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1.
QTL mapping for plant-height traits has not been hitherto reported in high-oil maize. A high-oil maize inbred ‘GY220’ was
crossed with two dent maize inbreds (‘8984’ and ‘8622’) to generate two connected F2:3 populations. Four plant-height traits were evaluated in 284 and 265 F2:3 families. Single-trait QTL mapping and multiple-trait joint QTL mapping was used to detect QTLs for the traits and the genetic
relationship between plant height (PH) and two other plant-height traits. A total of 28 QTLs and 12 pairs of digenic interactions
among detected QTLs for four traits were detected in the two F2:3 families. Only one marker was shared between the two populations. Joint analysis of PH with ear height (EH) and PH with top
height (TH) detected 32 additional QTLs. Our results showed that QTL detection for PH was dependent on the genetic background
of dent corn inbreds. Multiple-trait joint QTL analysis could increase the number of detected QTLs. 相似文献
2.
Breeding for fruit quality traits is complex due to the polygenic (quantitative) nature of the genetic control of these traits.
Therefore, to improve the speed and efficiency of genotype selection, attention in recent years has focused on the identification
of quantitative trait loci (QTLs) and molecular markers associated with these QTLs. However, despite the huge potential of
molecular markers in breeding programmes, their implementation in practice has been limited by the lack of information on
the stability of QTLs across different environments and within different genetic backgrounds. Here, we present the results
from a comprehensive analysis of the inheritance of fruit quality traits within a population derived from a cross between
the apple cultivars ‘Telamon’ and ‘Braeburn’ over two successive seasons. A total of 74 different QTLs were identified for
all the major fruit physiological traits including fruit height, diameter, weight and stiffness, flesh firmness, rate of flesh
browning, acidity, the oBrix content and harvest date. Seventeen of these QTLs were ‘major’ QTLs, accounting for over 20%
of the observed population variance of the trait. However, only one third (26) of the identified QTLs were stable over both
harvest years, and of these year-stable QTLs only one was a major QTL. A direct comparison with published QTL results obtained
using other populations (King et al., Theor Appl Genet 102:1227–1235, 2001; Liebhard et al., Plant Mol Biol 52:511–526, 2003)
is difficult because the linkage maps do not share a sufficient number of common markers and due to differences in the trait
evaluation protocols. Nonetheless, our results suggest that for the six fruit quality traits which were measured in all populations,
nine out of a total of 45 QTLs were common or stable across all population × environments combinations. These results are
discussed in the framework of the development and application of molecular markers for fruit quality trait improvement. 相似文献
3.
S. Doganlar S. D. Tanksley M. A. Mutschler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(2):249-255
Using RAPD marker analysis, two quantitative trait loci (QTLs) associated with earliness due to reduced fruit-ripening time
(days from anthesis to ripening = DTR) were identified and mapped in an F2 population derived from a cross between Lycopersicon esculentum’E6203’ (normal ripening) and Lycopersicon esculentum’Early Cherry’ (early ripening). One QTL, on chromosome 5, was associated with a reduction in both ripening time (5 days)
and fruit weight (29.3%) and explained 15.8 and 13% of the total phenotypic variation for DTR and fruit weight, respectively.
The other QTL, on chromosome 12, was primarily associated with a reduction only in ripening time (7 days) and explained 12.3%
of the total phenotypic variation for DTR. The gene action at this QTL was found to be partially dominant (d/a=0.41). Together,
these two QTLs explained 25.1% of the total phenotypic variation for DTR. Additionally, two QTLs associated with fruit weight
were identified in the same F2 population and mapped to chromosomes 4 and 6, respectively. Together, these two QTLs explained 30.9% of the total phenotypc
variation for fruit weight. For all QTLs, the ’Early Cherry’ alleles caused reductions in both ripening time and fruit weight.
The polymorphic band for the most significant RAPD marker (OPAB-06), linked to the reduced ripening time QTL on chromosome
12, was converted to a cleaved amplified polymorphism (CAP) assay for marker-aided selection and further introgression of
early ripening time (DTR) into cultivated tomato.
Received: 15 March 1999 / Accepted: 29 April 1999 相似文献
4.
Zorrilla-Fontanesi Y Cabeza A Domínguez P Medina JJ Valpuesta V Denoyes-Rothan B Sánchez-Sevilla JF Amaya I 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(5):755-778
Breeding for fruit quality traits in strawberry (Fragaria × ananassa, 2n = 8x = 56) is complex due to the polygenic nature of these traits and the octoploid constitution of this species. In order to
improve the efficiency of genotype selection, the identification of quantitative trait loci (QTL) and associated molecular
markers will constitute a valuable tool for breeding programs. However, the implementation of these markers in breeding programs
depends upon the complexity and stability of QTLs across different environments. In this work, the genetic control of 17 agronomical
and fruit quality traits was investigated in strawberry using a F1 population derived from an intraspecific cross between two contrasting selection lines, ‘232’ and ‘1392’. QTL analyses were
performed over three successive years based on the separate parental linkage maps and a pseudo-testcross strategy. The integrated
strawberry genetic map consists of 338 molecular markers covering 37 linkage groups, thus exceeding the 28 chromosomes. 33
QTLs were identified for 14 of the 17 studied traits and approximately 37% of them were stable over time. For each trait,
1–5 QTLs were identified with individual effects ranging between 9.2 and 30.5% of the phenotypic variation, indicating that
all analysed traits are complex and quantitatively inherited. Many QTLs controlling correlated traits were co-located in homoeology
group V, indicating linkage or pleiotropic effects of loci. Candidate genes for several QTLs controlling yield, anthocyanins,
firmness and l-ascorbic acid are proposed based on both their co-localization and predicted function. We also report conserved QTLs among
strawberry and other Rosaceae based on their syntenic location. 相似文献
5.
G. Pressoir L. Albar N. Ahmadi I. Rimbault M. Lorieux D. Fargette A. Ghesquière 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(7):1155-1161
The genetic basis of resistance to rice yellow mottle virus (RYMV) was studied in a doubled-haploid (DH) population derived
from a cross between the very susceptible indica variety ‘IR64’ and the resistant upland japonica variety Azucena. As a quantitative trait locus (QTL) involved in virus content estimated with an ELISA test has been previously
identified on chromosome 12, we performed a wide search for interactions between this QTL and the rest of the genome, and
between this QTL and morphological traits segregating in the population. Multiple regression with all identified genetic factors
was used to validate the interactions. Significant epistasis accounting for a major part of the total genetic variation was
observed. A complementary epistasis between the QTL located on chromosome 12 and a QTL located on chromosome 7 could be the
major genetic factor controlling the virus content. Resistance was also affected by a morphology-dependent mechanism since
tillering was interfering with the resistance mechanism conditioned by the epistasis between the two QTLs. Marker-assisted
backcross breeding was developed to introgress the QTLs of chromosome 7 and chromosome 12 in the susceptible ‘IR64’ genetic
background. First results confirmed that if both QTLs do not segregate in a backcross-derived F2 population, then the QTL of chromosome 12 cannot explain differences in virus content. A near-isogenic line (NIL) approach
is currently being developed to confirm the proposed genetic model of resistance to RYMV.
Received: 20 April 1990 / Accepted: 30 April 1998 相似文献
6.
Matsubara K Ando T Mizubayashi T Ito S Yano M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(2):179-186
One outcome of hybrid breakdown is poor growth, which we observed as a reduction in the number of panicles per plant and in
culm length in an F2 population derived from a cross between the genetically divergent rice (Oryza sativa L.) cultivars ‘Sasanishiki’ (japonica) and ‘Habataki’ (indica). Quantitative trait locus (QTL) analysis of the two traits and two-way ANOVA of the detected QTLs suggested that the poor
growth was due mainly to an epistatic interaction between genes at QTLs located on chromosomes 2 and 11. The poor growth was
likely to result when a plant was homozygous for the ‘Habataki’ allele at the QTL on chromosome 2 and homozygous for the ‘Sasanishiki’
allele at the QTL on chromosome 11. The results suggest that the poor growth found in the F2 population was due to hybrid breakdown of a set of complementary genes. To test this hypothesis and determine the precise
chromosomal location of the genes causing the hybrid breakdown, we performed genetic analyses using a chromosome segment substitution
line, in which a part of chromosome 2 from ‘Habataki’ was substituted into the genetic background of ‘Sasanishiki’. The segregation
patterns of poor growth in plants suggested that both of the genes underlying the hybrid breakdown were recessive. The gene
on chromosome 2, designated hybrid breakdown 2 (hbd2), was mapped between simple sequence repeat markers RM3515 and RM3730. The gene on chromosome 11, hbd3, was mapped between RM5824 and RM1341.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
7.
U. Kumar A. K. Joshi S. Kumar R. Chand M. S. R?der 《Molecular breeding : new strategies in plant improvement》2010,26(3):477-491
Spot blotch caused by Bipolaris sorokiniana is a destructive disease of wheat in warm and humid wheat growing regions of the world. To identify quantitative trait loci
(QTLs) for spot blotch resistance, two mapping populations were developed by making the crosses between common susceptible
cultivar ‘Sonalika’ with the resistant breeding lines ‘Ning 8201’ and ‘Chirya 3’. Single seed descent derived F6, F7, F8 lines of the first cross ‘Ning 8201’ × ‘Sonalika’ were evaluated for resistance to spot blotch in three blocks in each of
the 3 years. After screening of 388 pairs of simple sequence repeat primers between the two parents, 119 polymorphic markers
were used to genotype the mapping population. Four QTLs were identified on the chromosomes 2AS, 2BS, 5BL and 7DS and explained
62.9% of phenotypic variation in a simultaneous fit. The QTL on chromosome 2A was detected only in 1 year and explained 22.7%
of phenotypic variation. In the second cross (‘Chirya 3’ × ‘Sonalika’), F7 and F8 population were evaluated in three blocks in each of the 2 years. In this population, five QTLs were identified on chromosomes
2BS, 2DS, 3BS, 7BS and 7DS. The QTLs identified in the ‘Chirya 3’ × ‘Sonalika’ population explained 43.4% of phenotypic variation
in a simultaneous fit. The alleles for reduced disease severity in both the populations were derived from the respective resistant
parent. The QTLs QSb.bhu-2B and QSb.bhu-7D from both populations were placed in the same deletion bins, 2BS1-0.53-0.75 and 7DS5-0.36-0.61, respectively. The closely
linked markers Xgwm148 to the QTL on chromosome 2B and Xgwm111 to the QTL on chromosome 7D are potentially diagnostic markers for spot blotch resistance. 相似文献
8.
Detection and verification of malting quality QTLs using wild barley introgression lines 总被引:1,自引:0,他引:1
Inga Schmalenbach Klaus Pillen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(8):1411-1427
A malting quality quantitative trait locus (QTL) study was conducted using a set of 39 wild barley introgression lines (hereafter
abbreviated with S42ILs). Each S42IL harbors a single marker-defined chromosomal segment from the wild barley accession ‘ISR
42-8’ (Hordeum vulgare ssp. spontaneum) within the genetic background of the elite spring barley cultivar ‘Scarlett’ (Hordeum vulgare ssp. vulgare). The aim of the study was (1) to verify genetic effects previously identified in the advanced backcross population S42,
(2) to detect new QTLs, and (3) to identify S42ILs exhibiting multiple QTL effects. For this, grain samples from field tests
in three different environments were subjected to micro malting. Subsequently, a line × phenotype association study was performed
with the S42ILs in order to localize putative QTL effects. A QTL was accepted if the trait value of a particular S42IL was
significantly (P < 0.05) different from the recurrent parent as a control, either across all tested environments or in a particular environment.
For eight malting quality traits, altogether 40 QTLs were localized, among which 35 QTLs (87.5%) were stable across all environments.
Six QTLs (15.0%) revealed a trait improving wild barley effect. Out of 36 QTLs detected in a previous advanced backcross QTL
study with the parent BC2DH population S42, 18 QTLs (50.0%) could be verified with the S42IL set. For the quality parameters α-amylase activity and
Hartong 45°C, all QTLs assessed in population S42 were verified by S42ILs. In addition, eight new QTL effects and 17 QTLs
affecting two newly investigated traits were localized. Two QTL clusters harboring simultaneous effects on eight and six traits,
respectively, were mapped to chromosomes 1H and 4H. In future, fine-mapping of these QTL regions will be conducted in order
to shed further light on the genetic basis of the most interesting QTLs. 相似文献
9.
Zihong Ye Junmin Wang Qian Liu Minzhou Zhang Keqin Zou Xianshu Fu 《Journal of Plant Biology》2009,52(3):259-267
Using mixed-model-based composite interval mapping and conditional statistical methods, we studied quantitative trait loci
(QTLs) with epistatic effects and QTLs by environment interaction effects for rice seed set percent (SSP), filled grain number
per plant (FGP), and panicle length (PL). A population of 241 recombinant inbred lines was used which was derived from a cross
between “Zhenshan 97” and “Minghui 63.” Its linkage map included 221 molecular markers. Our QTL analysis detected 28, 25,
and 32 QTLs for SSP, FGP, and PL, respectively. Each QTL explained 1.37%∼13.19% of the mean phenotypic variation. A comparison
of conventional and conditional mapping provided information about the genetic control system involved in the synthetic process
of SSP, FGP, and PL at the level of individual QTLs. Conditional QTLs with reduced (or increased) effects were identified
for SSP, which were significantly influenced by FGP or PL. Some QTLs could express independently for the given traits, thereby
providing possibilities for simultaneous improvement of SSR and PL, and SSR and FGP. Epistasis was more sensitive to environmental
conditions than were additive effects. 相似文献
10.
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
11.
QTL mapping of aroma compounds analysed by headspace solid-phase microextraction gas chromatography in the apple progeny ‘Discovery’ × ‘Prima’ 总被引:2,自引:0,他引:2
F. Dunemann D. Ulrich A. Boudichevskaia C. Grafe W. E. Weber 《Molecular breeding : new strategies in plant improvement》2009,23(3):501-521
Improving fruit quality of apple varieties is an important but complex breeding goal. Flavour is among the key factors of
apple fruit quality but in spite of the analytical and biochemical knowledge about volatiles little is known about the genetic
and molecular bases of apple aroma. The aim of this study was to use a saturated molecular linkage map of apple to identify
QTLs for aroma compounds such as alcohols, esters and terpenes, but also for a number of unidentified volatile compounds (non-targeted
analysis approach). Two parental genetic maps were constructed for the apple cultivars ‘Discovery’ and ‘Prima’ by using mainly
AFLP and SSR markers. ‘Discovery’ and ‘Prima’ showed very different volatile patterns, and ‘Discovery’ mostly had the higher
volatile concentrations in comparison with the Vf-scab resistant ‘Prima’ which has its origin in the small-fruited apple species Malus floribunda. About 50 putative QTLs for a total of 27 different apple fruit volatiles were detected through interval mapping by using
genotypic data of 150 F1 individuals of the mapping population ‘C3’ together with phenotypic data obtained by head-space solid phase microextraction
gas chromatography. QTLs for volatile compounds putatively involved in apple aroma were found on 12 out of the 17 apple chromosomes,
but they were not evenly dispersed. QTLs were mainly clustered on linkage groups LG 2, 3 and 9. In a first attempt, a LOX
(lipoxygenase) candidate gene, putatively involved in volatile metabolism, was mapped on LG 9, genetically associated with
a cluster of QTLs for ester-type volatiles. Implications for aroma breeding in apple are discussed. 相似文献
12.
Rao GU Ben Chaim A Borovsky Y Paran I 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,106(8):1457-1466
An advanced backcross QTL study was performed in pepper using a cross between the cultivated species Capsicum annuum cv. Maor and the wild C. frutescens BG 2816 accession. A genetic map from this cross was constructed, based on 248 BC(2) plants and 92 restriction fragment length polymorphism (RFLP) markers distributed throughout the genome. Ten yield-related traits were analyzed in the BC(2) and BC(2)S(1) generations, and a total of 58 quantitative trait loci (QTLs) were detected; the number of QTLs per trait ranged from two to ten. Most of the QTLs were found in 11 clusters, in which similar QTL positions were identified for multiple traits. Unlike the high percentage of favorable QTL alleles discovered in wild species of tomato and rice, only a few such QTL alleles were detected in BG 2816. For six QTLs (10%), alleles with effects opposite to those expected from the phenotype were detected in the wild species. The use of common RFLP markers in the pepper and tomato maps enabled possible orthologous QTLs in the two species to be determined. The degree of putative QTL orthology for the two main fruit morphology traits-weight and shape-varied considerably. While all eight QTLs identified for fruit weight in this study could be orthologous to tomato fruit weight QTLs, only one out of six fruit shape QTLs found in this study could be orthologous to tomato fruit shape QTLs. 相似文献
13.
Identification of QTL for increased fibrous roots in soybean 总被引:2,自引:0,他引:2
Abdel-Haleem H Lee GJ Boerma RH 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(5):935-946
Drought stress adversely affects soybean at various developmental stages, which collectively results in yield reduction. Unpredictable
rainfall has been reported to contribute about 36% to variation of yield difference between the rain-fed and irrigated fields.
Among the drought resistance mechanisms, drought avoidance in genotypes with fibrous roots was recognized to be associated
with drought resistance in soybean. Plant introduction PI416937 was shown to possess fibrous roots and has been used as a
parent in breeding programs to improve soybean productivity. Little information is available on relative contribution and
chromosomal location of quantitative trait loci (QTL) conditioning fibrous roots in soybean. To identify the genomic locations
and genetic bases of this trait, a recombinant inbred line population was derived from a cross between PI416937 and ‘Benning’.
To detect associated QTLs, phenotypic data were collected and analyzed for 2 years under rain-fed field conditions. The selective
genotyping approach was used to reduce the costs and work associated with conducting the QTL analysis. A total of five QTLs
were identified on chromosomes Gm01 (Satt383), Gm03 (Satt339), Gm04 (Sct_191), Gm08 (Satt429), and Gm20 (Sat_299), and together
explained 51% of the variation in root score. Detected QTLs were co-localized with QTLs related to root morphology, suggesting
that fibrous roots QTL may be associated with other morpho-physiological traits and seed yield in soybean. Genetic dissection
of the fibrous roots trait at the individual marker loci will allow for marker-assisted selection to develop soybean genotypes
with enhanced levels of fibrous roots. 相似文献
14.
Accumulation of additive effects generates a strong photoperiod sensitivity in the extremely late-heading rice cultivar ‘Nona Bokra’ 总被引:1,自引:0,他引:1
Uga Y Nonoue Y Liang ZW Lin HX Yamamoto S Yamanouchi U Yano M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(8):1457-1466
Many rice cultivars that originated from lower-latitude regions exhibit a strong photoperiod sensitivity (PS) and show extremely
late heading under long-day conditions. Under natural day-length conditions during the cropping season in Japan, the indica rice cultivar ‘Nona Bokra’ from India showed extremely late heading (202 days to heading) compared to the japonica cultivar ‘Koshihikari’ (105 days), from Japan. To elucidate the genetic factors associated with such extremely late heading,
we performed quantitative trait locus (QTL) analyses of heading date using an F2 population and seven advanced backcross progeny (one BC1F2 and six BC2F2) derived from a cross between ‘Nona Bokra’ and ‘Koshihikari’. The analyses revealed 12 QTLs on seven chromosomes. The ‘Nona
Bokra’ alleles of all QTLs contributed to an increase in heading date. Digenic interactions were rarely observed between QTLs.
Based on the genetic parameters of the QTLs, such as additive effects and percentage of phenotypic variance explained, these
12 QTLs are likely generate a large proportion of the phenotypic variation observed in the heading dates between ‘Nona Bokra’
and ‘Koshihikari’. Comparison of chromosomal locations between heading date QTLs detected in this study and QTLs previously
identified in ‘Nipponbare’ × ‘Kasalath’ populations revealed that eight of the heading date QTLs were recognized nearby the
Hd1, Hd2, Hd3a, Hd4, Hd5, Hd6, Hd9, and Hd13. These results suggest that the strong PS in ‘Nona Bokra’ was generated mainly by the accumulation of additive effects of
particular alleles at previously identified QTLs. 相似文献
15.
Lerceteau-Köhler E Moing A Guérin G Renaud C Petit A Rothan C Denoyes B 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(6):1059-1077
Fruit quality traits are major breeding targets in the Rosaceae. Several of the major Rosaceae species are current or ancient
polyploids. To dissect the inheritance of fruit quality traits in polyploid fleshy fruit species, we used a cultivated strawberry
segregating population comprising a 213 full-sibling F1 progeny from a cross between the variety ‘Capitola’ and the genotype
‘CF1116’. We previously developed the most comprehensive strawberry linkage map, which displays seven homoeology groups (HG),
including each four homoeology linkage groups (Genetics 179:2045–2060, 2008). The map was used to identify quantitative trait loci (QTL) for 19 fruit traits related to fruit development, texture, colour,
anthocyanin, sugar and organic acid contents. Analyses were carried out over two or three successive years on field-grown
plants. QTL were detected for all the analysed traits. Because strawberry is an octopolyploid species, QTL controlling a given
trait and located at orthologous positions on different homoeologous linkage groups within one HG are considered as homoeo-QTL.
We found that, for various traits, about one-fourth of QTL were putative homoeo-QTL and were localised on two linkage groups.
Several homoeo-QTL could be detected the same year, suggesting that several copies of the gene underlying the QTL are functional.
The detection of some other homoeo-QTL was year-dependent. Therefore, changes in allelic expression could take place in response
to environmental changes. We believe that, in strawberry as in other polyploid fruit species, the mechanisms unravelled in
the present study may play a crucial role in the variations of fruit quality. 相似文献
16.
Molecular-marker analysis of quantitative traits for growth and development in juvenile apple trees 总被引:1,自引:0,他引:1
P. J. Conner S. K. Brown N. F. Weeden 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(8):1027-1035
Random amplified polymorphic DNAs (RAPDs) were used in combination with a double pseudo-testcross mapping strategy to estimate
the position and effects of quantitative trait loci (QTLs) for traits influencing juvenile tree growth and development in
two apple cultivars. The mapping population consisted of 172 F1 trees from a cross between the columnar mutant ‘Wijcik McIntosh’ and a standard form disease-resistant selection NY 75441-58.
Significant associations were found between markers and height increment, internode number, internode length, base diameter
increment, base diameter after 9 years of growth, branch number, and leaf break. The number of genomic regions associated
with each trait varied from one to eight. The amount of variation explained by linear regression on individual marker loci
(R2) ranged from 3.9 to 24.3%, with an average of 7%. Multiple regression using markers for each putative QTL explained from
6.6 to 41.6% of the phenotypic variation, with an average value of 24.3%. A large number of traits had significant variation
associated with the map position of the dominant columnar gene, Co. QTL stability over years was estimated by comparing the locations of putative QTLs for traits measured in multiple years.
The majority of genomic regions were associated with a trait in only a single year, although regions associated with a trait
in more than 1 year were also detected. The limitations of dominant markers and an outbred mapping pedigree for QTL analysis
are discussed.
Received: 27 August 1997 / Accepted: 10 February 1998 相似文献
17.
QTL mapping of fruit-related traits in pepper (Capsicum annuum) 总被引:11,自引:0,他引:11
A. Ben Chaim I. Paran R. C. Grube M. Jahn R. van Wijk J. Peleman 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(6-7):1016-1028
QTL analysis of pepper fruit characters was performed in an F3 population derived from a cross between two Capsicum annuum genotypes, the bell-type cultivar Maor and the Indian small-fruited line Perennial. RFLP, AFLP®1, RAPD and morphological markers (a total of 177) were used to construct a comparative pepper-tomato genetic map for this cross, and 14 quantitatively inherited traits were evaluated in 180 F3 families. A total of 55 QTL were identified by interval analysis using LOD 3.0 as the threshold for QTL detection. QTL for several traits including fruit diameter and weight, pericarp thickness and pedicel diameter were often located in similar chromosomal regions, thus reflecting high genetic correlations among these traits. A major QTL that accounts for more than 60% of the phenotypic variation for fruit shape (ratio of fruit length to fruit diameter) was detected in chromosome 3. This chromosome also contained QTL for most of the traits scored in the population. Markers in linkage groups 2, 3, 8 and 10 were associated with QTL for multiple traits, thereby suggesting their importance as loci that control developmental processes in pepper. Several QTL in pepper appeared to correspond to positions in tomato for loci controlling the same traits, suggesting the hypothesis that these QTL may be orthologous in the two species. 相似文献
18.
Identification of molecular markers linked to quantitative trait loci for soybean resistance to corn earworm 总被引:7,自引:0,他引:7
B. G. Rector J. N. All W. A. Parrott H. R. Boerma 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(6-7):786-790
One hundred and thirty nine restriction fragment length polymorphisms (RFLPs) were used to construct a soybean (Glycine max L. Merr.) genetic linkage map and to identify quantitative trait loci (QTLs) associated with resistance to corn earworm (Helicoverpa zea Boddie) in a population of 103 F2-derived lines from a cross of ‘Cobb’ (susceptible) and PI229358 (resistant). The genetic linkage map consisted of 128 markers
which converged onto 30 linkage groups covering approximately 1325 cM. There were 11 unlinked markers. The F2-derived lines and the two parents were grown in the field under a plastic mesh cage near Athens, Ga., in 1995. The plants
were artificially infested with corn earworm and evaluated for the amount of defoliation. Using interval-mapping analysis
for linked markers and single-factor analysis of variance (ANOVA), markers were tested for an association with resistance.
One major and two minor QTLs for resistance were identified in this population. The PI229358 allele contributed insect resistance
at all three QTLs. The major QTL is linked to the RFLP marker A584 on linkage group (LG) ‘M’ of the USDA/Iowa State University
public soybean genetic map. It accounts for 37% of the total variation for resistance in this cross. The minor QTLs are linked
to the RFLP markers R249 (LG ‘H’) and Bng047 (LG ‘D1’). These markers explain 16% and 10% of variation, respectively. The
heritability (h2) for resistance was estimated as 64% in this population.
Received: 15 October 1997 / Accepted: 4 November 1997 相似文献
19.
Zygier S Chaim AB Efrati A Kaluzky G Borovsky Y Paran I 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(3):437-445
Quantitative trait locus (QTL) mapping for fruit weight and shape in pepper (Capsicum spp.) was performed using C. chinense and C. frutescens introgression lines of chromosomes 2 and 4. In chromosome 2, a single major fruit-weight QTL, fw2.1, was detected in both populations that explained 62% of the trait variation. This QTL, as well as a fruit-shape QTL, fs2.1, which had a more minor effect, were localized to the tomato fruit-shape gene ovate. The cloned tomato fruit-weight QTL, fw2.2, did not play a major role in controlling fruit size variations in pepper. In chromosome 4, two fruit-weight QTLs, fw4.1 and fw4.2, were detected in the same genomic regions in both mapping populations. In addition, a single fruit-shape QTL was detected in each of the mapping populations that co-localized with one of the fruit-weight QTLs, suggesting pleiotropy or close linkage of the genes controlling size and shape. fw2.1 and fw4.2 represent major fruit-weight QTLs that are conserved in the three Capsicum species analyzed to date for fruit-size variations. Co-localization of the pepper QTLs with QTLs identified for similar traits in tomato suggests that the pepper and tomato QTLs are orthologous. Compared to fruit-shape QTLs, fruit-weight QTLs were more often conserved between pepper and tomato. This implies that different modes of selection were employed for these traits during domestication of the two Solanaceae species.S. Zygier and A. Ben Chaim contributed equally to this work. 相似文献
20.
Fusarium head blight (FHB) is one of the most devastating wheat diseases, causing both yield loss and quality reduction. To detect
quantitative trait loci (QTL) responsible for FHB resistance, plants of the F
2:3 population derived from a ‘Wangshui-bai’ × ‘Sy95-7’ cross were artificially inoculated. Of 396 simple sequence repeats (SSRs),
125 amplified fragment length polymorphisms were used for FHB resistance QTL analysis. Five QTLs for FHB resistance were detected
on chromosomes 3B, 6B, 7A, 1B and 2D. The effect of the QTL located on chromosome 3B on phenotypic variation was 31.69%, while
that of the QTL found on 2D was the smallest and only accounted for 4.98% of the variation. The resistance alleles originated
from ‘Wangshibai’ and association of the QTLs using these SSR markers may facilitate marker-assisted selection to improve
FHB resistance in the wheat breeding programs of southwest China. 相似文献