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1.
Aegiliops tauschii is classified into two subspecies： Ae. tauschii ssp. tauschii and Ae. tauschii ssp. strangulata. Novel genetic variations exist in Ae. tauschii ssp. tauschii that can be utilized in wheat improvement. We synthesized a hexaploid wheat genotype（SHW-L1） by crossing an Ae. tauschii ssp. tauschii accession（AS60） with a tetraploid wheat genotype（AS2255）. A population consisting of 171 F8 recombinant inbred lines was developed from SHW-L1 and Chuanmai 32 to identify QTLs associated with agronomic traits. A new genetic map with high density was constructed and used to detect the QTLs for heading date, kernel width, spike length, spikelet number, and thousand kernel weight. A total of 30 putative QTLs were identified for five investigated traits. Thirteen QTLs were located on D genomes of SHW-L1, six of them showed positive effect on agronomic traits. Chromosome region flanked by wPt-6133–wPt-8134 on 2D carried five environment-independent QTLs. Each QTL accounted for more than 10% phenotypic variance. These QTLs were highly consistent across environments and should be used in wheat breeding.  相似文献   

2.
Adzuki bean(Vigna angularis(Willd.) Ohwi Ohashi) is an annual cultivated leguminous crop commonly grown in Asia and consumed worldwide. However, there has been limited research regarding adzuki bean genetics, which has prevented the efficient application of genes during breeding. In the present study, we constructed a high-density genetic map based on whole genome re-sequencing technology and validated its utility by mining QTLs related to seed size. Moreover, we analyzed the sequences flanking insertions/deletions(In Dels) to develop a set of PCR-based markers useful for characterizing adzuki bean genetics. A total of 2 904 markers were mapped to 11 linkage groups(LGs). The total length of the map was 1 365.0 cM, with an average distance between markers of 0.47 cM. Among the LGs, the number of markers ranged from 208(LG7) to 397(LG1) and the total distance ranged from 97.4 cM(LG9) to 155.6 cM(LG1). Twelve QTLs related to seed size were identified using the constructed map. The two major QTLs in LG2 and LG9 explained 22.1 and 18.8% of the total phenotypic variation, respectively. Ten minor QTLs in LG4, LG5 and LG6 explained 3.0–10.4% of the total phenotypic variation. A total of 9 718 primer pairs were designed based on the sequences flanking In Dels. Among the 200 selected primer pairs, 75 revealed polymorphisms in 24 adzuki bean germplasms. The genetic map constructed in this study will be useful for screening genes related to other traits. Furthermore, the QTL analysis of seed size and the novel markers described herein may be relevant for future molecular investigations of adzuki bean and will be useful for exploiting the mechanisms underlying legume seed development.  相似文献   

3.
To dissect the genetic control of the sensory and textural quality traits of Chinese white noodles,a population of recombinant inbred lines(RILs),derived from the cross of waxy wheat Nuomai 1(NM1) and Gaocheng 8901(Gc8901),was used. The RILs were tested in three different environments to determine the role of environmental effects on quantitative trait loci(QTL) analysis. A total of 45 QTLs with additive effects for 17 noodle sensory and textural properties under three environments were mapped on 15 chromosomes. These QTLs showed 4.23–42.68% of the phenotypic variance explained(PVE). Nineteen major QTLs were distributed on chromosomes 1B,1D,2A,3B,3D,4A,and 6A,explaining more than 10% of the phenotypic variance(PV). Clusters were detected on chromosomes 2B(3 QTLs),3B(11 QTLs) and 4A(5 QTLs). The cluster detected on chromosome 4A was close to the Wx-B1 marker. Five co-located QTLs with additive effects were identified on chromosomes 2B,3D,4A,6A,and 7B. The two major QTLs,Qadh.sdau-3B.1 and Qspr.sdau-3B.1,in cluster w Pt666008–w Pt5870 on chromosome 3B were detected in three different environments,which perhaps can be directly applied to improve the textural properties of noodles. These findings could offer evidence for the selection or development of new wheat varieties with noodle quality using molecular marker-assisted selection(MAS).  相似文献   

4.
Sheath blight(SB) disease,caused by Rhizoctonia solani K(u|¨)hn,is one of the most serious diseases causing rice(Oryza sativa L.) yield loss worldwide.A doubled haploid(DH) population was constructed from a cross between a japonica variety CJ06 and an indica variety TN1,and to analyze the quantitative trait loci(QTLs) for SB resistance under three different environments(environments 1-3).Two traits were recorded to evaluate the SB resistance,namely lesion height(LH) and disease rating(DR).Based on field evaluation of SB resistance and a genetic map constructed with 214 markers,a total of eight QTLs were identified for LH and eight QTLs for DR under three environments,respectively.The QTLs for LH were anchored on chromosomes 1,3,4,5,6,and 8,and explained 4.35-17.53%of the phenotypic variation.The SB resistance allele of qHNLH4 from TN1 decreased LH by 3.08 cm,and contributed to 17.53%of the variation at environment 1.The QTL for LH(qHZaLH8) detected on chromosome 8 in environment 2 explained 16.71%of the variation,and the resistance allele from CJ06 reduced LH by 4.4 cm.Eight QTLs for DR were identified on chromosomes 1,5,6,8,9,11,and 12 under three conditions with the explained variation from 2.0 to 11.27%.The QTL for DR(qHZaDR8),which explained variation of 11.27%,was located in the same interval as that of qHZaLH8,both QTLs were detected in environment 2.A total of six pairs of digenic epistatic loci for DR were detected in three conditions,but no epistatic locus was observed for LH.In addition,we detected 12 QTLs for plant height(PH) in three environments.None of the PH-QTLs were co-located with the SB-QTLs.The results facilitate our understanding of the genetic basis for SB resistance in rice.  相似文献   

5.
Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is a severe foliar disease of common wheat (Triticum aestivum L.) in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene(s) for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 (M169). Seedlings of the parents, and F 1 , F 2 and F 2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat (SSR) techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F 2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively; and the two markers in combination could distinguish the alleles at the resistance locus in 97.9% of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.  相似文献   

6.
General combining abilities(GCAs) are very important in utilization of heterosis in maize breeding. However, its genetic basis is unclear. In the present study, a set of 118 doubled haploid(DH) lines were induced from F_1 generations produced from the cross between the inbred line Zheng 58 and the inbred line W499 belonging to the Reid subgroup. Using the Maize SNP50 Bead Chip, a high-density genetic map was constructed based on the DH population which included 1 147 bin markers with an average interval length of 2.00 cM. Meanwhile, the DH population was crossed with three testers including W16-5, HD568, and W556, which belong to the Sipingtou subgroup. The GCAs of the ear height(EH), the kernel moisture content(KMC), the kernel ratio(KR), and the yield per plant(YPP) were estimated using these hybrids in three environments. Combining the high-density genetic map and the GCAs, a total of 14 QTLs were detected for the GCAs of the four traits. Especially, one pleiotropic QTL was identified on chromosome 1 between the SNP SYN16067 and the SNP PZE-101169244 which was simultaneously associated with the GCAs of the EH, the KR, and the YPP. These QTLs pave the way for further dissecting the genetic architecture underlying GCAs of the traits, and they may be used to enhance GCAs of inbred lines under the fixed heterotic pattern Reid×Sipingtou in China through a marker-assisted selection approach.  相似文献   

7.
Grain number per spike(GNPS) is a major factor in wheat yield breeding.A new wheat germplasm Pubing 3504 shows superior features in spike traits.To elucidate the genetic basis of spike and yield related traits in Pubing 3504,282 F2:3 families were generated from the cross Pubing 3504×Jing 4839,and seven spike and yield related traits,including GNPS,spike length(SL),kernel number per spikelet(KPS),spikelet number per spike(SNS),thousand-grain weight(TGW),spike number per plant(SNP),and plant height(HT) were investigated.Correlation analysis indicated significant positive correlations between GNPS and spike-related traits,including KPS,SNS,and SL,especially KPS.A genetic map was constructed using 190 polymorphic simple sequence repeat(SSR),expressed sequence tag(EST)-SSR,and sequencetagged-site(STS) markers.For the seven traits measured,a total of 37 quantitative trait loci(QTLs) in a single-environment analysis and 25 QTLs in a joint-environment analysis were detected.Additive effects of 70.3%(in a single environment) and 57.6%(in a joint environment) of the QTLs were positively contributed by Pubing 3504 alleles.Five important genomic regions on chromosomes 1 A,4 A,4 B,2 D,and 4 D could be stably detected in different environments.Among these regions,the marker interval Xmag834–Xbarc83 on the short arm of chromosome 1 A was a novel important genomic region that included QTLs controlling GNPS,KPS,SNS,TGW,and SNP with stable environmental repeatability.This genomic region can improve the spike trait and may play a key role in improving wheat yield in the future.We deduced that this genomic region was vital to the high GNPS of Pubing 3504.  相似文献   

8.
Molecular genetic maps of crop species can be used in a variety of ways in breeding and genomic research such as identification and mapping of genes and quantitative trait loci （QTLs） for morphological, physiological and economic traits of crop species. However, a comprehensive genetic linkage map for cultivated peanut has not yet been developed due to the extremely low frequency of DNA polymorphism in cultivated peanut. In this study, 142 recombinant inbred lines （RILs） derived from a cross between Yueyou 13 and Zhenzhuhei were used as mapping population in peanut （Arachis hypogaea L.）. A total 652 pairs of genomic-SSR primer and 392 pairs of EST-SSR primer were used to detect the polymorphisms between the two parents. 141 SSR primer pairs, 127 genomic-SSR and 14 EST-SSR ones, which can be used to detect polymorphisms between the two parents, were selected to analyze the RILs population. Thus, a linkage genetic map which consists of 131 SSR loci in 20 linkage groups, with a coverage of 679 cM and an average of 6.12 cM of inter-maker distance was constructed. The putative functions of 12 EST-SSR markers located on the map were analyzed. Eleven showed homology to gene sequences deposited in GenBank. This is the first report of construction of a comprehensive genetic map with SSR markers in peanut （Arachis hypogaea L.）. The map presented here will provide a genetic framework for mapping the qualitative and quantitative trait in peanut.  相似文献   

9.
The construction of high density genetic linkage map provides a powerful tool to detect and map quantitative trait loci(QTLs) controlling agronomically important traits. In this study, simple sequence repeat(SSR) markers and Illumina 9K i Select single nucleotide polymorphism(SNP) genechip were employed to construct one genetic linkage map of common wheat(Triticum aestivum L.) using 191 recombinant inbred lines(RILs) derived from cross Yu 8679×Jing 411. This map included 1 901 SNP loci and 178 SSR loci, covering 1 659.9 c M and 1 000 marker bins, with an average interval distance of 1.66 c M. A, B and D genomes covered 719.1, 703.5 and 237.3 c M, with an average interval distance of 1.66, 1.45 and 2.9 c M, respectively. Notably, the genetic linkage map covered 20 chromosomes, with the exception of chromosome 5D. Bioinformatics analysis revealed that 1 754(92.27%) of 1 901 mapped SNP loci could be aligned to 1 215 distinct wheat unigenes, among which 1 184(97.4%) were located on o ne single chromosome, and the rest 31(2.6%) were located on 2 to 3 chromosomes. By performing in silico comparison, 214 chromosome deletion bin-mapped expressed sequence tags(ESTs), 1 043 Brachypodium genes and 1 033 rice genes were further added onto the genetic linkage map. This map not only integrated genetic and physical maps, SSR and SNP loci, respectively, but also provided the information of Brachypodium and rice genes corresponding to 1 754 SNP loci. Therefore, it will be a useful tool for comparative genomics analysis, fine mapping of QTL/gene controlling agronomically important traits and marker-assisted selection breeding in wheat.  相似文献   

10.
In order to understand the genetic basis for Zeleny sedimentation value （ZSV） of wheat, a doubled haploid （DH） population Huapei 3 × Yumai 57 （Yumai 57 is superior to Huapei 3 for ZSV）, and a linkage map consisting of 323 marker loci were used to search QTLs for ZSV. This program was based on mixed linear models and allowed simultaneous mapping of additive effect QTLs, epistatic QTLs, and QTL x environment interactions （QEs）. The DH population and the parents were evaluated for ZSV in three field trials. Mapping analysis produced a total of 8 QTLs and 2 QEs for ZSV with a single QTL explaining 0.64-14.39% of phenotypic variations. Four additive QTLs, 4 pairs of epistatic QTLs, and two QEs collectively explained 46.11% of the phenotypic variation （PVE）. This study provided a precise location of ZSV gene within the Xwmc 93 and GluD1 interval, which was designated as Qzsv-1D. The information obtained in this study should be useful for manipulating the QTLs for ZSV by marker assisted selection （MAS） in wheat breeding programs.  相似文献   

11.
Triticum aestivum-Hayaldia villosa translocation line V3 has shown effective all-stage resistance to the seven dominant pathotypes of Puccinia striiforms f.sp.tritici prevalent in China.To elucidate the genetic basis of the resistance,the segregating populations were developed from the cross between V3 and susceptible genotype Mingxian 169,seedlings of the parents and F 2 progeny were tested with six prevalent pathotypes,including CYR29,CYR31,CYR32-6,CYR33,Sun11-4,and Sun11-11,F 1 plants and F 3 lines were also inoculated with Sun11-11 to confirm the result further.The genetic studied results showed that the resistance of V3 against CYR29 was conferred by two dominant genes,independently,one dominant gene and one recessive gene conferring independently or a single dominant gene to confer resistance to CYR31,two complementary dominant genes conferring resistance to both CYR32-6 and Sun11-4,two independently dominant genes or three dominant genes（two of the genes show cumulative effect） conferring resistance to CYR33,a single dominant gene for resistance to Sun11-11.Resistance gene analog polymorphism（RGAP） and simple-sequence repeat（SSR） techniques were used to identify molecular markers linked to the single dominant gene（temporarily designated as YrV3） for resistance to Sun11-11.A linkage map of 2 RGAP and 7 SSR markers was constructed for the dominant gene using data from 221 F 2 plants and their derived F 2：3 lines tested with Sun11-11 in the greenhouse.Amplification of the complete set of nulli-tetrasomic lines of Chinese Spring with a RGAP marker RG1 mapped the gene on the chromosome 1B,and then the linked 7 SSR markers located this gene on the long arm of chromosome 1B.The linkage map spanned a genetic distance of 25.0 cM,the SSR markers Xgwm124 and Xcfa2147 closely linked to YrV3 with genetic distances of 3.0 and 3.8 cM,respectively.Based on the linkage map,it concluded that the resistance gene YrV3 was located on chromosome arm 1BL.Given chromosomal location,the reaction patterns and pedigree analysis,YrV3 should be a novel gene for resistance to stripe rust in wheat.These closely linked markers should be useful in stacking genes from different sources for wheat breeding and diversification of resistance genes against stripe rust.  相似文献   

12.
Stripe rust is one of the most important diseases of wheat worldwide. Inheritance of stripe rust resistance and mapping of resistance gene with simple sequence repeat （SSR） markers are studied to formulate efficient strategies for breeding cultivars resistant to stripe rust. Zhongliang 88375, a common wheat line, is highly resistant to all three rusts of wheat in China. The gene conferring rust disease was deduced originating from Elytrigia intermedium. Genetic analysis of Zhongliang 88375 indicated that the resistance to PST race CYR31 was controlled by a single dominant gene, temporarily designated as Yr88375. To molecular map Yr88375, a F2 segregating population consisting of 163 individuals was constructed on the basis of the hybridization between Zhongliang 88375 and a susceptible wheat line Mingxian 169; 320 SSR primer pairs were used for analyzing the genetic linkage relation. Six SSR markers, Xgwm335, Xwmc289, Xwmc810, Xgdmll6, Xbarc59, and Xwmc783, are linked to Yr88375 as they were all located on chromosome 5BL Yr88375 was also located on that chromosome arm, closely linked to Xgdmll6 and Xwmc810 with genetic distances of 3.1 and 3.9 cM, respectively. The furthest marker Xwmc783 was 13.5 cM to Yr88375. Hence, pedigree analysis of Zhongliang 88375 combined with SSR markers supports the conclusion that the highly resistance gene Yr88375 derived from Elytrigia intermedium is a novel gene for resistance to stripe rust in wheat. It could play an important role in wheat breeding programs for stripe rust resistance.  相似文献   

13.
Micronutrient malnutrition affects over three billion people worldwide, especially women and children in developing countries. Increasing the bioavailable concentrations of essential elements in the edible portions of crops is an effective resolution to address this issue. To determine the genetic factors controlling micronutrient concentration in wheat, the quantitative trait locus （QTL） analysis for iron, zinc, copper, manganese, and selenium concentrations in two recombinant inbred line populations was performed. In all, 39 QTLs for ifve micronutrient concentrations were identiifed in this study. Of these, 22 alleles from synthetic wheat SHW-L1 and seven alleles from the progeny line of the synthetic wheat Chuanmai 42 showed an increase in micronutrient concentrations. Five QTLs on chromosomes 2A, 3D, 4D, and 5B found in both the populations showed signiifcant phenotypic variation for 2-3 micronutrient concentrations. Our results might help understand the genetic control of micronutrient concentration and allow the utilization of genetic resources of synthetic hexaploid wheat for improving micronutrient efifciency of cultivated wheat by using molecular marker-assisted selection.  相似文献   

14.
The paste viscosity attributes of starch, measured by rapid visco analyzer(RVA), are important factors for the evaluation of the cooking and eating qualities of rice in breeding programs. To determine the genetic roots of the paste viscosity attributes of rice grains, quantitative trait loci(QTLs) associated with the paste viscosity attributes were mapped, using a double haploid(DH) population derived from Zhongjiazao 17(YK17), a super rice variety, crossed with D50, a tropic japonica variety. Fifty-four QTLs, for seven parameters of the RVA profiles, were identified in three planting seasons. The 54 QTLs were located on all of the 12 chromosomes, with a single QTL explaining 5.99 to 47.11% of phenotypic variation. From the QTLs identified, four were repeatedly detected under three environmental conditions and the other four QTLs were repeated under two environments. Most of the QTLs detected for peak viscosity(PKV), trough viscosity(TV), cool paste viscosity(CPV), breakdown viscosity(BDV), setback viscosity(SBV), and peak time(PeT) were located in the interval of RM6775–RM3805 under all three environmental conditions, with the exception of pasting temperature(PaT). For digenic interactions, eight QTLs with six traits were identified for additive×environment interactions in all three planting environments.The epistatic interactions were estimated only for PKV, SBV and PaT. The present study will facilitate further understanding of the genetic architecture of eating and cooking quality(ECQ) in the rice quality improvement program.  相似文献   

15.
A segregating population with 410 F 2 individuals from the cross MERCIA(Rht-B1a) ×Dwarf 123 was made to identify a new major dwarfing gene carrying by novel wheat germplasm Dwarf 123.Combination of bulk segerant analysis method was used.A total of 145 SSR markers were tested for polymorphisms among parental lines and DNA bulks of F 2 population.Out of 145 primer pairs only three markers revealed corresponding polymorphism among parental lines and F 2 DNA bulks.The marker Barc20 was close to the dwarfing gene with a genetic distance of 1.8 cM,and markers Gwm513 and Gwm495 were linked to the gene with genetic distance of 6.7 and 13 cM,respectively.Linkage analysis mapped the dwarfing gene to the long arm of chromosome 4B with the order of Barc20-dwarfing gene-Gwm513-Gwm495.The Comparision between the new gene and the known Rht-B1 alleles showed that dwarfing gene Rht-Ai123 was different from the others.The identification of the new dwarfing gene and its linked markers will greatly facilitate its utilization in wheat high yield breeding for reducing plant height.  相似文献   

16.
Based on the former constructed ‘Tyr1’ locus genetic map in family 9145, from LB6-2 [Clementine mandarin (C. reticulata) × Hamlin orange (C. sinensis)] × Swingle citrumelo (C. paradise × P. trifoliata), 9 markers were chosen for application in evaluating their effectiveness in marker-assisted selection (MAS) for citrus rootstock breeding program from many F1 progeny of Poncirus trifoliata. As the mapping revealed that these markers were estimated within a range of 12.1 cM in the linkage group, and among them, SCO07 co-segregated with ‘Tyr1’, and 7A4R as the closest to ‘Tyr1’ with a distance of 1.5 cM, these markers were basically fitful to go MAS screening. The results of screening P. trifoliata F1 progeny indicated that all the markers were inherited in codominant fashion and most of them were heterozygous on PT (Pomery of P. trifoliata)., marker 4L17R/CfoI and 7A4(1407)/BfaI were proved to be consistently reliable for accurate scoring of genotypes and the revealed polymorphism was basically coincided with the citrus nematode resistant phenotype within tested populations. The polymorphic genotype with marker 4L17R/CfoI was found completely matched up with the phenotype of individuals that conferred high resistance to citrus nematode when the USDA hybrid rootstocks were screened. Utilization of these markers, especially the highly specific 4L17R/CfoI and 7A4(1407)/BfaI, should result in great benefit to world citrus industry for early selection in rootstock-breeding program.  相似文献   

17.
Based on the former constructed ＇Tyrl＇ locus genetic map in family 9145, from LB6-2 [Clementine mandarin （C. reticulata） × Hamlin orange （C. sinensis）] × Swingle citrumelo （C. paradise × P. trifoliata）, 9 markers were chosen for application in evaluating their effectiveness in marker-assisted selection （MAS） for citrus rootstock breeding program from many F1 progeny of Poncirus trifoliata. As the mapping revealed that these markers were estimated within a range of 12.1 cM in the linkage group, and among them, SCO07 co-segregated with ＂Tyrl＇, and 7A4R as the closest to ＇Tyrl＇ with a distance of 1.5 cM, these markers were basically fitful to go MAS screening. The results of screening P. trifoliata F1 progeny indicated that all the markers were inherited in codominant fashion and most of them were heterozygous on PT （Pomery of P. trifoliata）., marker 4L17R/CfoI and 7A4（1407）/BfaI were proved to be consistently reliable for accurate scoring of genotypes and the revealed polymorphism was basically coincided with the citrus nematode resistant phenotype within tested populations. The polymorphic genotype with marker 4L17R/Cfol was found completely matched up with the phenotype of individuals that conferred high resistance to citrus nematode when the USDA hybrid rootstocks were screened. Utilization of these markers, especially the highly specific 4L17R/Cfol and 7A4（1407）/Bfal, should result in great benefit to world citrus industry for early selection in rootstock-breeding program.  相似文献   

18.
It had been demonstrated that the strong and highly significant quantitative trait locus（QTL） can affect protein percentage on Bos Taurus Autosome 3（BTA3） at the position 52 cM, near the microsatellite DIK4353, with the 95% confidence interval spanning from 25 to 57 cM in Chinese Holstein population using QTL-express, MQREML, and GRIDQTL softwares. This study herein focused on such region of fine mapping QTLs for milk production and functional traits with 16 microsatellite markers with coverage of 33 cM between the markers BMS2904 and MB099 on BTA3 in a daughter-designed Chinese Holstein population. A total of 1 298 Holstein cows and 7 sires were genotyped for 16 microsatellites with ABI 3700 DNA sequencer. The variance components QTL linkage analysis（LA） and linkage-disequilibrium（LD） analysis（LA/LD） was performed to map QTLs for 7 traits, i.e., 305-d milk yield, fat yield, protein yield, fat percentage, protein percentage, somatic cell score and persistency of milk yield. Four strong and highly significant QTLs were detected for fat yield, fat percentage, protein percentage and somatic cell score at the position 40, 30, 27 and 26 cM, respectively. Two minor QTLs for milk yield and persistency of milk yield were identified at 42 and 46 cM, respectively. These findings provided a general idea for the fine mapping of the causal mutation for milk production and functional traits on BTA3 in the future.  相似文献   

19.
The property of starch in rice grain endosperm is a very important determinant for rice quality, and it is essential to understand the genetic effect of the genes related to starch synthesis in high-yielding rice varieties for rice quality improvement. The physicochemical properties （e.g., amylose content, gel consistency, and RVA profile） were assessed on 53 rice varieties, including certain typical indica/japonica landraces and certain high-yielding modern varieties. And molecular markers for Sbel, Sbe3 developed on the basis of sequence diversities between the rice subspecies indica and japonica, together with PCR-Acc I marker for Wx gene were used to investigate the genotypes of 53 rice cultivars. The result showed that the developed molecular markers for Wx, Sbel, Sbe3 could distinguish indica or japonica alleles at three loci. Among all the 53 rice cultivars, six genotypes were observed when Sbel, Sbe3, and Wx loci were considered together, while the genotypes of WxiSbelJSbe3i and WxiSbelJSbe3J were absent. In order to explore the genetic effects of the three genes, especially for starch branching enzyme genes, ANOVA and multiple comparison analysis were conducted. The results showed that rice cultivars with different genotypes exhibited different phenotypes, including amylose content, gel consistency and certain RVA characteristics, and the significant differences among the six genotypes were observed. It was concluded that these three genes had randomly recombined during the process of the rice variety development. And the genetic effects of indica and japonica alleles at three gene loci were different, of which, Wx gene plays a major role in determining the starch properties, followed by Sbel and Sbe3, and the genetic effects of Sbel and Sbe3 in different backgrounds （Wx~, WxJ） are different. The results have provided a clue for rice good quality variety development, and the molecular markers will benefit to the improvement in quality of rice.  相似文献   

20.
Genetic diversity of 62 Sichuan wheat landraces accessions of China was investigated by agronomic traits and SSR markers. The landrace population showed the characters of higher tiller capability and more kernels/spike,especially tiller no./plant of six accessions was over 40 and kernels/spike of three accessions was more than 70. A total of 547 alleles in 124 polymorphic loci were detected with an average of 4.76 alleles per locus by 114 SSR markers. Parameters analysis indicated that the genetic diversity ranked as genome A>genome B>genome D,and the homoeologous groups ranked as 5>4>3>1>2>7>6 based on genetic richness (Ri). Furthermore,chromosomes 2A,1B and 3D had more diversity than that of chromosomes 4A,7A and 6B. The variation of SSR loci on chromosomes 1B,2A,2D,3B,and 4B implied that,in the past,different selective pressures might have acted on different chromosome regions of these landraces. Our results suggested that Sichuan common wheat landraces is a useful genetic resource for genetic research and wheat improvement.  相似文献   

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