Pythium stalk rot(PSR)is a destructive disease of maize,severely affecting yield and grain quality.The identification of quantitative trait loci(QTL)or genes for resistance to PSR forms the basis of diseaseresistant h...Pythium stalk rot(PSR)is a destructive disease of maize,severely affecting yield and grain quality.The identification of quantitative trait loci(QTL)or genes for resistance to PSR forms the basis of diseaseresistant hybrids breeding.In this study,a major QTL,Resistance to Pythium stalk rot 1(RPSR1),was identified from a set of recombinant inbred lines derived from MS71 and POP.Using a recombinant progeny testing strategy,RPSR1 was fine-mapped in a 472 kb interval.Through candidate gene expression,gene knock-down and knock-out studies,a leucine-rich repeat receptor-like kinase gene,PEP RECEPTOR 2(ZmPEPR2),was assigned as a PSR resistance gene.These results provide insights into the genetic architecture of resistance to PSR in maize,which should facilitate breeding maize for resistance to stalk rot.展开更多
Several quantitative trait genes(QTGs)related to rice heading date,a key factor for crop development and yield,have been identified,along with complex interactions among genes.However,a comprehensive genetic interacti...Several quantitative trait genes(QTGs)related to rice heading date,a key factor for crop development and yield,have been identified,along with complex interactions among genes.However,a comprehensive genetic interaction network for these QTGs has not yet been established.In this study,we use 18K-rice lines to identify QTGs and their epistatic interactions affecting rice heading date.We identify 264 pairs of interacting quantitative trait loci(QTL)and construct a comprehensive genetic network of these QTL.On average,the epistatic effects of QTL pairs are estimated to be approximately 12.5%of additive effects of identified QTL.Importantly,epistasis varies among different alleles of several heading date genes.Additionally,57 pairs of interacting QTGs are also significant in their epistatic effects on 12 other agronomic traits.The identified QTL genetic interactions are further validated using near-isogenic lines,yeast two-hybrid,and split-luciferase complementation assays.Overall,this study provides a genetic network of rice heading date genes,which plays a crucial role in regulating rice heading date and influencing multiple related agronomic traits.This network serves as a foundation for understanding the genetic mechanisms of rice quantitative traits and for advancing rice molecular breeding.展开更多
Gossypium raimondii(2n=2x=26,D_(5)),an untapped wild species,is the putative progenitor of the D-subgenome of G.hirsutum(2n=4x=52,AD_(1)),an extensively cultivated species.Here,we developed a G.hirsutum(recipient)–G....Gossypium raimondii(2n=2x=26,D_(5)),an untapped wild species,is the putative progenitor of the D-subgenome of G.hirsutum(2n=4x=52,AD_(1)),an extensively cultivated species.Here,we developed a G.hirsutum(recipient)–G.raimondii(donor)introgression population to exploit the favorable QTLs/genes and mapped potential quantitative trait loci(QTLs)from wild cotton species.The introgression population consisted of 256 lines with an introgression rate of 52.33%for the G.raimondii genome.The introgression segment length range was 0.03–19.12 Mb,with an average of 1.22 Mb.The coverage of total introgression fragments from G.raimondii was 386.98 Mb.Further genome-wide association analysis(Q+K+MLM)and QTL mapping(RSTEP-LRT)identified 59 common QTLs,including 14 stable QTLs and six common QTL(co-QTL)clusters,and one hotspot of micronaire(MIC).The common QTLs for seed index all showed positive additive effects,while the common QTLs for boll weight all had negative additive effects,indicating that the linkage between seed index and boll weight could be broken.QTLs for lint percentage showed positive effects and could be beneficial for improving cotton yield.Most QTLs for fiber quality had negative additive effects,implying these QTLs were domesticated/improved in G.hirsutum.A few fiber quality QTLs showed positive additive effects,so they could be used to improve cotton fiber quality.The introgression lines developed could be useful for molecular marker-assisted breeding and mapping QTLs precisely for mining desirable genes from the wild species G.raimondii.Such genes can improve cultivated cotton in the future through a designbreeding approach.展开更多
Efficient and accurate identification of candidate causal genes within quantitative trait loci(QTL)is a significant challenge in genetic research.Conventional linkage analysis methods often require substantial time an...Efficient and accurate identification of candidate causal genes within quantitative trait loci(QTL)is a significant challenge in genetic research.Conventional linkage analysis methods often require substantial time and resources to identify causal genes.This paper proposes a QTG-LGBM method for prioritizing causal genes in maize based on the Light GBM algorithm.QTG-LGBM dynamically adjusts gene weights and sample proportions during training to mitigate the effects of class imbalance.The method prevents overfitting in datasets with small samples by introducing a regularization term.Experimental results on maize traits,including plant height(PH),flowering time(FT),and tassel branch number(TBN),demonstrated that QTG-LGBM outperforms the commonly used methods QTG-Finder,GBDT,XGBoost,Bernoulli NB,SVM,CNN,and ensemble learning.We validated the generalization of QTG-LGBM using Arabidopsis,rice,Setaria,and sorghum.We also applied QTG-LGBM using reported QTL that affect traits of maize PH,FT and TBN,and FT in Arabidopsis,rice,and sorghum,as well as known causal genes within the QTL.When examining the top 20%of ranked genes,QTG-LGBM demonstrated a significantly higher recall rate of causal genes compared to random selection methods.We identified key gene features affecting phenotypes through feature importance analysis.QTG-LGBM is available at http://www.deepcba.com/QTG-LGBM.展开更多
Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD...Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD)conditions due to the synergistic regulation of many photosensitive genes.Using a set of chromosome segment substitution lines(CSSLs)with the indica cultivar Huanghuazhan(HHZ)as the recipient parent and Basmati Surkh 89-15(BAS)as the donor parent,we identified a QTL locus.展开更多
A genetic linkage map with 89 SSR marker loci was constructed based on a maize (Zea mays L.) population consisting of 184 F-2 individuals from the cross, Huangzao 4 X Ye 107. The 184 F-3 families were evaluated in the...A genetic linkage map with 89 SSR marker loci was constructed based on a maize (Zea mays L.) population consisting of 184 F-2 individuals from the cross, Huangzao 4 X Ye 107. The 184 F-3 families were evaluated in the field under well-watered and drought-stressed regimes in Shanxi Province of China. The objectives of the study were to identify genetic segments responsible for the expression of anthesis-silking interval (ASI), ear setting and grain yield, and to examine if the quantitative trait loci (QTLs) for ASI or yield components can be used in marker-assisted selection (MAS) to improve grain yield under drought conditions. Results showed that under well-watered and drought-stressed regimes, three and two QTLs involved in the expression of ASI were detected on chromosomes 1, 2 and 3, and 2 and 5, respectively. Under well-watered regime, two QTLs for ear setting were detected on chromosomes 3 and 6, explaining about 19.9% of the phenotypic variance, and displayed additive and partial dominant effects, respectively. Under drought-stressed condition, four QTLs for ear setting were detected on chromosomes 3, 7 and 10, which were responsible for interpreting 60.4% of the phenotypic variance, and showed dominant or partial dominant effects. Under well-watered condition, four QTLs controlling grain yield were identified on chromosomes 3, 6 and 7, while five QTLs were identified under drought stress on chromosomes 1, 2, 4 and 8. The gene action was of additive or partial dominant effects, and each QTL could explain 7.3% to 22.0% of the phenotypic variance, respectively. Under drought conditions, ASI and ear setting percentage were highly correlated with grain yield, which can be used as secondary traits for grain yield selection. Based on linked markers detected and gene action analyzed, an MAS strategy for yield improvement under drought condition could be established, which consists of QTLs contributing to decreased ASI and to increased ear setting and grain yield, respectively.展开更多
Two hundred and forty recombinant inbred lines （RIL） derived from a cross TD70/Kasalath and its linkage map including 141 SSR markers were used to map QTLs controlling panicle length （PL）, total seeds per panicle ...Two hundred and forty recombinant inbred lines （RIL） derived from a cross TD70/Kasalath and its linkage map including 141 SSR markers were used to map QTLs controlling panicle length （PL）, total seeds per panicle （TSP） and grain density （GD） in 2010 and 2011. The results showed that a total of 23 QTLs controlling three panicle traits were detected on chromosomes 2, 3, 4, 6, 7, 8 and 10, respec- tively, including 5 QTLs controlling PL, 8 QTLs controlling TSP, 10 QTLs controlling GD, with the LOD value ranging between 2.5-9.3, and the QTLs explained the ob- served phenotypic by 4.0%-20.8%. The marker interval RM5699-RM424 on chro- mosome 2, RM489-RM1278 on chromosome 3, RM3367-RM1018 on chromosome 4, RM3343-RM412 on chromosome 6 were common marker intervals for TSP and GD; six QTLs （qPL3, qTSP4, qTSP6-2, qTSP7, qGD3-2 and qGDT） were detected in two years. Among these QTLs, the qPL3, qTSP6-2, qGD3-2 and qGD7 were major QTLs. All QTLs for PL mapped in the present study had been mapped QTLs previously by other research groups, 16 QTLs controlling TSP and GD were new ones which contributed the observed phenotypic variance range by 4%-9.5%. These results laid a founda^ion for further fine positioning or cloning these QTLs.展开更多
Quantitative trait loci(QTL)were detected for 8 internal organ traits,3 carcass length traits,and teat number trait in 214 pigs in a resource population that included 180 F2 individuals.A total of 39 microsatellite ma...Quantitative trait loci(QTL)were detected for 8 internal organ traits,3 carcass length traits,and teat number trait in 214 pigs in a resource population that included 180 F2 individuals.A total of 39 microsatellite markers were examined on SSC4,SSC6,SSC7,SSC8,and SSC13.The genetic traits included heart weight(HW),lung weight(LW),liver and gallbladder weight(LGW),spleen weight(SPW),stomach weight(STW),small intestine weight(S1W),large intestine weight(LIW),kidney weight(KW),carcass length to the first cervical vertebra(CL1),carcass length to the first thoracic vertebra(CL2),rib numbers(RNS),and teat numbers(TNS).Results indicated that,3 highly significant QTL(P≤0.01 at chromosome-wise level)for HW(at 30 cM on SSC6),RNS(at 115 cM on SSC7),TNS(at 110 cM on SSC7),and 6 significant QTL(P≤0.05 at chromosome-wise level)for LW(at 119 cM on SSC13),LGW(at 94 cM on SSC6),SPW(at 106 cM on SSC8),SIW(0 cM on SSC4),LIW(170 cM on SSC 4),and TNS(at 95 cM on SSC6)were detected.The phenotypic variances for which these QTL were accounted ranged from 0.04%to 14.06%.Most of these QTL had not been previously reported.展开更多
To identify genetic factors underlying phosphorus (P) uptake and use efficiency under low_P stress in rice (Oryza sativa L.), 84 selected genotypes (recombinant inbred lines) and their parents (which differed in toler...To identify genetic factors underlying phosphorus (P) uptake and use efficiency under low_P stress in rice (Oryza sativa L.), 84 selected genotypes (recombinant inbred lines) and their parents (which differed in tolerance for low_P stress) “IR20” and IR55178_3B_9_3, were cultured in liquid medium supplemented with adequate and low P levels in a greenhouse. Plants were sampled after 6 weeks in culture for measurements of plant dry weight, P concentration, P uptake and P use efficiency under both P sufficient and stress conditions. A total of 179 molecular markers, including 26 RFLPs and 153 AFLPs, mapped on all 12 chromosomes of rice based on the 84 selected genotypes were used to detect the quantitative trait loci (QTLs) underlying tolerance for low_P stress. Three QTLs were detected on chromosomes 6, 7 and 12, respectively, for relative plant dry weight (RPDW) and relative P uptake (RPUP). One of the QTLs flanked by RG9 and RG241 on chromosome 12 had a major effect which explained about 50% of the variations in the two parameters across the population. The results coincided with the QTLs for low_P stress based on relative tillering ability from the same population from a cross between Nipponbare and Kasalath under soil condition. The identical major QTL for P uptake and plant growth under low_P stress in both liquid medium and soil strongly suggests that the ability of P uptake mainly controls rice tolerance for low_P stress.展开更多
Genome-wide association study（GWAS） can be used to identify genes that increase the risk of psychiatric diseases.However,much of the disease heritability is still unexplained,suggesting that there are genes to be di...Genome-wide association study（GWAS） can be used to identify genes that increase the risk of psychiatric diseases.However,much of the disease heritability is still unexplained,suggesting that there are genes to be discovered.Functional annotation of the genetic variants may increase the power of GWAS to identify disease genes,by providing prior information that can be used in Bayesian analysis or in reducing the number of tests.Expression quantitative trait loci（eQTLs） are genomic loci that regulate gene expression.Genetic mapping of eQTLs can help reveal novel functional effects of thousands of single nucleotide polymorphisms（SNPs）.The present review mainly focused on the current knowledge on brain eQTL mapping,and discussed some major methodological issues and their possible solutions.The frequently ignored problems of batch effects,covariates,and multiple testing were emphasized,since they can lead to false positives and false negatives.The future application of eQTL data in GWAS analysis was also discussed.展开更多
Rice (Oryza sativa L.) eating and cooking quality is mainly influenced by its starch properties. Mapping quantitative trait loci (QTL) for starch properties not only helps us understand their genetic basis leading to ...Rice (Oryza sativa L.) eating and cooking quality is mainly influenced by its starch properties. Mapping quantitative trait loci (QTL) for starch properties not only helps us understand their genetic basis leading to acceleration of quality improvement, but also helps us find possible genes participating in the synthesis of starch. A recombinant inbred line (RIL) population consisting of 107 lines, derived from an indica (Zaiyeqing 8, ZYQ 8) and a japonica (Jingxi 17, JX 17) rice, was used to investigate the genetic factors affecting starch quality parameters, such as apparent amylose content (AAC), gel consistency (GC), starch pasting viscosity parameters, gel textural properties, gelatinization temperature (GT) and starch retrogradation properties. A total of 44 QTLs covered chromosomes 2-6, 8, 9 and 11 were detected for the 22 traits, with at least one QTL and as many as four QTLs for each individual trait. The results indicated that two major genes were responsible for most starch property traits. The Wx gene that encodes granule bound starch synthase on chromosome 6 was significant for AAC, GC, starch pasting viscosity parameters, gel textural properties and starch retrogradation properties. The alk gene linked with Wx on chromosome 6 was significant for starch gelatinization temperature characteristics. All other QTLs were minor genes. One QTL on chromosome 9 flanked by RZ404 and G295 was significant for gel hardness (HD), gumminess (GUM), chewiness (CHEW), peak temperature of retrogradated starch (RTp), and percentage retrogradation (R%) and all these traits were not tested before.展开更多
In this paper, based on the DUS testing of new Lavandula spp., the differences and correlations of main phenotypic traits between Lavandula angustifolia and L. heterophylla were observed and analyzed. The results show...In this paper, based on the DUS testing of new Lavandula spp., the differences and correlations of main phenotypic traits between Lavandula angustifolia and L. heterophylla were observed and analyzed. The results showed that the plant morphological traits of L. angustifolia were better than that of L. heterophylla, moreover, L. angustifolia exhibited relatively high adaptive capacity to the environmental conditions in introduction areas of north China. For the inflorescence, the ornamental traits of L. heterophylla were totally superior to that of L. angustifolia, especially in flower color diversity. It had obvious differences in both quantitative traits and qualitative traits between the two species, and these traits remained relatively stable in the growth progress. The correlation coefficients among the traits of two species were high, and the trait matching numbers at the 1% significance level of L. angustifolia were slightly more than that of L. heterophylla.展开更多
Soil salinity is one of the major abiotic stresses affecting plant growth and crop production.In the present study,salt tolerance at rice seedling stage was evaluated using 87 introgression lines（ILs）,which were der...Soil salinity is one of the major abiotic stresses affecting plant growth and crop production.In the present study,salt tolerance at rice seedling stage was evaluated using 87 introgression lines（ILs）,which were derived from a cross between an elite indica cultivar Teqing and an accession of common wild rice（Oryza rufipogon Griff.）.Substantial variation was observed for four traits including salt tolerance score（STS）, relative root dry weight（RRW）,relative shoot dry weight（RSW） and relative total dry weight（RTW）.STS was significantly positively correlated with all other three traits.A total of 15 putative quantitative trait loci（QTLs） associated with these four traits were detected using single-point analysis,which were located on chromosomes 1,2,3,6,7,9 and 10 with 8%-26%explaining the phenotypic variance.The O. rufipogon-derived alleles at 13 QTLs（86.7%） could improve the salt tolerance in the Teqing background.Four QTL clusters affecting RRW, RSW and RTW were found on chromosomes 6,7,9 and 10,respectively.Among these four QTL clusters,a major cluster including three QTLs （qRRWIO,qRSWIO and qRTWIO） was found near the maker RM271 on the long arm of chromosome 10,and the O.rufipogon-derived alleles at these three loci increased RRW,RSW and RTW with additive effects of 22.7%,17.3%and 18.5%,respectively,while the phenotypic variance explained by these three individual QTLs for the three traits varied from 19%to 26%.In addition,several salt tolerant ILs were selected and could be used for identifying and utilizing favorable salt tolerant genes from common wild rice and used in the salt tolerant rice breeding program.展开更多
Seed vigor is an important characteristic of seed quality,and rice cultivars with strong seed vigor are desirable in direct-sowing rice production for optimum stand establishment.In the present study,the quantitative ...Seed vigor is an important characteristic of seed quality,and rice cultivars with strong seed vigor are desirable in direct-sowing rice production for optimum stand establishment.In the present study,the quantitative trait loci (QTLs) of three traits for rice seed vigor during the germination stage,including germination rate,final germination percentage,and germination index,were investigated using one recombinant inbred line (RIL) population derived from a cross between japonica Daguandao and indica IR28,and using the multiple interval mapping (MIM) approach.The results show that indica rice presented stronger seed vigor during the germination stage than japonica rice.A total of ten QTLs,and at least five novel alleles,were detected to control rice seed vigor,and the amount of variation (R2) explained by an individual QTL ranged from 7.5% to 68.5%,with three major QTLs with R2>20%.Most of the QTLs detected here are likely to coincide with QTLs for seed weight,seed size,or seed dormancy,suggesting that the rice seed vigor might be correlated with seed weight,seed size,and seed dormancy.At least five QTLs are novel alleles with no previous reports of seed vigor genes in rice,and those major or minor QTLs could be used to significantly improve the seed vigor by marker-assisted selection (MAS) in rice.展开更多
Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of co...Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of commercial three-line hybrids of indica rice.Two of the populations showed great variations on heading date,and the other had a short range of heading date variation.A total of 40 QTLs were detected and fell into 15 regions of 10 chromosomes,of which 5 regions were detected for 1 or more same traits over different populations,2 were detected for different traits in different populations,3 were detected for 2 or all the 3 traits in a single population,and 5 were detected for a single trait in a single population.Most of these QTLs have been reported previously,but a region located on the long arm of chromosome 10 showing significant effects in all the 3 populations has not been reported before.It was shown that a number of gene cloned,including the Wx and Alk for the physiochemical property of rice grain,and GW2,GS3 and GW5 for grain weight and grain size,could have played important roles for the genetic control of grain chalkiness in rice,but there are many more QTLs exerting stable effects for rice chalkiness over different genetic backgrounds.It is worth paying more attentions to these regions which harbor QTL such as the qPCG5.2/qDC5.2/qET5.2 and qPCG10/qDC10/qET10 detected in our study.Our results also showed that the use of segregating populations having high-uniform heading date could greatly increase the efficiency of the identification of QTL responsible for traits that are subjected to great environmental influence.展开更多
The quantitative trait loci （QTLs） for the dead leaf rate （DLR） and the dead seedling rate （DSR） at the different rice growing periods after transplanting under alkaline stress were identified using an F2：3 pop...The quantitative trait loci （QTLs） for the dead leaf rate （DLR） and the dead seedling rate （DSR） at the different rice growing periods after transplanting under alkaline stress were identified using an F2：3 population, which included 200 individuals and lines derived from a cross between two japonica rice cultivars Gaochan 106 and Changbai 9 with microsatellite markers. The DLR detected at 20 days to 62 days after transplanting under alkaline stress showed continuous normal or near normal distributions in F3 lines, which was the quantitative trait controlled by multiple genes. The DSR showed a continuous distribution with 3 or 4 peaks and was the quantitative trait controlled by main and multiple genes when rice was grown for 62 days after transplanting under alkaline stress. Thirteen QTLs associated with DLR were detected at 20 days to 62 days after transplanting under alkaline stress. Among these, qDLR9-2 located in RM5786-RM160 on chromosome 9 was detected at 34 days, 41 days, 48 days, 55 days, and 62 days, respectively; qDLR4 located in RM3524-RM3866 on chromosome 4 was detected at 34 days, 41 days, and 48 days, respectively; qDLR7-1 located in RM3859-RM320 on chromosome 7 was detected at 20 days and 27 days; and qDLR6-2 in RM1340-RM5957 on chromosome 6 was detected at 55 days and 62 days, respectively. The alleles of both qDLR9-2 and qDLR4 were derived from alkaline sensitive parent ＂Gaochanl06＂. The alleles of both qDLR7-1 and qDLR6-2 were from alkaline tolerant parent Changbai 9. These gene actions showed dominance and over dominance primarily. Six QTLs associated with DSR were detected at 62 days after transplanting under alkaline stress. Among these, qDSR6-2 and qDSR8 were located in RM1340-RM5957 on chromosome 6 and in RM3752-RM404 on chromosome 8, respectively, which were associated with DSR and accounted for 20.32% and 18.86% of the observed phenotypic variation, respectively; qDSR11-2 and qDSR11-3 were located in RM536-RM479 and RM2596-RM286 on chromosome 11, respectively, which were associated with DSR explaining 25.85% and 15.41% of the observed phenotypic variation, respectively. The marker flanking distances of these QTLs were quite far except that of qDSR6-2, which should be researched further.展开更多
1000-Grain weight and spikelet number per panicle are two important components for rice grain yield. In our previous study, eight quantitative trait loci （QTLs） conferring spikelet number per panicle and 1000-grain ...1000-Grain weight and spikelet number per panicle are two important components for rice grain yield. In our previous study, eight quantitative trait loci （QTLs） conferring spikelet number per panicle and 1000-grain weight were mapped through sequencing-based genotyping of 150 rice recombinant inbred lines （RILs）. In this study, we validated the effects of four QTLs from Nipponbare using chromosome segment substitution lines （CSSLs）, and pyramided eight grain yield related QTLs. The new lines containing the eight QTLs with positive effects showed increased panicle and spikelet size as compared with the parent variety 93-11. We further proposed a novel pyramid breeding scheme based on marker-assistant and phenotype selection （MAPS）. This scheme allowed pyramiding of as many as 24 QTLs at a single hybridization without massive cross work. This study provided insights into the molecular basis of rice grain yield for direct wealth for high-yielding rice breeding.展开更多
Stalk related traits, comprising plant height （PH）, ear height （EH）, internode number （IN）, average internode length （ALL）, stalk diameter （SD）, and ear height coefficient （EHC）, are significantly correlat...Stalk related traits, comprising plant height （PH）, ear height （EH）, internode number （IN）, average internode length （ALL）, stalk diameter （SD）, and ear height coefficient （EHC）, are significantly correlated with yield, density tolerance, and lodging resistance in maize. To investigate the genetic basis for stalk related traits, a doubled haploid （DH） population derived from a cross between NX531 and NX110 were evauluated under two densities over 2 yr. The additive quantitative trait loci （QTLs）, epistatic QTLs were detected using inclusive composite interval mapping and QTL-by-environment interaction were detected using mixed linear model. Differences between the two densities were significant for the six traits in the DH population. A linkage map that covered 1 721.19 cM with an average interval of 10.50 cM was constructed with 164 simple sequence repeat （SSR）. Two, two, seven, six, two, and eight additive QTLs for PH, IN, AIL, EH, SD, and EHC, respectively. The extend of their contribution to penotypic variation ranged from 10.10 to 31.93%. Seven QTLs were indentified simultaneously under both densities. One pair, two pairs and one pair of epistatic effects were detected for AIL, SD and EHC, respectively. No epistatic effects were detected for PH, EH, and IN. Nineteen QTLs with environment interactions were detected and their contribution to phenotypic variation ranged from 0.43 to 1.89%. Some QTLs were stably detected under different environments or genetic backgrounds comparing with previous studies. These QTLs could be useful for genetic improvement of stalk related traits in maize breeding.展开更多
The shell traits and weight traits are measured in cultured populations of bay scallop, Argopecten irradians. The results of regression analysis show that the regression relationships for all the traits are significan...The shell traits and weight traits are measured in cultured populations of bay scallop, Argopecten irradians. The results of regression analysis show that the regression relationships for all the traits are significant (P<0.01). The correlative coefficients between body weight, as well as tissue weight with shell length, shell height and shell width are significant (P<0.05). But the correlative coefficients between the anterior and posterior auricle length with body weight as well as tissue weight are not significant (P>0.05). The multiple regression equation is obtained to estimate live body weight and tissue weight. The above traits except anterior and posterior auricle length are used for the growth and production comparison among three cultured populations, Duncan's new multiple range procedure analysis shows that all the traits in the Lingshuiqiao (LSQ) population are much more significant than those of the other two populations (P<0.01), and there is no significant difference between the Qipanmo (QPM) and Dalijia (DLJ) populations in all traits (P>0.05). The results indicate that the LSQ population has a higher growth rate and is expected to be more productive than the other two populations.展开更多
To understand genetic patterns of the morphological and physiological traits in flag leaf of barley, a double haploid （DH） population derived from the parents Yerong and Franklin was used to determine quantitative t...To understand genetic patterns of the morphological and physiological traits in flag leaf of barley, a double haploid （DH） population derived from the parents Yerong and Franklin was used to determine quantitative trait loci （QTL） controlling length, width, length/width, and chlorophyll content of flag leaves. A total of 9 QTLs showing significantly additive effect were detected in 8 intervals on 5 chromosomes. The variation of individual QTL ranged from 1.9% to 20.2%. For chlorophyll content expressed as SPAD value, 4 QTLs were identified on chromosomes 2H, 3H and 6H; for leaf length and width, 2 QTLs located on chromosomes 5H and 7H, and 2 QTLs located on chromosome 5H were detected; and for length/width, I QTL was detected on chromosome 7H. The identification of these QTLs associated with the properties of flag leaf is useful for barley improvement in breeding programs.展开更多
基金supported by National Natural Science Foundation of China(32302371 to Junbin Chen)the National Key Research and Development Program,Ministry of Science and Technology of China(2022YFD1201802 to Wangsheng Zhu)Research Program from State Key Laboratory of Maize Biobreeding(SKLMB2424 to Wangsheng Zhu).
文摘Pythium stalk rot(PSR)is a destructive disease of maize,severely affecting yield and grain quality.The identification of quantitative trait loci(QTL)or genes for resistance to PSR forms the basis of diseaseresistant hybrids breeding.In this study,a major QTL,Resistance to Pythium stalk rot 1(RPSR1),was identified from a set of recombinant inbred lines derived from MS71 and POP.Using a recombinant progeny testing strategy,RPSR1 was fine-mapped in a 472 kb interval.Through candidate gene expression,gene knock-down and knock-out studies,a leucine-rich repeat receptor-like kinase gene,PEP RECEPTOR 2(ZmPEPR2),was assigned as a PSR resistance gene.These results provide insights into the genetic architecture of resistance to PSR in maize,which should facilitate breeding maize for resistance to stalk rot.
基金supported by the National Natural Science Foundation of China(32222064 and 32341030)the Natural Science Foundation of Shanghai(22ZR1445800)Zhejiang Provincial Natural Science Foundation of China(LQ24C130008).
文摘Several quantitative trait genes(QTGs)related to rice heading date,a key factor for crop development and yield,have been identified,along with complex interactions among genes.However,a comprehensive genetic interaction network for these QTGs has not yet been established.In this study,we use 18K-rice lines to identify QTGs and their epistatic interactions affecting rice heading date.We identify 264 pairs of interacting quantitative trait loci(QTL)and construct a comprehensive genetic network of these QTL.On average,the epistatic effects of QTL pairs are estimated to be approximately 12.5%of additive effects of identified QTL.Importantly,epistasis varies among different alleles of several heading date genes.Additionally,57 pairs of interacting QTGs are also significant in their epistatic effects on 12 other agronomic traits.The identified QTL genetic interactions are further validated using near-isogenic lines,yeast two-hybrid,and split-luciferase complementation assays.Overall,this study provides a genetic network of rice heading date genes,which plays a crucial role in regulating rice heading date and influencing multiple related agronomic traits.This network serves as a foundation for understanding the genetic mechanisms of rice quantitative traits and for advancing rice molecular breeding.
基金funded by the National Key Research and Development Program of China(2016YFD0100203 and 2016YFD0102000)the Key Scientific and Technological Projects of the Eighth Division of the Xinjiang Production and Construction Corps(XPCC),China(2024NY01,2023 NY09,2023 NY10)+2 种基金the Key Scientific and Technological Project of XPCC,China(2021AB010)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(KYCX22_0748)supported by the High-performance Computing Platform of the Bioinformatics Center,Nanjing Agricultural University,China。
文摘Gossypium raimondii(2n=2x=26,D_(5)),an untapped wild species,is the putative progenitor of the D-subgenome of G.hirsutum(2n=4x=52,AD_(1)),an extensively cultivated species.Here,we developed a G.hirsutum(recipient)–G.raimondii(donor)introgression population to exploit the favorable QTLs/genes and mapped potential quantitative trait loci(QTLs)from wild cotton species.The introgression population consisted of 256 lines with an introgression rate of 52.33%for the G.raimondii genome.The introgression segment length range was 0.03–19.12 Mb,with an average of 1.22 Mb.The coverage of total introgression fragments from G.raimondii was 386.98 Mb.Further genome-wide association analysis(Q+K+MLM)and QTL mapping(RSTEP-LRT)identified 59 common QTLs,including 14 stable QTLs and six common QTL(co-QTL)clusters,and one hotspot of micronaire(MIC).The common QTLs for seed index all showed positive additive effects,while the common QTLs for boll weight all had negative additive effects,indicating that the linkage between seed index and boll weight could be broken.QTLs for lint percentage showed positive effects and could be beneficial for improving cotton yield.Most QTLs for fiber quality had negative additive effects,implying these QTLs were domesticated/improved in G.hirsutum.A few fiber quality QTLs showed positive additive effects,so they could be used to improve cotton fiber quality.The introgression lines developed could be useful for molecular marker-assisted breeding and mapping QTLs precisely for mining desirable genes from the wild species G.raimondii.Such genes can improve cultivated cotton in the future through a designbreeding approach.
基金supported by the Biological Breeding-Major Projects(2023ZD04067)Hubei Provincial Natural Science Foundation of China(2023AFB832)+1 种基金Guizhou Provincial Basic Research Program(Natural Science)(MS[2025]096)Major Project of Hubei Hongshan Laboratory(2022HSZD031)。
文摘Efficient and accurate identification of candidate causal genes within quantitative trait loci(QTL)is a significant challenge in genetic research.Conventional linkage analysis methods often require substantial time and resources to identify causal genes.This paper proposes a QTG-LGBM method for prioritizing causal genes in maize based on the Light GBM algorithm.QTG-LGBM dynamically adjusts gene weights and sample proportions during training to mitigate the effects of class imbalance.The method prevents overfitting in datasets with small samples by introducing a regularization term.Experimental results on maize traits,including plant height(PH),flowering time(FT),and tassel branch number(TBN),demonstrated that QTG-LGBM outperforms the commonly used methods QTG-Finder,GBDT,XGBoost,Bernoulli NB,SVM,CNN,and ensemble learning.We validated the generalization of QTG-LGBM using Arabidopsis,rice,Setaria,and sorghum.We also applied QTG-LGBM using reported QTL that affect traits of maize PH,FT and TBN,and FT in Arabidopsis,rice,and sorghum,as well as known causal genes within the QTL.When examining the top 20%of ranked genes,QTG-LGBM demonstrated a significantly higher recall rate of causal genes compared to random selection methods.We identified key gene features affecting phenotypes through feature importance analysis.QTG-LGBM is available at http://www.deepcba.com/QTG-LGBM.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LZ24C130004 and LQ24C130008)。
文摘Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD)conditions due to the synergistic regulation of many photosensitive genes.Using a set of chromosome segment substitution lines(CSSLs)with the indica cultivar Huanghuazhan(HHZ)as the recipient parent and Basmati Surkh 89-15(BAS)as the donor parent,we identified a QTL locus.
文摘A genetic linkage map with 89 SSR marker loci was constructed based on a maize (Zea mays L.) population consisting of 184 F-2 individuals from the cross, Huangzao 4 X Ye 107. The 184 F-3 families were evaluated in the field under well-watered and drought-stressed regimes in Shanxi Province of China. The objectives of the study were to identify genetic segments responsible for the expression of anthesis-silking interval (ASI), ear setting and grain yield, and to examine if the quantitative trait loci (QTLs) for ASI or yield components can be used in marker-assisted selection (MAS) to improve grain yield under drought conditions. Results showed that under well-watered and drought-stressed regimes, three and two QTLs involved in the expression of ASI were detected on chromosomes 1, 2 and 3, and 2 and 5, respectively. Under well-watered regime, two QTLs for ear setting were detected on chromosomes 3 and 6, explaining about 19.9% of the phenotypic variance, and displayed additive and partial dominant effects, respectively. Under drought-stressed condition, four QTLs for ear setting were detected on chromosomes 3, 7 and 10, which were responsible for interpreting 60.4% of the phenotypic variance, and showed dominant or partial dominant effects. Under well-watered condition, four QTLs controlling grain yield were identified on chromosomes 3, 6 and 7, while five QTLs were identified under drought stress on chromosomes 1, 2, 4 and 8. The gene action was of additive or partial dominant effects, and each QTL could explain 7.3% to 22.0% of the phenotypic variance, respectively. Under drought conditions, ASI and ear setting percentage were highly correlated with grain yield, which can be used as secondary traits for grain yield selection. Based on linked markers detected and gene action analyzed, an MAS strategy for yield improvement under drought condition could be established, which consists of QTLs contributing to decreased ASI and to increased ear setting and grain yield, respectively.
基金Supported by Fund for Jiangsu Agricultural Scientific Self-innovation Fund[CX(12)1003]Jiangsu Province Agricultural Science&Technology Support Program(BE2013301)+1 种基金Super Rice Breeding and Demonstration Program of the Ministry of AgricultureSpecial Fund of Modern Agricultural Industry Technology System(CARS-0147)~~
文摘Two hundred and forty recombinant inbred lines （RIL） derived from a cross TD70/Kasalath and its linkage map including 141 SSR markers were used to map QTLs controlling panicle length （PL）, total seeds per panicle （TSP） and grain density （GD） in 2010 and 2011. The results showed that a total of 23 QTLs controlling three panicle traits were detected on chromosomes 2, 3, 4, 6, 7, 8 and 10, respec- tively, including 5 QTLs controlling PL, 8 QTLs controlling TSP, 10 QTLs controlling GD, with the LOD value ranging between 2.5-9.3, and the QTLs explained the ob- served phenotypic by 4.0%-20.8%. The marker interval RM5699-RM424 on chro- mosome 2, RM489-RM1278 on chromosome 3, RM3367-RM1018 on chromosome 4, RM3343-RM412 on chromosome 6 were common marker intervals for TSP and GD; six QTLs （qPL3, qTSP4, qTSP6-2, qTSP7, qGD3-2 and qGDT） were detected in two years. Among these QTLs, the qPL3, qTSP6-2, qGD3-2 and qGD7 were major QTLs. All QTLs for PL mapped in the present study had been mapped QTLs previously by other research groups, 16 QTLs controlling TSP and GD were new ones which contributed the observed phenotypic variance range by 4%-9.5%. These results laid a founda^ion for further fine positioning or cloning these QTLs.
基金supported by the State Key Basic Research and Development Plan of China(No.2006CB102102)the National Natural Science Foundation of China(No.30500358).
文摘Quantitative trait loci(QTL)were detected for 8 internal organ traits,3 carcass length traits,and teat number trait in 214 pigs in a resource population that included 180 F2 individuals.A total of 39 microsatellite markers were examined on SSC4,SSC6,SSC7,SSC8,and SSC13.The genetic traits included heart weight(HW),lung weight(LW),liver and gallbladder weight(LGW),spleen weight(SPW),stomach weight(STW),small intestine weight(S1W),large intestine weight(LIW),kidney weight(KW),carcass length to the first cervical vertebra(CL1),carcass length to the first thoracic vertebra(CL2),rib numbers(RNS),and teat numbers(TNS).Results indicated that,3 highly significant QTL(P≤0.01 at chromosome-wise level)for HW(at 30 cM on SSC6),RNS(at 115 cM on SSC7),TNS(at 110 cM on SSC7),and 6 significant QTL(P≤0.05 at chromosome-wise level)for LW(at 119 cM on SSC13),LGW(at 94 cM on SSC6),SPW(at 106 cM on SSC8),SIW(0 cM on SSC4),LIW(170 cM on SSC 4),and TNS(at 95 cM on SSC6)were detected.The phenotypic variances for which these QTL were accounted ranged from 0.04%to 14.06%.Most of these QTL had not been previously reported.
文摘To identify genetic factors underlying phosphorus (P) uptake and use efficiency under low_P stress in rice (Oryza sativa L.), 84 selected genotypes (recombinant inbred lines) and their parents (which differed in tolerance for low_P stress) “IR20” and IR55178_3B_9_3, were cultured in liquid medium supplemented with adequate and low P levels in a greenhouse. Plants were sampled after 6 weeks in culture for measurements of plant dry weight, P concentration, P uptake and P use efficiency under both P sufficient and stress conditions. A total of 179 molecular markers, including 26 RFLPs and 153 AFLPs, mapped on all 12 chromosomes of rice based on the 84 selected genotypes were used to detect the quantitative trait loci (QTLs) underlying tolerance for low_P stress. Three QTLs were detected on chromosomes 6, 7 and 12, respectively, for relative plant dry weight (RPDW) and relative P uptake (RPUP). One of the QTLs flanked by RG9 and RG241 on chromosome 12 had a major effect which explained about 50% of the variations in the two parameters across the population. The results coincided with the QTLs for low_P stress based on relative tillering ability from the same population from a cross between Nipponbare and Kasalath under soil condition. The identical major QTL for P uptake and plant growth under low_P stress in both liquid medium and soil strongly suggests that the ability of P uptake mainly controls rice tolerance for low_P stress.
文摘Genome-wide association study（GWAS） can be used to identify genes that increase the risk of psychiatric diseases.However,much of the disease heritability is still unexplained,suggesting that there are genes to be discovered.Functional annotation of the genetic variants may increase the power of GWAS to identify disease genes,by providing prior information that can be used in Bayesian analysis or in reducing the number of tests.Expression quantitative trait loci（eQTLs） are genomic loci that regulate gene expression.Genetic mapping of eQTLs can help reveal novel functional effects of thousands of single nucleotide polymorphisms（SNPs）.The present review mainly focused on the current knowledge on brain eQTL mapping,and discussed some major methodological issues and their possible solutions.The frequently ignored problems of batch effects,covariates,and multiple testing were emphasized,since they can lead to false positives and false negatives.The future application of eQTL data in GWAS analysis was also discussed.
文摘Rice (Oryza sativa L.) eating and cooking quality is mainly influenced by its starch properties. Mapping quantitative trait loci (QTL) for starch properties not only helps us understand their genetic basis leading to acceleration of quality improvement, but also helps us find possible genes participating in the synthesis of starch. A recombinant inbred line (RIL) population consisting of 107 lines, derived from an indica (Zaiyeqing 8, ZYQ 8) and a japonica (Jingxi 17, JX 17) rice, was used to investigate the genetic factors affecting starch quality parameters, such as apparent amylose content (AAC), gel consistency (GC), starch pasting viscosity parameters, gel textural properties, gelatinization temperature (GT) and starch retrogradation properties. A total of 44 QTLs covered chromosomes 2-6, 8, 9 and 11 were detected for the 22 traits, with at least one QTL and as many as four QTLs for each individual trait. The results indicated that two major genes were responsible for most starch property traits. The Wx gene that encodes granule bound starch synthase on chromosome 6 was significant for AAC, GC, starch pasting viscosity parameters, gel textural properties and starch retrogradation properties. The alk gene linked with Wx on chromosome 6 was significant for starch gelatinization temperature characteristics. All other QTLs were minor genes. One QTL on chromosome 9 flanked by RZ404 and G295 was significant for gel hardness (HD), gumminess (GUM), chewiness (CHEW), peak temperature of retrogradated starch (RTp), and percentage retrogradation (R%) and all these traits were not tested before.
基金Supported by the Project of Technology Pilot Demonstration under Beijing Municipal Agricultural Commission(No.2023299039)the Project of Innovative Platform under Beijing Municipal Education Commission(No.PXM2014-014207-000018)~~
文摘In this paper, based on the DUS testing of new Lavandula spp., the differences and correlations of main phenotypic traits between Lavandula angustifolia and L. heterophylla were observed and analyzed. The results showed that the plant morphological traits of L. angustifolia were better than that of L. heterophylla, moreover, L. angustifolia exhibited relatively high adaptive capacity to the environmental conditions in introduction areas of north China. For the inflorescence, the ornamental traits of L. heterophylla were totally superior to that of L. angustifolia, especially in flower color diversity. It had obvious differences in both quantitative traits and qualitative traits between the two species, and these traits remained relatively stable in the growth progress. The correlation coefficients among the traits of two species were high, and the trait matching numbers at the 1% significance level of L. angustifolia were slightly more than that of L. heterophylla.
基金supported by the Project of Conservation and Utilization of Agro-Wild Plants of the Ministry of Agriculture of China and Special Fund for Agro-scientific Research in the Public Interest(No.201003021)
文摘Soil salinity is one of the major abiotic stresses affecting plant growth and crop production.In the present study,salt tolerance at rice seedling stage was evaluated using 87 introgression lines（ILs）,which were derived from a cross between an elite indica cultivar Teqing and an accession of common wild rice（Oryza rufipogon Griff.）.Substantial variation was observed for four traits including salt tolerance score（STS）, relative root dry weight（RRW）,relative shoot dry weight（RSW） and relative total dry weight（RTW）.STS was significantly positively correlated with all other three traits.A total of 15 putative quantitative trait loci（QTLs） associated with these four traits were detected using single-point analysis,which were located on chromosomes 1,2,3,6,7,9 and 10 with 8%-26%explaining the phenotypic variance.The O. rufipogon-derived alleles at 13 QTLs（86.7%） could improve the salt tolerance in the Teqing background.Four QTL clusters affecting RRW, RSW and RTW were found on chromosomes 6,7,9 and 10,respectively.Among these four QTL clusters,a major cluster including three QTLs （qRRWIO,qRSWIO and qRTWIO） was found near the maker RM271 on the long arm of chromosome 10,and the O.rufipogon-derived alleles at these three loci increased RRW,RSW and RTW with additive effects of 22.7%,17.3%and 18.5%,respectively,while the phenotypic variance explained by these three individual QTLs for the three traits varied from 19%to 26%.In addition,several salt tolerant ILs were selected and could be used for identifying and utilizing favorable salt tolerant genes from common wild rice and used in the salt tolerant rice breeding program.
基金Project supported by the National Natural Science Foundation of China (No. 31000748)the Natural Science Foundation of Jiangsu Province (No. BK2010452)the Science and Technology Innovation Foun-dation of Nanjing Agricultural University (No. KJ09003), China
文摘Seed vigor is an important characteristic of seed quality,and rice cultivars with strong seed vigor are desirable in direct-sowing rice production for optimum stand establishment.In the present study,the quantitative trait loci (QTLs) of three traits for rice seed vigor during the germination stage,including germination rate,final germination percentage,and germination index,were investigated using one recombinant inbred line (RIL) population derived from a cross between japonica Daguandao and indica IR28,and using the multiple interval mapping (MIM) approach.The results show that indica rice presented stronger seed vigor during the germination stage than japonica rice.A total of ten QTLs,and at least five novel alleles,were detected to control rice seed vigor,and the amount of variation (R2) explained by an individual QTL ranged from 7.5% to 68.5%,with three major QTLs with R2>20%.Most of the QTLs detected here are likely to coincide with QTLs for seed weight,seed size,or seed dormancy,suggesting that the rice seed vigor might be correlated with seed weight,seed size,and seed dormancy.At least five QTLs are novel alleles with no previous reports of seed vigor genes in rice,and those major or minor QTLs could be used to significantly improve the seed vigor by marker-assisted selection (MAS) in rice.
基金supported by the National 863 Program of China (2011AA10A101)the Chinese High-Yielding Transgenic Program (2011ZX08001-004)a project of the State Key Laboratory of Rice Biology,China(ZZKT201101)
文摘Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of commercial three-line hybrids of indica rice.Two of the populations showed great variations on heading date,and the other had a short range of heading date variation.A total of 40 QTLs were detected and fell into 15 regions of 10 chromosomes,of which 5 regions were detected for 1 or more same traits over different populations,2 were detected for different traits in different populations,3 were detected for 2 or all the 3 traits in a single population,and 5 were detected for a single trait in a single population.Most of these QTLs have been reported previously,but a region located on the long arm of chromosome 10 showing significant effects in all the 3 populations has not been reported before.It was shown that a number of gene cloned,including the Wx and Alk for the physiochemical property of rice grain,and GW2,GS3 and GW5 for grain weight and grain size,could have played important roles for the genetic control of grain chalkiness in rice,but there are many more QTLs exerting stable effects for rice chalkiness over different genetic backgrounds.It is worth paying more attentions to these regions which harbor QTL such as the qPCG5.2/qDC5.2/qET5.2 and qPCG10/qDC10/qET10 detected in our study.Our results also showed that the use of segregating populations having high-uniform heading date could greatly increase the efficiency of the identification of QTL responsible for traits that are subjected to great environmental influence.
文摘The quantitative trait loci （QTLs） for the dead leaf rate （DLR） and the dead seedling rate （DSR） at the different rice growing periods after transplanting under alkaline stress were identified using an F2：3 population, which included 200 individuals and lines derived from a cross between two japonica rice cultivars Gaochan 106 and Changbai 9 with microsatellite markers. The DLR detected at 20 days to 62 days after transplanting under alkaline stress showed continuous normal or near normal distributions in F3 lines, which was the quantitative trait controlled by multiple genes. The DSR showed a continuous distribution with 3 or 4 peaks and was the quantitative trait controlled by main and multiple genes when rice was grown for 62 days after transplanting under alkaline stress. Thirteen QTLs associated with DLR were detected at 20 days to 62 days after transplanting under alkaline stress. Among these, qDLR9-2 located in RM5786-RM160 on chromosome 9 was detected at 34 days, 41 days, 48 days, 55 days, and 62 days, respectively; qDLR4 located in RM3524-RM3866 on chromosome 4 was detected at 34 days, 41 days, and 48 days, respectively; qDLR7-1 located in RM3859-RM320 on chromosome 7 was detected at 20 days and 27 days; and qDLR6-2 in RM1340-RM5957 on chromosome 6 was detected at 55 days and 62 days, respectively. The alleles of both qDLR9-2 and qDLR4 were derived from alkaline sensitive parent ＂Gaochanl06＂. The alleles of both qDLR7-1 and qDLR6-2 were from alkaline tolerant parent Changbai 9. These gene actions showed dominance and over dominance primarily. Six QTLs associated with DSR were detected at 62 days after transplanting under alkaline stress. Among these, qDSR6-2 and qDSR8 were located in RM1340-RM5957 on chromosome 6 and in RM3752-RM404 on chromosome 8, respectively, which were associated with DSR and accounted for 20.32% and 18.86% of the observed phenotypic variation, respectively; qDSR11-2 and qDSR11-3 were located in RM536-RM479 and RM2596-RM286 on chromosome 11, respectively, which were associated with DSR explaining 25.85% and 15.41% of the observed phenotypic variation, respectively. The marker flanking distances of these QTLs were quite far except that of qDSR6-2, which should be researched further.
基金supported by the Ministry of Science and Technology(Grant No. 2011 CB 100205)the Ministry of Agriculture of China (Grant Nos.2011ZX08001-004 and 2011ZX08009-002)the National Natural Science Foundation of China(Grant No. 31121063)
文摘1000-Grain weight and spikelet number per panicle are two important components for rice grain yield. In our previous study, eight quantitative trait loci （QTLs） conferring spikelet number per panicle and 1000-grain weight were mapped through sequencing-based genotyping of 150 rice recombinant inbred lines （RILs）. In this study, we validated the effects of four QTLs from Nipponbare using chromosome segment substitution lines （CSSLs）, and pyramided eight grain yield related QTLs. The new lines containing the eight QTLs with positive effects showed increased panicle and spikelet size as compared with the parent variety 93-11. We further proposed a novel pyramid breeding scheme based on marker-assistant and phenotype selection （MAPS）. This scheme allowed pyramiding of as many as 24 QTLs at a single hybridization without massive cross work. This study provided insights into the molecular basis of rice grain yield for direct wealth for high-yielding rice breeding.
基金the support of the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2011BAD35B01)the National High-Tech R&D Program of China(2011AA10A103-3)
文摘Stalk related traits, comprising plant height （PH）, ear height （EH）, internode number （IN）, average internode length （ALL）, stalk diameter （SD）, and ear height coefficient （EHC）, are significantly correlated with yield, density tolerance, and lodging resistance in maize. To investigate the genetic basis for stalk related traits, a doubled haploid （DH） population derived from a cross between NX531 and NX110 were evauluated under two densities over 2 yr. The additive quantitative trait loci （QTLs）, epistatic QTLs were detected using inclusive composite interval mapping and QTL-by-environment interaction were detected using mixed linear model. Differences between the two densities were significant for the six traits in the DH population. A linkage map that covered 1 721.19 cM with an average interval of 10.50 cM was constructed with 164 simple sequence repeat （SSR）. Two, two, seven, six, two, and eight additive QTLs for PH, IN, AIL, EH, SD, and EHC, respectively. The extend of their contribution to penotypic variation ranged from 10.10 to 31.93%. Seven QTLs were indentified simultaneously under both densities. One pair, two pairs and one pair of epistatic effects were detected for AIL, SD and EHC, respectively. No epistatic effects were detected for PH, EH, and IN. Nineteen QTLs with environment interactions were detected and their contribution to phenotypic variation ranged from 0.43 to 1.89%. Some QTLs were stably detected under different environments or genetic backgrounds comparing with previous studies. These QTLs could be useful for genetic improvement of stalk related traits in maize breeding.
文摘The shell traits and weight traits are measured in cultured populations of bay scallop, Argopecten irradians. The results of regression analysis show that the regression relationships for all the traits are significant (P<0.01). The correlative coefficients between body weight, as well as tissue weight with shell length, shell height and shell width are significant (P<0.05). But the correlative coefficients between the anterior and posterior auricle length with body weight as well as tissue weight are not significant (P>0.05). The multiple regression equation is obtained to estimate live body weight and tissue weight. The above traits except anterior and posterior auricle length are used for the growth and production comparison among three cultured populations, Duncan's new multiple range procedure analysis shows that all the traits in the Lingshuiqiao (LSQ) population are much more significant than those of the other two populations (P<0.01), and there is no significant difference between the Qipanmo (QPM) and Dalijia (DLJ) populations in all traits (P>0.05). The results indicate that the LSQ population has a higher growth rate and is expected to be more productive than the other two populations.
基金supported by the National Natural Science Foundation of China (No. 30630047) the Project on Absorption of Intellects by Institutions of Higher Education for Academic Disciplinary Innova-tions (the 111 Project) (No. B06014), China
文摘To understand genetic patterns of the morphological and physiological traits in flag leaf of barley, a double haploid （DH） population derived from the parents Yerong and Franklin was used to determine quantitative trait loci （QTL） controlling length, width, length/width, and chlorophyll content of flag leaves. A total of 9 QTLs showing significantly additive effect were detected in 8 intervals on 5 chromosomes. The variation of individual QTL ranged from 1.9% to 20.2%. For chlorophyll content expressed as SPAD value, 4 QTLs were identified on chromosomes 2H, 3H and 6H; for leaf length and width, 2 QTLs located on chromosomes 5H and 7H, and 2 QTLs located on chromosome 5H were detected; and for length/width, I QTL was detected on chromosome 7H. The identification of these QTLs associated with the properties of flag leaf is useful for barley improvement in breeding programs.
