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1.
Increasing crop productivity is one of the prime goals of crop breeding research. Rice grain yield is a complex quantitative trait governed by polygenes. Although several QTLs governing grain yield traits have been reported and limited attempts have been made to map QTLs for grain yield parameters in Basmati rice. A population from the cross Sonasal and Pusa Basmati 1121 comprising 352 RILs was generated through the single seed descent method. A total of 12 QTLs governing yield and yield-related traits were mapped on six chromosomes, namely, 1, 2, 3, 7, 8 and 9, of which five QTLs were novel. We identified a novel and robust epistatic QTL (qPH1.1 and qPL1.1) governing plant height and panicle length, flanked by the markers RM5336-RM1 on chromosome 1. The gene encoding brassinosteroid insensitive 1-associated receptor kinase 1 precursor is the putative candidate gene underlying this epistatic QTL. Another novel QTL, qNT3.1, governing tiller number was bracketed to a region of .77 Mb between the markers RM15247 and RM15281 on chromosome 3. Of the 57 annotated gene models, Os03g0437600 encoding alpha/beta-fold hydrolase, a homologous to AtKai2 is a putative candidate gene underlying the novel QTL qNT3.1. The other QTLs such as qDFF1.1 governing days to 50% flowering co-localizes with the gene Ghd7, QTL for plant height qPH1.2 co-localizes with the gene sd1, the QTLs for panicle length co-localizes with FUWA and DEP2, the QTL for tiller number co-localizes with OsRLCK57 and QTLs for thousand-grain weight co-localize with the major gene GS3. The QTLs identified in the current study can be effectively used in marker-assisted selection for developing Basmati rice varieties with a higher yield.  相似文献   

2.
Additive effects (A) and additive‐by‐environment interactions (A×E) for five rice yield components were analysed using 20 SSSLs under mixed linear model methodology. Thirty‐one QTLs were detected. Different yield components have different QTL‐by‐environment (Q×E) interaction patterns. No A×E interaction effects were detected for the four QTLs for panicle number (PN). Four QTLs detected for spikelets per panicle (SPP) had A×E interactions. Five of seven QTLs detected for grains per panicle (GPP), two of 10 QTLs detected for 1000‐grains weight (GWT) and three of six QTLs detected for seed set ratio (SSR) showed significant A×E interaction. Most of these QTLs were distributed in clusters across the genome. The complexity of linkage and pleiotropy of these QTLs plus environmental effect may result in the diversity of the yield phenotype in the SSSLs. Only S19 exhibited a significant increase in yield with a predicted gain by 281.58 kg ha?1. The results may be useful to design a better breeding strategy that takes advantage of QTL‐by‐environment interaction effects in each of the SSSLs.  相似文献   

3.
Temperature and photoperiod fluctuate rapidly in different seasons of the year, and analyzing their effects on rice yield components is crucial for adaptation of rice under various climatic conditions. To study the effects of seasonal changes on yield components, 168 recombinant inbred lines derived from a cross between two Oryza sativa L. indica varieties, Zhenshan 97 and Zhongzao 18 were grown for phenotype collection, in three different seasons, within a year. The results implied that temperatures across the three seasons played a crucial role in determining the trait effects. Spikelets per panicle (SPP), panicle length (PL) and plant height (PH) traits increased with high temperatures in middle season. Genetic analysis detected major quantitative trait loci (QTLs) qSPP10, qPL10 and qPH10 for SPP, PL and PH in the interval between markers RM1375 and RM3229 on chromosome 10, in all the three seasons. Two-way ANOVA showed that genotype by environment and QTL by environment interactions for these traits were highly significant (P < 0.0001). The region with a cluster of QTLs detected in all three seasons could be the preferred target to breeders in developing rice varieties that can be accustomed to different seasonal changes.  相似文献   

4.
Rice grain shape and yield are usually controlled by multiple quantitative trait loci (QTL). This study used a set of F9–10 recombinant inbred lines (RILs) derived from a cross of Huahui 3 (Bt/Xa21) and Zhongguoxiangdao, and detected 27 QTLs on ten rice chromosomes. Among them, twelve QTLs responsive for grain shape/ or yield were mostly reproducibly detected and had not yet been reported before. Interestingly, the two known genes involved in the materials, with one insect-resistant Bt gene, and the other disease-resistant Xa21 gene, were found to closely link the QTLs responsive for grain shape and weight. The Bt fragment insertion was firstly mapped on the chromosome 10 in Huahui 3 and may disrupt grain-related QTLs resulting in weaker yield performance in transgenic plants. The introgression of Xa21 gene by backcrossing from donor material into receptor Minghui 63 may also contain a donor linkage drag which included minor-effect QTL alleles positively affecting grain shape and yield. The QTL analysis on rice grain appearance quality exemplified the typical events of transgenic or backcrossing breeding. The QTL findings in this study will in the future facilitate the gene isolation and breeding application for improvement of rice grain shape and yield.  相似文献   

5.
粒型、株高及穗部组成性状与产量形成密切相关,是水稻重要农艺性状,但遗传基础复杂。染色体片段代换系是用于复杂性状遗传研究的良好材料。本研究鉴定了一个以日本晴为受体、西恢18为供体亲本的水稻优良染色体片段代换系Z746。Z746携带来自西恢18的7个代换片段,平均代换长度为3.99 Mb,其株高、粒长和穗部性状均与受体存在显著差异。进一步通过日本晴与Z746杂交构建的次级F2群体共检测到36个相关QTL,分布于2号、3号、4号、6号和11号染色体。其中5个可能与已克隆基因等位,如qPH3-1等,8个可被多次检出,表明这些是遗传稳定的主效QTL。Z746的粒长主要由4个QTL(qGL3、qGL4、qGL2、qGL6)控制,其中qGL3和qGL4对粒长变异的贡献率分别为60.28%和27.47%。株高由5个QTL控制,穗长由4个QTL控制,每穗粒数由2个QTL控制,千粒重由2个QTL控制。然后以MAS在F3共选出8个单片段代换系,并以此在F4进行了相关QTL验证,共有24个QTL可被8个单片段代换系(SSSL)检出,重复检出率为66.7%,表明这些QTL遗传稳定。本研究为目的QTL的进一步遗传机制研究及分子设计育种奠定了良好基础。  相似文献   

6.
Grain yield is the most important and complicated trait in maize. In this study, a total of 498 recombinant inbred lines (RIL) derived from a biparental cross of two elite inbred lines, 178 and P53, were grown in six different environments. Quantitative trait locus (QTL) mapping was conducted for three grain yield component traits (100 grain weight, ear weight and kernel weight per plant). Subsequently, meta‐analysis was performed after a comprehensive review of the research on QTL mapping for grain weight (100, 300 and 1000) using BioMercator V4.2. In total, 62 QTLs were identified for 100 grain weight, ear weight and kernel weight per plant in six environments. Forty‐three meta‐QTLs (MQTLs) were detected by meta‐analysis. A total of 13 candidate genes homologous to eight functionally characterized rice genes were found, and four candidate genes were located in the two hot spot regions of MQTL1.5 and MQTL2.3. Our results suggest that the combination of literature collection, meta‐analysis and homologous blast searches can offer abundant information for further fine mapping, marker‐assisted selection (MAS) breeding and map‐based cloning for maize.  相似文献   

7.
X. Luo  F. Tian  Y. Fu  J. Yang  C. Sun 《Plant Breeding》2009,128(6):559-567
Panicle‐related traits are important agronomic traits which directly associated with grain yield. In this study, we investigated quantitative trait loci (QTLs) associated with panicle‐related traits using a set of 265 introgression lines (ILs) of common wild rice (Oryza rufipogon Griff.) in the background of Indica high‐yielding cultivar Guichao 2 (O. sativa L.). A total of 39 QTLs associated with panicle‐related traits including panicle length (PL), primary branch number (PBN), secondary branch number (SBN), spikelet number per panicle (SPP) and spikelet density (SD), were detected in the ILs with single‐point analysis. The alleles of 20 QTLs derived from wild rice showed positive effects, and some QTLs, such as, QPl1b for PL, QPbn8 for PBN, QSd4 and QSd11b for SD and QSpp4 for SPP showed larger positive effects, providing good candidates and useful information for marker‐aided improvement of yield potential of rice. Most of the QTLs controlling SPP, SBN and SD were located in cluster or closely linked on chromosomes, and the directions of their additive effects were consistent, which explained the genetic basis of significant correlations between their phenotypic characters.  相似文献   

8.
多环境下稻米粒重的QTL定位   总被引：2，自引：0，他引：2  
以粳稻Asominori为遗传背景的染色体片段置换系（CSSLs）群体为材料,利用基于性状-标记多元回归分析方法对稻谷粒重和精米粒重进行多环境的QTL定位。结果在5个环境共检测到6个粒重相关QTL,分布于第1、6、7和8染色体上,对表型变异的贡献率介于13%~35%;其中控制精米粒重的qMRW-1a和稻谷粒重的qPRW-1在不同环境中均能稳定表达,且均位于第1染色体RFLP标记XNpb113附近,该基因座还同时控制着粒宽。qMRW-1a和qPRW-1共同对应的置换系AIS8和AIS11与Asominori 的粒重差异在不同环境中均显著(P < 0.05),表明该QTL的等位基因在不同环境中效应显著。比较发现该QTL在不同遗传群体中均能被重复检测到,且与蔗糖磷酸合酶基因（SPS）位置一致,推测该QTL与淀粉合成代谢有关。qMRW-1a 和qPRW-1在不同环境条件和遗传背景中表达,因此可用于进一步的精细定位研究。  相似文献   

9.
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   

10.
To advance the identification of quantitative trait loci (QTLs) to reduce Cd content in rice (Oryza sativa L.) grains and breed low-Cd cultivars, we developed a novel population consisting of 46 chromosome segment substitution lines (CSSLs) in which donor segments of LAC23, a cultivar reported to have a low grain Cd content, were substituted into the Koshihikari genetic background. The parental cultivars and 32 CSSLs (the minimum set required for whole-genome coverage) were grown in two fields with different natural levels of soil Cd. QTL mapping by single-marker analysis using ANOVA indicated that eight chromosomal regions were associated with grain Cd content and detected a major QTL (qlGCd3) with a high F-test value in both fields (F = 9.19 and 5.60) on the long arm of chromosome 3. The LAC23 allele at qlGCd3 was associated with reduced grain Cd levels and appeared to reduce Cd transport from the shoots to the grains. Fine substitution mapping delimited qlGCd3 to a 3.5-Mbp region. Our results suggest that the low-Cd trait of LAC23 is controlled by multiple QTLs, and qlGCd3 is a promising candidate QTL to reduce the Cd level of rice grain.  相似文献   

11.
Xieyou9308 is the first commercial super hybrid rice released in 1996 in China. To clarify its genetic mechanism underlying high yield potential, a recombinant inbred line (RIL) population derived from the cross between the maintainer line XieqingzaoB (XQZB) and the restorer line Zhonghui9308 (ZH9308) and two derived backcross F1 (BCF1) populations were developed for the identification of quantitative trait loci (QTLs) related to ten important agronomic traits (tiller number (TN), heading date (HD), and grain yield per plant (GYPP), etc.). The BCF1 performance was closely correlated with the performance of their parental RILs according to both the analysis of broad-sense heritability (h B 2) and phenotypic correlation coefficient (PCC) in the two BCF1 populations, but not proved by QTL analysis. A total of 21 additive-effect main QTLs (M-QTLs), 22 dominant-effect M-QTLs, and 19 dominant-effect M-QTLs were detected with the WinQTLCart 2.50 software for the ten traits in the RIL and two BCF1 populations, respectively. Of theses, three QTLs (qHD7a, qPPP3a, and qPL10) of 21 were detected repeatedly in the RIL and one BCF1 populations, ten QTLs underlying four traits were only detected repeatedly in two BCF1 populations, and nine QTLs controlling more than two traits were detected repeatedly, the additive-effect QTLs and dominant-effect QTLs play an important role in the performance of agronomic traits and no epistatic QTL of additive by additive effect and dominant by dominant-effect was detected for all traits in three populations. This research is valuable for M-QTL related to important agronomic trait in future fine mapping and positional cloning.  相似文献   

12.
In the present study, quantitative trait loci (QTLs) controlling seed storability based on relative germination rate (%) were dissected using a saturated linkage map and a recombinant inbred lines (RILs) derived from a cross of japonica cultivar Asominori (Oryza sativa L.) and indica cultivar IR24 (Oryza sativa L.). A total of three QTLs (qRGR-1, qRGR-3 and qRGR-9) were detected on chromosomes 1, 3 and 9 with LOD score ranging from 3.45 to 6.95 and the phenotypic variance explained from 16.72% to 28.63%. The IR24 alleles were all associated with seed storability at all the three QTLs. The existence of these QTLs was confirmed using IR24 chromosome segment substitution lines (CSSLs) in Asominori genetic background (AIS). By QTL comparative analysis, the QTL, qRGR-9 on chromosomes 9 appeared to be consistent with another rice population, this region may provide an important region for isolating this responsible gene. These results also provide the possibilities of enhancing Seed storability in rice breeding program by marker-assisted selection (MAS) and pyramiding QTLs. Y. Xue and S. Q. Zhang—joint first authors.  相似文献   

13.
Yield is a complex trait. To improve it, the accumulation of the favourable alleles of valuable genes is required for each yield‐related trait. In this study, we used two high‐yielding rice cultivars developed in Japan, indica‐type ‘Takanari’ and japonica‐type ‘Momiroman’, for a genetic analysis of the sink capacity‐related traits. An F2 population showed transgressive segregation for the number of spikelets per panicle. Quantitative trait locus (QTL) analysis detected four QTLs for the trait. Two of the QTLs were most likely identical to previously cloned GN1a and APO1, and their Takanari alleles had positive effects. The Momiroman alleles of the other two QTLs had positive effects, and one of these QTLs was most likely identical to SPIKE/GPS. The QTL on the long arm of chromosome 3 appeared to be novel; it clustered with QTLs for grain length and days‐to‐heading. Substitution mapping revealed that the close linkage of QTLs caused the clustering. These results suggest that the combination of the favourable alleles of detected QTLs could lead to greater sink capacity than that of the parental cultivars.  相似文献   

14.
Root traits are key components of plant adaptation to drought environment. By using a 120 recombined inbred lines (RILs) rice population derived from a cross between IRAT109, a japonica upland rice cultivar and Yuefu, a japonica lowland rice cultivar, a complete genetic linkage map with 201 molecular markers covering 1,833.8 cM was constructed and quantitative trait loci (QTLs) associated with basal root thickness (BRT) were identified. A major QTL, conferring thicker BRT, located on chromosome 4, designated brt4, explained phenotypic variance of 20.6%, was selected as target QTL to study the effects of marker-assisted selection (MAS) using two early segregating populations derived from crosses between IRAT109 and two lowland rice cultivars. The results showed that the flanking markers of brt4 were genetically stable in populations with different genetic backgrounds. In the two populations under upland conditions, the difference between the means of BRT of plants carrying positive and negative favorable alleles at brt4 flanking markers loci was significant. Phenotypic effects of BRT QTL brt4 were 5.05–8.16%. When selected plants for two generations were planted at Beijing and Hainan locations under upland conditions, MAS effects for BRT QTL brt4 were 4.56–18.56% and 15.46–26.52% respectively. The means of BRT for the homozygous plants were greater than that of heterozygous plants. This major QTL might be useful for rice drought tolerance breeding. L. Liu and P. Mu are contributed equally to this work.  相似文献   

15.
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   

16.
Hybrid rice has contributed substantially to the improvement of grain production worldwide, yet its poor cooking and tasting characteristics have long been recognized. In this study, 132 recombinant inbred lines derived from LYPJ were used to identify quantitative trait loci (QTLs) for 12 cooking traits with the high‐density SNP linkage map recently developed by our team. We identified 17 QTLs on chromosomes 1, 2, 4, 5, 6, 7, 8, 9 and 11, which accounted for 7.50% to 23.50% of the phenotypic variations. A novel major QTL qBGL7 for boiled grain length was further fine‐mapped to an interval of 440 Kb between the two markers RM21906 and gl3 using a BC3F2 population. Two near‐isogenic lines with extreme boiled grain length, GX5‐176 and GX5‐101, could be directly used in improving cooking quality. We also identified a QTL for soaked grain width expansion rate, qSGWE6, in the Wx gene region on chromosome 6. The Wx differential regulation coincided with sequential variation between the two parents. Our work offered a theoretical basis for molecular breeding of high‐quality hybrid rice.  相似文献   

17.
Heterosis is a phenomenon whereby hybrids of inbred lines produce favourable phenotypes that exceed those of their parents. Traits of interest are higher yield and stronger stress tolerance. The two‐line super‐hybrid rice ‘Liangyoupei9’ (LYP9) shows superiority to both its elite inbred line ‘93‐11’ and ‘Pei'ai64s’ (‘PA64s’) parents and conventional hybrids. However, the genetic basis of its hybrid vigour, especially yield determination, remains elusive. In the present study, a set of 156 chromosome segment substitution lines (CSSLs) carrying overlapping segments from ‘PA64s’ in a genetic background of ‘93‐11’ were constructed and planted in six environments. Three major agronomic traits, viz. panicle length (PL), heading date (HD) and plant height (PH), and five yield‐related traits, viz. grain weight per panicle (GWP), number of grains per panicle (GPP), 1000‐grain weight (TGW), seed set (SS) and number of panicles of per plant (PPP), were evaluated over 3 years. Quantitative trait loci (QTL) analysis was conducted using a likelihood ratio test based on stepwise regression. Forty‐six putative QTL distributed on 11 chromosomes were detected in more than one year. Remarkably, GWP of four CSSLs carrying positive yield QTL outperformed the recurrent parent ‘93‐11’ by more than 15%, in at least two environments. These results indicate that CSSLs are effective in identifying yield‐associated traits, and lines harbouring such QTL will be rich in resources for future molecular breeding programmes.  相似文献   

18.
不同生态环境下玉米产量性状QTL分析   总被引：35，自引：10，他引：25  
以玉米（Zea mays L.）自交系黄早四和Mo17为亲本得到的191个F2单株为作图群体,衍生的184个F2∶3 家系作为性状评价群体,分析了单株穗数、穗行数、行粒数、百粒重和单株籽粒产量在北京和新疆2个生态环境下的表现和数量性状基因位点的定位结果。QTL检测结果表明,2个环境共检测出47个QTL,分布于除第10染色体以外的9条染色体,其中与单株穗数相关的QTL共10个,可解释的表型变异为5.3%~25.6%;与穗行数相关的QTL共13个,可解释的表型变异为4.5%~23.2%;与行粒数相关的QTL有9个,解释的表型变异为5.4%~13.7%;与百粒重相关的QTL达10个,可解释的表型变异为4.9%~13.3%;与单株籽粒产量相关的QTL有5个,可解释的表型变异为6.1%~35.8 %。大部分产量QTL只在单一环境下被检测到,说明产量相关QTL与环境之间存在明显的互作。表型相关显著的产量性状,它们的QTL容易在相同或相邻标记区间检测到。研究还发现了若干个QTL富集区域,可能是发掘通用QTL的候选位点。  相似文献   

19.
J. L. Xu    S. B. Yu    L. J. Luo    D. B. Zhong    H. W. Mei  Z. K. Li 《Plant Breeding》2004,123(1):43-50
The genetic mechanism underlying the relationship between three traits of the primary sink size ‐ spikelet number per panicle (SNP), panicle number per plant (PN), and 1000‐grain weight (GWT), and their 10 component traits in rice was dissected in 292 F13 recombinant inbred lines using a complete linkage map. A total of 43 genomic regions on 12 rice chromosomes were found to contain quantitative trait loci (QTLs) affecting the sink size traits, which revealed several important aspects of the genetic basis of sink capacity in rice. First, QTLs for SNP, PN and GWT were largely independent. Secondly, most QTLs affecting SNP and GWT showed close characteristics in both genomic locations and directions of effects to QTLs for their components, suggesting that pleiotropy, rather than linkage, was the primary genetic basis of the correlated panicle and grain traits. Thirdly, some QTLs affecting component traits did not contribute to SNP or GWT. In these cases, two or more QTLs with opposite effects on their component traits were detected, which could be due to either linkage or pleiotropy. Fourthly, some QTLs had large effects on panicle number (QPn4), panicle branching and length (QPbn3a, QPbn3b and QPb14), grain length and volume (QG13, QG15 and QGv2), and grain shape (QGs1 and QGs7), which were consistently detected in the related rice mapping populations and in different environments, providing good candidates and useful information for marker‐aided improvement of sink size and yield potential of rice.  相似文献   

20.
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   

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