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1.
A genetic linkage map with 70 loci (55 SSR, 12 AFLP and 3 morphological loci) was constructed using 117 F2 plants obtained from a cross between two upland cotton cultivars Yumian 1 and T586, which have relatively high levels of DNA marker polymorphism and differ remarkably in fiber-related traits. The linkage map comprised of 20 linkage groups, covering 525 cM with an average distance of 7.5 cM between two markers, or approximately 11.8% of the recombination length of the cotton genome. The present genetic linkage map was used to identify and map the quantitative trait loci (QTLs) affecting lint percentage and fiber quality traits in 117 F2:3 family lines. Sixteen QTLs for lint percentage and fiber quality traits were identified in six linkage groups by multiple interval mapping: four QTLs for lint percentage, two QTLs for fiber 2.5% span length, three QTLs for fiber length uniformity, three QTLs for fiber strength, two QTLs for fiber elongation and two QTLs for micronaire reading. The QTL controlling fiber-related traits were mainly additive, and meanwhile including dominant and overdominant. Several QTLs affecting different fiber-related traits were detected within the same chromosome region, suggesting that genes controlling fiber traits may be linked or the result of pleiotropy.  相似文献   

2.
A. Blanco    C. de  Giovanni  B. Laddomada    A. Sciancalepore    R. Simeone    K. M. Devos    M. D. Gale 《Plant Breeding》1996,115(5):310-316
Seed storage protein content of durum wheat (Triticum turgidum var. durum) has an important effect on nutritional value and pasta-making characteristics. The objective of this study was to determine by association with genetic markers the number, chromosomal location, and magnitude of effect of quantitative trait loci (QTLs) controlling protein concentration in kernels. A set of 65 recombinant inbred lines (RIs) was developed by single seed descent from a cross between cultivated durum wheat cv. ‘Messapia’ (low protein content) and accession MG4343 of the wild tetraploid wheat var. dicoccoides (high protein content). This population was characterized for eight morphological, six storage protein, one isozyme and 124 RFLP loci. Field trials were conducted in one location in 1993 and two locations in 1994. QTLs were mapped by regression analysis on each marker locus for each location and for the average across environments. A total of six putative QTLs were located on chromosome arms 4BS, SAL, 6AS, 6BS and 7BS. The number and size of QTLs detected varied across environments. The marker with the highest r2 value per QTL in each environment and across environments was chosen for a multiple linear regression analysis, which explained 49.2- 56.4% of the phenotypic variation for protein content. Only some of the markers were found to be negatively associated with plant grain yield and/or seed weight in one or two of the environments.  相似文献   

3.
Cooking quality in rice grains is a complex trait which requires improvement. Earlier reports show varying genetic influence on these traits, except for a common agreement on waxy (Wx) and alkali degeneration (Alk) loci on chromosome 6. The present study involved 86 doubled haploid lines derived from an indica × japonica cross involving IR64 and Azucena. Grain parameters viz., raw grain length (RGL), raw grain breadth (RGB), cooked grain length (CGL), cooked grain breadth (CGB), gelatinization temperature (GT), grain shape (RGS), length elongation ratio (LER) and breadth expansion ratio (BER) were subjected to mixed model mapping of quantitative trait loci (QTL). Segregation data of 175 markers covering a distance of 2395.5 cM spanning the entire genome were used. Fifteen main effect QTLs were detected spread over the genome, except on chromosomes 4, 8 and 11. Thirty epistatic interactions significantly influencing the traits were detected. Twelve of the main effect QTLs were involved in epistatic interactions. One main effect QTL associated with LER was detected near Alk locus. QTLs located for grain length on chromosomes 9 and 10 are reported for the first time. Detection of many epistatic loci and involvement of main effect QTLs in interactions demand for judicious selection of QTLs in marker-assisted selection programmes.  相似文献   

4.
To study the genetic basis of rice flag leaf morphology, quantitative genetic analysis was conducted in a population of 37 chromosome segment substitution lines (CSSLs) of indica elite variety ‘Habataki’ in the background of japonica cultivar ‘Sasanishiki’ across three different environments. The CSSLs showed normal distribution with transgressive segregation, indicating that these four traits are controlled by polygenes. Moreover, analyses of variance showed that these traits were highly influenced by the growing environment, which are typical for polygenic quantitative traits. Seven quantitative trait loci (QTLs) on four chromosomes were detected in total: four for flag leaf width, one for flag leaf area and two for flag leaf angle. Two key QTLs, qFLW4 and qFLAG5 controlling flag leaf width and angle, respectively, were identified in all three environments. These QTLs could provide useful information for marker‐assisted selection in improving the performance of plant architecture with regard to leaf angle and area. Moreover, developed CSSLs with these QTLs information are also useful research materials to reveal the importance of leaf morphology in relation to grain yield.  相似文献   

5.
Dry matter accumulation (DMA) and photosynthetic capacity are important traits that influence biological yield and ultimate grain yield in wheat. In this study, quantitative trait loci (QTLs) analyses for DMA of stem, leaves, total plant and photosynthesis traits (Fv/Fm) at the jointing and anthesis stages were studied, using a set of 168 doubled haploid lines (DHLs) derived from the cross Huapei 3 (HP3)/Yumai 57 (YM57). QTL analyses were performed using QTL-Network 2.0 software based on the mixed linear model approach. A total of 18 additive QTLs and 12 pairs of epistatic QTLs were distributed on 16 of the 21 chromosomes. Most of the additive QTLs associated with DMA co-located in the same or adjacent chromosome intervals with QTLs for grain yield and related traits. A major locus Qculmc.sau-5D.1 (14.2%) close to the molecular marker Xwmc215 detected at the jointing stage was shared by QTLs for heading date and vernalization sensitivity, indicating tight linkages or pleiotropisms. One pair of epistatic QTLs, Qleavesc.sau-4A and Qleavesc.sau- 6B, explained 13.11% of the phenotypic variation at anthesis. All QTL × environment interactions were detected at the jointing stage, showing the importance of the jointing stage in determining the final outcome of plant development.  相似文献   

6.
日本水稻品种越光稻米的外观品质性状的QTL遗传剖析   总被引：1，自引：0，他引：1  
稻米外观品质是稻米品质的一个重要方面,是消费者选择的重要依据之一,在一定程度上影响稻米市场价格。本研究利用一个日本优质粳稻品种越光(轮回亲本)和一个印度的籼稻品种Kasalath杂交产生的回交重组自交系(backcross recombinant inbred lines,BILs)对7个控制稻米外观品质主要性状(粒长、粒宽、粒厚、粒长宽比、垩白粒率、垩白大小和垩白度)数量性状基因位点（quantitative trait locus,QTL）进行定位分析。共检测到影响7个性状的22个QTLs,分布在8条染色体上,贡献率为5.65％-29.20％。其中在第5染色体上的R2232分子标记附近区域检测到影响4个性状的QTLs;在第3染色体上C1448和第6染色体G200分子标记附近区域分别检测到同时影响3个性状的QTLs,表明了这3个染色体区域对控制稻米外观品质性状中的有着重要作用。本研究检测到的QTLs及其两侧的分子标记可以用于改良稻米外观品质的分子辅助育种。  相似文献   

7.
X. J. Ge    Y. Z. Xing    C. G. Xu  Y. Q. He 《Plant Breeding》2005,124(2):121-126
The traits of elongation, volume expansion, and water absorption are very important in determining the quality of cooked rice grains. In this study, quantitative trait loci (QTL) analysis of these traits was performed using a recombinant inbred population derived from a cross between two indica cultivars, ‘Zhenshan 97’ and ‘Minghui 63 ,’ which are the parents of the most widely grown hybrid rice in China. Using a linkage map based on 221 molecular marker loci covering a total of 1796 cM, a total of 33 QTLs were identified for the nine traits tested. QTLs were detected on chromosomes 1– 3 , 5– 9 , and 11 , respectively. The QTLs identified included three for cooked rice grain length elongation (chromosomes 2 , 6 , and 11), six for width expansion (chromosomes 1‐ 3 , 6 , 9 , and 11) and two for water absorption (chromosomes 2 and 6). Interestingly, a single QTL located near the wx gene on chromosome 6 seemed to influence all the traits tested for the cooked rice quality.  相似文献   

8.
Y. Xu  S. Li  L. Li  X. Zhang  H. Xu  D. An 《Plant Breeding》2013,132(3):276-283
Quantitative trait loci (QTLs) for salt tolerance with additive, epistatic and QTL × treatment interaction effects at seedling stage in wheat were identified. A set of 131 recombinant inbred lines derived from cross Chuan 35050 × Shannong 483 were evaluated under salt stress and normal conditions. Wide variation was found for all studied traits. A total of 18 additive and 16 epistatic QTLs were detected, among which five and 11 were with significant QTL × treatment effects. Ten QTL clusters were identified, and each may represent a single gene or closely linked genes. The locus controlling shoot K+/Na+ concentration ratio and shoot Na+ concentration on chromosome 5A may be identical to Nax2. The interval Xgwm6‐Xgwm538 on chromosome 4B for total dry weight was also identified in a previous study, both near the marker Xgwm6. The marker Xgwm6 may be useful for marker‐assisted selection. Six pairs of homoeologous QTLs were detected, showing synteny among the A, B and D genomes. These results facilitate understanding the mechanisms and the genetic basis of salt tolerance in wheat.  相似文献   

9.
稻米直链淀粉含量基因座位的分子标记定位   总被引：29，自引：0，他引：29  
以直链淀粉含量(AC)中等的CT9993和泰国优质的香软米KDML105杂交产生的152个重组近交系 (RIL)为材料, 构建了含83个RFLP、 69个AFLP和15个微卫星(SSLP)标记的分子标记连锁图 , 标记间平均距离为12.98 cM。 应用该连锁图对控制稻米AC的基因座位(QTL)进行了分析 。 结果表明： 稻米AC主要受两个主效QTL和5个微效QTL的共同控制  相似文献   

10.
Y. Li  Y. Song  R. Zhou  G. Branlard  J. Jia 《Plant Breeding》2009,128(3):235-243
Whereas gluten fraction accounts for 30–60% of the variation in wheat bread‐making quality, there remains substantial variation determined by non‐gluten factors. The objective of this study was to detect new loci for wheat quality. The genetics of sodium dodecyl sulphate‐sedimentation volume (Ssd), grain hardness (GH), grain protein content, wet gluten content (WGC) and water absorption (Abs) in a set of 198 recombinant inbred lines derived from two commercial varieties was studied by quantitative trait loci (QTL) analysis. A genetic map based on 255 marker loci, consisting of 250 simple sequence repeat markers and five glutenin loci, Glu‐A1, Glu‐B1, Glu‐D1, Glu‐B3 and Glu‐D3, was constructed. A total of 73 QTLs were detected for all traits. A major QTL for GH was detected on chromosome 1B and its relative contribution to phenotypic variation was 27.7%. A major QTL for Abs on chromosome 5D explained more than 30% of the phenotypic variation. Variations in Ssd were explained by four kinds of genes. Some QTLs for correlated traits mapped to the same regions forming QTL clusters or indicated pleiotropic effects.  相似文献   

11.
Grain shape is an important trait for improving rice yield. A number of quantitative trait loci (QTLs) for this trait have been identified by using primary F2 mapping populations and recombinant inbred lines, in which QTLs with a small effect are harder to detect than they would be in advanced generations. In this study, we developed two advanced mapping populations (chromosome segment substitution lines [CSSLs] and BC4F2 lines consisting of more than 2000 individuals) in the genetic backgrounds of two improved cultivars: a japonica cultivar (Koshihikari) with short, round grains, and an indica cultivar (IR64) with long, slender grains. We compared the ability of these materials to reveal QTLs for grain shape with that of an F2 population. Only 8 QTLs for grain length or grain width were detected in the F2 population, versus 47 in the CSSL population and 65 in the BC4F2 population. These results strongly suggest that advanced mapping populations can reveal QTLs for agronomic traits under complicated genetic control, and that DNA markers linked with the QTLs are useful for choosing superior allelic combinations to enhance grain shape in the Koshihikari and IR64 genetic backgrounds.  相似文献   

12.
Low grain cadmium (Cd) and high grain zinc (Zn) rice cultivars have become the current rice breeding objectives. However, the genetic control of Cd and Zn concentrations in brown rice remains poorly understood, especially when grown in Cd-contaminated soil. In this study, quantitative trait loci (QTLs) associated with grain Cd and Zn concentrations and Cd/Zn ratio were identified using a doubled haploid population derived from a cross between japonica JX17 and indica ZYQ8 rice cultivars. Three and two QTLs were detected for Cd and Zn concentration in brown rice, respectively. Two QTLs associated with grain Cd/Zn ratio on chromosomes 3 and 6 were initially mapped. These QTLs accounted for 10.83–41.66% of the total variance of the three traits measured. Only one common locus on chromosome 6 was found for Cd concentration and Cd/Zn ratio. The lack of co-location of the QTLs for Cd and Zn concentrations in this mapping population suggests different genetic mechanisms. In summary, our results provide insight into the genetic basis of rice grain Cd and Zn accumulation; the isolated QTLs may be useful for marker-assisted selection and identification of genes associated with Cd and Zn accumulation in rice.  相似文献   

13.
Barley—Pyrenophora graminea interaction: QTL analysis and gene mapping   总被引：2，自引：0，他引：2  
Pyrenophora graminea is a seed-borne pathogen and is the causal agent of the barley leaf stripe disease. Our aim is to study the genetic basis of barley resistance to leaf stripe. A qualitatively acting resistance factor has been identified in the cultivar ‘Vada’ and the partial resistance of the cultivar ‘Proctor’ to a P. graminea isolate has been demonstrated to be dominated by a major quantitative trait locus (QTL), mapped on barley chromosome 1. Map colinearity between the leaf stripe ‘Proctor’ resistance QTLs,‘Vada’ resistance to leaf stripe, and other disease resistance loci have been investigated in this work using molecular markers. Moreover, since inoculation of barley rootlets by the fungus had been shown to induce the accumulation of several PR (pathogen-related) mRNA families, seven barley PR genes have been mapped as RFLPs, and one assigned to a chromosome arm via ditelosomic analysis to verify possible map associations with resistance QTLs. This work discusses the genetic relationships between the known leaf stripe resistance loci, resistance loci towards other seed-borne pathogens and defence gene loci.  相似文献   

14.
K. Kato    H. Miura  S. Sawada 《Plant Breeding》1999,118(5):391-394
A homoeologous quantitative trait locus to that of eps5L on barley chromosome 5H was identified in a syntenic region of wheat chromosome 5A. Wheat single chromosome recombinant lines (SCRs) were developed from a cross between ‘Chinese Spring’(‘Cappelle-Desprez’ 5A) and ‘Chinese Spring’(Triticum spelta 5A), these were grown together with the parental controls under different vernalization and photoperiod regimes. The variation for ear emergence time accelerated heading induced by the T. spelta segment indicated an effect associated with the Xcdo412-Xbcd9 interval. Since no differences between the SCRs and controls in responses to vernalization and photoperiod treatments were detected, this effect was identified as an earliness per se gene, Q Eetocs-5 A.2, which may be homoeologous to the eps5L quantitative trait locus of barley. Xbcd926 has been found to be closely linked to the rice flowering time quantitative trait loci, QHd9a or FLTQ2, on chromosome 9, suggesting possible relationships among the quantitative trait loci across wheat, barley and rice genomes.  相似文献   

15.
Improving grain-quality is an important goal in rice breeding programs. One vital step is to find major quantitative trait loci (QTLs) for quality related traits and then investigate the relationships among them. We crossed ‘N22’, an indica variety with good appearance but low grain weight, to a japonica variety, ‘Nanjing35’, with superior grain yield but poor appearance. This enabled us to construct an F2 population and a set of backcross inbred lines (BILs) for QTL-mapping for the traits related grain appearance. In all, 37 QTLs were identified for grain length (GL), grain width (GW), grain thickness (GT), thousand-grain weight (TGW), and the percentage of grains with chalkiness (PGWC). Of these, 17 QTLs detected from 184 plants in the F2 population explained 4.97–27.26 % of the phenotypic variance, another 20 QTLs were identified using BILs from 2009 to 2010. Quantitative trait loci for major effects were detected in different populations and across years. A new QTL hot spot (marker interval RM504–RM520) was found on Chromosome 3, which harbored QTLs for GL, GW, GT, and TGW. Among our five examined traits, grain shape was significantly correlated with TGW and PGWC. The PGWC values of two heavier grains BILs, L93, and L145 are much lower than Nanjiing35, the analysis of genotype showed that this greater weight may due to the locus for GL occurring within RM504–RM520 on Chromosome 3. Therefore, those two lines will allow us to develop a long-grain high-yield rice variety with less chalkiness.  相似文献   

16.
Grain size is a main component of rice appearance quality. In this study, we performed the SSR mapping of quantitative trait loci (QTLs) controlling grain size (grain length and breadth) and shape (length/breadth ratio) using an F2 population of a cross between two Iranian cultivars, Domsephid and Gerdeh, comprising of 192 individuals. A linkage map with 88 markers was constructed, which covered 1367.9 cM of the rice genome with an average distance of 18 cM between markers. Interval mapping procedure was used to identify the QTLs controlling three grain traits, and QTLs detected were further confirmed using composite interval mapping. A total of 11 intervals carrying 18 QTLs for three traits were identifed, that included five QTLs for grain length, seven QTLs for grain breadth, and six QTLs for grain shape. A major QTL for grain length was detected on chromosome 3, that explained 19.3% of the phenotypic variation. Two major QTLs for grain breadth were mapped on chromosomes 3 and 8, which explained 34.1% and 20% of the phenotypic variation, respectively. Another two major QTLs were identified for grain shape on chromosomes 3 and 8, which accounted for 27.1% and 20.5% of the phenotypic variance, respectively. The two QTLs that were mapped for grain shape coincided with the major QTLs detected for grain length and grain breadth. Intrestingly, gs2 QTL specific to grain shape was detected on chromosome 2 that explained 15% of the phenotypic variation.  相似文献   

17.
Mapping QTLs in breeding for drought tolerance in maize (Zea mays L.)   总被引：13，自引：0，他引：13  
Summary Grain yield in the maize (Zea mays L) plant is sensitive to drought in the period three weeks either side of flowering. Maize is well-adapted to the use of restriction fragment length polymorphisms (RFLPs) to identify a tight linkage between gene(s) controlling the quantitative trait and a molecular marker. We have determined the chromosomal locations of quantitative trait loci (QTLs) affecting grain yield under drought, anthesis-silking interval, and number of ears per plant. The F3 families derived from the cross SD34(tolerant) × SD35 (intolerant) were evaluated for these traits in a two replicated experiment. RFLP analysis of the maize genome included non-radioactive DNA-DNA hybridization detection using chemiluminescence. To identify QTLs underlying tolerance to drought, the mean phenotypic performances of F3 families were compared based on genotypic classification at each of 70 RFLP marker loci. The genetic linkage map assembled from these markers was in good agreement with previously published maps. The phenotypic correlations between yield and other traits were highly significant. In the combined analyses, genomic regions significantly affecting tolerance to drought were found on chromosomes 1,3,5,6, and 8. For yield, a total of 50% of the phenotypic variance could be explained by five putative QTLs. Different types of gene action were found for the putative QTLs for the three traits.  相似文献   

18.
B. Kjær  J. Jensen 《Euphytica》1996,90(1):39-48
Summary The positions of quantitative trait loci (QTL) for yield and yield components were estimated using a 85-point linkage map and phenotype data from a F1-derived doubled haploid (DH) population of barley. Yield and its components were recorded in two growing seasons. Highly significant QTL effects were found for all traits at several sites in the genome. A major portion of the QTL was found on chromosome 2. The effect of the alleles in locus v on thousand grain weight and kernels per ear explained 70–80% of the genetic variation in the traits. QTL × year interaction was found for grain yield. Several different QTL were found within the two-rowed DH lines compared to those found in the six-rowed DH lines. Epistasis between locus v and several loci for yield and yield components indicates that genes are expressed differently in the two ear types. This may explain the difficulties of selecting high yielding lines from crosses between two-rowed and six-rowed barley.Abbreviations DH doubled haploid - QTL quantitative trait locus/loci - RAPD random amplified polymorphic DNA - RFLP restriction fragment length polymorphism - T. Prentice Tystofte Prentice - V. Gold Vogelsanger Gold  相似文献   

19.
The gene pool of Aegilops tauschii, the D-genome donor of common wheat (Triticum aestivum L.), can be easily accessed in wheat breeding, but remains largely unexplored. In our previous studies, many synthetic hexaploid wheat lines were produced through interspecific crosses between the tetraploid wheat cultivar Langdon and various A. tauschii accessions. The synthetic hexaploid wheat lines showed wide variation in many characteristics. To elucidate the genetic basis of variation in flowering-related traits, we analyzed quantitative trait loci (QTL) affecting time to heading, flowering and maturity, and the grain-filling period using four different F2 populations of synthetic hexaploid wheat lines. In total, 10 QTLs located on six D-genome chromosomes (all except 4D) were detected for the analyzed traits. The QTL on 1DL controlling heading time appeared to correspond to a flowering time QTL, previously considered to be an ortholog of Eps-A m 1 which is related to the narrow-sense earliness in einkorn wheat. The 5D QTL for heading time might be a novel locus associated with wheat flowering, while the 2DS QTL appears to be an allelic variant of the photoperiod response locus Ppd-D1. Some of the identified QTLs seemed to be novel loci regulating wheat flowering and maturation, including a QTL controlling the grain filling period on chromosome 3D. The exercise demonstrates that synthetic wheat lines can be useful for the identification of new, agriculturally important loci that can be transferred to, and used for the modification of flowering and grain maturation in hexaploid wheat.  相似文献   

20.
This study was conducted to identify new quantitative trait loci (QTLs) that have stable effects for eating and cooking quality (ECQ) of rice. Three recombinant inbred line populations of indica rice were each planted in two years. Three traits for ECQ, amylose content (AC), gel consistency (GC) and alkali spreading value (ASV), were measured for QTL analysis. A total of 13 QTLs were detected, including four for AC, six for ASV and three for GC. Two QTLs, qGC4 in the interval RM16252–RM335 on the short arm of chromosome 4 and qGC6.2 in the Alk region, were validated in a population derived from a residual heterozygote that was homozygous at the major locus Wx. In the absence of segregation at the Wx locus, qGC4 and qGC6.2 had additive effects of 2.46 and 8.18 mm, respectively, offering a potential for improving GC property of rice varieties. Comparison between qGC4 and previous results suggests that qGC4 is likely a new QTL for GC, providing a candidate for gene cloning and functional characterization.  相似文献   

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