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1.
Microsatellite markers were developed for epidemiological studies on the black locust gall midge Obolodiplosis robiniae (Haldeman) (Diptera: Cecidomyiidae), a native North America pest introduced to Europe and Asia. Polymorphism at each locus was tested on 68 individuals from six populations reared from infected host leaves of Robinia pseudoacacia L. collected in China. Fourteen loci were found to be polymorphic, with the number of alleles ranging from 3 to 10. The observed heterozygosity varied evenly from 0.2667 to 0.6540. For populations, the observed heterozygosity ranged from 0.1429 to 1.000. The allele frequency of the predominant allele varied from 0.250 to 0.500. All loci with negative FST values indicated heterozygote excess in each locus with six populations. Of 14 loci, four were observed to have FST values up to 0.05, which indicated negligible genetic differentiation within the population. Significant deviations (P < 0.05) from the expected Hardy–Weinberg equilibrium, as evaluated using the Markov chain algorithm for each locus and for all six populations, were observed, and genotypic linkage disequilibrium was clearly detected. These markers represent a useful tool to design strategies for integrated pest management and in the study of population evolution in this important introduced pest.  相似文献   

2.
The white-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), is a major pest of rice and has long-range migratory behavior in Asia. Microsatellite markers (simple sequence repeats) have been widely used to determine the origins and genetic diversity of insect pests. We identified novel microsatellite loci for S. furcifera samples collected from Laos, Vietnam, and three localities in Bangladesh from next-generation Roche 454 pyrosequencing data. Size polymorphism at 12 microsatellite loci was verified for 40 adult individuals collected from Shinan, South Korea. The average number of alleles per locus was 7.92. The mean values of observed (Ho) and expected heterozygosities (HE) were 0.615 and 0.757, respectively. These new microsatellite markers will be a resource for future ecological genetic studies of S. furcifera samples across more broad geographic regions in Asia and may assist in estimations of genetic differentiation and gene flow among populations for implementation of more effective management strategies to control this serious rice pest.  相似文献   

3.
【目的】评估273份水稻种质资源的遗传多样性和群体结构,为今后利用这些水稻种质资源进行遗传育种和关联分析提供参考。【方法】利用214个分子标记对来自14个国家的273份水稻地方品种和育种材料进行基因型检测,分析其遗传多样性、群体结构、连锁不平衡程度。【结果】群体结构分析将供试群体划分为2个亚群(SG1、SG2)以及1个混合群(AD),聚类分析和主成分分析结果与群体结构分析结果一致;遗传多样性分析结果显示,214个标记共检测到524个等位变异,变幅为2~5个,平均遗传多样性指数为0.44,平均多态性信息含量(PIC)为0.355,SG2群遗传多样性指数和PIC高于SG1群;分子方差分析表明34%的变异来源于种群内,66%的变异来源于种群间,SG1与SG2群体间存在显著的遗传分化(Fst=0.725,P<0.01);连锁不平衡分析结果显示,整个群体中存在较高程度连锁不平衡,平均r2为0.33,SG1和SG2中连锁不平衡衰减到75%以下所延伸的最小距离分别为13.7 Mb和90.5 kb。【结论】273份水稻种质资源群体内具有丰富的遗传变异,该群体适合通过关联作图来挖掘优异等位基因。  相似文献   

4.
Miridae (Hemiptera: Heteroptera: Cimicomorpha), or plant bugs, are one of the most diverse and species-rich families of insects. Most of them are phytophagous, but some are insect predators and used for biocontrol. Among this family, the mango bug, Orthops palus (Taylor 1947), is one of the most important pest of mango in Reunion Island. We developed 11 polymorphic microsatellite loci to study the population genetics of this pest species. The microsatellite markers were characterized by genotyping 78 field-collected insects sampled at different localities in Reunion Island. The number of alleles per locus ranged from 1 to 13 and heterozygosity levels ranged between 0.40 and 0.94. Several loci were not at Hardy–Weinberg equilibrium for the tested populations. These markers are the first to be developed for a species of the genus Orthops.  相似文献   

5.
The New Zealand cicada genus Kikihia Dugdale 1971 exhibits more than 20 contact zones between species pairs that vary widely in their divergence times (between 20,000 and 2 million years) in which some level of hybridization is evident. Mitochondrial phylogenies suggest some movement of genes across species boundaries. Biparentally inherited and quickly evolving molecular markers like microsatellites are useful for assessing gene flow levels. Here, we present six polymorphic microsatellite loci that amplify DNA from seven species across the genus Kikihia; Kikihia “northwestlandica,” Kikihia “southwestlandica,” Kikihia muta, Kikihia angusta, Kikihia “tuta,” Kikihia “nelsonensis,” and Kikihia “murihikua.” The markers were developed using whole-genome shotgun sequencing on the 454 pyrosequencing platform. Moderate to high levels of polymorphisms were observed with 14–47 alleles for 213 individuals from 15 populations. Observed and expected heterozygosity range from 0 to 1 and 0.129 to 0.945, respectively. These new markers will be instrumental for the assessment of gene flow across multiple contact zones in Kikihia.  相似文献   

6.
Cassava, Manihot esculenta Crantz subsp. Esculenta was a major food crop across Asia and Africa. The crop was a highly heterozygous perennial woody shrub cultivated from stem cuttings. Cassava improvement for starchy tuberous roots requires about 5-6 years from F1 hybrid seed germination to the selection of superior genotypes. Early selection with DNA markers could increase the number of elite genotypes identified. The aim here was to identify DNA markers associated with loci underlying plant and first branch height. In this study, 640 SSR primer pairs were used to screen for polymorphisms in two parental lines, cv. ‘Huaybong60’ (female) and cv. ‘Hanatee’ (male). There were 235 informative polymorphic markers used to genotype 100 individuals of an F1 mapping population. Genotype data was analyzed by JoinMap® version 3.0 software in order to construct a genetic linkage map. The map consisted of 156 linked SSR markers distributed across 25 linkage groups. The total length of the map was 845.2 cM (Kosambi cM) with 6.2 loci per linkage group, and an average distance between markers of 7.9 cM. Plant and first branch height of stem cuttings from the F1 mapping population were collected from individual lines planted in 2007-2009. Quantitative Trait Loci (QTL) underlying these traits were identified using mapQTL®/version 4.0. A total of seven QTL placed on four linkage groups were found for plant height. Of these, one major QTL was discovered on linkage group 2 near the marker SSRY155 with 17.9% of phenotypic variation explained (PVE). For first branch height, five QTL located on five linkage groups were identified. The two major QTL were located on linkage groups 2, and 20 at the loci SSRY323 and SSRY236 with 23.5% and 22.6% PVE, respectively. The QTL for plant and first branch height will serve as useful molecular markers in a cassava breeding program and may allow identification of the underlying genes in future.  相似文献   

7.
培育灰斑病抗性品种可降低灰斑病对大豆生产的危害。本研究以202份黑龙江省近25年主栽的大豆品种构建关联群体,在人工接种条件下鉴定大豆品种对灰斑病10号生理小种抗病指数。利用187对SSR标记对遗传多样性、群体结构和连锁不平衡位点进行分析,通过GLM 和MLM两种模型对大豆品种的灰斑病抗性与标记进行关联分析,进一步分析抗性关联位点等位变异与抗性表型效应关系。结果表明:202份大豆品种对灰斑病10号生理小种抗性遗传变异系数为14.26%;187个标记在群体中共获得809个等位变异,平均等位变异为4.42个,变幅2~10个,其中17号染色体的平均PIC值最高(0.64),12号染色体的平均PIC值最低(0.26);检测到稀有等位变异146个,特有等位变异位点58个;无论共线性组合位点还是非共线性组合位点均存在不同程度LD,连锁不平衡P<0.05支持的对数占总对数的21.65%;202份大豆品种被划分为3个亚群,亚群POP1与POP3之间遗传距离最小(0.03),亚群POP2与POP3之间遗传距离最大(0.35);两种模型共同检测到11个SSR标记与灰斑病10号生理小种抗性显著关联,其中位于3号染色体上的Satt549的贡献率最大,可解释表型变异14.74%;具有增效效应的等位变异共有24个,增效效应超过10的等位变异有7个,增效效应最大为Satt703-247(19.62),典型载体材料为合丰29;其次是Satt587-185(19.58),典型载体材料为东农50;Satt549位点增效等位变异的平均效应值最高(13.87),Sat_366位点增效等位变异的平均效应值最低(0.84)。聚合优异等位变异和载体材料可为培育抗灰斑病品种的亲本选配和后代等位条带辅助选择提供依据。  相似文献   

8.
为定位芸薹种抗根肿病基因的连锁标记,利用芸薹种单一基因微卫星(UGMS)标记及基因组SSR和抗根肿病(clubroot resistance,CR)基因的紧密连锁分子标记,构建了结球白菜59-1×芜菁(CR)WJ04遗传连锁图谱,对芜菁WJ04和结球白菜59-1进行根肿病抗性鉴定和连锁位点分析。结果表明:抗根肿病芜菁自交系WJ04对来自我国根肿病主要疫区的4个根肿菌生理小种2、4、7和10均具有显性抗性,而59-1则均表现为感病。UGMS标记在大白菜和芜菁亚种间的多态性比率为30.1%,低于基因组SSR的50.8%;图谱覆盖长度为1 116.2cM,包含分布在10条连锁群的59个UGMS、72个基因组SSR和4个分别与CR基因Crr1、Crr2、Crr3和CRb连锁的标记。  相似文献   

9.
This study presents the development of a core collection capturing the genetic diversity of a collection of 350 tetraploid cultivated potato varieties (Solanum tuberosum L.). The core collection was established by using simple sequence repeats (SSR) data and the M strategy, which aims at maximizing the allelic diversity. A 48-core collection was defined which captured 99.5% of the SSR alleles used to establish it, and 96.9% of the SSR alleles which belonged to an independent set of markers. The defined core collection was further validated by analysing 35 agro-morphological traits. The class coverage value and the estimates of the Shannon-Weaver diversity index indicated a good representation of the phenotypic diversity in the core collection. Furthermore, the core set included accessions having the most desirable status for several agronomic traits. A linkage disequilibrium (LD) analysis, using data obtained with the SolCAP SNP array on the defined core collection, was performed. The population structure analysis showed that the core collection did not present a clear genetic structure. The linkage disequilibrium analysis carried out between markers located on the same pseudomolecule within 10,000 bp concluded that 41.3% of these pairs of SNP markers have a significant LD. We conclude that this core collection, representative of the genetic diversity of cultivated potato varieties, is a relevant tool for a first screening for genetic variation regarding novel traits of interest.  相似文献   

10.
Forty pairs of SSR markers were used to compare the genetic diversity changes in 151 Chinese major rice varieties planted in 1950s and in the recent ten years. Of 40 SSR loci, 39 were found to be polymorphic while one locus (RM479) monomorphic. A total of 213 alleles were identified from the 39 polymorphic loci. The average number of alleles per locus (Na) was of 5.5, ranging from 2 to 11. Nei’s gene diversity index (He) varied drastically among loci from 0.309 at RM174 to 0.869 at RM418, with an average value of 0.649. There existed significant difference in SSR allelic diversity between indica and japonica subspecies, and indica had more variation than japonica both in Na and He. By comparison with the genetic changes in Na and He, it was revealed that the varieties planted in 1950s had more alleles and higher He than those in the recent ten years both for indica and japonica rices. The difference between two subspecies for Na was significant in a tendency over time (indica: z = 2.677, P = 0.007; japonica: z = 3.441, P = 0.001), but not significant for He (indica: z = 1.471, P = 0.141; japonica: z = 1.932, P = 0.053). Analysis of molecular variance (AMOVA) indicated that there existed significant difference (P < 0.05) in genetic variation between the two periods, of which more genetic variation was contributed by indica (Fst = 0.050) and japonica (Fst = 0.082) subsets. Using locus-by-locus AMOVA procedure, significant genetic differentiations were observed in 13 loci (RM21, RM128, RM147, RM169, RM190, RM221, RM231, RM251, RM253, RM317, RM341, RM418, and RM478) for indica varieties and 11 loci (RM101, RM135, RM152, RM159, RM169, RM190, RM251, RM253, RM311, RM418, and RM478) for japonica ones between the two periods. It was found some alleles had been lost in current major rice varieties as comparing with those in 1950s. Therefore, it should be necessary to exploit more alien elite genetic resources for extension of genetic background in current rice breeding program.  相似文献   

11.
Tuber dormancy and sprouting are important traits in commercial potato varieties. Since wild Solanum species can contribute new alleles in breeding, we combined Solanum chacoense and S. berthaultii species in a mapping population to develop a linkage map with genome wide markers and identify quantitative trait loci (QTL) for tuber dormancy and sprouting. There was genetic variation for the evaluated traits and high correlation (0.80) between dormancy and apical dominance release. QTL for tuber dormancy and sprouting traits were mapped to the same or similar positions on chromosomes 2, 3, 5, and 7, explaining from 9.5% to 16.3% of the phenotypic variance. We identified candidate genes associated with all major phytohormone regulation in close linkage with the QTL. The QTL on chromosomes 2, 3 and 7 are good candidates for marker assisted breeding, since they were associated with dormancy and apical dominance release and should be useful to delay or accelerate tuber sprouting.  相似文献   

12.
《Field Crops Research》2006,95(2-3):355-366
Nitrogen (N) demand of soybean [Glycine max (L.) Merrill] can be supplied via biological nitrogen fixation (BNF), however, higher yielding cultivars increase plant demand for N. Phenotypes differing for traits associated with biological nitrogen fixation result from the expression of the multiple genes of both the host plant and the microsymbiont, but limited studies have been done on the genetics of the soybean BNF. Integrated maps of soybean with simple sequence repeat (SSR) markers [Cregan, P.B., Jarvik, T., Bush, A.L., Shoemaker, R.C., Lark, K.G., Kahler, A.L., Kaya, N., Van Toai, T.T., Lohnes, D.G., Chung, J., Specht, J.E., 1999. An integrated genetic linkage map of the soybean genome. Crop Sci. 39, 1464–1491.] offer an excellent opportunity for the identification of traits related to BNF. This study aimed at the identification of quantitative trait loci (QTLs) controlling BNF and nodulation in an F2 population of 160 plants derived from an intraspecific cross between two Brazilian cultivars, Embrapa 20 × BRS 133, previously identified as having good potential for mapping of QTLs [Nicolás, M.F., Arias, C.A.A., Hungria, M., 2002. Genetics of nodulation and nitrogen fixation in Brazilian soybean cultivars. Biol. Fertil. Soils 36, 109–117.]. From 252 SSR markers tested in the parental genotypes 45 were polymorphic with high heterozygotes resolution. Mapping was performed with those 45 SSR markers for nodulation [nodule number (NN) and nodule dry weight (NDW)] and plant growth [shoot dry weight (SDW)] phenotypes in F2:3 lines. A total of 21 SSR loci were mapped with a likehood of odds (LOD) value of 3.0 and a maximum Haldane distance of 50 cM, and were distributed in nine linkage groups with coverage of 251.2 cM. The interval mapping analysis with Mapmaker/QTL revealed two genomic regions associated with NN and NDW, with a contribution of putative QTLs of 7.1 and 10%, respectively. The regression analysis identified 13 significant associations between the marker loci and QTLs due to additive effects, with some of them being significantly associated with more than one phenotypic trait. Effects were observed in all variables studied, ranging from 2 to 9%. A one-way analysis of variance (ANOVA) also detected 13 significant associations, related to dominance effects. A two-way-ANOVA showed six epistatic interactions among non-linked QTLs for SDW, NN and NDW, explaining up to 15% of the trait variation and increasing the phenotypic expression from 8 to 28%. The data obtained in this work establish the initial stage for additional studies of the QTLs controlling BNF and indicate that effective marker-assisted selection using SSR markers may be feasible for enhancing BFN traits in soybean breeding programs.  相似文献   

13.
The objective of the present study was to evaluate random amplified polymorphic DNA (RAPD) as a source of markers for use in investigations in potato genetics. Segregation of 18 loci in diploidSolanum goniocalyx xS. phureja and 12 loci in tetraploidS. tuberosum ssp.tuberosum ×S. tuberosum ssp.andigena families fitted Mendelian and tetrasomic ratios, respectively. Eight loci in the diploid progeny were arranged in three linkage groups. Segregations of these markers fitting expected ratios indicate that they can be effectively used in potato genetics, breeding and evolution.  相似文献   

14.
This study characterized Pokkali-derived quantitative trait loci (QTLs) for seedling stage salinity tolerance in preparation for use in marker-assisted breeding. An analysis of 100 SSR markers on 140 IR29/Pokkali recombinant inbred lines (RILs) confirmed the location of the Saltol QTL on chromosome 1 and identified additional QTLs associated with tolerance. Analysis of a series of backcross lines and near-isogenic lines (NILs) developed to better characterize the effect of the Saltol locus revealed that Saltol mainly acted to control shoot Na+/K+ homeostasis. Multiple QTLs were required to acquire a high level of tolerance. Unexpectedly, multiple Pokkali alleles at Saltol were detected within the RIL population and between backcross lines, and representative lines were compared with seven Pokkali accessions to better characterize this allelic variation. Thus, while the Saltol locus presents a complex scenario, it provides an opportunity for marker-assisted backcrossing to improve salt tolerance of popular varieties followed by targeting multiple loci through QTL pyramiding for areas with higher salt stress.  相似文献   

15.
为合理评价110份青稞品种(系)的农艺性状及遗传特性,对参试种质材料的株高、穗长、穗粒数、分蘖数和千粒重进行了调查统计,同时用分布于大麦全基因组的48对SSR标记进行了遗传多样性分析。结果表明,参试材料各农艺性状变异较大,变异系数为2.92%~42.33%,其中株高、穗长、分蘖数、穗粒数和千粒重变化范围分别为53~122cm、2.5~7cm、2~19个、20~90粒和25.46~60.34g。SSR标记共检测到168个等位变异,变化范围为2~6个。110份青稞种质材料分成三大类群。SSR标记的1 128个位点成对组合中,不论是共线性成对组合还是非共线性成对组合,都存在一定的连锁不平衡(linkage disequilibrium,LD)。D′统计概率(P0.01)支持的LD成对位点438个,占全部位点的38.8%,D′的平均值为0.36,整体LD水平较高。较高水平的LD位点(D′0.5)主要分布在2H、4H、6H和7H连锁群上。  相似文献   

16.
Grain protein content (GPC) is a major determinant of malting quality in barley, as it influences many aspects of the malting and brewing processes. The objective of the present study was to apply a quantitative trait loci (QTL) mapping approach towards a dissection of the genetic factors involved in phenotypic trait expression. The mapping population comprised 180 doubled haploid lines derived from a cross of parents (VB9524 and ND11231*12) with inherently low GPC. These lines were grown at eight environments in Australia and North Dakota, USA, between 2000 and 2002 and measured for GPC, grain yield, plant height and heading date. QTL analyses with a linkage map of 211 markers identified seven loci significantly (LOD>3.6) linked to variations in GPC. Collectively, these loci accounted for approximately 74% of the total genetic variance for GPC in the population, that is, after adjusting for QTL×environment interactions (QTL×E). QTL×E was highly (P<0.001) significant, but was largely due to differences in magnitude of QTL effects rather than changes in the direction of the effects. Of the seven identified QTLs, five were located at intervals adjacent to those for other agronomic traits, leading to the suggestion that genotype–environment interactions for GPC may also involve pleiotropic or linkage interactions with genes responsible for variation in these traits.  相似文献   

17.
The bread wheat elasticity, which is very important for bread-making quality, is largely determined by the composition of high-molecular-weight glutenin subunits (HMW-GS). The HMW-GS encoded by Glu-B1 loci are highly polymorphic and the combinations 17+18 and 14+15 are good for bread making. Thus it is very important to identify the alleles at Glu-B1 loci for wheat quality improvement. In this study, the five common HMW-GS types encoded by Glu-B1x locus carried by 18 Chinese bread wheat cultivars (or lines) were analyzed by SDS-PAGE. Two pairs of PCR primers which could distinguish the Glu-Blx alleles of the five common HMW-GS types were designed based on the Glu-B1x gene sequences (Reddy and Appels, 1993; Genbank accession: X13927; Genbank accession:AY367771). 22 recombinant inbred lines (RILs) derived from Jing711 (contains 17 subunit on Glu-B1x) and Pm97034 (contains 14 subunit on Glu-B1x) were used to validate the accuracy of the primers, which showed that the two specific markers could be used together to distinguish alleles at Glu-B1x locus and accelerate wheat quality breeding by marker assisted selection.  相似文献   

18.
The Waxy (Wx) gene is responsible for the synthesis of amylose, a key determinant of the cooking and processing qualities of rice. Polymorphisms of CT-microsatellite and G–T single-nucleotide polymorphism (SNP) in the Wx gene and their relationship to amylose content (Ac) were explored using 178 non-waxy rice genotypes. Nine Wx microsatellite alleles, namely (CT)10 and 11, and (CT)14–20 were identified and 11 haplotypes were recognised by different combinations of CT-microsatellite and G–T SNP. Amylose content analysed in a random set of 39 genotypes was correlated with different microsatellite alleles/haplotypes. The highest Ac levels (>30%) correlated with (CT)10 and 16, high (26–30%) with (CT)11, 15 and 20, and intermediate (21–25%) with (CT)14, in all cases with G at the G–T SNP. The CT-classes (CT)17 and 18 (mean Ac value of 21%), could be subdivided into low amylose haplotypes (16–20%) for 17T and 18T and intermediate amylose haplotypes (21–25%) for 17G and 18G. The use of haplotypes proved to discriminate between intermediate and low amylose accessions within the same microsatellite class. Analyses of a segregating population of a cross between low and high Ac parents showed that CT-microsatellite may help to classify breeding lines and identify pollen contamination. We suggest that CT-microsatellite together with G–T SNP may be used as molecular marker by breeders to develop varieties with desired amylose levels.  相似文献   

19.
为明确小麦材料中抗旱相关基因的组成,利用已报道的29个标记(11个新转化的KASP标记以及已报道的18个KASP 标记),对16份抗旱小麦品种和15份高产小麦品种进行KASP检测。结果表明,多数基因位点在抗旱小麦品种和高产小麦品种间的优异等位基因数目无明显差别;TaPYL1-1BWcor14-2BTaSRL1-4ATaSnRK2.3-1AQTDW.caas-6BL位点的优异等位基因在旱地品种中占比较高,而TaWRKY51-2BTaSnRK2.4-3A位点的优异等位基因仅存在于抗旱品种中,前者的供体材料为晋麦47、晋麦92和晋麦101,后者的供体材料为济麦379。  相似文献   

20.
Low molecular weight glutenin subunits (LMW-GS) encoded by the Glu-3 loci are known to contribute to wheat breadmaking quality. However, the specific effect of individual Glu-3 alleles is not well understood due to their complex protein banding patterns in SDS-PAGE and tight linkage with gliadins at the Gli-1 locus. Using DNA markers and a backcross program, we developed a set of nine near isogenic lines (NILs) including different Glu-A3/Gli-A1 or Glu-B3/Gli-B1 alleles in the genetic background of the Argentine variety ProINTA Imperial. The nine NILs and the control were evaluated in three different field trials in Argentina. Significant genotype-by-environment interactions were detected for most quality parameters indicating that the effects of the Glu-3/Gli-1 alleles are modulated by environmental differences. None of the NILs showed differences in total flour protein content, but relative changes in the abundance of particular classes of proteins cannot be ruled out. On average, the Glu-A3f, Glu-B3b, Glu-B3g and Glu-B3iMan alleles were associated with the highest values in gluten strength-related parameters, while Glu-A3e, Glu-B3a and Glu-B3iChu were consistently associated with weak gluten and low quality values. The value of different Glu-3/Gli-1 allele combinations to improve breadmaking quality is discussed.  相似文献   

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