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1.
Eva M. C. Mamani Nathalia W. Bueno Danielle A. Faria Lucio M. S. Guimarães Douglas Lau Acelino C. Alfenas Dario Grattapaglia 《Tree Genetics & Genomes》2010,6(6):953-962
In this report the major locus for Puccinia psidii rust resistance, Ppr1, was positioned on the reference genetic map for Eucalyptus. Additionally, its position was validated by association genetics in a related and two unrelated pedigrees involving different
Eucalyptus grandis resistant trees crossed to individuals of two other species, Eucalyptus tereticornis and Eucalyptus camaldulensis. These results are consistent with the hypothesis that Ppr1 controls a large proportion of the variation for rust resistance, strengthening its role as a major locus in Eucalyptus and providing its unequivocal genomic position on linkage group 3. A localized map with 19 microsatellite loci was built around Ppr1. Multiallelic profiles were observed at several mapped microsatellites suggesting recent tandem duplications in the genomic
landscape surrounding Ppr1. Markers EMBRA125 and EMBRA1071 flank Ppr1 at 9.5% and 7% recombination, respectively, and were found to be in linkage equilibrium in a E. grandis breeding population, consistent with the expectations in outcrossed Eucalyptus. Their potential use for MAS will specifically be directed to identifying resistant offspring of P. psidii resistant parent trees that are heterozygous at Ppr1. In these circumstances, a significant amount of LD is expected to occur between specific alleles at flanking microsatellites
and the resistance allele at Ppr1. Moreover, the positional information of Ppr1 paves the way for prospective undertakings in this genomic region with the upcoming availability of a draft genome for E. grandis. 相似文献
2.
In the present study, the first genetic linkage map of the loach Misgurnus anguillicaudatus was constructed with 164 microsatellite markers and a color locus, and it included 155 newly developed markers. A total of
159 microsatellite markers and a color locus were mapped in 27 linkage groups (LGs). The female map covered 784.5 cM with
153 microsatellite markers and a color locus, whereas the male map covered 662.2 cM with 119 microsatellite markers. The centromeric
position in each LG was estimated by marker-centromere mapping based on half-tetrad analysis. In 4 LGs (LG2, LG3, LG4, and
LG5), the centromere was estimated at the intermediate region. In LG1, LG11, and LG12, the centromere was estimated to shift
from the sub-intermediate region to the end (telomeric). The number of these LGs (7) was identical to the collective number
of bi-arm metacentric (5) and sub-metacentric chromosome (2) of the haploid chromosome set (n = 5) of the loach. In the other LGs, the position of the centromere was estimated at the end or outside. These results indicate
satisfactory compliance between the linkage map and the chromosome set. Our map would cover approximately almost the entire
loach genome because most markers were successfully mapped. 相似文献
3.
Skiba B Ford R Pang EC 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(8):1726-1735
A linkage map of the Lathyrus sativus genome was constructed using 92 backcross individuals derived from a cross between an accession resistant (ATC 80878) to ascochyta blight caused by Mycosphaerella pinodes and a susceptible accession (ATC 80407). A total of 64 markers were mapped on the backcross population, including 47 RAPD, seven sequence-tagged microsatellite site and 13 STS/CAPS markers. The map comprised nine linkage groups, covered a map distance of 803.1 cM, and the average spacing between markers was 15.8 cM. Quantitative trait loci (QTL) associated with ascochyta blight resistance were detected using single-point analysis and simple and composite interval mapping. The backcross population was evaluated for stem resistance in temperature-controlled growth room trials. One significant QTL, QTL1, was located on linkage group 1 and explained 12% of the phenotypic variation in the backcross population. A second suggestive QTL, QTL2, was detected on linkage group 2 and accounted for 9% of the trait variation. The L. sativus R-QTL regions detected may be targeted for future intergenus transfer of the trait into accessions of the closely related species Pisum sativum. 相似文献
4.
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
5.
Bala R. Thumma Simon G. Southerton John C. Bell John V. Owen Martin L. Henery Gavin F. Moran 《Tree Genetics & Genomes》2010,6(2):305-317
To identify the chromosomal regions affecting wood quality traits, we conducted a genome-wide quantitative trait locus (QTL)
analysis of wood quality traits in Eucalyptus nitens. This information is important to exploit the full potential of the impending Eucalyptus genome sequence. A three generational mapping population consisting of 296 progeny trees was used to identify QTL associated
with several wood quality traits in E. nitens. Thirty-six QTL positions for cellulose content, pulp yield, lignin content, density, and microfibril angle (MFA) were identified
across different linkage groups. On linkage groups (LG)2 and 8, cellulose QTL cluster with pulp yield and extractives QTL
while on LG4 and 10 cellulose and pulp yield QTLs cluster together. Similarly, on LG4, 5, and 6 QTL for lignin traits were
clustered together. At two positions, QTL for MFA, a physical trait related to wood stiffness, were clustered with QTL for
lignin traits. Several cell wall candidate genes were co-located to QTL positions affecting different traits. Comparative
QTL analysis with Eucalyptus globulus revealed two common QTL regions for cellulose and pulp yield. The QTL positions identified in this study provide a resource
for identifying wood quality genes using the impending Eucalyptus genome sequence. Candidate genes identified in this study through co-location to QTL regions may be useful in association
studies. 相似文献
6.
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
7.
Carla Cristina Gonçalves Rosado Lúcio Mauro da Silva Guimarães Danielle Assis Faria Marcos Deon Vilela de Resende Cosme Damião Cruz Dario Grattapaglia Acelino Couto Alfenas 《Tree Genetics & Genomes》2016,12(4):72
Ceratocystis wilt caused by the fungus Ceratocystis fimbriata, is currently one of the major diseases in commercial plantations of Eucalyptus trees in Brazil. Deployment of resistant genotypes has been the main strategy for effective disease management. The present study aimed at identifying genomic regions underlying the genetic control of resistance to Ceratocystis wilt in Eucalyptus by quantitative trait loci (QTL) mapping in an outbred hybrid progeny derived from a cross between (Eucalyptus dunnii × Eucalyptus grandis) × (Eucalyptus urophylla × Eucalyptus globulus). A segregating population of 127 individuals was phenotyped for resistance to Ceratocystis wilt using controlled inoculation under a completely randomized design with five clonal replicates per individual plant. The phenotypic resistance response followed a continuous variation, enabling us to analyze the trait in a quantitative manner. The population was genotyped with 114 microsatellite markers and 110 were mapped with an average interval of 12.3 cM. Using a sib-pair interval-mapping approach five QTLs were identified for disease resistance, located on linkage groups 1, 3, 5, 8, and 10, and their estimated individual heritability ranged from 0.096 to 0.342. The QTL on linkage group 3 overlaps with other fungal disease-resistance QTLs mapped earlier and is consistent with the annotation of several disease-resistance genes on this chromosome in the E. grandis genome. This is the first study to identify and attempt to quantify the effects of QTLs associated with resistance to Ceratocystis wilt in Eucalyptus. 相似文献
8.
The LEW/Ztm-ci2 rat is an autosomal recessive mutant that displays circling behavior, deafness, progressive retinopathy, locomotor hyperactivity, ataxia, and opisthotonus. We performed a genome-wide scan of a (LEW/Ztm-ci2 × BN/Ztm) F1 × LEW/Ztm-ci2 backcross population with anonymous microsatellite markers to analyze the genetics of this mutant rat. This linkage analysis demonstrated a very strong association of RNO10 SSLP markers to the phenotype with a core region in the central part of the chromosome. The knowledge of genes mapping to this part of the rat genome and their linkage to SSLP markers is still poor. We developed SSLP markers closely linked to genes, which might be responsible for the mutant phenotype by using the growing amount of rat-specific DNA sequences available at World Wide Web databases. Application of this method facilitated the search for candidate genes for the phenotype of the LEW-ci2 rat. We were able to map Myo15 and its neighboring genes, Znf179 and Aldh3a1, to the region of interest and Myo1c to a more distal location on RNO10. Further rat BAC clones were used to create a physical map of the region of interest. This map revealed the position of further genes. Among those is Kcnj12. Owing to their localization on RNO10 and their involvement in a similar pathology in human and mouse, Myo15 and Kcnj12 can be regarded as candidate genes for the deafblind phenotype of the LEW-ci2 rat. 相似文献
9.
Habibur Rahman Rick A. Bennett Berisso Kebede 《Molecular breeding : new strategies in plant improvement》2017,37(1):5
Earliness of flowering and maturity and high seed yield are important objectives of breeding spring Brassica napus canola. Previously, we have introgressed earliness of flowering from Brassica oleracea into spring B. napus canola through interspecific crossing between these two species. In this paper, we report quantitative trait locus (QTL) mapping of days to flower and seed yield by use of publicly available markers and markers designed based on flowering time genes and a doubled haploid population, derived from crossing of the spring canola parent and an early flowering line developed from a B. napus × B. oleracea cross, tested in nine field trials for over 5 years. Five genomic regions associated with days to flower were identified on C1, C2, C3, and C6 of which the single QTL of C1 was detected in all trials; in all cases, the allele introgressed from B. oleracea reduced the number of days to flower. BLASTn search in the Brassica genomes located the physical position of the QTL markers and identified putative flowering time genes in these regions. In the case of seed yield, ten QTL from eight linkage groups were detected; however, none could be consistently detected in all trials. The QTL region of C1 associated with days to flower did not show significant association with seed yield in more than 80% of the field trials; however, in a single trial, the allele introgressed from B. oleracea exerted a negative effect on seed yield. Thus, the genomic regions and molecular markers identified in this research could potentially be used in breeding for the development of early flowering B. napus canola cultivars without affecting seed yield in a majority of the environments. 相似文献
10.
Isabella Paolucci Muriel Gaudet Véronique Jorge Isacco Beritognolo Serena Terzoli Elena Kuzminsky Rosario Muleo Giuseppe Scarascia Mugnozza Maurizio Sabatti 《Tree Genetics & Genomes》2010,6(6):863-875
White poplar (Populus alba L.) is native to Eurasia and is unexploited for its growth potential and stress-adaptive mechanisms. A better knowledge of
its genome will allow for more effective protection and use of critical genetic resources. The main objective of this study
was the construction of highly informative P. alba genetic maps. Two genotypes were selected from contrasting natural Italian populations and crossed to generate an F1 mapping pedigree. Amplified fragment length polymorphism and simple sequence repeat markers were used to genotype 141 F1 individuals. The pseudo-testcross strategy was applied for linkage analysis. The generated maps showed good overall colinearity
to each other and allowed for a complete alignment with the 19 haploid chromosomes of the Populus genome sequence. The locus that determines sex as a morphological trait was positioned on a non-terminal position of LG XIX
of the female parent map. Comparison among Populus species revealed differences in the location of the sex locus on LG XIX as well as inconsistencies in the heterogametic sex.
The genetic analysis of the sex locus in P. alba provides insights into sex determination in the genus and is useful for the identification of sex-linked markers and the
early assessment of plant gender. Furthermore, these genetic maps will greatly facilitate the study of the genomics of Populus and how it can be exploited in applied breeding programs. 相似文献
11.
Eitaro Sawayama Shiho Tanizawa Shin-Ichi Kitamura Kei Nakayama Kohei Ohta Akiyuki Ozaki Motohiro Takagi 《Marine biotechnology (New York, N.Y.)》2017,19(6):601-613
Red sea bream iridoviral disease (RSIVD) is a major viral disease in red sea bream farming in Japan. Previously, we identified one candidate male individual of red sea bream that was significantly associated with convalescent individuals after RSIVD. The purpose of this study is to identify the quantitative trait loci (QTL) linked to the RSIVD-resistant trait for future marker-assisted selection (MAS). Two test families were developed using the candidate male in 2014 (Fam-2014) and 2015 (Fam-2015). These test families were challenged with RSIV, and phenotypes were evaluated. Then, de novo genome sequences of red sea bream were obtained through next-generation sequencing, and microsatellite markers were searched and selected for linkage map construction. One immune-related gene, MHC class IIβ, was also used for linkage map construction. Of the microsatellite markers searched, 148 and 197 were mapped on 23 and 27 linkage groups in the female and male linkage maps, respectively, covering approximately 65% of genomes in both sexes. One QTL linked to an RSIVD-resistant trait was found in linkage group 2 of the candidate male in Fam-2014, and the phenotypic variance of the QTL was 31.1%. The QTL was closely linked to MHC class IIβ. Moreover, the QTL observed in Fam-2014 was also significantly linked to an RSIVD-resistant trait in the candidate male of Fam-2015. Our results suggest that the RSIVD-resistant trait in the candidate male was controlled by one major QTL closely linked to the MHC class IIβ gene and could be useful for MAS of red sea bream. 相似文献
12.
Amine Zraidi Gertraud Stift Martin Pachner Abdolali Shojaeiyan Li Gong Tamas Lelley 《Molecular breeding : new strategies in plant improvement》2007,20(4):375-388
Using random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), simple sequence repeats (SSR),
and morphological traits, the first genetic maps for Cucurbita pepo (2n=2x=40) were constructed and compared. The two mapping populations consisted of 92 F2 individuals each. One map was developed from a cross between an oil-seed pumpkin breeding line and a zucchini accession,
into which genes for resistance to Zucchini Yellow Mosaic Virus (ZYMV) from a related species, C. moschata, had been introgressed. The other map was developed from a cross between an oil-seed pumpkin and a crookneck variety. A total
of 332 and 323 markers were mapped in the two populations. Markers were distributed in each map over 21 linkage groups and
covered an average of 2,200 cM of the C. pepo genome. The two maps had 62 loci in common, which enabled identification of 14 homologous linkage groups. Polyacrylamide
gel analyses allowed detection of a high number of markers suitable for mapping, 10% of which were co-dominant RAPD loci.
In the Pumpkin-Zucchini population, bulked segregant analysis (BSA) identified seven markers less than 7 cM distant from the
locus n, affecting lignification of the seed coat. One of these markers, linked to the recessive hull-less allele (AW11-420), was
also found in the Pumpkin-Crookneck population, 4 cM from n. In the Pumpkin-Zucchini population, 24 RAPD markers, previously introduced into C. pepo from C. moschata, were mapped in two linkage groups (13 and 11 markers in LGpz1 and LGpz2, respectively), together with two sequence characterized
amplified region (SCAR) markers linked to genes for resistance to ZYMV. 相似文献
13.
Yan CJ Zhou JH Yan S Chen F Yeboah M Tang SZ Liang GH Gu MH 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(8):1093-1100
Panicle erectness (PE) is one of the most important traits for high-yielding japonica cultivars. Although several cultivars
with PE trait have been developed and released for commercial production in China, there is little information on the inheritance
of PE traits in rice. In the present study, 69 widely cultivated japonica cultivars and a double haploid (DH) population derived from a cross between a PE cultivar (Wuyunjing 8) and a drooping panicle
cultivar (Nongken 57) were utilized to elucidate the mechanisms of PE formation and to map PE associated genes. Our data suggested
that panicle length (PL) and plant height (PH) significantly affected panicle curvature (PC), with shorter PL and PH resulting
in smaller PC and consequently more erect. A putative major gene was identified on chromosome 9 by molecular markers and bulk
segregant analysis in DH population. In order to finely map the major gene, all simple sequence repeats (SSR) markers on chromosome
9 as well as 100 newly developed sequence-tagged site (STS) markers were used to construct a linkage group for quantitative
trait locus (QTL) mapping. A major QTL, qPE9-1, between STS marker H90 and SSR marker RM5652, was detected, and accounted for 41.72% of PC variation with pleiotropic effect
on PH and PL. another QTL, qPE9-2, was also found to be adjacent to qPE9-1. In addition, we found that H90, the nearest marker to qPE9-1, used for genotyping 38 cultivars with extremely erect and drooping panicles, segregated in agreement with PC, suggesting
the H90 product was possibly part of the qPE9-1 gene or closely related to it. These data demonstrated that H90 could be used for marker-aided selection for the PE trait
in breeding and in the cloning of qPE9-1. 相似文献
14.
Liu X Yang Q Lin F Hua L Wang C Wang L Pan Q 《Molecular genetics and genomics : MGG》2007,278(4):403-410
Blast, caused by the ascomycete fungus Magnaporthe oryzae, is one of the most devastating diseases of rice worldwide. The Chinese native cultivar (cv.) Q15 expresses the broad-spectrum
resistance to most of the isolates collected from China. To effectively utilize the resistance, three rounds of linkage analysis
were performed in an F2 population derived from a cross of Q15 and a susceptible cv. Tsuyuake, which segregated into 3:1 (resistant/susceptible)
ratio. The first round of linkage analysis employing simple sequence repeat (SSR) markers was carried out in the F2 population through bulked-segregant assay. A total of 180 SSR markers selected from each chromosome equally were surveyed.
The results revealed that only two polymorphic markers, RM247 and RM463, located on chromosome 12, were linked to the resistance
(R) gene. To further define the chromosomal location of the R gene locus, the second round of linkage analysis was performed using additional five SSR markers, which located in the region
anchored by markers RM247 and RM463. The locus was further mapped to a 0.27 cM region bounded by markers RM27933 and RM27940
in the pericentromeric region towards the short arm. For fine mapping of the R locus, seven new markers were developed in the smaller region for the third round of linkage analysis, based on the reference
sequences. The R locus was further mapped to a 0.18 cM region flanked by marker clusters 39M11 and 39M22, which is closest to, but away from
the Pita/Pita
2 locus by 0.09 cM. To physically map the locus, all the linked markers were landed on the respective bacterial artificial
chromosome clones of the reference cv. Nipponbare. Sequence information of these clones was used to construct a physical map
of the locus, in silico, by bioinformatics analysis. The locus was physically defined to an interval of ≈37 kb. To further
characterize the R gene, five R genes mapped near the locus, as well as 10 main R genes those might be exploited in the resistance breeding programs, were selected for differential tests with 475 Chinese
isolates. The R gene carrier Q15 conveys resistances distinct from those conditioned by the carriers of the 15 R genes. Together, this valuable R gene was, therefore, designated as Pi39(t). The sequence information of the R gene locus could be used for further marker-based selection and cloning.
Xinqiong Liu and Qinzhong Yang contributed equally to this work. 相似文献
15.
Phillip A. Wadl Arnold M. Saxton Xinwang Wang Vince R. Pantalone Timothy A. Rinehart Robert N. Trigiano 《Molecular breeding : new strategies in plant improvement》2011,27(3):409-416
The objective of our investigation was to acquire information on the association between molecular markers and foliage color
in flowering dogwood in order to improve our understanding of the inheritance of this trait and to make possible early selection
of red foliage genotypes in breeding programs. A segregating pseudo-F2 population of 94 individuals of flowering dogwood (Cornus florida L.), together with 255 simple sequence repeat markers, was used to identify putative quantitative trait loci (QTL) for foliage
color. Foliage color segregated into green- and red-leaved phenotypes and was visually rated for color on five spring dates
over 3 years (2007–2009). Repeated measures single-marker categorical analysis of variance (ANOVA) identified four putative
QTL (CF309C, CF792A, CF367B, and CF367C) on three linkage groups. Single-marker categorical ANOVA was then used to determine
stability of QTL across dates. We identified different QTL, found a low percentage of phenotypic variance explained by the
QTL, and detected QTL instability over time, providing evidence of the complex genetics for red pigment expression in flowering
dogwood. 相似文献
16.
Okazaki K Sakamoto K Kikuchi R Saito A Togashi E Kuginuki Y Matsumoto S Hirai M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(4):595-608
The FLC gene product is an inhibitor of flowering in Arabidopsis. FLC homologs in Brassica species are thought to control vernalization. We cloned four FLC homologs (BoFLCs) from Brassica oleracea. Three of these, BoFLC1, BoFLC3 and BoFLC5, have been previously characterized. The fourth novel sequence displayed 98% sequence homology to the previously identified
gene BoFLC4, but also showed 91% homology to BrFLC2 from Brassica rapa. Phylogenetic analysis showed that this clone belongs to the FLC2 clade. Therefore, we designated this gene BoFLC2. Based on the segregation of RFLP, SRAP, CAPS, SSR and AFLP loci, a detailed linkage map of B. oleracea was constructed in the F2 progeny obtained from a cross of B. oleracea cv. Green Comet (broccoli; non-vernalization type) and B. oleracea cv. Reiho (cabbage; vernalization type), which covered 540 cM, 9 major linkage groups. Six quantitative trait loci (QTL)
controlling flowering time were detected. BoFLC1, BoFLC3 and BoFLC5 were not linked to the QTLs controlling flowering time. However, the largest QTL effect was located in the region where BoFLC2 was mapped. Genotyping of F2 plants at the BoFLC2 locus showed that most of the early flowering plants were homozygotes of BoFLC-GC, whereas most of the late- and non-flowering plants were homozygotes of BoFLC-Rei. The BoFLC2 homologs present in plants of the non-vernalization type were non-functional, due to a frameshift in exon 4. Moreover, duplications
and deletions of BoFLC2 were detected in broccoli and a rapid cycling line, respectively. These results suggest that BoFLC2 contributes to the control of flowering time in B. oleracea. 相似文献
17.
Yanbin Hong Xiaoping Chen Xuanqiang Liang Haiyan Liu Guiyuan Zhou Shaoxiong Li Shijie Wen C Corley Holbrook Baozhu Guo 《BMC plant biology》2010,10(1):17
Background
The construction of genetic linkage maps for cultivated peanut (Arachis hypogaea L.) has and continues to be an important research goal to facilitate quantitative trait locus (QTL) analysis and gene tagging for use in a marker-assisted selection in breeding. Even though a few maps have been developed, they were constructed using diploid or interspecific tetraploid populations. The most recently published intra-specific map was constructed from the cross of cultivated peanuts, in which only 135 simple sequence repeat (SSR) markers were sparsely populated in 22 linkage groups. The more detailed linkage map with sufficient markers is necessary to be feasible for QTL identification and marker-assisted selection. The objective of this study was to construct a genetic linkage map of cultivated peanut using simple sequence repeat (SSR) markers derived primarily from peanut genomic sequences, expressed sequence tags (ESTs), and by "data mining" sequences released in GenBank. 相似文献18.
Pacific white shrimp (Litopenaeus vannamei) is the leading species farmed in the Western Hemisphere and an economically important aquaculture species in China. In this
project, a genetic linkage map was constructed using amplified fragment length polymorphism (AFLP) and microsatellite markers.
One hundred and eight select AFLP primer combinations and 30 polymorphic microsatellite markers produced 2071 markers that
were polymorphic in either of the parents and segregated in the progeny. Of these segregating markers, 319 were mapped to
45 linkage groups of the female framework map, covering a total of 4134.4 cM; and 267 markers were assigned to 45 linkage
groups of the male map, covering a total of 3220.9 cM. High recombination rates were found in both parental maps. A sex-linked
microsatellite marker was mapped on the female map with 6.6 cM to sex and a LOD of 17.8, two other microsatellite markers
were also linked with both 8.6 cM to sex and LOD score of 14.3 and 16.4. The genetic maps presented here will serve as a basis
for the construction of a high-resolution genetic map, quantitative trait loci (QTLs) detection, marker-assisted selection
(MAS) and comparative genome mapping. 相似文献
19.
Pupilli F Martinez EJ Busti A Calderini O Quarin CL Arcioni S 《Molecular genetics and genomics : MGG》2004,270(6):539-548
In plants, gametophytic apomixis is a form of asexual reproduction that leads to the formation of seed-derived offspring that are genetically identical to the mother plant. A common set of RFLP markers, including five rice anchor markers previously shown to be linked to apomixis in Paspalum simplex, were used to detect linkage with apomixis in P. notatum and P. malacophyllum. A comparative map of the region around the apomixis locus was constructed for the three Paspalum species, and compared to the rice map. The locus that controls apomixis in P. simplex was almost completely conserved in the closely related species P. malacophyllum, whereas it was only partially represented in the distantly related species P. notatum. Although strong synteny of markers was noted between this locus and a portion of rice chromosome 12 in both P. simplex and P. malacophyllum, the same locus in P. notatum was localized to a hybrid chromosome which carries markers that map to rice chromosomes 2 and 12. All three Paspalum species showed recombination suppression at the apomixis locus; in the case of P. notatum, this might be due to a heterozygosity for a translocation that most probably negatively interferes with chromosomal pairing near the locus. A common set of markers that show linkage with apomixis in all three Paspalum species define a portion of the apomixis-controlling locus that is likely to contain genes critical for apomictic reproduction.Communicated by R. Hagemann 相似文献
20.
Soengas P Hand P Vicente JG Pole JM Pink DA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(4):637-645
Resistance to six known races of black rot in crucifers caused by Xanthomonas campestris pv. campestris (Pammel) Dowson is absent or very rare in Brassica oleracea (C genome). However, race specific and broad-spectrum resistance (to type strains of all six races) does appear to occur
frequently in other brassica genomes including B. rapa (A genome). Here, we report the genetics of broad spectrum resistance in the B. rapa Chinese cabbage accession B162, using QTL analysis of resistance to races 1 and 4 of the pathogen. A B. rapa linkage map comprising ten linkage groups (A01–A10) with a total map distance of 664 cM was produced, based on 223 AFLP bands
and 23 microsatellites from a F2 population of 114 plants derived from a cross between the B. rapa susceptible inbred line R-o-18 and B162. Interaction phenotypes of 125 F2 plants were assessed using two criteria: the percentage of inoculation sites in which symptoms developed, and the severity
of symptoms per plant. Resistance to both races was correlated and a cluster of highly significant QTL that explained 24–64%
of the phenotypic variance was located on A06. Two additional QTLs for resistance to race 4 were found on A02 and A09. Markers
closely linked to these QTL could assist in the transference of the resistance into different B. rapa cultivars or into B. oleracea. 相似文献