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1.
Zhang Y Luo L Xu C Zhang Q Xing Y 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(2):361-368
Near-isogenic lines (NILs) are ideal materials for precise estimation of quantitative trait loci (QTL) effects and map-based gene isolation. With the completion of the rice genome sequence, QTL isolation based on NILs is becoming a routine. In this study, a trait-performance derived NIL strategy was adopted to develop NILs. Two plants were identified within one inbred line of recombinant inbred lines (RILs, F7 generation), exhibiting a significant difference in panicle size. By marker screening of the whole genome the genetic background of the two plants was estimated to be 98.7% identical. These two plants were selected as parents to produce a near-isogenic F2 (NIL-F2) population, consisting of 125 individuals, in which spikelets per panicle (SPP), grains per panicle (GPP), heading date (HD) and plant height (PH) were recorded. These four traits expressed discontinuous or bimodal distribution in the NIL-F2 population and followed the expected segregation ratios for a single Mendelian factor by progeny tests. A partial dominant QTL for the four traits was mapped to the same interval flanked by RM310 and RM126 on chromosome 8. The QTL region explained 83.0, 80.2, 94.9 and 93.8% of trait variation of SPP, GPP, HD and PH in the progenies, respectively. Progeny tests also confirmed co-segregation of QTL for the four traits, tall plants consistently flowering late and carrying large panicles. Different NILs development strategies are discussed. 相似文献
2.
Four rice QTL controlling number of spikelets per panicle expressed the characteristics of single Mendelian gene in near isogenic backgrounds 总被引:2,自引:0,他引:2
Yushan Zhang Lijun Luo Touming Liu Caiguo Xu Yongzhong Xing 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(6):1035-1044
Development of quantitative trait loci (QTL) near isogenic lines is a crucial step to QTL isolation using the strategy of
map-based cloning. In this study, a recombinant inbred line (RIL) population derived from two indica rice varieties, Zhenshan 97 and HR5, was employed to map QTL for spikelets per panicle (SPP). One major QTL (qSPP7) and three minor QTL (qSPP1, qSPP2 and qSPP3) were identified on chromosomes 7, 1, 2 and 3, respectively. Four sets of near isogenic lines (NILs) BC4F2 targeted for the four QTL were developed by following a standard procedure of consecutive backcross, respectively. These
QTL were not only validated in corresponding NILs, but also explained amounts of phenotypic variation with much larger LOD
scores compared with those identified in RILs. SPP in the four QTL-NILs expressed bimodal or discontinuous distributions and
followed the expected segregation ratio of single Mendelian factor by progeny test. Finally, qSPP1, qSPP2, qSPP3 and qSPP7 were respectively mapped to a locus, 0.5 cM from MRG2746, 0.6 cM from MRG2762, 0.8 cM from RM49 and 0.7 cM from MRG4436,
as co-dominant markers on the basis of progeny tests. These results indicate no matter how small effect minor QTL is, QTL
may still express the characteristics of single Mendelian factor in NILs and isolation of minor QTL will be possible using
high quality NILs. Pyramiding these QTL into a variety will largely enhance rice grain yield. 相似文献
3.
Fine mapping of a major quantitative trait loci, qSSP7, controlling the number of spikelets per panicle as a single Mendelian factor in rice 总被引:2,自引:0,他引:2
Xing YZ Tang WJ Xue WY Xu CG Zhang Q 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(6):789-796
In our previous studies, one putative QTL affecting number of spikelets per panicle (SPP) was identified in the pericentromeric
region of rice chromosome 7 using a recombinant inbred population. In order to define the QTL (qSPP7), RI50, a recombinant inbred line with 70% of genetic background same as the female parent of Zhenshan 97, was selected to
produce near-isogenic lines for the target region in the present study. In a BC2F2 population consisting of 190 plants, the frequency distribution of SPP was shown to be discontinuous and followed the expected
Mendelian ratios (1:2:1 by progeny test) for single locus segregation. qSPP7 was mapped to a 0.4 cM region between SSR marker RM3859 and RFLP marker C39 based on tests of the BC2F2 population and its progeny. Its additive and dominant effects on SPP were 51.1 and 24.9 spikelets, respectively. Of great
interest, the QTL region also had effects on grain yield per plant (YD), 1,000 grain weight (GW), tillers per plant (TPP)
and seed setting ratio (SR). Significant correlations were observed between SPP and YD (r = 0.66) and between SPP and SR (r = −0.29) in the progeny test. 1082 extremely small panicle plants of a BC3F2 population containing 8,400 individuals were further used to fine map the QTL. It turns out that qSPP7 co-segregated with two markers, RM5436 and RM5499 spanning a physical distance of 912.4 kb. Overall results suggested that
recombination suppression occurred in the region and positional cloning strategy is infeasible for qSPP7 isolation. The higher grain yield of Minghui 63 homozygote as compared to the heterozygote suggested that Minghui 63 homozygote
at qSPP7 in hybrid rice could further improve its yield.
Y. Z. Xing and W. J. Tang contributed equally to this work. 相似文献
4.
Touming Liu Di Shao Mallikarjuna Rao Kovi Yongzhong Xing 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(5):933-942
This study identified four and five quantitative trait loci (QTLs) for 1,000-grain weight (TGW) and spikelets per panicle
(SPP), respectively, using rice recombinant inbred lines. QTLs for the two traits (SPP3a and TGW3a, TGW3b and SPP3b) were simultaneously identified in the two intervals between RM3400 and RM3646 and RM3436 and RM5995 on chromosome 3. To
validate QTLs in the interval between RM3436 and RM5995, a BC3F2 population was obtained, in which TGW3b and SPP3b were simultaneously mapped to a 2.6-cM interval between RM15885 and W3D16. TGW3b explained 50.4% of the phenotypic variance with an additive effect of 1.81 g. SPP3b explained 29.1% of the phenotypic variance with an additive effect of 11.89 spikelets. The interval had no effect on grain
yield because it increased SPP but decreased TGW and vice versa. Grain shape was strongly associated with TGW and was used
for QTL analysis in the BC3F2 population. Grain length, grain width, and grain thickness were also largely controlled by TGW3b. At present, it is not clear whether one pleiotropic QTL or two linked QTLs were located in the interval. However, the conclusion
could be made ultimately by isolation of TGW3b. The strategy for TGW3b isolation is discussed. 相似文献
5.
Fujita D Doi K Yoshimura A Yasui H 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(4):567-573
The green rice leafhopper (GRH), Nephotettix cincticeps Uhler, is one of the most serious insect pests affecting cultivated rice (Oryza sativa L.) in temperate regions of East Asia. An accession of the wild rice species, Oryza rufipogon Griff. (W1962), was found to be highly resistant to GRH by an antibiosis test. To understand the genetic basis of the GRH resistance, a BC1F1 population derived from a cross between a susceptible Japonica variety, Taichung 65 (T65), and a highly resistant accession W1962 was analyzed by quantitative trait loci (QTL) mapping. A single major QTL for GRH resistance was detected on rice chromosome 8. A nearly isogenic population containing segments of the targeted QTL region derived from W1962 was then developed through advanced backcrossing with marker-assisted selection. Further molecular mapping using a BC4F2 population revealed that a new resistance gene, designated as Green rice leafhopper resistance 5 (Grh5), was located on the distal region of the long arm of chromosome 8 and tightly linked to the simple sequence repeat markers RM3754 and RM3761. A nearly isogenic line (NIL) carrying Grh5 was subsequently developed in the progeny of the mapping population. The resistance level of Grh5-NIL was compared with those of developed NILs for GRH resistance and was found to have the highest resistance. The DNA markers found to be closely linked to Grh5 would be useful for marker-assisted selection for the improvement of resistance to GRH in rice. 相似文献
6.
Chengguo Pei Xu Liu Wenying Wang Hanfeng Ding Mingsong Jiang Guangxian Li Changxiang Zhu Fujiang Wen Fangyin Yao 《Journal of Plant Biology》2011,54(3):190-198
Heading date is one of the importance agronomic traits. A library consisting of 1,123 single segment substitution lines (SSSLs)
in the same genetic background of an elite rice variety Huajingxian 74 (HJX74) was evaluated for heading date (HD). From this
library, the SSSL W06-26-35-1-5-2 with the substituted interval of PSM152–PSM154–PSM155–RM25–RM547–RM72–RM404 was found having
a gene, which performed stable and late heading in the different environments of Shandong and Hainan provinces. To map the
gene governing heading date, the SSSL W06-26-35-1-5-2 was crossed with the recipient HJX74 to develop an F2 segregating population. The distribution of late and early heading plants in this population fitted a segregation ratio of
3:1, indicating the late heading was controlled by a dominant gene. The gene locus for heading date was tentatively designated
as qHD8-1. Using a random sample of 460 individuals from the F2 population, the qHD8-1 was narrowed down to a region flanking by two SSR markers PSM155 and RM547. For fine mapping of qHD8-1, a large F2:3 segregating population of 3,000 individuals were developed from F2 plants heterozygous in the PSM155–RM547 region. Recombinants analysis further mapped qHD8-1 to an interval of region 26 kb with markers RM22492 and P23 bounded on the left and right sides, respectively. Sequence analysis
of this 26-kb fragment revealed that it contains five putative open reading frames, which were regarded as candidates of qHD8-1. These results will be useful in cloning of the qHD8-1 gene. 相似文献
7.
Yusaku Uga Kazutoshi Okuno Masahiro Yano 《Molecular breeding : new strategies in plant improvement》2010,26(3):533-538
The stele (root vascular cylinder) in plants plays an important role in the transport of water and nutrients from the root
to the shoot. A quantitative trait locus (QTL) on rice chromosome 9 that controls stele transversal area (STA) was previously
detected in an F3 mapping population derived from a cross between the lowland cultivar ‘IR64’, with a small STA, and the upland cultivar ‘Kinandang
Patong’, with a large STA. To identify the gene(s) underlying this QTL, we undertook fine mapping of the locus. We screened
eight plants from BC2F3 lines in which recombination occurred near the QTL. Progeny testing of BC2F4 plants was used to determine the genotype classes for the QTL in each BC2F3 line. Accordingly, the STA QTL Sta1 (Stele Transversal Area 1) was mapped between the InDel markers ID07_12 and ID07_14. A candidate genomic region for Sta1 was defined more precisely between markers RM566 and RM24334, which delimit a 359-kb interval in the reference cultivar ‘Nipponbare’.
A line homozygous for the ‘Kinandang Patong’ allele of Sta1 had an STA approximately 28.4% larger than that of ‘IR64’. However, Sta1 did not influence maximum or total root length, suggesting that this QTL specifically controls STA. 相似文献
8.
Binbin Wang Changxiang Zhu Xu Liu Wenying Wang Hanfeng Ding Mingsong Jiang Guangxian Li Wei Liu Fangyin Yao 《Plant Molecular Biology Reporter》2011,29(3):702-713
A library consisting of 1,123 single-segment substitution lines (SSSLs) in the same genetic background of an elite rice variety
Huajingxian74 (HJX74) was evaluated for heading date. From this library, the SSSL W05-1-11-5-16-2-5 with the substituted interval
of PSM103—RM348-OSR15-PSM382-RM131-RM127—RM280 was found having a gene, which stably performed extreme late heading date which
performed stable and late heading in the different environments of Shandong, Guangdong, and Hainan. To map the gene governing
heading date, the SSSL W05-1-11-5-16-2-5 was crossed with the recipient HJX74 to develop an F2 segregating population. The distribution of late and early heading plants in this population fitted a segregation ratio of
3:1, indicating the late heading was controlled by a dominant gene. The gene locus for heading date was tentatively designated
as qHD4-1. Using a random sample of 460 individuals from the F2 segregation population, the qHD4-1 locus was mapped between two SSR markers RM3335 and RM17572, with genetic distances of 0.1 and 0.2 cM, respectively. For
fine mapping of qHD4-1, a large F2:3 segregating population of 3,000 individuals were developed from F2 plants heterozygous in the RM3335-RM17572 region. Recombinants analyses further mapped qHD4-1 to an interval of 20.7-kb-bounded WB05 and the WB06. Sequence analysis of this 20.7-kb region revealed that it contains three
open reading frames (ORFs), encoding wall-associated receptor kinase-like 5, putative F-box domain containing protein, and
putative arogenate/prephenate dehydratase. Of them, ORF1, predicting to encode serine/threonine kinase, is considered the
most likely as the candidate gene. The genetic and physical map of the qHD4-1 locus will be very useful in molecular cloning of the qHD4-1gene. 相似文献
9.
Identification and mapping of a new leaf stripe resistance gene in barley (Hordeum vulgare L.) 总被引:2,自引:0,他引:2
G. Tacconi L. Cattivelli N. Faccini N. Pecchioni A. M. Stanca G. Valé 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(8):1286-1291
Pyrenophora graminea is the seed-borne pathogen causal agent of barley leaf stripe disease. Near-isogenic lines (NILs) carrying resistance of
the cv ”Thibaut” against the highly virulent isolate Dg2 were obtained by introgressing the resistance into the genetic background
of the susceptible cv ”Mirco”. The segregation of the resistance gene was followed in a F2 population of 128 plants as well as on the F3 lines derived from the F2 plants; the segregation fitted the 1:2:1 ratio for a single gene. By using NILs, a RAPD marker associated with the resistance
gene was identified; sequence-specific (STS) primers were designed on the basis of the amplicon sequence and a RILs mapping
population with an AFLP-based map were used to position this molecular marker to barley chromosome 1 S (7HS). STS and CAPS
markers were developed from RFLPs mapped to the telomeric region of barley chromosome 7HS and three polymorphic PCR-based
markers were developed. The segregation of these markers was followed in the F2 population and their map position with respect to the resistance gene was determined. Our results indicate that the Thibaut
resistance gene, which we designated as Rdg2a, maps to the telomeric region of barley chromosome 7HS and is flanked by the markers OPQ-9700 and MWG 2018 at distances of 3.1 and 2.5 cM respectively. The suitability of the PCR-based marker MWG2018 in selection- assisted
barley breeding programs is discussed.
Received: 22 June 2000 / Accepted: 16 October 2000 相似文献
10.
Xie X Song MH Jin F Ahn SN Suh JP Hwang HG McCouch SR 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(5):885-894
A quantitative trait locus (QTL) for grain weight (GW) was detected near SSR marker RM210 on chromosome 8 in backcross populations derived from a cross between the Korean japonica cultivar Hwaseongbyeo and Oryza rufipogon (IRGC 105491). The O. rufipogon allele increased GW in the Hwaseongbyeo background despite the fact that O. rufipogon was the small-seeded parent. Using sister BC3F3 near-isogenic lines (NILs), gw8.1 was validated and mapped to a 6.1 cM region in the interval between RM42 and RM210 (P≤0.0001). Substitution mapping with eight BC3F4 sub-NILs further narrowed the interval containing gw8.1 to about 306.4 kb between markers RM23201.CNR151 and RM30000.CNR99. A yield trial using homozygous BC3F4 sister sub-NILs and the Hwaseongbyeo recurrent parent indicated that the NIL carrying an O. rufipogon chromosome segment across the entire gw8.1 target region out-yielded its sister NIL (containing Hwaseongbyeo chromosome in the RM42–RM210 interval) by 9% (P=0.029). The higher-yielding NIL produced 19.3% more grain than the Hwaseongbyeo recurrent parent (P=0.018). Analysis of a BC3F4 NIL indicated that the variation for GW is associated with variation in grain shape, specifically grain length. The locus, gw8.1 is of particular interest because of its independence from undesirable height and grain quality traits. SSR markers tightly linked to the GW QTL will facilitate cloning of the gene underlying this QTL as well as marker-assisted selection for variation in GW in an applied breeding program. 相似文献
11.
Background
The three-dimensional shape of grain, measured as grain length, width, and thickness (GL, GW, and GT), is one of the most important components of grain appearance in rice. Determining the genetic basis of variations in grain shape could facilitate efficient improvements in grain appearance. In this study, an F7:8 recombinant inbred line population (RIL) derived from a cross between indica and japonica cultivars (Nanyangzhan and Chuan7) contrasting in grain size was used for quantitative trait locus (QTL) mapping. A genetic linkage map was constructed with 164 simple sequence repeat (SSR) markers. The major aim of this study was to detect a QTL for grain shape and to fine map a minor QTL, qGL7.Results
Four QTLs for GL were detected on chromosomes 3 and 7, and 10 QTLs for GW and 9 QTLs for GT were identified on chromosomes 2, 3, 5, 7, 9 and 10, respectively. A total of 28 QTLs were identified, of which several are reported for the first time; four major QTLs and six minor QTLs for grain shape were also commonly detected in both years. The minor QTL, qGL7, exhibited pleiotropic effects on GL, GW, GT, 1000-grain weight (TGW), and spikelets per panicle (SPP) and was further validated in a near isogenic F2 population (NIL-F2). Finally, qGL7 was narrowed down to an interval between InDel marker RID711 and SSR marker RM6389, covering a 258-kb region in the Nipponbare genome, and cosegregated with InDel markers RID710 and RID76.Conclusion
Materials with very different phenotypes were used to develop mapping populations to detect QTLs because of their complex genetic background. Progeny tests proved that the minor QTL, qGL7, could display a single mendelian characteristic. Therefore, we suggested that minor QTLs for traits with high heritability could be isolated using a map-based cloning strategy in a large NIL-F2 population. In addition, combinations of different QTLs produced diverse grain shapes, which provide the ability to breed more varieties of rice to satisfy consumer preferences. 相似文献12.
Andaya VC Tai TH 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(3):467-475
The temperate japonica rice cultivar M202 is the predominant variety grown in California due to its tolerance to low temperature stress, good grain quality and high yield. Earlier analysis of a recombinant inbred line mapping population derived from a cross between M202 and IR50, an indica cultivar that is highly sensitive to cold stress, resulted in the identification of a number of QTL conferring tolerance to cold-induced wilting and necrosis. A major QTL, qCTS12, located on the short arm of chromosome 12, contributes over 40% of the phenotypic variance. To identify the gene(s) underlying qCTS12, we have undertaken the fine mapping of this locus. Saturating the short arm of chromosome 12 with microsatellite markers revealed that qCTS12 is closest to RM7003. Using RM5746 and RM3103, which are immediately outside of RM7003, we screened 1,954 F5-F10 lines to find recombinants in the qCTS12 region. Additional microsatellite markers were identified from publicly available genomic sequence and used to fine map qCTS12 to a region of approximately 87 kb located on the BAC clone OSJNBb0071I17. This region contains ten open reading frames (ORFs) consisting of five hypothetical and expressed proteins of unknown function, a transposon protein, a putative NBS-LRR disease resistance protein, two zeta class glutathione S-transferases (OsGSTZ1 and OsGSTZ2), and a DAHP synthetase. Further fine mapping with markers developed from the ORFs delimited the QTL to a region of about 55 kb. The most likely candidates for the gene(s) underlying qCTS12 are OsGSTZ1 and OsGSTZ2.The mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. 相似文献
13.
Silvana Grandillo Hsin-Mei Ku Steven D. Tanksley 《Molecular breeding : new strategies in plant improvement》1996,2(3):251-260
In two previous quantitative trait locus (QTL) mapping studies conducted inLycopersicon esculentum x L. pimpinellifolium BC1 and BC2 populations we had localized a major QTL for fruit shape,fs8.1, to a ca. 20 cM interval on the short arm of chromosome 8, flanked by markers TG176 and CT92. At this QTL the allele from the wild species reduces the length of fruit, giving round-shaped fruit. In order to define more precisely the location offs8.1, near-isogenic lines (NILs) segregating for the region of interest were developed. The results from substitution mapping show that no recombination occurred betweenfs8.1 and the marker CD40 in 322 meioses. The gene action forfs8.1 was determined in a BC4F3 population to be partial dominance. The main effect offs8.1 is exerted on fruit length while fruit diameter is not significantly affected. A highly significant correlation (r=0.89;P<0.01) was found between fruit shape and ovary shape indicating that thefs8.1 gene product acts early in ovary development (preanthesis). Implications for the evolution of fruit shape and the feasibility of map-based cloning of this QTL are discussed. 相似文献
14.
Huiying Wang Shaojie Shi Qin Guo Lingyun Nie Bo Du Rongzhi Chen Lili Zhu Guangcun He 《Molecular breeding : new strategies in plant improvement》2018,38(8):107
The brown planthopper (BPH), Nilaparvata lugens Stål, is one of the most destructive pests to the rice production in the world. Thus, there is an urgency to identify new resistant genes for breeding. AC-1613 is an indica variety that has been reported to confer broad-spectrum resistance to BPH. In the present study, we found that AC-1613 exhibited strong antibiosis towards BPH insects. The body weight was significantly decreased when the insects fed on AC-1613 plants. By using BPH weight gain as an index of phenotyping, a novel dominant locus for resistance to BPH, designed as Bph30, was identified and its near-isogenic line (NIL) in 9311 background was developed. The F2 population derived from a cross between AC-1613 and 9311 was used for mapping the gene. Through QTL scan, we located the gene on the short arm of chromosome 4 between RM16278 and RM16425, which explained 42.7% of the phenotypic variance (PEV) of BPH resistance in the F2 population. The gene was finally located in a region flanking by simple sequence repeat (SSR) markers SSR-28 and SSR-69 through high-resolution mapping, the distance between the two markers in Nipponbare genome is 37.5 kb. In addition, SSR markers RM16294 and RM16299 tightly linked to Bph30 were applied effectively in introgressing Bph30 into elite rice cultivars. The developed NILs showed a strong antibiosis and high resistance to BPH. 相似文献
15.
Qian Chen Jun Song Wen-Ping Du Li-Yuan Xu Yun Jiang Jie Zhang Xiao-Li Xiang Gui-Rong Yu 《Genes & genomics.》2018,40(10):1091-1099
Semi-dwarfism is an agronomically important trait in breeding for stable high yields and for resistance to damage by wind and rain (lodging resistance). Many QTLs and genes causing dwarf phenotype have been found in maize. However, because of the yield loss associated with these QTLs and genes, they have been difficult to use in breeding for dwarf stature in maize. Therefore, it is important to find the new dwarfing genes or materials without undesirable characters. The objectives of this study were: (1) to figure out the inheritance of semi-dwarfism in mutants; (2) mapping dwarfing gene or QTL. Maize inbred lines ‘18599’ and ‘DM173’, which is the dwarf mutant derived from the maize inbred line ‘173’ through 60Co-γ ray irradiation. F2 and BC1F1 population were used for genetic analysis. Whole genome resequencing-based technology (QTL-seq) were performed to map dwarfing gene and figured out the SNP markers in predicted region using dwarf bulk and tall bulk from F2 population. Based on the polymorphic SNP markers from QTL-seq, we were fine-mapping the dwarfing gene using F2 population. In F2 population, 398 were dwarf plants and 135 were tall plants. Results of χ2 tests indicated that the ratio of dwarf plants to tall plants was fitted to 3:1 ratio. Furthermore, the χ2 tests of BC1F1 population showed that the ratio was fitted to 1:1 ratio. Based on QTL-seq, the dwarfing gene was located at the region from 111.07 to 124.56 Mb of chromosome 9, and we named it rht-DM. Using traditional QTL mapping with SNP markers, the rht-DM was narrowed down to 400 kb region between SNP-21 and SNP-24. The two SNPs were located at 0.43 and 0.11 cM. Segregation analysis of F2 and BC1F1 indicated that the dwarfing gene was likely a dominant gene. This dwarfing gene was located in the region between 115.02 and 115.42 Mb on chromosome 9. 相似文献
16.
Detection and verification of quantitative trait loci for resistance to Fusarium ear rot in maize 总被引:4,自引:0,他引:4
Jiafa Chen Junqiang Ding Huimin Li Zhimin Li Xiaodong Sun Jingjing Li Ruixia Wang Xiaodong Dai Huafang Dong Weibin Song Wei Chen Zongliang Xia Jianyu Wu 《Molecular breeding : new strategies in plant improvement》2012,30(4):1649-1656
Fusarium ear rot caused by Fusarium verticillioides is a prevalent disease in maize which can severely reduce grain yields and quality. Identification of stable quantitative trait loci (QTL) for resistance to Fusarium ear rot is a basic prerequisite for understanding the genetic mechanism of resistance and for the use of marker-assisted selection. In this study, two hundred and ten F 2:3 families were developed from a cross between resistant inbred line BT-1 and susceptible inbred line Xi502, and were genotyped with 178 simple sequence repeat markers. The resistance of each line was evaluated in two environments by artificial inoculation using the nail-punch method. The resistance QTL were detected using the composite interval mapping method. Three QTL were detected on chromosomes 4, 5 and 10. Of them, the QTL on chromosome 4 (bin 4.05/06) had the largest resistance to Fusarium ear rot, and could explain 17.95?% of the phenotypic variation. For further verification of the QTL effect, we developed near-isogenic lines (NILs) carrying the QTL region on chromosome 4 using parental line Xi502 as the recurrent parent. In the NIL background, this QTL can increase the resistance by 33.7?C35.2?% if the resistance region is homozygous, and by 17.8?C26.5?% if the resistance region contains the heterozygous allele. The stable and significant resistance effect of the QTL on chromosome 4 lays the foundation for further marker-assisted selection and map-based cloning in maize. 相似文献
17.
QTL analysis and mapping of pi21, a recessive gene for field resistance to rice blast in Japanese upland rice 总被引:14,自引:0,他引:14
S. Fukuoka K. Okuno 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(2-3):185-190
Field resistance is defined as the resistance that allows effective control of a parasite under natural field conditions and
is durable when exposed to new races of that parasite. To identify the genes for field resistance to rice blast, quantitative
trait loci (QTLs) conferring field resistance to rice blast in Japanese upland rice were detected and mapped using RFLP and
SSR markers. QTL analysis was carried out in F4 progeny lines from the cross between Nipponbare (moderately susceptible, lowland) and Owarihatamochi (resistant, upland).
Two QTLs were detected on chromosome 4 and one QTL was detected on each of chromosomes 9 and 12. The phenotypic variation
explained by each QTL ranged from 7.9 to 45.7% and the four QTLs explained 66.3% of the total phenotypic variation. Backcrossed
progeny lines were developed to transfer the QTL with largest effect using the susceptible cultivar Aichiasahi as a recurrent
parent. Among 82 F3 lines derived from the backcross, resistance segregated in the expected ratio of resistant 1 : heterozygous 2 : susceptible
1. The average score for blast resistance measured in the field was 4.2 ± 0.67, 7.5 ± 0.51and 8.2 ± 0.66, for resistant, heterozygous
and susceptible groups, respectively. The resistance gene, designated pi21, was mapped on chromosome 4 as a single recessive gene between RFLP marker loci G271 and G317 at a distance of 5.0 cM and 8.5 cM, respectively. The relationship to previously reported major genes and QTLs conferring
resistance to blasts, and the significance of marker-assisted selection to improve field resistance, are discussed.
Received: 8 June 2000 / Accepted: 24 November 2000 相似文献
18.
H. F. Ding F. Y. Yao G. X. Li M. S. Jiang R. F. Li X. D. Zhang W. Y. Wang F. Chen Y. Zhang 《Russian Journal of Plant Physiology》2009,56(4):532-539
The fragrance gene plays an important role in high-quality rice varieties and has been widely used in breeding programs. Using
a random sample of 370 individuals from an F2 segregating population developed from a cross between a japonica rice variety 9407 with fragrant flavor and an indica variety IRBB60, the fgr locus was mapped on chromosome 8 between SSR markers, PSM465 and RM1109, with genetic distances of 0.3 cM and 0.1 cM to respective
markers. These mapping efforts confirmed the previous mapping results. A large F3 mapping population with 7300 individuals was then developed from F2 plants, in which a small chromosomal region defined by the SSR markers, PSM465 and RM1109, was heterozygous. The analysis
of recombinants in the fgr region anchored the gene locus to an interval of 28 kb flanked by the left marker NS9 and the right marker L06. Sequence
analysis of this fragment predicted three open reading frames encoding putative 3-methylcrotonyl-CoA carboxylase, putative
isoleucyl-tRNA synthetase, and betaine aldehyde dehydrogenase (BADH2). The latter was presumed to be the candidate gene for
fragrance. This result will be very useful in molecular cloning of the fgr gene and marker-assisted transfer of the fgr gene in rice breeding programs.
Published in Russian in Fiziologiya Rastenii, 2009, vol. 56, No. 4, pp. 587–595.
This text was submitted by the authors in English. 相似文献
19.
QTL analysis for rice grain length and fine mapping of an identified QTL with stable and major effects 总被引:32,自引:0,他引:32
Wan XY Wan JM Jiang L Wang JK Zhai HQ Weng JF Wang HL Lei CL Wang JL Zhang X Cheng ZJ Guo XP 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(7):1258-1270
Grain length in rice plays an important role in determining rice appearance, milling, cooking and eating quality. In this
study, the genetic basis of grain length was dissected into six main-effect quantitative trait loci (QTLs) and twelve pairs
of epistatic QTLs. The stability of these QTLs was evaluated in four environments using an F7 recombinant inbred line (RIL) population derived from the cross between a Japonica variety, Asominori, and an Indica variety, IR24. Moreover, chromosome segment substitution lines (CSSLs) harboring each of the six main-effect QTLs were used
to evaluate gene action of QTLs across eight environments. A major QTL denoted as qGL-3a, was found to express stably not only in the isogenic background of Asominori but also in the recombinant background of Asominori
and IR24 under multiple environments. The IR24 allele at qGL-3a has a positive effect on grain length. Based on the test of advanced backcross progenies, qGL-3a was dissected as a single Mendelian factor, i.e., long rice grain was controlled by a recessive gene gl-3. High-resolution genetic and physical maps were further constructed for fine mapping gl-3 by using 11 simple sequence repeat (SSR) markers designed using sequence information from seven BAC/PAC clones and a BC4F2 population consisting of 2,068 individuals. Consequently, the gl-3 gene was narrowed down to a candidate genomic region of 87.5 kb long defined by SSR markers RMw357 and RMw353 on chromosome
3, which provides a basis for map-based cloning of this gene and for marker-aided QTL pyramiding in rice quality breeding. 相似文献
20.