants were obtained from protoplast fusion between Arabidopsis thaliana and UV-treated/untreated B. scorzonerifolium. To compare the effects of UV and γ-ray irradiation on the B. scorzonerifolium partner and obtain Arabidopsis-like hybrids, we designed a novel combination of somatic hybridization between A. thaliana and B. scorzonerifolium. Before protoplast isolation and fusion, the suspension cells of B. scorzonerifolium were irradiated by gamma ray (60Co, 50 Gy with 1.3 Gy min−1). Both parental protoplasts lost regeneration capacity, but over 100 somatic hybrids restored the capacity and developed
to Arabidopsis-like inflorescences and flowers with some characteristics of B. scorzonerifolium. Some hybrid flowers showed yellow sepal, petal, or carpel, whose color was similar to the petal of B. scorzonerifolium; the others had silique of Arabidopsis with angularity of B. scorzonerifolium, and their parts possessed five stamens, the same as B. scorzonerifolium. Cytological analysis showed that three hybrids had Arabidopsis-like karyotypes. Random Amplified Polymorphic DNA (RAPD) and Simple Sequence Repeats (SSR) profiles revealed that both parental
fragments were amplified from these hybrids. These results indicated chromatin introgression from B. scorzonerifolium to A. thaliana, which may be related to the complementation of hybrid inflorescence and flower generation. 相似文献
12.
Background
Three mutations in Arabidopsis thaliana strain Columbia – cpr1, snc1, and bal – map to the RPP5 locus, which contains a cluster of disease Resistance genes. The similar phenotypes, gene expression patterns, and genetic interactions observed in these mutants are related to constitutive activation of pathogen defense signaling. However, these mutant alleles respond differently to various conditions. Exposure to mutagens, such as ethyl methanesulfonate (EMS) and γ-irradiation, induce high frequency phenotypic instability of the bal allele. In addition, a fraction of the bal and cpr1 alleles segregated from bal × cpr1 F1 hybrids also show signs of phenotypic instability. To gain more insight into the mechanism of phenotypic instability of the bal and cpr1 mutations, we systematically compared the behavior of these unusual alleles with that of the missense gain-of-function snc1 allele in response to DNA damage or passage through F1 hybrids. 相似文献13.
Post-pollination hybridization barriers in <Emphasis Type="Italic">Nicotiana</Emphasis> section <Emphasis Type="Italic">Alatae</Emphasis> 总被引:1,自引:1,他引:0
Christopher B. Lee Lawrence E. Page Bruce A. McClure Timothy P. Holtsford 《Sexual plant reproduction》2008,21(3):183-195
Nicotiana section Alatae contains eight species with variable flower sizes and morphologies. Section members readily hybridize in the glasshouse,
but no hybrids have been observed in natural sympatric and parapatric populations. To investigate interspecific crossing relationships
with respect to mechanisms preventing hybridization, all members of section Alatae were intercrossed in a complete diallel. We found positive correlation between the pistil length of the pollen donor and
interspecific seed set relative to the conspecific cross. Pollen tube growth rate and pollen donor pistil length were positively
correlated as well. Furthermore, pollen from short-pistil members of section Alatae could only grow a maximum distance proportional to, but greater than, their own pistil lengths. Our results show that pollen
tube growth capacity (i.e., rate and distance), provides a hybridization barrier in long-pistil species × short-pistil species
crosses. We also found another hybridization barrier not specifically related to pollen tube growth capacity in short-pistil
species × long-pistil species. Taken together, these barriers can generally be described by a ‘pistil-length mismatch’ rule;
in section Alatae, pollen has the most success fertilizing ovules from species with pistil lengths similar to their own. This rule could contribute
to hybridization barriers in Section Alatae because the species display dramatically different pistil lengths.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
14.
Wild rice is a valuable resource for the genetic improvement of cultivated rice (Oryza sativa L., AA genome). Molecular markers are important tools for monitoring gene introgression from wild rice into cultivated rice. In this study, Simple sequence repeat (SSR) markers were used to analyze interspecific hybrids of O. sativa-O. officinalis (CC genome), the backcrossing progenies and the parent plants. Results showed that most of the SSR primers (335 out of 396, 84.6%) developed in cultivated rice successfully amplified products from DNA samples of wild rice O. officinalis. The polymorphism ratio of SSR bands between O. sativa and O. officinalis was as high as 93.9%, indicating differences between the two species with respect to SSRs. When the SSR markers were applied in the interspecific hybrids, only a portion of SSR primers amplified O. officinalis-specific bands in the F(1) hybrid (52.5%), BC(1) (52.5%), and MAALs (37.0%); a number of the bands disappeared. Of the 124 SSR loci that detected officinalis-specific bands in MAAL plants, 96 (77.4%) showed synteny between the A and C-genomes, and 20 (16.1%) showed duplication in the C-genome. Sequencing analysis revealed that indels, substitution and duplication contribute to the diversity of SSR loci between the genomes of O. sativa and O. officinalis. 相似文献
15.
Artificial interspecific hybrids between large scale loach P. dabryanus and tetraploid pond loach M. anguillicaudatus (Cobitidae, Cypriniformes) are viable. To detect the occurrence of possible natural hybridization, genetic analyses by using
microsatellite markers were performed for natural populations of large scale loach and pond loach, the reciprocal laboratory
hybrids, and “supposed hybrids” with ambiguous morphology. The fertility of the artificial hybrids was also tested. At one
diagnostic microsatellite (Mac50), one out of 20 “supposed hybrids” was identified to be F1 hybrid between the two loach species because it had the same genotype as that of the laboratory hybrids. The triploid hybrids
between the two species were confirmed to be female-sterile. The results show that rare hybridization has occurred between
diploid large scale loach and tetraploid pond loach in nature although it may have little effect in genetic introgression.
This study is helpful for fish conservation and encourages further investigation on natural hybridization and introgression
of loaches. 相似文献
16.
Rakshit S Rakshit A Matsumura H Takahashi Y Hasegawa Y Ito A Ishii T Miyashita NT Terauchi R 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(4):731-743
Polymorphism over ∼26 kb of DNA sequence spanning 22 loci and one region distributed on chromosomes 1, 2, 3 and 4 was studied
in 30 accessions of cultivated rice, Oryza sativa, and its wild relatives. Phylogenetic analysis using all the DNA sequences suggested that O. sativa ssp. indica and ssp. japonica were independently domesticated from a wild species O. rufipogon. O. sativa ssp. indica contained substantial genetic diversity (π = 0.0024), whereas ssp. japonica exhibited extremely low nucleotide diversity (π = 0.0001) suggesting the origin of the latter from a small number of founders. O. sativa ssp. japonica contained a larger number of derived and fixed non-synonymous substitutions as compared to ssp. indica. Nucleotide diversity and genealogical history substantially varied across the 22 loci. A locus, RLD15 on chromosome 2, showed
a distinct genealogy with ssp. japonica sequences distantly separated from those of O. rufipogon and O. sativa ssp. indica. Linkage disequilibrium (LD) was analyzed in two different regions. LD in O. rufipogon decays within 5 kb, whereas it extends to ∼50 kb in O. sativa ssp. indica.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
Yohei Koide Mary Jeanie Telebanco-Yanoria Daisuke Fujita Analiza G. Tagle Yoshimichi Fukuta Nobuya Kobayashi 《Molecular breeding : new strategies in plant improvement》2011,28(3):359-366
An introgression line (INL) for a major rice blast resistance gene, Pia, was developed, with the genetic background of a blast susceptible variety, US-2. The reaction pattern of the INL was characterized
by using 20 standard blast isolates from the Philippines. The introgression of the Pia gene was confirmed by DNA markers on the short arm of chromosome 11 where Pia was previously mapped. A genome-wide DNA marker survey revealed that most of the chromosomal regions were US-2 type. By using
an F2 population derived from a cross between the INL and US-2, the chromosomal location of the Pia locus was mapped between RM26281 and RM3701. For fine mapping of the Pia locus, five additional markers were developed based on the genomic sequence of the corresponding region of a japonica-type variety, Nipponbare. The candidate region of Pia was delimited between two DNA markers, RM26281 and 82N19365, corresponding to a 140 kb region on the Nipponbare genome sequence.
We obtained three DNA markers within this region. The developed INL, information on the map position of Pia, and DNA markers developed in the candidate region of the Pia locus are useful tools for blast resistance studies and a marker-aided breeding strategy. 相似文献
18.
Agbeko Kodjo Tounou Christiann Kooyman Ouro Kobi Douro-Kpindou Hans Michael Poehling 《BioControl》2008,53(5):813-828
Field trials were conducted to evaluate the efficacy of wheat bran bait formulations of Paranosema locustae and Metarhizium anisopliae for controlling grasshoppers in southeast Niger. Treatments consisted of wheat bran baits mixed with M. anisopliae, P. locustae + M. anisopliae or with P. locustae spores and P. locustae + sugar. Oedaleus senegalensis, Pyrgomorpha cognata and Acrotylus blondeli were the predominant species at the time of application representing ca. 94% of the total population. Bran application was
done when O. senegalensis (ca. 75% of the population) was at its early developmental stages, with first, second and third instars accounting for 64–85%.
Grasshopper population reduction, P. locustae prevalence and level of infections in the predominant species were monitored. Manual application of P. locustae and M. anisopliae formulated in wheat bran has proven to induce consistent pathogen infection in grasshopper populations. Population density
over the three weeks monitoring, typically decreased by 44.7 ± 6.9%, 52.8 ± 8.4%, 73.7 ± 5.5% and 89.1 ± 1.8% in P. locustae, P. locustae + sugar, M. anisopliae and P. locustae + M. anisopliae treated plots respectively. Paranosema locustae prevalence in surviving adult grasshoppers at 28 after application was 48.1 ± 2.3%, 28.9 ± 4.8% and 27.4 ± 3.7%, with infection
level of 6.2 ± 0.8 × 106, 2.3 ± 0.3 × 104 and 2.1 ± 0.3 × 103 spores mg−1 host weight in O. senegalensis, A blondeli and P. cognate respectively. Other species that each accounted for <2% of the community, namely Aiolopus thalassinus, A. simulatrix, Acorypha glaucopsis, Acrotylus patruelis, Anacridium melanorhodon, Diabolocatantops axillaris, Kraussaria angulifera and Schistocerca gregaria were found to show sign of infection. The results from this study suggest that wheat bran application of M. anisopliae and P. locustae alone or in combination, targeting early instars grasshopper could be a valuable option in grasshopper control programs. 相似文献
19.
George ML Regalado E Li W Cao M Dahlan M Pabendon M Warburton ML Xianchun X Hoisington D 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(1):80-91
We have developed and evaluated sequence-tagged site (STS) primers based on expressed sequence-tag information derived from sugi (Cryptomeria japonica) for use in hinoki (Chamaecyparis obtusa), a species that belongs to a different family (although it appears to be fairly closely related to sugi). Of the 417 C. japonica STS primer pairs we screened, 120 (~30%) were transferable and provided specific PCR amplification products from 16 C. obtusa plus trees. We used haploid megagametophytes to investigate the homology of 80 STS fragments between C. obtusa and C. japonica and to identify orthologous loci. Nearly 90% of the fragments showed high (>70%) degrees of similarity between the species, and 35 STSs indicated homology to entries with the same putative function in a public DNA database. Of the 120 STS fragments amplified, 72 showed restriction fragment length polymorphisms; in addition, the CC2430 primers detected amplicon length polymorphism. We assessed the inheritance pattern of 27 cleaved amplified polymorphic sequence markers, using 20 individuals from the segregation population. All the markers analyzed were consistent with the marker inheritance patterns obtained from the screening panel, and no markers (except CC2716) showed significant (P<0.01) deviation from the expected segregation ratio. In total, 136 polymorphic markers were developed using C. japonica-based STS primers without any sequence modification. In addition, the applicability of STS-based markers developed in one species to other species was found to closely reflect the evolutionary distance between the species, which is roughly concordant with the difference between their rbcL sequences. We plan to use these markers for genetic studies in C. obtusa. Most of the markers should also provide reliable anchor loci for comparative mapping studies of the C. obtusa and C. japonica genomes. 相似文献
20.
Kang H Weng Y Yang Y Zhang Z Zhang S Mao Z Cheng G Gu X Huang S Xie B 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(4):795-803
Scab, caused by Cladosporium cucumerinum, is an important disease of cucumber, Cucumis sativus. In this study, we conducted fine genetic mapping of the single dominant scab resistance gene, Ccu, with 148 F9 recombinant inbred lines (RILs) and 1,944 F2 plants derived from the resistant cucumber inbred line 9110Gt and the susceptible line 9930, whose draft genome sequence
is now available. A framework linkage map was first constructed with simple sequence repeat markers placing Ccu into the terminal 670 kb region of cucumber Chromosome 2. The 9110Gt genome was sequenced at 5× genome coverage with the
Solexa next-generation sequencing technology. Sequence analysis of the assembled 9110Gt contigs and the Ccu region of the 9930 genome identified three insertion/deletion (Indel) markers, Indel01, Indel02, and Indel03 that were closely
linked with the Ccu locus. On the high-resolution map developed with the F2 population, the two closest flanking markers, Indel01 and Indel02, were 0.14 and 0.15 cM away from the target gene Ccu, respectively, and the physical distance between the two markers was approximately 140 kb. Detailed annotation of the 180 kb
region harboring the Ccu locus identified a cluster of six resistance gene analogs (RGAs) that belong to the nucleotide binding site (NBS) type R
genes. Four RGAs were in the region delimited by markers Indel01 and Indel02, and thus were possible candidates of Ccu. Comparative DNA analysis of this cucumber Ccu gene region with a melon (C. melo) bacterial artificial chromosome (BAC) clone revealed a high degree of micro-synteny and conservation of the RGA tandem repeats
in this region. 相似文献