共查询到20条相似文献,搜索用时 31 毫秒
1.
Wenyin Zhu Jing Lin Dewei Yang Ling Zhao Yadong Zhang Zhen Zhu Tao Chen Cailin Wang 《Plant Molecular Biology Reporter》2009,27(2):126-131
Chromosome segment substitution lines (CSSLs) are powerful tools for detecting and precisely mapping quantitative trait loci
(QTLs) and evaluating gene action as a single factor. In this study, 103 CSSLs were produced using two sequenced rice cultivars:
93-11, an elite restorer indica cultivar as recipient, and Nipponbare, a japonica cultivar, as donor. Each CSSL carried a single chromosome substituted segment. The total length of the substituted segments
in the CSSLs was 2,590.6 cM, which was 1.7 times of the rice genome. To evaluate the potential application of these CSSLs
for QTL detection, phenotypic variations of seed shattering, grain length and grain width in 10 CSSLs were observed. Two QTLs
for seed shattering and three for grain length and grain width were identified and mapped on rice chromosomes. The results
demonstrate that CSSLs are excellent genetic materials for dissecting complex traits into a set of monogenic loci. These CSSLs
are of great potential value for QTL mapping and plant marker-assisted breeding (MAB). 相似文献
2.
Madoka Y Kashiwagi T Hirotsu N Ishimaru K 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(5):603-612
Rice (Oryza sativa L.) chromosome segment substitution lines (CSSLs), in which chromosomal segments of the Indian landrace “Kasalath” replace
the corresponding endogenous segments in the genome of the Japanese premium rice “Koshihikari”, are available and together
cover the entire genome. Chromosome regions affecting a trait (CRATs) can be identified by comparison of phenotypes with genotypes of CSSLs. We detected 99 CRATs for 15 agronomic
or morphological traits. “Kasalath” had positively acting alleles in 53 CRATs. Its CRATs increased panicle number per plant
by up to 23.3%, grain number per panicle by up to 30.8%, and total grain number by up to 15.1%, relative to “Koshihikari”.
CRATs were identified for grain size (grain thickness and width), with positive effects of about 5.0%. A CRAT on chromosome 8
almost doubled the weight of roots in uppermost soil layers compared to “Koshihikari”. Additionally, “Kasalath” possessed
CRATs for higher lodging resistance (reduction in plant height and increase in stem diameter). In some cases, multiple CRATs
were detected in the same chromosome regions. Therefore, CSSLs with these chromosome segments might be useful breeding materials
for the simultaneous improvement of multiple traits. Five CRATs, one for plant height on chromosome 1, one for stem diameter
on chromosome 8, and three for heading date on chromosomes 6, 7, and 8 overlapped with the corresponding QTLs that already
had been mapped with back-crossed inbred lines of “Nipponbare” and “Kasalath”. In both “Koshihikari” CRATs and “Nipponbare”
QTLs, “Kasalath” had similar effects.
Both Y. Madoka and T. Kashiwagi have contributed equally to this article. 相似文献
3.
Shimizu A Kato K Komatsu A Motomura K Ikehashi H 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,117(6):987-996
Root elongation induced by phosphorus deficiency has been reported as one of the adaptive mechanisms in plants. Genetic differences
were found in rice for the root elongation under phosphorus deficiency (REP), for which a distinct quantitative trait locus
(QTL) was detected on the long arm of chromosome 6. Subsequently, the effect and position of the QTL, designated as qREP-6, were confirmed using chromosome segment substitution lines (CSSLs), in which the background of a japonica cultivar, ‘Nipponbare’ with non-REP, was partially substituted by chromosomal segments from an indica cultivar, ‘Kasalath’ with remarkable REP. Out of 54 CSSLs, two lines (CSSL28 and CSSL29) that retain a common ‘Kasalath’-derived
segment on the long arm of chromosome 6 showed a significantly high REP. The high REP lines also showed high adaptabilities
such as enhanced tillering ability and shoot phosphorus content. Accordingly, conditional dependencies between the related
traits were assessed using a graphical Gaussian model (GGM). Direct interactions between REP and root length, and between
root length and tiller number were detected under P deficiency in CSSLs. Furthermore, qREP-6 for REP and qTNP-6 for tiller number under P deficiency were fine-mapped with an F2 population of a cross between Nipponbare and CSSL29. A region containing qREP-6 accounted for more than half of the phenotypic variance, the most plausible interval of which contained 37 candidate genes.
The result provides a foundation for cloning of the qREP-6 gene which will be applicable to study P deficiency-dependent response and to improve rice’s adaptability to P deficiency
stress.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
4.
Mature seed-derived callus of the model indica rice variety Kasalath is highly competent in Agrobacterium-mediated transformation 总被引:1,自引:0,他引:1
We previously established an efficient Agrobacterium-mediated transformation system using primary calli derived from mature seeds of the model japonica rice variety Nipponbare. We expected that the shortened tissue culture period would reduce callus browning—a common problem
with the indica transformation system during prolonged tissue culture in the undifferentiated state. In this study, we successfully applied
our efficient transformation system to Kasalath—a model variety of indica rice. The Luc reporter system is sensitive enough to allow quantitative analysis of the competency of rice callus for Agrobacterium-mediated transformation. We unexpectedly discovered that primary callus of Kasalath exhibits a remarkably high competency
for Agrobacterium-mediated transformation compared to Nipponbare. Southern blot analysis and Luc luminescence showed that independent transformation
events in primary callus of Kasalath occurred successfully at ca. tenfold higher frequency than in Nipponbare, and single
copy T-DNA integration was observed in ~40% of these events. We also compared the competency of secondary callus of Nipponbare
and Kasalath and again found superior competency in Kasalath, although the identification and subsequent observation of independent
transformation events in secondary callus is difficult due to the vigorous growth of both transformed and non-transformed
cells. An efficient transformation system in Kasalath could facilitate the identification of QTL genes, since many QTL genes
are analyzed in a Nipponbare × Kasalath genetic background. The higher transformation competency of Kasalath could be a useful
trait in the establishment of highly efficient systems involving new transformation technologies such as gene targeting. 相似文献
5.
Fine mapping of quantitative trait loci Hd-1, Hd-2 and Hd-3, controlling heading date of rice, as single Mendelian factors 总被引:32,自引:0,他引:32
T. Yamamoto Y. Kuboki S. Y. Lin T. Sasaki M. Yano 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):37-44
Fine mapping was carried out on three putative QTLs (tentatively designated as Hd-1 to Hd-3) of five such QTLs controlling heading date in rice that had been earlier identified using an F2 population derived from a cross between a japonica variety, ‘Nipponbare’, and an indica variety, ‘Kasalath’, using progeny backcrossed with ‘Nipponbare’ as the recurrent parent. One BC3F2 and two BC3F1 plants, in which the target QTL regions were heterozygous and most other chromosomal regions were homozygous for the ‘Nipponbare’
allele, were selected as the experimental material. Self-pollinated progeny (BC3F2 and BC3F3) of the BC3F1 or BC3F2 showed continuous variation in days to heading. By means of progeny testing based on BC3F3 or BC3F4 lines, we determined the genotypes of each BC3F2 or BC3F3 individual at target QTLs. Their segregation patterns fitted Mendelian inheritance ratios. When the results obtained by RFLP
analysis and progeny tests were combined, Hd-1, Hd-2 and Hd-3 were mapped precisely on chromosomes 6, 7 and 6, respectively, of a rice RFLP linkage map. The results demonstrated that
QTLs can be treated as Mendelian factors. Moreover, these precise locations were in good agreement with the regions estimated
by QTL analysis of the initial F2 population, demonstrating the high reliability of QTL mapping using a high-density linkage map.
Received: 5 November 1997 / Accepted: 10 February 1998 相似文献
6.
S. Negrão M. M. Oliveira K. K. Jena D. Mackill 《Molecular breeding : new strategies in plant improvement》2008,22(2):159-168
The cultivated rice (Oryza sativa L.) has two subspecies, indica and japonica. The japonica rice germplasm has a narrower genetic diversity compared to the indica subspecies. Rice breeders aim to develop new varieties with a higher yield potential, with enhanced resistances to biotic
and abiotic stresses, and improved adaptation to environmental changes. In order to face some of these challenges, japonica rice germplasm will have to be diversified and new breeding strategies developed. Indica rice improvement could also profit from more “genepool mingling” for which japonica rice could play an important role. Interesting traits such as low-temperature tolerance, and wider climate adaptation could
be introgressed into the indica subspecies. In the past decade, huge developments in rice genomics have expanded our available knowledge on this crop and
it is now time to use these technologies for improving and accelerating rice breeding research. With the full sequence of
the rice genome, breeders may take advantage of new genes. Also new genes may be discovered from the genepool of wild relatives,
or landraces of the genus Oryza, and incorporated into elite japonica cultivars in a kind of “gene revolution” program. Expectedly, new technologies that are currently being optimized, aiming
for novel gene discovery or for tracking the regions under selection, will be suggested as new breeding approaches. This paper
revisits breeding strategies successfully employed in indica rice, and discusses their application in japonica rice improvement (e.g. ideotype breeding, wide hybridization and hybrid performance). 相似文献
7.
Selvaraj Michael Gomez N. Manikanda Boopathi S. Satheesh Kumar T. Ramasubramanian Zhu Chengsong P. Jeyaprakash A. Senthil R. Chandra Babu 《Acta Physiologiae Plantarum》2010,32(2):355-364
Drought is a major limitation for rice production in rainfed ecosystems. Identifying quantitative trait loci (QTLs) linked
to drought resistance provides opportunity to breed high yielding rice varieties suitable for drought-prone areas. Although
considerable efforts were made in mapping QTLs associated with drought-resistance traits in rice, most of the studies involved
indica × japonica crosses and hence, the drought-resistance alleles were contributed mostly by japonica ecotypes. It is desirable to look for genetic variation within indica ecotypes adapted to target environment (TE) as the alleles from japonica ecotype may not be expressed under lowland conditions. A subset of 250 recombinant inbred lines (RILs) of F8 generation derived from two indica rice lines (IR20 and Nootripathu) with contrasting drought-resistance traits were used to map the QTLs for morpho-physiological
and plant production traits under drought stress in the field in TE. A genetic linkage map was constructed using 101 polymorphic
PCR-based markers distributed over the 12 chromosomes covering a total length of 1,529 cM in 17 linkage groups with an average
distance of 15.1 cM. Composite interval mapping analysis identified 22 QTLs, which individually explained 4.8–32.2% of the
phenotypic variation. Consistent QTLs for drought-resistance traits were detected using locally adapted indica ecotypes, which may be useful for rainfed rice improvement. 相似文献
8.
Zhao ZG Jiang L Zhang WW Yu CY Zhu SS Xie K Tian H Liu LL Ikehashi H Wan JM 《Planta》2007,226(5):1087-1096
Partial abortion of female gametes and the resulting semi-sterility of indica × japonica inter-subspecific rice hybrids have been ascribed to an allelic interaction, which can be avoided by the use of wide compatibility
varieties. To further understand the genetic mechanism of hybrid sterility, we have constructed two sets of hybrids, using
as male parent either the typical japonica variety Asominori, or the wide compatibility variety 02428; and as female, a set of 66 chromosome segment substitution lines
in which various chromosomal segments from the indica variety IR24 have been introduced into a common genetic background of Asominori. Spikelet semi-sterility was observed in
hybrid between CSSL34 and Asominori, which is known to carry the sterility gene S31 (Zhao et al. in Euphytica 151:331–337, 2006). Cytological analysis revealed that the semi-sterility of the CSSL34 × Asominori hybrid was caused primarily by partial
abortion of the embryo sac at the stage of the mitosis of the functional megaspore. A population of 1,630 progeny of the three-way
cross (CSSL34 × 02428) × Asominori was developed to map S31. Based on the physical location of linked molecular markers, S31 was thereby delimited to a 54-kb region on rice chromsome 5. This fragment contains eight predicted open reading frames,
four of which encode known proteins and four putative proteins. These results are relevant to the map-based cloning of S31, and the development of marker-assisted transfer of non-sterility allele inducing alleles to breeding germplasm, to allow
for a more efficient exploitation of heterosis in hybrid rice. 相似文献
9.
Prasanta K. Subudhi Teresa De Leon Pradeep K. Singh Arnold Parco Marc A. Cohn Takuji Sasaki 《PloS one》2015,10(6)
Chromosome segment substitution lines (CSSLs) are a powerful alternative for locating quantitative trait loci (QTL), analyzing gene interactions, and providing starting materials for map-based cloning projects. We report the development and characterization of a CSSL library of a U.S. weedy rice accession ‘PSRR-1’ with genome-wide coverage in an adapted rice cultivar ‘Bengal’ background. The majority of the CSSLs carried a single defined weedy rice segment with an average introgression segment of 2.8 % of the donor genome. QTL mapping results for several agronomic and domestication traits from the CSSL population were compared with those obtained from two recombinant inbred line (RIL) populations involving the same weedy rice accession. There was congruence of major effect QTLs between both types of populations, but new and additional QTLs were detected in the CSSL population. Although, three major effect QTLs for plant height were detected on chromosomes 1, 4, and 8 in the CSSL population, the latter two escaped detection in both RIL populations. Since this was observed for many traits, epistasis may play a major role for the phenotypic variation observed in weedy rice. High levels of shattering and seed dormancy in weedy rice might result from an accumulation of many small effect QTLs. Several CSSLs with desirable agronomic traits (e.g. longer panicles, longer grains, and higher seed weight) identified in this study could be useful for rice breeding. Since weedy rice is a reservoir of genes for many weedy and agronomic attributes, the CSSL library will serve as a valuable resource to discover latent genetic diversity for improving crop productivity and understanding the plant domestication process through cloning and characterization of the underlying genes. 相似文献
10.
Li M Sun P Zhou H Chen S Yu S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(3):411-420
Rapid and uniform seed germination under diverse environmental conditions is a desirable characteristic for most crop plants,
such as rice, wheat, and maize. However, the genetic base of the variations in the rate of germination is not well understood.
In this study, quantitative trait loci (QTL) for germination rate were mapped with a set of 143 chromosome segment substitution
lines (CSSL) each contains a small genomic fragment from a japonica variety Nipponbare in the uniform genetic background of an indica variety Zhenshan97. Nine CSSL showed significantly lower germination rate than that in Zhenshan97. Four germination-related
QTL were identified located on chromosomes 2, 5, 6 and 10, at which all japonica alleles decreased germination rate. By using the CSSL-derived F2 population, a major QTL (qGR2) on chromosome 2 was confirmed, and delimited to a 10.4 kb interval containing three putative candidate genes, of which OsMADS29 was only expressed preferentially in the seed. These results would facilitate cloning of the major gene that affects germination
rate, and provide an insight into the genetic basis of germination. 相似文献
11.
Zhang H Zhang CQ Sun ZZ Yu W Gu MH Liu QQ Li YS 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(7):1247-1256
Chromosome segment duplications are integral in genome evolution by providing a source for the origin of new genes. In the
rice genome, besides an ancient polyploidy event known in the rice common ancestor, it had been identified that there was
a special segmental duplication involving chromosomes 11 and 12, but the biological role of this duplication remains unknown.
In this study, by using a set of chromosome segment substitution lines (CSSLs) and near isogenic lines (NILs) derived from
the indica cultivar 9311 and japonica cultivar Nipponbare, a major QTL (qS12) resulting in hybrid male sterility was mapped within ~400 kb region adjacent to the special duplicated segment on the short
arm of chromosome 12. Compared to the japonica cultivar Nipponbare, the two sides of the qS12 candidate region were inverted in the indica cultivar 9311. Among 47 of the 111 rice genotypes evaluated by molecular markers, the inverted sides were detected, and found
completely homologous to indica cultivar 9311. These results suggested that the two inverted sides protect the sequence in the qS12 regions from recombination. On the short-arm of chromosome 12, two QTLs S-e and S25, in addition to qS12, were previously detected as a distinct segregation distortion and pollen semi-sterility loci. We propose these three hybrid
sterility loci are the same locus, and the duplicated segment on chromosome 12 may play a prominent role in diversification,
i.e., sub-speciation of cultivated rice. 相似文献
12.
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
13.
Aluminum (Al) toxicity is considered as one of the primary causes of low-rice productivity in acid soils. In the present study, quantitative trait loci (QTLs) controlling Al resistance based on relative root elongation (RRE) were dissected using a complete linkage map and a recombinant inbred lines (RILs) derived from a cross of Al-tolerant japonica cultivar Asominori (Oryza sativa L.) and Al-sensitive indica cultivar IR24 (O. sativa L.). A total of three QTLs (qRRE-1, qRRE-9, and qRRE-11) were detected on chromosomes 1, 9, and 11 with LOD score ranging from 2.64 to 3.60 and the phenotypic variance explained from 13.5 to 17.7%. The Asominori alleles were all associated with Al resistance at all the three QTLs. The existence of these QTLs was confirmed using Asominori chromosome segment substitution lines (CSSLs) in IR24 genetic background (IAS). By QTL comparative analysis, the two QTLs (qRRE-1and qRRE-9) on chromosomes 1 and 9 appeared to be consistent among different rice populations while qRRE-11 was newly detected and syntenic with a major Al resistance gene on chromosome 10 of maize. This region may provide an important case for isolating genes responsible for different mechanisms of Al resistance among different cereals. These results also provide the possibilities of enhancing Al resistance in rice breeding program by marker-assisted selection (MAS) and pyramiding QTLs. 相似文献
14.
Detection and analysis of QTLs for resistance to the brown planthopper, Nilaparvata lugens, in a doubled-haploid rice population 总被引:5,自引:0,他引:5
S. N. Alam M. B. Cohen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(8):1370-1379
We used a mapping population of 131 doubled-haploid lines, produced from a cross between an improved indica rice variety (IR64) and a traditional japonica variety (Azucena), to detect quantitative trait loci (QTLs) for resistance to the brown planthopper (BPH), Nilaparvata lugens. We evaluated the parents and mapping population with six tests that measure varying combinations of the three basic mechanisms
of insect host plant resistance, i.e., antixenosis, antibiosis, and tolerance. To factor-out the effect of the major resistance
gene Bph1 from IR64, the screening was done with two BPH populations from Luzon Island, The Philippines, that are almost completely
adapted to this gene. A total of seven QTLs associated with resistance were identified, located on 6 of the 12 rice chromosomes.
Individual QTLs accounted for between 5.1 and 16.6% of the phenotypic variance. Two QTLs were predominantly associated with
a single resistance mechanism: one with antixenosis and one with tolerance. Most of the QTLs were derived from IR64, which
has been shown to have a relatively durable level of moderate resistance under field conditions. The results of this study
should be useful in transferring this resistance to additional rice varieties.
Received: 10 May 1998 / Accepted: 4 June 1998 相似文献
15.
Yujia Leng Shuilian Wang Ruoan Wang Tao Tao Shuwen Jia Tao Song Lina Xu Xiuling Cai Sukui Jin Jiping Gao 《Phyton》2022,91(5):943-958
Grain size traits are critical agronomic traits which directly determine grain yield, but the genetic bases of these traits are still not well understood. In this study, a total of 154 chromosome segment substitution lines (CSSLs) population derived from a cross between a japonica variety Koshihikari and an indica variety Nona Bokra was used to investigate grain length (GL), grain width (GW), length-width ratio (LWR), grain perimeter (GP), grain area (GA), and thousand grain weight (TGW) under four environments. QTL mapping analysis of six grain size traits was performed by QTL IciMapping 4.2 with an inclusive composite interval mapping (ICIM) model. A total of 64 QTLs were identified for these traits, which mapped to chromosomes 1, 2, 3, 4, 6, 7, 8, 10, 11, and 12 and accounted for 1.6%–27.1% of the total phenotypic variations. Among these QTLs, thirty-six loci were novel and seven QTLs were identified under four environments. One locus containing the known grain size gene, qGL3/GL3.1/OsPPKL1, also have been found. Moreover, five pairs of digenic epistatic interactions were identified except for GL and GP. These findings will facilitate fine mapping of the candidate gene and QTL pyramiding to genetically improve grain yield in rice. 相似文献
16.
Yojiro Taniguchi Motoshige Kawata Ikuo Ando Tsutomu Shimizu Masahiro Ohshima 《Plant cell reports》2010,29(11):1287-1295
Bispyribac sodium (BS), a pyrimidinyl carboxy herbicide, is a well-known inhibitor of acetolactate synthase (ALS) activity.
ALS is an enzyme in the biosynthetic pathway for branched-chain amino acids. A mutant form of rice ALS (OsmALS [W548L/S627I]) that confers resistance to BS can be used as an in vitro selection marker gene for plant transformation. Since indica and indica-derived cultivars are thought to have lower BS sensitivity than japonica rice, the application of BS as a selectable reagent for genetic transformation in indica and indica-derived cultivars is more challenging than for japonica cultivars. In this study, callus and seedlings of eight different rice cultivars (five indica-derived cultivars, two indica cultivars and one japonica cultivar) were tested for BS sensitivity. Our study indicates for the first time that callus shows a higher sensitivity to
BS than seedlings in indica and indica-derived cultivars. We used BS with OsmALS [W548L/S627I] to select transformed calli, and transgenic rice plants from indica and indica-derived cultivars were successfully obtained. 相似文献
17.
Mapping and characterization of seed dormancy QTLs using chromosome segment substitution lines in rice 总被引:1,自引:0,他引:1
Marzougui S Sugimoto K Yamanouchi U Shimono M Hoshino T Hori K Kobayashi M Ishiyama K Yano M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(5):893-902
Seed dormancy—the temporary failure of a viable seed to germinate under favorable conditions—is a complex characteristic influenced
by many genes and environmental factors. To detect the genetic factors associated with seed dormancy in rice, we conducted
a QTL analysis using chromosome segment substitution lines (CSSLs) derived from a cross between Nona Bokra (strong dormancy)
and Koshihikari (weak dormancy). Comparison of the levels of seed dormancy of the CSSLs and their recurrent parent Koshihikari
revealed that two chromosomal regions—on the short arms of chromosomes 1 and 6—were involved in the variation in seed dormancy.
Further genetic analyses using an F2 population derived from crosses between the CSSLs and Koshihikari confirmed the allelic differences and the chromosomal locations
of three putative QTLs: Sdr6 on chromosome 1 and Sdr9 and Sdr10 on chromosome 6. The Nona Bokra alleles of the three QTLs were associated with decreased germination rate. We discuss the
physiological features of the CSSLs and speculate on the possible mechanisms of dormancy in light of the newly detected QTLs. 相似文献
18.
A "defeated" rice resistance gene acts as a QTL against a virulent strain of Xanthomonas oryzae pv. oryzae 总被引:7,自引:0,他引:7
Li ZK Luo LJ Mei HW Paterson AH Zhao XH Zhong DB Wang YP Yu XQ Zhu L Tabien R Stansel JW Ying CS 《Molecular & general genetics : MGG》1999,261(1):58-63
The genetic components responsible for qualitative and quantitative resistance of rice plants to three strains (CR4, CXO8,
and CR6) of Xanthomonas oryzae pv. oryzae (Xoo) were investigated using a set of 315 recombinant inbred lines (RILs) from the cross Lemont (japonica) × Teqing (indica) and a complete linkage map with 182 well distributed RFLP markers. We mapped a major gene (Xa4) and ten quantitative trait loci (QTLs) which were largely responsible for segregation of the resistance phenotype in the
RILs. The Teqing allele at the Xa4 locus, Xa4
T
, acted as a dominant resistance gene against CR4 and CXO8. The breakdown of Xa4
T
-associated resistance mediated by the mutant allele at the avrXa4 locus in the virulent strain CR6 results from significant changes in both gene action (lose of dominance) and the magnitude
of gene effect (≈50% reduction). Nevertheless, Xa4
T
still acted as a recessive QTL with a significant residual effect against CR6. The mutant alleles at the avrXa4 locus in CXO8 and CR6 that lead to a reduction in effect, or “breakdown”, of Xa4
T
were apparently accompanied by corresponding penalties for their fitness. The quantitative component of resistance to Xoo in the RILs was largely due to a number of resistance QTLs. Most resistance QTLs mapped to genomic locations where major
resistance genes and/or QTLs for resistance to Xoo, blast and sheath blight were identified in the same cross. Most QTLs showed consistent levels of resistance against all
three Xoo strains. Our results suggest that a high level of durable resistance to Xoo may be achieved by the cumulative effects of multiple QTLs, including the residual effects of “defeated” major resistance
genes.
Received: 28 April 1998 / Accepted: 9 October 1998 相似文献
19.
Analysis of indica- and japonica-specific markers of Oryza sativa and their applications 总被引:1,自引:0,他引:1
Xiao-Jun Dai Yuan-Zhu Yang Liang Zhou Li-Jun Ou Man-Zhong Liang Wen-Jia Li Gong-Ping Kang Liang-Bi Chen 《Plant Systematics and Evolution》2012,298(2):287-296
Asian rice, Oryza sativa L., is one of the most important crop species. Genetic analysis has established that rice consists of several genetically
differentiated variety groups, with two main groups, namely, O. sativa ssp. japonica kata and ssp. indica
kata. To determine the genetic diversity of indica and japonica rice, 45 rice varieties, including domesticated rice and Asia common wild rice (O. rufipogon Griff.), were analyzed using sequence-related amplified polymorphism, target region amplified polymorphism, simple sequence
repeat, and intersimple sequence repeat marker systems. A total of 90 indica- and japonica-specific bands between typical indica and japonica subspecies were identified, which greatly helped in determining whether domesticated rice is of the indica or japonica type, and in analyzing the consanguinity of hybrid rice with japonica, which were bred from indica and japonica crossed offspring. These specific bands were both located in the coding and non-encoding region, and usually connected with
quantitative trait loci. Utilizing the indica-japonica-specific markers, japonica consanguinity was detected in sterile hybrid rice lines. Many indica-japonica-specific bands were found in O. rufipogon. This result supports the multiple-origin model for domesticated rice. Javanica exhibited a greater number of indica-japonica-specific bands, which indicates that it is a subspecies of O. sativa L. 相似文献
20.
本研究分别利用SSR标记、InDel标记以及简化基因组测序技术对一套以普通野生稻为供体亲本,9311为受体亲本的染色体置换系进行基因型鉴定,并通过对其不同生育期的耐盐性鉴定,共发掘2个与发芽期耐盐相关的QTL,13个与苗期耐盐性相关的QTL。其中与苗期存活率相关的QTL qSSR5.1、苗期耐盐等级相关的QTL qSSG5.1均被定位于同一位点,该位点对苗期存活率、苗期耐盐等级均具有增效作用,贡献率分别为6.36%、8.13%。在此QTL内包含与非生物胁迫相关基因OsDi19-1。经序列比对发现,OsDi19-1启动子区域在两亲本间存在较大差异,且受到盐胁迫时该基因表达量上升。同时,鉴定出水稻芽期耐盐的优异种质资源CSSL72、苗期耐盐的优异种质资源CSSL23、CSSL153,为水稻育种中耐盐性的改良提供了新的种质资源。 相似文献