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1.
Ergon A Fang C Jørgensen Ø Aamlid TS Rognli OA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(2):232-242
The “BF14/16×HF2/7” mapping population of meadow fescue (Festuca pratensis Huds.) was characterised for number of panicles produced by non-vernalised plants in the field, vernalisation requirement
(number of weeks at 6°C and 8 h photoperiod), as well as days to heading, number of panicles and proportion of shoots heading
after a 12 weeks vernalisation treatment. Quantitative trait loci (QTLs) were identified and compared to QTLs and genes related
to the induction of flowering in cereals and grasses. A region on chromosome 1F affected days to heading and the proportion
of shoots heading. Chromosome 4F appeared to have several genes with a strong effect on vernalisation requirement. The strongest
effects were located in the proximal end of 4F and may correspond to the earliness per se (eps) QTL eps6L.2 in barley and
a heading time QTL in perennial ryegrass. A part of the meadow fescue orthologue of VRN1 was sequenced and mapped to another region of 4F that also had a strong effect on vernalisation requirement. The proximal
end of chromosome 5F had QTLs for days to heading and proportion of heading shoots. Syntenic regions in wheat and barley contain
eps-loci. A QTL for number of panicles in the field and a QTL for proportion of heading shoots were present on chromosome
6. A region on 7F affected the variation in number of panicles among plants without a vernalisation requirement, and is syntenic
to regions in perennial ryegrass, barley and rice containing orthologues of Arabidopsis thaliana
CO. 相似文献
2.
Kuchel H Williams KJ Langridge P Eagles HA Jefferies SP 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(8):1029-1041
Grain yield forms one of the key economic drivers behind a successful wheat (Triticum aestivum L.) cropping enterprise and is consequently a major target for wheat breeding programmes. However, due to its complex nature,
little is known regarding the genetic control of grain yield. A doubled-haploid population, comprising 182 individuals, produced
from a cross between two cultivars ‘Trident’ and ‘Molineux’, was used to construct a linkage map based largely on microsatellite
molecular makers. ‘Trident’ represents a lineage of wheat varieties from southern Australia that has achieved consistently
high relative grain yield across a range of environments. In comparison, ‘Molineux’ would be rated as a variety with low to
moderate grain yield. The doubled-haploid population was grown from 2002 to 2005 in replicated field experiments at a range
of environments across the southern Australian wheat belt. In total, grain yield data were recorded for the population at
18 site-year combinations. Grain yield components were also measured at three of these environments. Many loci previously
found to be involved in the control of plant height, rust resistance and ear-emergence were found to influence grain yield
and grain yield components in this population. An additional nine QTL, apparently unrelated to these traits, were also associated
with grain yield. A QTL associated with grain yield on chromosome 1B, with no significant relationship with plant height,
ear-emergence or rust resistance, was detected (LOD ≥2) at eight of the 18 environments. The mean yield, across 18 environments,
of individuals carrying the ‘Molineux’ allele at the 1B locus was 4.8% higher than the mean grain yield of those lines carrying
the ‘Trident’ allele at this locus. Another QTL identified on chromosome 4D was also associated with overall gain yield at
six of the 18 environments. Of the nine grain yield QTL not shown to be associated with plant height, phenology or rust resistance,
two were located near QTL associated with grain yield components. A third QTL, associated with grain yield components at each
of the environments used for testing, was located on chromosome 7D. However, this QTL was not associated with grain yield
at any of the environments. The implications of these findings on marker-assisted selection for grain yield are discussed. 相似文献
3.
Kuchel H Langridge P Mosionek L Williams K Jefferies SP 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(8):1487-1495
Improving the end-use quality of wheat is a key target for many breeding programmes. With the exception of the relationship between glutenin alleles and some dough rheological characters, knowledge concerning the genetic control of wheat quality traits is somewhat limited. A doubled haploid population produced from a cross between two Australian cultivars ‘Trident’ and ‘Molineux’ has been used to construct a linkage map based largely on microsatellite molecular makers. ‘Molineux’ is superior to ‘Trident’ for a number of milling, dough rheology and baking quality characteristics, although by international standards ‘Trident’ would still be regarded as possessing moderately good end-use quality. This population was therefore deemed useful for investigation of wheat end-use quality. A number of significant QTL identified for dough rheological traits mapped to HMW and LMW glutenin loci on chromosomes 1A and 1B. However, QTL associated with dough strength and loaf volume were also identified on chromosome 2A and a significant QTL associated with loaf volume and crumb quality was identified on chromosome 3A. A QTL for flour protein content and milling yield was identified on chromosome 6A and a QTL associated with flour colour reported previously on chromosome 7B was confirmed in this population. The detection of loci affecting dough strength, loaf volume and flour protein content may provide fresh opportunities for the application of marker-assisted selection to improve bread-making quality. 相似文献
4.
Shuwen Wang Brett Carver Liuling Yan 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(7):1339-1349
Responses to photoperiod and low temperature are the two primary adaptive mechanisms which enable wheat plants to synchronize
developmental processes with changes in seasonal climate. In this study, the developmental process was characterized at two
stages: stem length during the onset of stem elongation and heading date. These two developmental events were monitored and
mapped in recombinant inbred lines (RILs) of a population generated from a cross between two complementary and locally adapted
hard winter wheat cultivars. ‘Intrada’ undergoes stem elongation earlier but reaches heading later, whereas ‘Cimarron’ undergoes
stem elongation later but reaches heading earlier. Variation in the developmental process in this population was associated
with three major QTLs centered on Xbarc200 on chromosome 2B, PPD-D1 on chromosome 2D, and Xcfd14 on chromosome 7D. The Intrada Xbarc200 and Xcfd14 alleles and the Cimarron PPD-D1 allele accelerated both stem elongation and heading stages, or the Cimarron Xbarc200 and Xcfd14 alleles and the Intrada PPD-D1 allele delayed both stem elongation and heading stages. Integrative effects of the three QTLs accounted for 43% (initial
stem length) and 68% (heading date) of the overall phenotypic variation in this population. PPD-D1 is a reasonable candidate gene for the QTL on chromosome 2D, PPD-B1 could be associated with the QTL on chromosome 2B, but VRN-D3 (=FT-D1) was not linked with the QTL on chromosome 7D, suggesting that this is a novel locus involved in winter wheat development.
Because the PPD-D1 QTL was observed to interact with other two QTLs, all of these QTLs could play a role in the same pathway as involved in
photoperiod response of winter wheat. 相似文献
5.
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
6.
Muhammad A. Khan Brion Duffy Cesare Gessler Andrea Patocchi 《Molecular breeding : new strategies in plant improvement》2006,17(4):299-306
Fire blight caused by the bacterium Erwinia amylovora is a severe threat to apple and pear orchards worldwide. Apple varieties exhibit a wide range of relative susceptibility/tolerance to fire blight. Although, no monogenic resistance against fire blight has been identified yet, recent evidence indicates the existence of quantitative resistance. Potential sources of fire blight resistance include several wild Malus species and some apple cultivars. F1 progenies of ‘Fiesta’בDiscovery’ were inoculated with the Swiss strain Ea 610 and studied under controlled conditions to identify quantitative trait loci (QTLs) for fire blight resistance. Disease was evaluated at four time points after inoculation. Shoot lesion length and the area under disease progress curve (AUDPC) values were used for QTL analysis. One significant (LOD score of 7.5–8.1, p<0.001) QTL was identified on the linkage group 7 of ‘Fiesta’ (F7). The F7 QTL explained about 37.5–38.6% of the phenotypic variation. 相似文献
7.
Detection of QTLs for heading time and photoperiod response in wheat using a doubled-haploid population. 总被引:16,自引:0,他引:16
The genetic basis of heading time in wheat (Triticum aestivum L.) was investigated through the study of flowering under normal autumn sown field conditions as well as photoperiod responses under a controlled environment. Quantitative trait loci (QTLs) for these traits were mapped in a doubled-haploid (DH) population derived from a cross between the wheat cultivars 'Courtot' and 'Chinese Spring'. A molecular marker linkage map of this cross that was previously constructed based on 187 DH lines and 380 markers was used for QTL mapping. The genome was well covered (85%) except for chromosomes 1D and 4D, and a set of anchor loci regularly spaced over the genome (one marker each 15.5 cM) was chosen for marker regression analysis. The presence of a QTL was declared at a significance threshold of alpha = 0.005. The population was grown under field conditions in Clermont-Ferrand, France during two years (1994-1995), in Norwich, U.K. over one year (1998), and also under controlled environments in Norwich. For each trait, between 2 and 4 QTLs were identified with individual effects ranging between 6.3% and 44.4% of the total phenotypic variation. Two QTLs were detected that simultaneously affected heading time and photoperiod response. For heading time, these two QTLs were detected in more than one year. One QTL located on chromosome arm 2BS near the locus Xfbb121-2B, co-segregated with the gene Ppd-B1 known to be involved in photoperiod response. This chromosome region explained a large part of the variation (23.4-44.4% depending on the years or the traits). Another region located on chromosome arm 7BS between the loci Xfbb324-7B and Xfbb53-7B also had a strong effect (7.3-15.3%). This region may correspond to a QTL for earliness per se. 相似文献
8.
We report the fine mapping of the previously described quantitative trait loci (QTL) for grain weight QTgw.ipk-7D associated with microsatellite marker Xgwm1002-7D by using introgression lines (ILs) carrying introgressions of the synthetic wheat W-7984 in the genetic background of the
German winter wheat variety ‘Prinz’. The BC4F3 ILs had a 10% increased thousand grain weight compared to the control group and the recurrent parent ‘Prinz’, and 84.7% of
the phenotypic variance could be explained by the segregation of marker Xgwm1002-7D, suggesting the presence of a gene modulating grain weight, which was preliminarily designated gw1. It was possible to delimit the QTL QTgw.ipk-7D to the interval Xgwm295–Xgwm1002, which is located in the most telomeric bin 7DS4-0.61-1.00 in the physical map of wheat chromosome arm 7DS. Furthermore,
our data suggest the presence of a novel plant height-reducing locus Rht on chromosome arm 7DS of ‘Prinz’. Larger grain and increased plant height may reflect the pleiotropic action of one gene
or may be caused by two linked genes. In general, our data support the concept of using nearly isogenic ILs for validating
and dissecting QTLs into single Mendelian genes and open the gateway for map-based cloning of a grain-weight QTL in wheat. 相似文献
9.
Comparative mapping of the wheat chromosome 5A Vrn-A1 region with rice and its relationship to QTL for flowering time 总被引:3,自引:0,他引:3
R. N. Sarma B. S. Gill T. Sasaki G. Galiba J. Sutka D. A. Laurie J. W. Snape 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):103-109
The vernalization gene Vrn-A1 on chromosome 5A is the predominant gene determining the spring/winter habit difference in bread wheat. Vrn-A1 was physically mapped using a set of deletion lines which located it to the region of chromosome 5A flanked by deletion breakpoints
0.68 and 0.78. This interval was shown to be homoeologous to a region of rice chromosome 3 that contains the flowering-time
QTL Hd-6, previously mapped in a Nipponbare×Kasalath cross, and FLTQ1, a novel QTL identified by analysis of 78 F3 families derived from a cross of ‘IR20’ב63–83’. Possible relationships between Vrn-A1 and rice QTL are discussed. Analysis of the chromosome 5A deletion lines showed evidence for a second, more proximal flowering-time
effect located between deletion breakpoints 0.56 and 0.64. The proximal part of chromosome 5A is homoeologous to rice chromosome
9, on which two QTL were detected in the ‘IR20ב63–83’ cross. The possible relationship between these effects is also discussed.
Received: 23 December 1997 / Accepted: 12 January 1998 相似文献
10.
Martin Löffler Chris-Carolin Schön Thomas Miedaner 《Molecular breeding : new strategies in plant improvement》2009,23(3):473-488
Fusarium head blight (FHB) in wheat results in reduced yield and quality and in accumulation of mycotoxins. The objective of this
study was to identify genomic regions in wheat involved in the control of FHB resistance applying a QTL meta-analysis approach
by combining QTL of 30 mapping populations to propose independent meta-QTL (MQTL). A consensus map was created on which initial
QTL were projected. Nineteen MQTL comprising 2–13 initial QTL with widely varying confidence intervals were found on 12 chromosomes.
Some of them coincided with genomic regions previously identified (e.g. chromosomes 3BS, 6B), however, some MQTL were newly
detected by this study. Separate analysis of populations with the same resistant parent showed a rather high consistency for
the Chinese spring wheat donor ‘Sumai 3’, but little consistency for the Chinese donor ‘Wangshuibai’ and the Swiss donor ‘Arina’.
According to our results breeders can in future (1) choose parents for crossing not comprising the same resistance loci or
QTL intervals, (2) exploit new MQTL, and (3) select markers of some of these MQTL to be used in marker-assisted selection.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
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
12.
Peng Wang Yongzhong Xing Zhikang Li Sibin Yu 《Molecular breeding : new strategies in plant improvement》2012,29(4):903-913
To facilitate marker-assisted transfer of desirable genes for improvement of yield traits, we used a set of backcross recombinant
inbred lines (BRIL) derived from two elite parental lines, ‘Zhenshan97’ and ‘93-11’, to resolve a quantitative trait loci
(QTL) cluster for heading date and yield-related traits in rice. Four main-effect QTL (qHD6.1, qHD6.2, qHD7, and qHD8) and four epistatic QTL affecting heading date in the BRIL were detected in two experimental trials. The major QTL (qHD8) was confirmed in three heterogeneous inbred families (HIF) that segregated for this target region, and narrowed down to
a 20-kb segment in a large HIF-derived population. qHD8 was found to interact with qHD7 and had a pleiotropic effect responsible for heading date and yield components. To test usability of the identified QTL in
rice improvement, we further developed near-isogenic lines (NIL) containing one or more target genes by marker-assisted transfer
of ‘93-11’ alleles at qHD8, qHD7, and qHD6.1, and the GS3 gene for grain size into ‘Zhenshan97’. The pyramid line NIL(qHD8 + GS3) had higher yield potential, longer grains, and a more suitable heading date than ‘Zhenshan97’. Comparison of the NIL showed
existence of epistasis between alleles at different loci and background effect on qHD8, which are very important for pyramiding of desirable alleles at the target QTL. These results will be particularly useful
not only to understand the genetic basis of yield-related traits but also to improve the efficiency of marker-assisted selection
for favorable loci in rice breeding programs. 相似文献
13.
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
14.
Detection of quantitative trait loci for heading date based on the doubled haploid progeny of two elite Chinese wheat cultivars 总被引:3,自引:0,他引:3
Quantitative trait loci (QTLs) with epistatic and QTL × environment (QE) interaction for heading date were studied using a
doubled haploid (DH) population containing 168 progeny lines derived from a cross between two elite Chinese wheat cultivars
Huapei 3 × Yumai 57 (Triticum aestivum L.). A genetic map was constructed based on 305 marker loci, consisting of 283 SSR loci and 22 EST-SSR markers, which covered
a total length of 2141.7 cM with an average distance of 7.02 cM between adjacent markers in the genome. QTL analyses were
performed using a mixed linear model approach. Two main-effect QTLs and two pairs of digenic epistatic effects were detected
for heading date on chromosomes 1B, 2B, 5D, 6D, 7A, and 7D at three different environments in 2005 and 2006 cropping seasons.
A highly significant QTL with an F-value 148.96, designated as Qhd5D, was observed within the Xbarc320-Xwmc215 interval on chromosome 5DL, accounting for 53.19% of the phenotypic variance and reducing days-to-heading by 2.77 days. The
Qhd5D closely links with a PCR marker Xwmc215 with the genetic distance 2.1 cM, which can be used in molecular marker-assisted selection (MAS) in wheat breeding programs.
Moreover, the Qhd5D was located on the similar position of well-characterised vernalization sensitivity gene Vrn-D1. We are also spending more efforts to develop near-isogenic lines to finely map the Qhd5D and clone the gene Vrn-D1 through map-based cloning. The Qhd1B with additive effect on heading date has not been reported in previous linkage mapping studies, which might be a photoperiod-sensitive
gene homoeologous to the Ppd-H2 gene on chromosome 1B. No main-effect QTLs for heading date were involved in epistatic effects. 相似文献
15.
Mapping QTLs for pre-harvest sprouting tolerance on chromosome 2D in a synthetic hexaploid wheat×common wheat cross 总被引:1,自引:0,他引:1
Ren Xiao-bo Lan Xiu-jin Liu Deng-cai Wang Jia-li Zheng You-liang 《Journal of applied genetics》2008,49(4):333-341
Based on segregation distortion of simple sequence repeat (SSR) molecular markers, we detected a significant quantitative
trait loci (QTL) for pre-harvest sprouting (PHS) tolerance on the short arm of chromosome 2D (2DS) in the extremely susceptible
population of F2 progeny generated from the cross of PHS tolerant synthetic hexaploid wheat cultivar ‘RSP’ and PHS susceptible bread wheat
cultivar ‘88–1643’. To identify the QTL of PHS tolerance, we constructed two SSR-based genetic maps of 2DS in 2004 and 2005.
One putative QTL associated with PHS tolerance, designatedQphs.sau-2D, was identified within the marker intervalsXgwm261-Xgwm484 in 2004 and in the next year, nearly in the same position, between markerswmc112 andXgwm484. Confidence intervals based on the LOD-drop-off method ranged from 9 cM to 15.4 cM and almost completely overlapped with
marker intervalXgwm261-Xgwm484. Flanking markers near this QTL could be assigned to the C-2DS1-0.33 chromosome bin, suggesting that the gene(s) controlling
PHS tolerance is located in that chromosome region. The phenotypic variation explained by this QTL was about 25.73–27.50%.
Genotyping of 48 F6 PHS tolerant plants derived from the cross between PHS tolerant wheat cultivar ‘RSP’ and PHS susceptible bread wheat cultivar
‘MY11’ showed that the allele ofQphs.sau-2D found in the ‘RSP’ genome may prove useful for the improvement of PHS tolerance. 相似文献
16.
Bennett D Izanloo A Edwards J Kuchel H Chalmers K Tester M Reynolds M Schnurbusch T Langridge P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(4):697-711
In southern Australia, where the climate is predominantly Mediterranean, achieving the correct flowering time in bread wheat
minimizes the impact of in-season cyclical and terminal drought. Flag leaf glaucousness has been hypothesized as an important
component of drought tolerance but its value and genetic basis in locally adapted germplasm is unknown. From a cross between
Kukri and RAC875, a doubled-haploid (DH) population was developed. A genetic linkage map consisting of 456 DArT and SSR markers
was used to detect QTL affecting time to ear emergence and Zadoks growth score in seven field experiments. While ear emergence
time was similar between the parents, there was significant transgressive segregation in the population. This was the result
of segregation for the previously characterized Ppd-D1a and Ppd-B1 photoperiod responsive alleles. QTL of smaller effect were also detected on chromosomes 1A, 4A, 4B, 5A, 5B, 7A and 7B. A
novel QTL for flag leaf glaucousness of large, repeatable effect was detected in six field experiments, on chromosome 3A (QW.aww-3A) and accounted for up to 52 percent of genetic variance for this trait. QW.aww-3A was validated under glasshouse conditions in a recombinant inbred line population from the same cross. The genetic basis
of time to ear emergence in this population will aid breeders’ understanding of phenological adaptation to the local environment.
Novel loci identified for flag leaf glaucousness and the wide phenotypic variation within the DH population offers considerable
scope to investigate the impact and value of this trait for bread wheat production in southern Australia. 相似文献
17.
Wang G Leonard JM Ross AS Peterson CJ Zemetra RS Garland Campbell K Riera-Lizarazu O 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(1):207-221
Kernel hardness or texture, used to classify wheat (Triticum aestivum L.) into soft and hard classes, is a major determinant of milling and baking quality. Wheat genotypes in the soft class that
are termed ‘extra-soft’ (with kernel hardness in the lower end of the spectrum) have been associated with superior end-use
quality. In order to better understand the relationship between kernel hardness, milling yield, and various agronomic traits,
we performed quantitative trait mapping using a recombinant inbred line population derived from a cross between a common soft
wheat line and a genotype classified as an ‘extra-soft’ line. A total of 47 significant quantitative trait loci (QTL) (LOD ≥ 3.0)
were identified for nine traits with the number of QTL affecting each trait ranging from three to nine. The percentage of
phenotypic variance explained by these QTL ranged from 3.7 to 50.3%. Six QTL associated with kernel hardness and break flour
yield were detected on chromosomes 1BS, 4BS, 5BS, 2DS, 4DS, and 5DL. The two most important QTL were mapped onto orthologous
regions on chromosomes 4DS (Xbarc1118–Rht-D1) and 4BS (Xwmc617–Rht-B1). These results indicated that the ‘extra-soft’ characteristic was not controlled by the Hardness (Ha) locus on chromosome 5DS. QTL for eight agronomic traits occupied two genomic regions near semi-dwarf genes Rht-D1 on chromosome 4DS and Rht-B1 on chromosome 4BS. The clustering of these QTL is either due to the pleiotropic effects of single genes or tight linkage
of genes controlling these various traits. 相似文献
18.
Yihua Chen Brett F. Carver Shuwen Wang Shuanghe Cao Liuling Yan 《Molecular breeding : new strategies in plant improvement》2010,26(4):573-582
The orderly development of winter wheat through its life cycle can be marked at three stages: stem elongation, heading date,
and physiological maturity. The duration of a developmental phase between two stages is important in yield component generation.
In this study the three developmental stages were characterized and 350 markers were mapped in a population of recombinant
inbred lines (RILs) generated from a cross between two winter wheat cultivars (‘Jagger’ and ‘2174’). Three major QTLs were
found to control variation in developmental process, and each of them was tightly associated with a known flowering gene,
VRN-A1 on chromosome 5A, PPD-D1 on chromosome 2D, and VRN-D3 on chromosome 7D. The average contribution of the gene marker for each QTL to the total phenotypic variation (R
2) was evaluated over 3 years. The effect of VRN-A1 ranged from 21.5% at stem elongation to 17.4% at physiological maturity. The effect of PPD-D1 was minor (6.7%) at stem elongation but increased to 29.7% at heading and 20.1% at physiological maturity. The effect of
VRN-D3 was not detected at stem elongation but increased to 14.6% at heading and to 20.5% at physiological maturity. Hence, the
VRN-A1 locus, the PPD-D1 locus, and the VRN-D3 locus had greatest impact on development at stem elongation, heading date, and physiological maturity, respectively. Whereas
the Jagger VRN-A1 and VRN-D3 alleles accelerated development, the Jagger PPD-D1 allele delayed the developmental process due to its sensitivity to photoperiod. Our findings suggest that through the appropriate
combination of alleles at these three loci one would be able to regulate the various developmental phases to accommodate different
agricultural needs. 相似文献
19.
Meng F Han Y Teng W Li Y Li W 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(8):1459-1465
Soybean aphid (Aphis glycines Matsumura) results in severe yield loss of soybean in many soybean-growing countries of the world. A few loci have been previously
identified to be associated with the aphid resistance in soybean. However, none of them was via isoflavone-mediated antibiosis
process. The aim of the present study was to conduct genetic analysis of aphid resistance and to identify quantitative trait
loci (QTL) underlying aphid resistance in a Chinese soybean cultivar with high isoflavone content. One hundred and thirty
F5:6 derived recombinant inbred lines from the ‘Zhongdou 27’ × ‘Jiunong 20’ cross were used. Two QTL were directly associated
with resistance to aphid as measured by aphid damage index. qRa_1, close to Satt470 on soybean linkage group (LG) A2 (chromosome
8), was consistently detected for 3- and 4-week ratings and explained a large portion of phenotypic variations ranging from
25 to 35%. qRa_2, close to Satt144 of LG F (chromosome 13), was detected for 3- and 4-week ratings and could explain 7 and
11% of the phenotypic variation, respectively. These two QTL were highly associated with high isoflavone content and both
positive alleles were derived from ‘Zhongdou 27’, a cultivar with higher isoflavone content. The results revealed that higher
individual or total isoflavones contents in soybean lines could protect soybean against aphid attack. These two QTL detected
jointly provide potential for marker-assisted selection to improve the resistance of soybean cultivars to aphid along with
the increase of isoflavone content. 相似文献
20.
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