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1.
Identification of QTLs involved in the resistance to South American leaf blight (Microcyclus ulei) in the rubber tree 总被引:6,自引:0,他引:6
D. Lespinasse L. Grivet V. Troispoux M. Rodier-Goud F. Pinard M. Seguin 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(6):975-984
South American leaf blight (SALB) is a disease of the rubber tree caused by the fungus Microcyclus ulei. Quantitative trait loci (QTLs) for resistance were mapped using 195 F1 progeny individuals derived from the cross between a susceptible cultivated clone, PB260, and a resistant clone, RO38, derived
from interspecific hybridization. The resistance level of the progeny individuals was evaluated in controlled conditions.
The reaction type (RT) and the lesion diameter (LD) were measured on immature leaves after artificial inoculation of the fungus.
Five different strains of the fungus were used, all highly sporulating on PB260. Among those, four did not sporulate and one
sporulated partially on RO38. Both pseudo-testcross parental genetic maps and the consensus map were constructed. The search
for QTLs was performed using the Kruskal-Wallis marker-by-marker test and the Interval-Mapping method for the three maps.
Eight QTLs for resistance were identified on the RO38 map. Only one QTL was detected on the PB260 map. The analysis of the
F1 consensus map confirmed results obtained with the parental maps. A common QTL was detected for resistance to the five strains
for both RT and LD. Two QTLs were common for complete resistance to four strains, for RT and LD respectively. Resistance determinism
for complete and partial resistance, and perspectives for breeding for durable resistance to SALB are discussed.
Received: 1 August 1999 / Accepted: 27 August 1999 相似文献
2.
Genetic resistance components of the Hevea brasiliensis x H. benthamiana RO 38 cultivar to Microcyclus ulei disease were investigated by inoculating isolates which succeeded in partially or completely infecting genotypes of a mapping population. Progeny of a cross between RO 38 and a susceptible cultivar was inoculated under controlled conditions with three isolates and scored for two resistance traits. Interval mapping and a nonparametric test were used to detect resistance quantitative trait loci (QTLs). Eight significant QTLs were detected, all of them inherited from the interspecific parent. Among these QTLs, only one contributed to the partial resistance against a highly pathogenic isolate, and no QTL was detected for resistance against the most pathogenic isolate. As an unexpected result, a single isolate can thus completely bypass this polygenic resistance. This complex situation, where no clear relationship can be established between number of resistance factors and qualitative vs quantitative or partial vs complete resistance, is discussed and suggestions as to the detection of new and sustainable resistance sources are proposed. 相似文献
3.
B. M. Prasanna A. H. Beiki J. C. Sekhar A. Srinivas J.-M. Ribaut 《Journal of plant biochemistry and biotechnology.》2009,18(2):151-160
The present study was aimed at mapping of Quantitative Trait Loci (QTL) for various traits influencing the performance of maize genotypes under drought stress conditions in India. A set of 210 Recombinant Inbred Lines (RILs) developed at CIMMYT (Mexico) was analyzed in drought trials undertaken at Karimnagar (2002-03) and Hyderabad (2003-04). Analyses of the RIL datasets using Composite Interval Mapping (CIM) models led to the detection of 52 QTLs, including 22 QTLs under the control conditions and 30 QTLs under drought stress conditions at Karimnagar, and 14 QTLs influencing various characters under drought stress conditions at Hyderabad. A significant digenic epistatic QTL effect, other than the main effect QTLs, was detected for kernel number per ear under drought stress conditions. A comparison of the QTL information obtained from independent analyses of the Karimnagar and Hyderabad datasets revealed colocalization of QTLs on chromosomes 1, 2, 8 and 10 in the RILs influencing specific characters under drought stress conditions. Comparison of the QTL information with that reported from previous analyses of the same set of RILs at Mexico, Kenya and Zimbabwe revealed some ‘consensus QTLs’, which could be of significance in molecular marker-assisted breeding for drought tolerance in maize, besides functional genomics. 相似文献
4.
Sarah Danan Jean-Eric Chauvin Bernard Caromel Jean-Denis Moal Roland Pellé Véronique Lefebvre 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(4):705-719
To find out new resistance sources to late blight in the wild germplasm for potato breeding, we examined the polygenic resistance
of Solanum sparsipilum and S. spegazzinii by a quantitative trait locus (QTL) analysis. We performed stem and foliage tests under controlled conditions in two diploid
mapping progenies. Four traits were selected for QTL detection. A total of 30 QTLs were mapped, with a large-effect QTL region
on chromosome X detected in both potato relatives. The mapping of literature-derived markers highlighted colinearities with
published late blight QTLs or R-genes. Results showed (a) the resistance potential of S. sparsipilum and S. spegazzinii for late blight control, and (b) the efficacy of the stem test as a complement to the foliage test to break down the complex
late blight resistance into elementary components. The relationships of late blight resistance QTLs with R-genes and maturity
QTLs are discussed. 相似文献
5.
QTL mapping of yield, agronomic and quality traits in tetraploid potato (Solanum tuberosum subsp. tuberosum) 总被引:2,自引:0,他引:2
Bradshaw JE Hackett CA Pande B Waugh R Bryan GJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(2):193-211
Interval mapping of quantitative trait loci (QTL) for 16 yield, agronomic and quality traits in potato was performed on a
tetraploid full-sib family comprising 227 clones from a cross between processing clone 12601ab1 and table cultivar Stirling.
Thirty-eight AFLP primer combinations and six SSRs provided 514 informative markers which formed a molecular marker map comprising
12 linkage groups (LGs) in 12601ab1 (nine with four homologous chromosomes) which were aligned with 12 in Stirling (11 with
four homologous chromosomes), with four partial groups remaining in 12601ab1. Two LGs were identified unequivocally as chromosomes
IV and V and eight others were tentatively assigned with chromosomes VII and X unidentified. All of the traits scored had
moderately high heritabilities with 54–92% of the variation in clone means over 3 years and two replicates being due to genetic
differences. A total of 39 QTLs were identified. A QTL for maturity was identified on chromosome V which explained 56% of
the phenotypic variance, whereas the other QTLs individually explained between 5.4 and 16.5%. However, six QTLs were detected
for after-cooking blackening and four for each of regularity of tuber shape, fry colour both after storage at 4 and 10°C and
sprouting. Just two QTLs were found for each of yield, the two ‘overall’ scores, crop emergence, tuber size and common scab
and just one QTL was detected for each of dry matter content, keeping quality, growth cracks and internal condition. The implications
for practical potato breeding and for practical linkage and QTL analysis in autotetraploids are discussed. 相似文献
6.
The objective of this study was to dissect the genetic control of days to flowering (DTF) and photoperiod sensitivity (PS)
into the various components including the main-effect quantitative trait loci (QTLs), epistatic QTLs and QTL-by-environment
interactions (QEs). Doubled haploid (DH) lines were produced from an F1 between two spring Brassica napus cultivars Hyola 401 and Q2. DTF of the DH lines and parents were investigated in two locations, one location with a short
and the other with a long photoperiod regime over two years. PS was calculated by the delay in DTF under long day as compared
to that under short day. A genetic linkage map was constructed that comprised 248 marker loci including SSR, SRAP, and AFLP
markers. Further QTL analysis resolved the genetic components of flowering time and PS into the main-effect QTLs, epistatic
QTLs, and QEs. A total of 7 main-effect QTLs and 11 digenic interactions involving 21 loci located on 13 out of the 19 linkage
groups were detected for the two traits. Three main-effect QTLs and four pairs of epistatic QTLs were involved in QEs conferring
DTF. One QTL on linkage group (LG) 18 was revealed to simultaneously affect DTF and PS and explain for the highest percentage
of the phenotypic variation. The implications of the results for B. napus breeding have been discussed.
The text was submitted by the authors in English. 相似文献
7.
C. Lanaud O. Fouet D. Clément M. Boccara A. M. Risterucci S. Surujdeo-Maharaj T. Legavre X. Argout 《Molecular breeding : new strategies in plant improvement》2009,24(4):361-374
Theobroma cacao, is a tropical understorey tree that is a major economic resource to several tropical countries. However, the crop is under increased threat from several diseases that are responsible for 30% loss of harvest globally. Although QTL data related to the genetic determinism of disease resistance exist in cocoa, QTL mapping experiments are heterogeneous, thus making comparative QTL mapping essential for marker assisted selection (MAS). Sixteen QTL experiments were analysed, and the 76 QTLs detected were projected on a progressively established consensus map. Several hot spots, with QTLs related to different Phytophthora species and other diseases, were observed. The likely number of “real” QTLs was estimated by using a meta-analysis implemented in BioMercator software. There was a twofold reduction in average confidence interval observed when compared to the confidence interval of individual QTLs. This alternative approach confirms the existence of several sources of resistance to different diseases of cocoa which could be cumulated in new varieties to increase the sustainability of cocoa resistance using MAS strategies. 相似文献
8.
P. Haddadi B. Yazdi-samadi M. R. Naghavi A. Kalantari P. Maury A. Sarrafi 《Plant biotechnology reports》2011,5(2):135-146
The objective of the present research was to map QTLs associated with agronomic traits such as days from sowing to flowering,
plant height, yield and leaf-related traits in a population of recombinant inbred lines (RILs) of sunflower (Helianthus annuus). Two field experiments were conducted with well-irrigated and partially irrigated conditions in randomized complete block
design with three replications. A map with 304 AFLP and 191 SSR markers with a mean density of 1 marker per 3.7 cM was used
to identify QTLs related to the studied traits. The difference among RILs was significant for all studied traits in both conditions.
Three to seven QTLs were found for each studied trait in both conditions. The percentage of phenotypic variance (R
2) explained by QTLs ranged from 4 to 49%. Three to six QTLs were found for each yield-related trait in both conditions. The
most important QTL for grain yield per plant on linkage group 13 (GYP-P-13-1) under partial-irrigated condition controls 49% of phenotypic variance (R
2). The most important QTL for 1,000-grain weight (TGW-P-11-1) was identified on linkage group 11. Favorable alleles for this QTL come from RHA266. The major QTL for days from sowing
to flowering (DSF-P-14-1) were observed on linkage group 14 and explained 38% of the phenotypic variance. The positive alleles for this QTL come from
RHA266. The major QTL for HD (HD-P-13-1) was also identified on linkage group 13 and explained 37% of the phenotypic variance. Both parents (PAC2 and RHA266) contributed
to QTLs controlling leaf-related traits in both conditions. Common QTL for leaf area at flowering (LAF-P-12-1, LAF-W-12-1) was detected in linkage group 12. The results emphasise the importance of the role of linkage groups 2, 10 and 13 for studied
traits. Genomic regions on the linkage groups 9 and 12 are specific for QTLs of leaf-related traits in sunflower. 相似文献
9.
Identification of QTLs for partial resistance to leaf rust (Puccinia hordei) in barley 总被引:1,自引:0,他引:1
X. Qi R. E. Niks P. Stam P. Lindhout 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(8):1205-1215
The partial resistance to leaf rust in barley is a quantitative resistance that is not based on hypersensitivity. To map
the quantitative trait loci (QTLs) for partial resistance to leaf rust, we obtained 103 recombinant inbred lines (RILs) by
single-seed descent from a cross between the susceptible parent L94 and the partially resistant parent Vada. These RILs were
evaluated at the seedling and adult plant stages in the greenhouse for the latent period (LP) of the rust fungus, and in the
field for the level of infection, measured as area under the disease progress curve (AUDPC). A dense genetic map based on
561 AFLP markers had been generated previously for this set of RILs. QTLs for partial resistance to leaf rust were mapped
using the “Multiple Interval Mapping” method with the putative QTL markers as cofactors. Six QTLs for partial resistance were
identified in this population. Three QTLs, Rphq1, Rphq2 and Rphq3, were effective at the seedling stage and contributed approximately 55% to the phenotypic variance. Five QTLs, Rph2, Rphq3, Rphq4, Rphq5, and/or Rphq6 contributed approximtely. 60% of the phenotypic variance and were effective at the adult plant stage. Therefore, only the
QTLs Rphq2 and Rhpq3 were not plant-stage dependent. The identified QTLs showed mainly additive effects and only one significant interaction was
detected, i.e. between Rphq1 and Rphq2. The map positions of these QTLs did not coincide with those of the race-specific resistance genes, suggesting that genes
for partial resistance and genes for hypersensitive resistance represent entirely different gene families. Also, three QTLs
for days to heading, of which two were also involved in plant height, were identified in the present recombinant inbred population.
These QTLs had been mapped previously on the same positions in different populations. The perspectives of these results for
breeding for durable resistance to leaf rust are discussed.
Received: 15 July 1997 / Accepted: 30 December 1997 相似文献
10.
Foulongne Marie Pascal Thierry Pfeiffer Frédéric Kervella Jocelyne 《Molecular breeding : new strategies in plant improvement》2003,12(1):33-50
Powdery mildew, caused by Sphaerotheca pannosa var. persicae is one of the most important diseases in European peach orchards. Quantitative trait loci controlling powdery mildew resistance were detected using three related F1, F2 and BC2 populations derived from the cross between the resistant parent P. davidiana clone P1908 and the susceptible peach cultivar Summergrand. Powdery mildew resistance of each population was evaluated under natural exposure, in several locations and over several years. Thirteen QTLs were detected. For nine of them, the favourable allele came from the resistant parent. Five QTLs were consistently detected across the three populations. The F1 hybrid used to produce F2 and BC2 populations had not inherited the favourable allele from P1908 for QTL detected on LG3 and LG8 in F1 population. QTLs were not detected in the corresponding regions in F2 and BC2 populations. In two other genomic areas, significant substitution effects between P1908 alleles were evidenced in the F1 population, but the favourable allele came from Summergrand in the F2 and BC2 populations. Analysis of phenotypic data suggested an important qualitative change in the distribution of powdery mildew resistance after 1996, confirmed by QTL analysis. Indeed, a dramatic decrease of the effect of the major QTL previously detected on LG6 was observed after 1996, while the QTL on LG8 was increasingly involved in the control of powdery mildew resistance. Consequences for peach breeding strategies to improve powdery mildew resistance are discussed. 相似文献
11.
Villalta I Bernet GP Carbonell EA Asins MJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(6):1001-1017
Salt tolerance has been analysed in two populations of F7 lines developed from a salt sensitive genotype of Solanum lycopersicum var. cerasiforme, as female parent, and two salt tolerant lines, as male parents, from S. pimpinellifolium, the P population (142 lines), and S. cheesmaniae, the C population (116 lines). Salinity effects on 19 quantitative traits including fruit yield were investigated by correlation,
principal component analysis, ANOVA and QTL analysis. A total of 153 and 124 markers were genotyped in the P and C populations,
respectively. Some flowering time and salt tolerance candidate genes were included. Since most traits deviated from a normal
distribution, results based on the Kruskal–Wallis non-parametric test were preferred. Interval mapping methodology and ANOVA
were also used for QTL detection. Eight out of 15 QTLs at each population were detected for the target traits under both control
and high salinity conditions, and among them, only average fruit weight (FW) and fruit number (FN) QTLs (fw1.1, fw2.1 and fn1.2) were detected in both populations. The individual contribution of QTLs were, in general, low. After leaf chloride concentration,
flowering time is the trait most affected by salinity because different QTLs are detected and some of their QTL×E interactions
have been found significant. Also reinforcing the interest on information provided by QTL analysis, it has been found that
non-correlated traits may present QTL(s) that are associated with the same marker. A few salinity specific QTLs for fruit
yield, not associated with detrimental effects, might be used to increase tomato salt tolerance. The beneficial allele at
two of them, fw8.1 (in C) and tw8.1 (for total fruit weight in P) corresponds to the salt sensitive parent, suggesting that the effect of the genetic background
is crucial to breed for wide adaptation using wild germplasm. 相似文献
12.
S. Moharramipour H. Tsumuki K. Sato H. Yoshida 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(5):592-596
A set of 150 doubled-haploid (DH) barley (Hordeum vulgare L.) lines derived from the cross of Harrington/TR306 was used to determine the number and chromosomal location of quantitative
trait loci (QTLs) controlling resistance to cereal aphids. The experiments were conducted under natural infestation in the
field during two growing seasons: 1994 and 1995. Aphid resistance was measured by counting the number of aphids per plot.
Counts were made on a weekly basis. Each year at the time of maximum aphid density there was an obvious difference in reaction
between the parental genotypes. The DH lines showed continuous variation for aphid density. Simple interval mapping and simplified
composite interval mapping revealed that the principal QTL determining cereal aphid resistance is on the distal region of
the short arm of chromosome 1. This aphid-resistance QTL is linked with a heading-date QTL. At the time of highest aphid infestation,
this QTL accounted for 31% and 22% of the total variance of aphid density in 1994 and 1995, respectively. A QTL on chromosome
5 was also detected but only by simplified composite interval mapping. However, the largest consistent effect was due to the
QTL on the short arm of chromosome 1. This QTL may be a useful target for marker-assisted selection for adult plant cereal
aphid resistance in barley.
Received: 10 September 1996/Accepted: 11 October 1996 相似文献
13.
Mapping of quantitative trait loci associated with ultraviolet-B resistance in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) 总被引:2,自引:0,他引:2
Sato T Ueda T Fukuta Y Kumagai T Yano M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(6):1003-1008
The detection of quantitative trait loci (QTLs) associated with UV-B resistance in rice should allow their practical application in breeding for such a complex trait, and may lead to the identification of gene characteristics and functions. Considerable variation in UV-B resistance exists within cultivated rice (Oryza sativa L.), but its detailed genetic control mechanism has not been well elucidated. We detected putative QTLs associated with the resistance to enhanced UV-B radiation in rice, using 98 BC1F5 (backcross inbred lines; BILs) derived from a cross between Nipponbare (a resistant japonica rice variety) and Kasalath (a sensitive indica rice variety). We used 245 RFLP markers to construct a framework linkage map. BILs and both parents were grown under visible light with or without supplemental UV-B radiation in a growth chamber. In order to evaluate UV-B resistance, we used the relative fresh weight of aerial parts (RFW) and the relative chlorophyll content of leaf blades (RCC). The BIL population exhibited a wide range of variation in RFW and RCC. Using composite interval mapping with a LOD threshold of 2.9, three putative QTLs associated with both RFW and RCC were detected on chromosomes 1, 3 and 10. Nipponbare alleles at the QTLs on chromosome 1 and 10 increased the RFW and RCC, while the Kasalath allele at the QTL on chromosome 3 increased both traits. Furthermore, the existence of both QTLs on chromosomes 1 and 10 for UV-B resistance was confirmed using chromosome segment substitution lines. Plants with Kasalath alleles at the QTL on chromosome 10 were more sensitive to UV-B radiation than plants with them on chromosome 1. These results also provide the information not only for the improvement of UV-B resistance in rice though marker-associated selection, but also for the identification of UV-B resistance mechanisms by using near-isogenic lines.Communicated by D.J. Mackill 相似文献
14.
QTL analysis of resistance to Fusarium head blight in Swiss winter wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) 总被引:9,自引:0,他引:9
Paillard S Schnurbusch T Tiwari R Messmer M Winzeler M Keller B Schachermayr G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(2):323-332
Fusarium head blight (FHB) of wheat is a widespread and destructive disease which occurs in humid and semi-humid areas. FHB epidemics can cause serious yield and quality losses under favorable climatic conditions, but the major concern is the contamination of grains with mycotoxins. Resistance to FHB is quantitatively inherited and greatly influenced by the environment. Its evaluation is costly and time-consuming. The genetic basis of FHB resistance has mainly been studied in spring wheat. The objective of this study was to map quantitative trait loci (QTLs) for resistance to FHB in a population of 240 recombinant inbred lines (RILs) derived from a cross between the two Swiss winter wheat cultivars Arina (resistant) and Forno (susceptible). The RILs were genotyped with microsatellite and RFLP markers. The resulting genetic map comprises 380 loci and spans 3,086 cM. The 240 RILs were evaluated for resistance to FHB in six field trials over 3 years. Composite interval mapping (CIM) analyses carried out on FHB AUDPC (i.e. mean values across six environments) revealed eight QTLs which altogether explained 47% of the phenotypic variance. The three main QTLs were mapped on the long arms of chromosomes 6D (R2=22%), 5B (R2=14%) and 4A (R2=10%). The QTL detected on 5B originated from the susceptible parent Forno. Other QTLs with smaller effects on FHB resistance were detected on chromosomes 2AL, 3AL, 3BL, 3DS and 5AL.Communicated by H.C. Becker 相似文献
15.
E. S. Jones C. J. Liu M. D. Gale C. T. Hash J. R. Witcombe 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(3):448-456
Quantitative trait loci (QTLs) for resistance to pathogen populations of Scelerospora graminicola from India, Nigeria, Niger and Senegal were mapped using a resistant x susceptible pearl millet cross. An RFLP map constructed using F2 plants was used to map QTLs for traits scored on F4 families. QTL analysis was carried out using the interval mapping programme Mapmaker/QTL. Independent inheritance of resistance to pathogen populations from India, Senegal, and populations from Niger and Nigeria was shown. These results demonstrate the existence of differing virulences in the pathogen populations from within Africa and between Africa and India. QTLs of large effect, contributing towards a large porportion of the variation in resistance, were consistently detected in repeated screens. QTLs of smaller and more variable effect were also detected. There was no QTLs that were effective against all four pathogen populations, demonstrating that pathotype-specific resistance is a major mechanism of downy mildew resistance in this cross. For all but one of the QTLs, resistance was inherited from the resistant parent and the inheritance of resistance tended to be the result of dominance or over-dominance. The implications of this research for pearl millet breeding are discussed. 相似文献
16.
Identification of QTLs related to cocoa resistance to three species of<Emphasis Type="Italic"> Phytophthora</Emphasis> 总被引:1,自引:0,他引:1
Risterucci AM Paulin D Ducamp M N'Goran JA Lanaud C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,108(1):168-174
This study aimed to compare the genetic control of cacao resistance to three species of Phytophthora: Phytophthora palmivora, Phytophthora megakarya and Phytophthora capsici. The study was conducted on 151 hybrid progenies created in Côte d'Ivoire and grown in a green-house in Montpellier. Phytophthora resistance was screened by leaf-test inoculation with two different strains per species. Selection of the best individuals for resistance to P. palmivora at a 10% selection rate, would lead to a genetic progress of 47% in the disease evaluation for this species and a genetic progress of 42% and 21% for the two other species. A genetic map with a total length of 682 cM was built with 213 markers, 190 AFLPs and 23 microsatellites. QTLs were identified using composite interval mapping. QTLs were found located in six genomic regions. One of these was detected with five strains belonging to the three Phytophthora species. Two other regions were detected with two or three strains of two different species. Three additional QTLs were detected for only one species of Phytophthora. Each QTL explained between 8 to 12% of the phenotypic variation. For each strain, between 11.5% to 27.5% of the total phenotypic variation could be explained by the QTLs identified. The identification of multiple QTLs involved in resistance to Phytophthora offers the possibility to improve durability of resistance in cocoa by a possible cumulation of many different resistance genes located in different chromosome regions using marker-aided selection.Communicated by H.F. Linskens 相似文献
17.
Fine Mapping QTL for Drought Resistance Traits in Rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) Using Bulk Segregant Analysis 总被引:1,自引:0,他引:1
Salunkhe AS Poornima R Prince KS Kanagaraj P Sheeba JA Amudha K Suji KK Senthil A Babu RC 《Molecular biotechnology》2011,49(1):90-95
Drought stress is a major limitation to rice (Oryza sativa L.) yields and its stability, especially in rainfed conditions. Developing rice cultivars with inherent capacity to withstand
drought stress would improve rainfed rice production. Mapping quantitative trait loci (QTLs) linked to drought resistance
traits will help to develop rice cultivars suitable for water-limited environments through molecular marker-assisted selection
(MAS) strategy. However, QTL mapping is usually carried out by genotyping large number of progenies, which is labour-intensive,
time-consuming and cost-ineffective. Bulk segregant analysis (BSA) serves as an affordable strategy for mapping large effect
QTLs by genotyping only the extreme phenotypes instead of the entire mapping population. We have previously mapped a QTL linked
to leaf rolling and leaf drying in recombinant inbred (RI) lines derived from two locally adapted indica rice ecotypes viz., IR20/Nootripathu using BSA. Fine mapping the QTL will facilitate its application in MAS. BSA was done
by bulking DNA of 10 drought-resistant and 12 drought-sensitive RI lines. Out of 343 rice microsatellites markers genotyped,
RM8085 co-segregated among the RI lines constituting the respective bulks. RM8085 was mapped in the middle of the QTL region
on chromosome 1 previously identified in these RI lines thus reducing the QTL interval from 7.9 to 3.8 cM. Further, the study
showed that the region, RM212–RM302–RM8085–RM3825 on chromosome 1, harbours large effect QTLs for drought-resistance traits
across several genetic backgrounds in rice. Thus, the QTL may be useful for drought resistance improvement in rice through
MAS and map-based cloning. 相似文献
18.
Qi Xiaoquan Fufa Fekadu Sijtsma Dick Niks Rients E. Lindhout Pim Stam Piet 《Molecular breeding : new strategies in plant improvement》2000,6(1):1-9
Using AFLP markers, a linkage map was constructed based on a recombinant inbred population of barley derived from a cross between a leaf rust susceptible line, L94, and a partially resistant line, 116-5. The constructed map showed a similar marker distribution pattern as the L94 × Vada map. However, it contained more large gaps, and for some chromosome regions no markers were identified. These regions are most likely derived from L94 because 116-5 was selected from the progeny of a cross of L94 × cv. Cebada Capa. Five QTLs for partial resistance to isolate 1.2.1. were mapped on the L94 × 116-5 map. Three QTLs were effective in the seedling stage, jointly contributing 42% to the total phenotypic variance. Three QTLs were effective in the adult plant stage, collectively explaining 35% of the phenotypic variance. Evidence for two additional linked minor-effect QTLs effective in the adult plant stage was also uncovered. The major-effect QTL, Rphq3, was the only one that was effective in both developmental stages. Moreover, Rphq3, was also identified in the L94 × Vada population, being effective to two rust isolates. The other QTLs were detected in either of the two populations, providing evidence for the existence of many loci for partial resistance to leaf rust on the barley genome. To date, 13 QTLs for partial resistance have been mapped, therefore, a strategy of accumulating many resistance genes in a single cultivar, resulting in a high level of partial resistance, is feasible. 相似文献
19.
Comparative mapping of QTLs for agronomic traits of rice across environments using a doubled haploid population 总被引:30,自引:0,他引:30
C. Lu L. Shen Z. Tan Y. Xu P. He Y. Chen L. Zhu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(8):1211-1217
We report here the RFLP mapping of quantitative triat loci (QTLs) that affect some important agronomic traits in cultivated rice. An anther culturederived doubled haploid (DH) population was established from a cross between an indica and a japonica rice variety. On the basis of this population a molecular linkage map comprising 137 markers was constructed that covered the rice genome at intervals of 14.8cM on average. Interval mapping of the linkage map was used to locate QTLs for such important agronomic traits as heading date, plant height, number of spikelets per panicle, number of grains Per panicle, 1000-grain weight and percentage of seed set. Evidence of genotype-byenvironment interaction was found by comparing QTL maps of the same population grown in three diverse environments. A total of 22 QTLs for six agronomic traits were detected that were significant in at least one environment, but only 7 were significant in all three environments, 7 were significant in two environments and 8 could only be detected in a single environment. However, QTL-by-environment interaction was traitdependent. QTLs for spikelets and grains per panicle were common across environments, while traits like heading date and plant height were more sensitive to environment. 相似文献
20.
A. Pernet D. Hoisington J. Dintinger D. Jewell C. Jiang M. Khairallah P. Letourmy J.-L. Marchand J.-C. Glaszmann D. González de León 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(3-4):540-553
The streak disease has a major effect on maize in sub-Saharan Africa. Various genetic factors for resistance to the virus
have been identified and mapped in several populations; these factors derive from different sources of resistance. We have
focused on the Réunion island source and have recently identified several factors in the D211 line. A second very resistant
line, CIRAD390, was crossed to the same susceptible parent, B73. The linkage map comprised 124 RFLP markers, of which 79 were
common with the D211×B73 map. A row-column design was used to evaluate the resistance to maize streak virus (MSV) of 191 F2:3 families under artificial infestation at two locations: Harare (Zimbabwe) and in Réunion island. Weekly ratings of resistance
were taken and disease incidence and severity calculated. QTL analyses were conducted for each scoring date and for the integration
over time of the disease scores, of incidence, and of severity. Heritability estimates (71–98%) were as high as for the D211×B73
population. Eight QTLs were detected on chromosomes 1, 2, 3, 5 (two QTLs), 6, 8, and 10. The chr1-QTL explained the highest
proportion of phenotypic variation, about 45%. The QTLs on chromosomes 1, 2, and 10 were located in the same chromosomal bin
as QTLs for MSV resistance in the D211×B73 population. In a simultaneous fit, QTLs explained together 43–67% of the phenotypic
variation. The QTLs on chromosomes 3, 5, and 6 appeared to be specific for one or the other component of the resistance. For
the chr3-QTL, resistance was contributed by the susceptible parent. There were significant QTL × environment interactions
for some of the variables studied, but QTLs were stable in the two environments. They also appeared to be stable over time.
Global gene action ranged from partial dominance to overdominance, except for disease severity. Some additional putative QTLs
were also detected. The major QTL on chromosome 1 seemed to be common to the other sources of resistance, namely Tzi4, a tolerant
line from IITA, and CML202 from CIMMYT. However, the distribution of the other QTLs within the genome revealed differences
in Réunion germplasm and across these other resistance sources. This diversity is of great importance when considering the
durability of the resistance.
Received: 15 June 1998 / Accepted: 30 January 1999 相似文献