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1.
Barfin flounder (Verasper moseri) and spotted halibut (Verasper variegatus) are two economically important marine fish species for aquaculture in China, Korea and Japan. Construction of genetic linkage
maps is an interesting issue for molecular marker-assisted selection (MAS) and for better understanding the genome structure.
In the present study, we constructed genetic linkage maps for both fish species using AFLP and microsatellite markers based
on an interspecific F1 hybrid family (female V. moseri and male V. variegatus). The female genetic map comprised 98 markers (58 AFLP markers and 40 microsatellite markers), distributing in 27 linkage
groups, and spanning 637 cM with an average resolution of 8.9 cM. Whereas the male genetic map consisted of 86 markers (48
AFLP and 38 microsatellite markers) in 24 linkage groups, covering a length of 625 cM with an average marker spacing of 10 cM.
The expected genome length was 1,128 cM in female and 1,115 cM in male, and the estimated coverage of genome was 56% for both
genetic maps. Moreover, five microsatellite markers were observed to be common to both genetic maps. This is the first time
to report the genetic linkage maps of V. moseri and V. variegatus that could serve as the basis for genetic improvement and selective breeding, candidate genes cloning, and genome structure
research. 相似文献
2.
Qin Yao Ronghua Zhou Tihua Fu Weiren Wu Zhendong Zhu Aili Li Jizeng Jia 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(6):1005-1012
A lesion-mimic phenotype appeared in a segregating population of common wheat cross Yanzhan 1/Zaosui 30. The parents had non-lesion
normal phenotypes. Shading treatment and histochemical analyses showed that the lesions were caused by light-dependent cell
death and were not associated with pathogens. Studies over two cropping seasons showed that some lines with more highly expressed
lesion-mimic phenotypes exhibited significantly lower grain yields than those with the normal phenotype, but there were no
significant effects in the lines with weakly expressed lesion-mimic phenotypes. Among yield traits, one-thousand grain weight
was the most affected by lesion-mimic phenotypes. Genetic analysis indicated that this was a novel type of lesion mimic, which
was caused by interaction of recessive genes derived from each parent. The lm1 (lesion
mimic
1) locus from Zaosui 30 was flanked by microsatellite markers Xwmc674 and Xbarc133/Xbarc147 on chromosome 3BS, at genetic distances of 1.2 and 3.8 cM, respectively, whereas lm2 from Yanzhan 1 was mapped between microsatellite markers Xgwm513 and Xksum154 on chromosome 4BL, at genetic distances of 1.5 and 3 cM, respectively. The linked microsatellite makers identified in this
study might be useful for evaluating whether potential parents with normal phenotype are carriers of lesion-mimic alleles. 相似文献
3.
Qiang Fan Sufang Chen Renchao Zhou Xu Xiang Wenbo Liao Suhua Shi 《Conservation Genetics》2011,12(3):753-760
Understanding the amount and distribution of genetic diversity in natural populations can inform the conservation strategy
for the species in question. In this study, genetic variation at eight nuclear microsatellite loci was used to investigate
genetic diversity and population structure of wild litchi (Litchi chinensis Sonn. subsp. chinensis). Totally 215 individuals were sampled, representing nine populations of wild litchi. All eight loci were polymorphic, with
a total of 51 alleles. The expected heterozygosity in the nine populations ranged from 0.367 to 0.638 with an average value
of 0.526. Inbreeding within wild litchi populations was indicated by a strong heterozygote defect. Significant bottleneck
events were detected in the populations from Yunnan and Vietnam, which could be responsible for lower levels of genetic diversity
in these populations. Measures of genetic differentiation (F
ST = 0.269) indicated strong differentiation among wild litchi populations. Significant correlation was found between genetic
differentiation and geographical distance (r = 0.655, P = 0.002), indicating a strong isolation by distance in these populations. Bayesian clustering suggested genetic separation
among three regional groups, namely, the western group, the central group and the eastern group. Some conservation strategies
for wild litchi populations were also proposed based on our results. 相似文献
4.
In order to investigate the genetic diversity and structure of Hieracium pilosella L., we developed eleven pairs of primers for nuclear microsatellites through screening of three genomic DNA enriched libraries.
About 127 individuals from six locations of the Trentino region (Italy) were analysed. These loci were all polymorphic and
displayed 5–33 alleles per locus. These microsatellite markers constitute an efficient tool in investigating the genetic patterns
of H. pilosella L. populations. 相似文献
5.
Kouichi Kawamura Masashi Kubota Miki Furukawa Yasushi Harada 《Conservation Genetics》2007,8(5):1163-1176
The amago salmon, Oncorhynchus masou ishikawae, is an endemic subspecies of O. masou in Japan. Owing to the extensive stocking of hatchery fish throughout Japan, indigenous populations of O. m. ishikawae are now on the verge of extinction. We examined the genetic effects of stocking hatchery fish on wild populations in the
River Koza, Japan, using microsatellite and mitochondrial DNA (mtDNA) markers. For mtDNA, haplotype mt1, which is common in
wild populations, was present exclusively in isolated wild populations assumed to be unaffected by previous stocking, while
it was never observed in hatchery fish. Genetic diversity was much higher in wild populations in the stocked area, which shared
many mtDNA haplotypes with hatchery fish, than in isolated wild populations with haplotype mt1. Pairwise F
ST estimates based on microsatellites showed significant differentiation among the isolated populations with many microsatellite
loci monomorphic. Significant deviation from Hardy–Weinberg equilibrium was observed in wild populations in the area subject
to stocking, where a Bayesian-based assignment test showed a high level of introgression with hatchery fish. These results
suggest that wild populations with haplotype mt1, which became isolated through anthropogenic environmental change in the
1950–1960s, represent indigenous populations of O. m. ishikawae in the River Koza. They have low genetic diversity, most likely caused by genetic bottlenecks following damming and environmental
deterioration, while stocking of hatchery fish over the past 30 years apparently had a large impact on the genetic structure
of wild populations in the main channel of the River Koza. 相似文献
6.
Fanna Kong Yunxiang Mao Hui Yang Haijun Qu Xinghong Yan Li Wang 《Plant Molecular Biology Reporter》2009,27(4):496-502
Microsatellites are repetitive genomic elements that show high levels of variation and therefore are useful tools for studying
genetic polymorphism and constructing genetic linkage maps of eukaryotic organisms. Porphyra yezoensis Ueda is an economically important seaweed that is being targeted for genetic improvement using marker-assisted breeding.
Hence, in an attempt to develop microsatellite markers for P. yezoensis, a microsatellite (or simple sequence repeat)-enriched library was constructed to identify (GA)n and (CA)n motifs. A total
of 71 perfect microsatellite clones were identified, of which 30 simple sequence repeat primer pairs were developed. Of these,
24 (80%) amplified polymerase chain reaction products of expected sizes. Twelve primer pairs amplified two to four bands,
whereas another 12 primer pairs produced monomorphic banding patterns. Data for 12 loci were analyzed using POPGENE software
version 1.32. A total of 29 alleles were produced at 12 loci, with an average of 2.42 alleles (Na) and 1.81 effective alleles (Ne) per locus. These markers were used to analyze the genetic diversity within 11 geographically different lines of P. yezoensis. Overall, these lines were clustered into two divisions with those from close geographic locations clustering together. Further
cloning and sequencing of size variant alleles at two microsatellite loci revealed that the variable numbers of motif repeats
in different alleles were major sources of polymorphisms. 相似文献
7.
Fuli Liu Xiuliang Wang Jianting Yao Wandong Fu Delin Duan 《Journal of applied phycology》2010,22(1):109-111
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
8.
Cupressus chenggiana S. Y. Hu (Cupressaceae) is an endemic and endangered conifer species in southwest China. In order to study the population
genetics and design the effective conservation methods, we aimed to develop microsatellite primers for this species in the
present study. We developed eight new microsatellite loci for this species through biotin capture method. Polymorphism of
each locus was further assessed in 18 individuals from three geographically distant populations. The number of alleles per
locus ranged from 6 to 11 with an average of 8.13. The observed and expected heterozygosities ranged from 0.219 to 0.296 and
from 0.374 to 0.470, with averages of 0.254 and 0.417, respectively. We further found that three of nine microsatellite loci
developed previously for another congeneric species showed polymorphic banding patters. We performed primer-crossing tests
of these loci in the other two congeneric species which are closely related to C. chenggiana (C. gigantea and C. duclouxiana). These microsatellite markers would be effective for analyzing genetic diversity and population genetic structure of this
species and its morphological differentiation with the close relatives. 相似文献
9.
In a previous study, several quantitative trait loci (QTLs) affecting vegetative propagation traits were detected in a hybrid
cross between Eucalyptus tereticornis and Eucalyptus globulus. The objective of this work was to confirm stable QTL linked markers (detected in different years) for propagation traits
in an independent set of the same segregating population and in two related crosses involving the original E. globulus parent. Phenotypic averages of groups of individuals carrying alternative allelic forms of the stable QTL linked markers
were statistically tested for significant differences. Adventitious rooting and petrification marker–trait associations, detected
previously in the E. tereticornis parent, were verified in an independent sample of the original progeny. In the E. globulus parent, the QTL linked marker was only verified in one related genetic background. Verification was possible only for high-effect
QTL linked markers. This study highlights the importance of sample size in QTL detection for low-heritability traits. 相似文献
10.
Studies describing the population genetic structure and breeding system of basal lineages of termite species remain rare.
Such species, however, may reveal ancestral life history attributes potentially influential in the evolution of social life
within the Isoptera. Through the development and application of microsatellite DNA loci, we investigated patterns of genetic
diversity and differentiation within the dampwood termite Zootermopsis angusticollis collected from three geographically distinct locations in California, USA. Significant genetic differentiation was identified
among all sites, which were located 40–150 km apart, and each site was found to represent unique populations with limited
levels of gene flow. While Z. angusticollis alates have previously been described as being strong fliers, genetic evidence suggests limited dispersal, possibly due to
habitat characteristics restricting long-range flights. Additionally, we characterize patterns of colony genetic structure
and breeding system within both Z. angusticollis and its congener Z. nevadensis nuttingi. In Z. angusticollis, simple, extended, and mixed family colonies were observed. The frequency of simple families ranged from 16 to 64%, whereas
mixed families were found in only two locations and at low frequencies. In contrast, Z. n. nuttingi, formed primarily extended family colonies. Estimates of relatedness suggest that monogamous pairs heading simple families
consist of reproductives showing variable degrees of relatedness from unrelated to close relatives. Additionally, the effective
number of neotenic reproductives appears to be low within extended families of both species. 相似文献
11.
Komulainen P Brown GR Mikkonen M Karhu A García-Gil MR O'Malley D Lee B Neale DB Savolainen O 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(4):667-678
A genetic map of Pinus sylvestris was constructed using ESTP (expressed sequence tag polymorphism) markers and other gene-based markers, AFLP markers and microsatellites. Part of the ESTP markers (40) were developed and mapped earlier in Pinus taeda, and additional markers were generated based on P. sylvestris sequences or sequences from other pine species. The mapping in P. sylvestris was based on 94 F1 progeny from a cross between plus-tree parents E635C and E1101. AFLP framework maps for the parent trees were first constructed. The ESTP and other gene sequence-based markers were added to the framework maps, as well as five published microsatellite loci. The separate maps were then integrated with the aid of AFLPs segregating in both trees (dominant segregation ratios 3:1) as well as gene markers and microsatellites segregating in both parent trees (segregation ratios 1:1:1:1 or 1:2:1). The integrated map consisted of 12 groups corresponding to the P. taeda linkage groups, and additionally three and six smaller groups for E1101 and E635C, respectively. The number of framework AFLP markers in the integrated map is altogether 194 and the number of gene markers 61. The total length of the integrated map was 1,314 cM. The set of markers developed for P. sylvestris was also added to existing maps of two P. taeda pedigrees. Starting with a mapped marker from one pedigree in the source species resulted in a mapped marker in a pedigree of the other species in more than 40% of the cases, with about equal success in both directions. The maps of the two species are largely colinear, even if the species have diverged more than 70 MYA. Most cases of different locations were probably due to problems in identifying the orthologous members of gene families. These data provide a first ESTP-containing map of P. sylvestris, which can also be used for comparing this species to additional species mapped with the same markers.Communicated by C. Möllers 相似文献
12.
Azhaguvel P Rudd JC Ma Y Luo MC Weng Y 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(3):555-564
The greenbug, Schizaphis graminum (Rondani), is an important aphid pest of small grain crops especially wheat (Triticum aestivum L., 2n = 6x = 42, genomes AABBDD) in many parts of the world. The greenbug-resistance gene Gb3 originated from Aegilops tauschii Coss. (2n = 2x = 14, genome DtDt) has shown consistent and durable resistance against prevailing greenbug biotypes in wheat fields. We previously mapped Gb3 in a recombination-rich, telomeric bin of wheat chromosome arm 7DL. In this study, high-resolution genetic mapping was carried
out using an F2:3 segregating population derived from two Ae. tauschii accessions, the resistant PI 268210 (original donor of Gb3 in the hexaploid wheat germplasm line ‘Largo’) and susceptible AL8/78. Molecular markers were developed by exploring bin-mapped
wheat RFLPs, SSRs, ESTs and the Ae. tauschii physical map (BAC contigs). Wheat EST and Ae. tauschii BAC end sequences located in the deletion bin 7DL3-0.82–1.00 were used to design STS (sequence tagged site) or CAPS (Cleaved
Amplified Polymorphic Sequence) markers. Forty-five PCR-based markers were developed and mapped to the chromosomal region
spanning the Gb3 locus. The greenbug-resistance gene Gb3 now was delimited in an interval of 1.1 cM by two molecular markers (HI067J6-R and HI009B3-R). This localized high-resolution
genetic map with markers closely linked to Gb3 lays a solid foundation for map based cloning of Gb3 and marker-assisted selection of this gene in wheat breeding. 相似文献
13.
LV Dos Santos MV de Queiroz MF Santana MA Soares EG de Barros EF de Araújo T Langin 《World journal of microbiology & biotechnology》2012,28(3):1087-1095
A nonautonomous element of 624 bp, called RetroCl1 (Retroelement Colletotrichum lindemuthianum 1), was identified in the plant pathogenic fungus Colletotrichum lindemuthianum. RetroCl1 contains terminal direct repeats (223 bp) that are surrounded by CTAGT sequences. It has a short internal domain of 178 bp
and shows characteristics of terminal-repeat retrotransposon in miniature (TRIM) family. We used RetroCl1 sequence to develop molecular markers for the Colletotrichum genus. IRAP (Inter-Retrotransposon Amplified Polymorphism) and REMAP (Retrotransposon-Microsatellite Amplified Polymorphism)
markers were used to analyze the genetic diversity of C. lindemuthianum. Fifty-four isolates belonging to different races were used. A total of 45 loci were amplified. The Nei index showed significant
differences among the populations divided according to race, indicating that they are structured according to pathotype. No
clear correlation between IRAP and REMAP markers with pathogenic characterization was found. C. lindemuthianum has high genetic diversity, and the analysis of molecular variance showed that 51% of variability is found among the populations
of different races. The markers were also tested in different Colletotrichum species. In every case, multiple bands were amplified, indicating that these markers can be successfully used in different
species belonging to the Colletotrichum genus. 相似文献
14.
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
15.
16.
David N. Kuhn Antonio Figueira Uilson Lopes Juan Carlos Motamayor Alan W. Meerow Kathleen Cariaga Barbie Freeman Donald S. LivingstoneIII Raymond J. Schnell 《Tree Genetics & Genomes》2010,6(5):783-792
The seeds of Theobroma cacao (cacao) are the source of cocoa, the raw material for the multi-billion dollar chocolate industry. Cacao’s two most important
traits are its unique seed storage triglyceride (cocoa butter) and the flavor of its fermented beans (chocolate). The genome
of T. cacao is being sequenced, and to expand the utility of the genome sequence to the improvement of cacao, we are evaluating Theobroma grandiflorum, the closest economically important species of Theobroma for its potential use in a comparative genomic study. T. grandiflorum differs from cacao in important agronomic traits such as flavor of the fermented beans, disease resistance to witches’ broom
and abscission of mature fruits. By comparing genomic sequences and analyzing viable inter-specific hybrids, we hope to identify
the key genes that regulate cacao’s most important traits. We have investigated the utility in T. grandiflorum of three types of markers (microsatellite markers, single-strand conformational polymorphism markers and single nucleotide
polymorphism (SNP) markers) developed in cacao. Through sequencing of amplicons of 12 diverse individuals of both cacao and
T. grandiflorum, we have identified new intra- and inter-specific SNPs. Two markers which had no overlap of alleles between the species were
used to genotype putative inter-specific hybrid seedlings. Sequence conservation was significant and species-specific differences
numerous enough to suggest that comparative genomics of T. grandiflorum and T. cacao will be useful in elucidating the genetic differences that lead to a variety of important agronomic trait differences. 相似文献
17.
Allelopathy of the eucalypt has been considered as an important mechanism for the biodiversity reduction in the eucalypt plantation.
To understand the allelopathic potential of the eucalypt (Eucalyptus grandis) roots and rhizosphere soil along a chronosequence (2, 4, 6, 8, 10 years), the germination and growth characteristics of
three plant species (Raphanus sativus, Phaseolus aureus, and Lolium perenne) growing nearby or beneath the eucalypt plantations were measured. The results showed that aqueous extract of E. grandis root suppressed the germination and early seedling growth of the target plants. The younger E. grandis exhibited a comparatively stronger allelopathic potential. The highest dose root extracts from 4 years old E. grandis showed the strongest inhibitory effects on the germination rates of the target species, the inhibitory rates were about 48,
51.2, and 56.56% for R. sativus, P. aureus, and L. perenne, respectively. However, present biotests of rhizosphere soils from 6, 8, and 10-year-old plantations exhibited a remarkable
stimulative effect on L. perenne, which indicated that the soil might neutralize or dilute allelopathic agents with the increase of plantation age. In addition,
according to GC–MS analysis, more allelopathic potential compounds were found in the rhizosphere soil and roots of younger
E. grandis plantation. Moreover, more allelochemicals were obtained from soil than from roots. The allelopathic compounds in roots
and rhizosphere soil may play important roles in allelopathy of E. grandis plantation. More attention should be paid to the younger E. grandis plantations for the relative higher allelopathic effects. 相似文献
18.
Shen Chen Zhanghui Huang Liexian Zeng Jianyuan Yang Qiongguang Liu Xiaoyuan Zhu 《Molecular breeding : new strategies in plant improvement》2008,22(3):433-441
Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a devastating disease in rice worldwide. The resistance gene Xa7, which provides dominant resistance against the pathogen with avirulence (Avr) gene AvrXa7, has proved to be durably resistant to BB. A set of SSR markers were selected from the “gramene” database based on the Xa7 gene initial mapping region on chromosome 6. These markers were used to construct a high-resolution genetic map of the chromosomal
region surrounding the Xa7 gene. An F2 mapping population with 721 highly susceptible individuals derived from a cross between the near isogenic lines (NILs) IRBB7
and IR24 were constructed to localize the Xa7 gene. In a primary analysis with eleven polymorphic SSR markers, Xa7 was located in approximately the 0.28-cM region. To walk closer to the target gene, recombinant F2 individuals were tested using newly developed STMS (sequence tagged microsatellite) markers. Finally, the Xa7 gene was mapped to a 0.21-cM interval between the markers GDSSR02 and RM20593. The Xa7-linked markers were landed on the reference sequence of cv. Nipponbare through bioinformatics analysis. A contig map corresponding
to the Xa7 gene was constructed. The target gene was assumed to span an interval of approximately 118.5-kb which contained a total of
fourteen genes released by the TIGR Genome Annotation Version 5.0. Candidate-gene analysis of Xa7 revealed that the fourteen genes encode novel domains that have no amino acid sequence similar to other cloned Xa(xa) genes.
Shen Chen and Zhanghui Huang are contributed equally to this work. 相似文献
19.
Commiphora wightii is a medicinally important endangered species endemic to the Thar Desert of Rajasthan, India and adjoining areas of Pakistan.
The populations of this species are declining sharply because of its extensive use as a natural herb. Random amplified polymorphic
DNA analysis was conducted to find the genetic variation among 7 populations of C. wightii. Of the 100 random primers screened, 44 primers yielded 220 loci. Statistical analysis indicated low genetic diversity (H
pop = 0.0958; I = 0.1498; mean polymorphic loci = 14.28%), and high genetic differentiation among the populations (G
ST = 0.3990; AMOVA Φ
ST of 0.3390; Bayesian θ
(II) = 0.3002). The low genetic diversity may be due to geographic isolation and restricted gene flow (N
m = 0.7533) between the fragmented populations. Unsustainable utilization of the plant has fragmented the population continuum
which served the purpose of genetic exchange between populations. Mantel’s test was performed which revealed a highly significant
positive correlation between genetic and geographic distance (r
2 = 0.614, P = 0.023) among the populations studied. Low variation can also be attributed to poor seed setting and the slow growth pattern
of the species, which is also an apomict. In UPGMA dendrogram the Commiphora wightii samples were divided into two major and one minor cluster. These findings can serve as a guide to preserving the genetic
resources of this medicinal plant species. 相似文献
20.
The flagfish (Jordanella floridae) is commonly used in studies of wetlands ecology. Here we describe the isolation of ten microsatellite loci, six of which
were polymorphic. The observed number of alleles ranged from 4 to 24 and observed heterozygosities ranged from 0.59 to 0.81
for the polymorphic loci. The isolation of these markers will enable estimations of genetic diversity in natural populations. 相似文献