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1.
小麦种质资源农艺性状变异及其遗传多样性分析   总被引:5,自引:2,他引:3  
为了解不同小麦种质资源农艺性状变异及其遗传多样性,利用SSR分子标记分析了44份CIMMYT春小麦和45份国内主栽小麦种质资源的遗传变异。结果表明,小麦单株产量、株高和穗粒数的变异系数分别为36.7%、16.4%和15.6%,说明国内外种质材料在表型上存在较大差异。利用20对分子标记对89份小麦种质资源进行了多态性检测,结果显示,共检测到162个等位变异,每对引物检测到等位变异数目为6~9个,平均每对SSR标记能够检测到8.1个变异,其中Xgwm314的多态性最丰富;SSR标记的多态性信息含量(PIC)介于0.0223~0.8177,平均值为0.5109;平均每位点的有效等位基因数的变异范围为0.2984~8.7818,Xgwm165的多态性最丰富,平均值为1.2215;Shannon’s信息指数的变异范围为0.1114~0.3162,平均值为0.2307。聚类分析结果显示,89份小麦种质资源分为2大类群,第一类有25份,该类群株高较低,第二类有64份,国外材料大多集中在这一类中。本研究表明,44份CIMMYT春小麦及45份国内主栽小麦种质资源遗传相似性较大,地域性分布特征显著,聚类结果反映出小麦品种(系)多样性水平复杂,可为小麦新品种选育提供优异的亲本材料。  相似文献   

2.
为揭示小麦自然群体干旱胁迫条件下旗叶叶绿素含量的变化, 筛选相关标记的优异等位变异, 以262份小麦种质资源组成的自然群体为材料, 分别种植在北京的2个试验地点, 均设雨养和灌溉处理, 于开花期和灌浆期检测旗叶叶绿素含量。以分布于21条染色体的169个SSR标记检测所有材料的基因型, 利用STRUCTURE 2.3.2软件分析群体结构, 用TASSEL软件的MLM (mixed linear model)方法对小麦自然群体的旗叶叶绿素含量进行关联分析。在此基础上, 将携带某等位变异的所有材料表型均值与携带无效等位基因(null allele)材料表型均值比较, 估计等位变异的表型效应, 鉴别优异等位变异。共检测到2048个等位变异, 每位点2~37个等位变异, 平均12个。每位点的标记多态性信息量(PIC)为0.008~0.936, 平均0.628。在22个标记位点共检测出40个(次)与旗叶叶绿素含量极显著的关联, 其中11个标记位点有2次以上的关联, Xwmc419-1B和Xgwm501-2B分别有3次关联。在Xcfa2123-7A、Xgwm232- 1D和Xgwm429-2B位点分别检测到效应值大于4.0的等位变异。  相似文献   

3.
Granule‐bound starch synthase of ancient wheat and related species was examined by sodium dodecyl sulphate polyacrylamide gel. A total of 13 different alleles were revealed in a collection of three accessions of diploid wheat, six accessions of tetraploid wheat, 49 accessions of spelt wheat, nine accessions of Sitopsis and two accessions of Aegilops tauschii. A new allele named Wx‐A1a′ appeared in four spelt wheat accessions. The tetraploid wheat accessions evaluated did not show any polymorphism; nevertheless the tetraploid accessions of Sitopsis section revealed three novel alleles. The novel allele Wx‐Ddn1g was found in two accessions of A. ventricosa and the Wx‐Ddcm1h and Wx‐Ddcm1i in two accessions of A. crassa. A novel allele named Wx‐Au1g was found in Triticum urartu, which is different from the also new Wx‐Am1h allele of T. monococcum. The diploid‐related species accessions revealed two novel alleles named Wx‐Bsl1h and Wx‐Bs1g found, respectively, in A. longissima and A. speltoides. The amylose content was measured for the different alleles found in all evaluated species and no significant effects of the allele composition on the amylose content were detected.  相似文献   

4.
为了解小麦品种资源的遗传多样性, 筛选株高、产量相关性状相关标记的等位变异, 选用108对覆盖小麦各同源染色体且多态性高的SSR引物, 对黄淮麦区175个小麦品种进行分析。共检测到448个等位变异, 平均每个标记4.15个等位变异, 变化范围为2~14个;全部SSR位点的多态性信息含量(PIC)变化范围为0.075~0.869, 平均为0.561。聚类分析显示同一地区或同一育种单位育成的、具有共同亲本的品种多数聚为一类。关联分析表明, 与株高、产量相关性状显著关联(P<0.01)的标记有23个, 其中3个标记达到极显著(P<0.001)水平。标记wmc128(1B)和wmc236(3B)与小穗数极显著相关, 分别解释小穗数变异的10.5%和8.0%;标记Xgwm129(2B)与千粒重达到极显著相关, 可以解释千粒重变异的19.3%。  相似文献   

5.
亚洲棉种质资源的SSR遗传多样性分析   总被引:2,自引:0,他引:2  
 对我国棉花中期库保存的200份不同地理来源的亚洲棉代表性样本进行了SSR遗传多样性分析,结果表明:亚洲棉分子水平的遗传多样性较高。83个多态性位点共检测到368个等位基因变异,其中多态性的等位基因数为329个,平均每个SSR位点3.964个。位点多态性信息量(PIC)变幅为0.010~0.882,平均0.578,PIC值大于0.7的标记有33个(占39.8%)。基因多样性(H′)变幅为0.031~2.163,有效等位基因数(Ne)变幅为1.010~8.496。华南棉区基因遗传多样性最高,其次为长江流域棉区、黄河流域棉区,从理论上支持被广泛接受的亚洲棉在我国的传播路线是由南到北,华南棉区是中棉种系的遗传多样性富集中心。利用软件NYSTS-pc2.20,采用类平均法(UPGMA)进行聚类分析,种质间SSR相似系数变幅为0.58~0.997,平均0.745,在阈值0.73处200份亚洲棉聚为8个类群,贵池小子棉白子单独聚为一群,与其他种质遗传距离较远。遗传距离和地理距离没有必然联系,但种质间亲缘关系处于极端远或极端近时,则地理距离一般也趋于较远或较近。  相似文献   

6.
The renewed interest in spelt (Triticum spelta L.) for wheat improvement programmes requires the study of the available genetic diversity. The purpose of this study was to assess genetic diversity within a Spanish spelt collection. Sixty‐six Spanish spelt accessions, 19 accessions of T. spelta and T. macha from different origins, three bread wheat cultivars (T. aestivum) and one accession of T. dicoccum were screened using simple sequence repeats (SSRs). The diversity observed within the Spanish group was comparable with that observed in the other wheat varieties, despite their broader geographical diversity. Indeed, the highest polymorphic information content value calculated with SSRs for Spanish material (0.90) is similar to that observed for the other wheat varieties (0.98). Principal component analysis explained 46.5% of the cumulative variation and confirmed the Spanish accessions as a separate group. This study showed the Spanish spelt collection to be a variable and unique genetic resource for wheat and spelt breeding programmes.  相似文献   

7.
小麦纹枯病抗源的遗传多样性及抗性基因位点SSR标记分析   总被引:1,自引:0,他引:1  
为揭示小麦纹枯病抗源的遗传多样性,发掘优异的抗性种质,利用沟带接种法对前期筛选出的88份抗性种质进行了3年田间抗性鉴定,鉴定出抗或中抗纹枯病的小麦种质32份。利用分布于全基因组的SSR标记对这些抗源进行了遗传多样性分析,59个SSR标记共检测到308个等位变异,每个标记可以检测到2~13个等位基因,平均5.2个;多态性信息含量(PIC)的变异范围为0.12~0.89,平均为0.61,表明材料的遗传丰富度较高。根据聚类分析和主成分(PCA)分析,32份小麦纹枯病抗源按照遗传相似系数可划分为2个组群,国外引进品种和国内改良品种聚为一类,国内农家品种聚为一类,并且与地理分布特征相符。利用与纹枯病抗性QTL紧密连锁的14个SSR标记对32份抗源进行基因型分析,发现与抗性QTL连锁的2BS上的Xwmc154和7DS上的Xbarc126普遍存在,可用于分子标记辅助选择。在武农148、陕983、陕农78、Coker 983、H-Line、Mason和Compair中仅检测到一个已报道的抗病QTL,而在Tyalt中没有检测到已知抗病QTL,这些材料有可能携带新的纹枯病抗性基因/QTL,可以在育种中加以利用。  相似文献   

8.
The high molecular weight glutenin subunit (HMW-GS) compositions of 66 Chinese endemic wheats were determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Ten alleles at the Glu-1 loci were detected in 50 Tibetan weedrace wheat accessions which in combination resulted in seven different HMW-GS patterns. Four HMW-GS patterns were observed among 10 Yunnan hulled wheat accessions, and two patterns in six Xingjiang rice wheat accessions. Two novel alleles (Bx7** + By8, Bx7 + By8**) and two rare alleles (Dx2 + 1Dy12*, Dx2 + null) were found in Tibetan weedrace accessions, with one of the latter (Dx2 + Dy12*) also being found in Yunnan hulled wheat. The mean indices of genetic variation at the Glu-1 loci in Yunnan hulled wheat, Tibetan weedrace wheat and Xingjiang rice wheat were 0.2232, 0.1655 and 0.0926, respectively, showing that Yunnan hulled wheat and Tibetan weedrace wheat had higher genetic variation than Xingjiang rice wheat.  相似文献   

9.
The objective of this study was to assess genetic diversity within old and modern common spring wheat (Triticum aestivumL.) varieties cultivated in Siberia and to find out whether old Siberian varieties could be a potential source for genetic diversity in modern wheat breeding in Siberia. A set of 54 varieties was analysed using 22 wheat microsatellite markers (WMS), determining 23 loci located on 19 different chromosomes. In total, 151 alleles were detected with an average of 6.6, ranging from three to 11 alleles per locus. The average genetic diversity value (polymorphic information content) was 0.70. WMS located in the B genome produced more alleles per locus (7.6) compared with WMS located in the A (6.0) and D (6.0) genomes. Genetic similarity values between varieties ranged from 0.19 to 0.96 and were used to produce a dendrogram. With a few exceptions the varieties studied were clustered in two nearly equal groups consisting of predominantly old (released before 1960) and modern (released in 1960‐90s) varieties, respectively. Genetic diversity values within these two groups were similar with 0.60 and 0.58, respectively. The numbers of group‐specific alleles were 34 and 29, respectively. A significant variation in frequencies of 79 shared alleles was observed. The results obtained by using genomic microsatellite sequences demonstrated that breeding has not resulted in a decrease in the genetic diversity in Siberian spring wheat. However, significant quantitative and qualitative changes in allelic frequencies of different loci were detected. It may be suggested, that old Siberian common spring wheat varieties are a potential basis for genetic diversity in modern wheat breeding in Siberia.  相似文献   

10.
The high molecular weight glutenin subunit (HMW-GS) composition of 42 Ethiopian-grown bread wheat and 31 durum wheat cultivars and lines were examined using SDS-PAGE. Low variability in HMW-GS composition was present in both classes of wheat. A total of 10 variants with 14 different HMW patterns and seven variants with six different patterns were identified in bread and durum wheat, respectively, reflecting the limited ability of HMW-GS for cultivar identification. The most predominant alleles were 2*, 7 + 9 and 5 + 10 in bread wheat and nul and 7 + 8 in durum wheat. The Glu-1 quality scores for bread wheat ranged from 6 to 10, with an average value of 8.7. The variation in HMW-GS significantly correlated with and accounted for 44 % of the total variation in gluten quality, measured by the sodium dodecyl sulphate sedimentation test. In durum wheat, HMW-GS variation at Glu-B1 explained about 25 % of the variation in gluten quality. The high frequency of the 7 + 8 alleles among the landraces and the significant contribution of Glu-B1 alleles to the total variation in gluten quality indicate the potential benefit of Ethiopian tetraploid landraces in the development of lines suitable for both bread and pasta production.  相似文献   

11.
Association mapping is a method to identify associations between target traits and genetic markers based on linkage disequilibrium (LD) of a quantitative trait locus. Synthetic hexaploid wheat (SHW) is derived from a cross between Triticum durum Desf. and Aegilops tauschii Coss. that enhances genetic diversity and broadens breeding resources. In this study, phenotypic diversity in 110 wheat accessions (86 SHW germplasm specimens and 24 conventional wheat varieties) was evaluated quantitatively for yield characteristics of grains per spike, thousand kernel weight, and spike length. Phenotypic data were collected over two years at two locations, and 1785 alleles were detected (mean 6.59), ranging from 3 to 11 alleles per locus. The average genetic diversity index was 0.749, with a range from 0.239 to 0.923. The polymorphic information content (PIC) ranged from 0.145 to 0.968, with a mean value of 0.695. The genetic diversity index and PIC indicated that genome B > D > A. Accessions were grouped into three subgroups based on STRUCTURE and unweighted pair-group with arithmetic mean clustering. The mean LD decay across the genome was 11.78 cM. Association mapping between traits and simple sequence repeat markers was performed using the generalized linear model approach. Forty-six SSR loci were significantly associated with the measured agronomic traits in two geographic locations. Together, these results broaden our knowledge of how to harness elite genes and genetic diversity in SHW in genomic and marker-assisted selection.  相似文献   

12.
利用SSR标记进行优质冬小麦品种(系)的遗传多样性研究   总被引:36,自引:3,他引:36  
遗传多样性研究对于作物育种具有重要意义. 选择分布于21条小麦染色体上的59对SSR引物对48个优质冬小麦新品种(系)进行了遗传多样性分析. 共检测出209个等位位点, 每对引物等位位点数在2~9之间, 平均为3.5个. 位点多态性信息含量PIC变幅为0.16~0.87, 平均0.56. 8个引物组合在一起可将全部品种区分开来, 48个品种可分为五类,  相似文献   

13.
L. Y. Zhang    M. Bernard    C. Ravel    F. Balfourier    P. Leroy    C. Feuillet    P. Sourdille 《Plant Breeding》2007,126(3):251-258
Transferability of 116 common wheat expressed sequence tag–simple sequence repeats (EST-SSR) markers was investigated on 168 accessions representing 18 grass species to identify new alleles useful for wheat improvement. Transferability among the Triticeae ranged from 73.7% for Aegilops longissima to 100% for wheat subspecies ( Triticum compactum ) but was also good for less related species such as rye (72.8%) or maize (40.4%). On average, the number of alleles/locus detected by EST-SSR markers was 3.1 for hexaploid wheat. The polymorphism information content (PIC) values simultaneously estimated for Triticum aestivum and Triticum durum were similar for the two species (0.40 and 0.39, respectively). The allelic diversity within allogamous species was higher (0.352–0.423) compared with that of T. aestivum and T. durum (0.108 and 0.093, respectively). T. aestivum and T. durum shared the largest number of alleles (74.6%) while among the three ancestral diploid species of bread wheat, Aegilops tauschii had the highest percentage of alleles with T. aestivum (57.4%). These results indicate that grass orphan species can be studied using wheat EST-SSRs and can serve as a source of new alleles for wheat genetic improvement.  相似文献   

14.
A collection of 89 accessions of diploid species of wheat was analysed for waxy protein in the grain: 39 accessions of Einkorn wheats, 41 accessions of Sitopsis section wheat and nine accessions of Triticum tauschii. The electrophoretic patterns showed low polymorphism. In each group of wheat, a single and different allele was detected. In accessions of Einkorn wheats that allele had a similar electrophoretical mobility to the Wx‐A1a allele of the bread wheat ‘Chinese Spring’, in accessions of the Sitopsis section it had a similar mobility to that of the Wx‐B1f allele of tetraploid wheat, and in the accessions of T. tauschii, it was similar to the Wx‐D1a allele of the bread wheat ‘Chinese Spring’. The accessions were also analysed for apparent amylose content. Results showed that amylose content ranged from 22 to 35% in Einkorn wheats, from 28 to 41% in the Sitopsis section and from 26 to 35% in accessions of T. tauschii.  相似文献   

15.
利用EST-SSR标记评价羽扇豆属(Lupinus L.)遗传多样性   总被引:1,自引:0,他引:1  
利用基于窄叶羽扇豆转录组开发并筛选出的95对多态性EST-SSR标记,对羽扇豆属的22个种133份资源进行全基因组扫描,初步探究羽扇豆属下种间的进化关系,分析来源于"旧世界"羽扇豆种间的遗传多样性,为羽扇豆优异资源的挖掘和创新利用提供理论依据。结果表明,用95对SSR标记共检测出1318个等位变异,每对标记平均检测出3~37个等位变异,平均为13.87个;多态性信息量(PIC)变化范围0.39~0.91,平均为0.75;基因多样性变化范围0.41~0.92,平均为0.78。基于邻接法(NJ)的系统发育初步探究了羽扇豆种间的进化关系,22个羽扇豆种分别来源于"旧世界"和"新世界",与之前研究结果相对一致。聚类分析、群体结构分析和主成分分析结果均表明,来源于"旧世界"的7个羽扇豆种被划分为4个组群,各组群所包含的参试资源没有种间交叉重叠。  相似文献   

16.
大麦遗传多样性及连锁不平衡分析   总被引:1,自引:0,他引:1  
为了合理评价引进种质资源,为大麦基因发掘及育种组合配置提供依据,选用分布于全基因组的64个SSR标记,对221份大麦材料进行了基因型分析。共检测到192个等位变异,变幅为2~7个;基因频率变异范围为0.0090~0.9729,平均0.3333;全部位点的基因多样性变化范围在0.0528~0.7807,平均0.4813;多态性信息含量(PIC)变异范围在0.0514~0.7464,平均0.4113。供试材料间遗传相似系数变幅为0.4844~0.9792,平均0.7023。221份材料被划分成两大群7个亚群,国内地方品种与1份北京品种为一大群,国内育种品种与所有国外引进品种为另一群。遗传结构分析与聚类结果基本一致,两大类群间的遗传距离为0.3358,且第二大群多样性比第一大群丰富。2016个SSR位点成对组合中,不论共线性组合还是非共线性组合,都存在一定程度的连锁不平衡(LD)。D′统计概率(P<0.01)支持的LD成对位点830个,占全部位点组合的41.2%,D′平均值为0.4,整体LD水平较高。栽培品种的LD水平高于地方品种,且现代遗传改良的目标性状集中于2H、4H、6H和7H染色体。  相似文献   

17.
Waxy proteins in diploid, tetraploid and hexaploid wheats   总被引:4,自引:0,他引:4  
Electrophoretic analyses of waxy proteins, encoded by genes present at the Wx‐1 loci, present in several cultivars and accessions of hexaploid wheat, Triticum aestivum, have permitted the detection of null alleles at the Wx‐B1 and Wx‐D1 loci. Polymorphism at the Wx‐A1 and Wx‐B1 loci was also investigated in several accessions of tetraploid wheats, Triticum durum, Triticum dicoccoides and Triticum timopheevi, and in diploid species, Triticum urartu, Triticum boeoticum and Triticum monococcum. One null allele at the Wx‐A1 locus and three polymorphic alleles at Wx‐B1 locus were detected in T. durum; a new allele at one of the two waxy loci was identified in the tetraploid wheat T. timopheevi; no polymorphism was detected in diploid species. Polymerase chain reaction techniques made possible the detection of further polymorphism existing at the Wx‐1 loci and the reason for the lack of expression of the null genotypes to be investigated. The null forms detected at each locus have been used to produce complete sets of partial and total waxy lines in durum and bread wheat.  相似文献   

18.
本研究利用21对小麦EST-SSR引物对23份黄淮海地区新育成冬小麦品种及其亲本(近似品种)的遗传多样性进行了分析比较。在23份新育成品种中共检测到61个位点,每个位点的等位基因个数在2~8之间,平均2.90;基因多样性指数在0.08~0.79之间,平均为0.38。23份新育成品种的遗传距离在0.12~0.69之间,平均为0.40。在23份亲本品种中,共检测到63个位点,每个位点的等位基因个数在2~7之间,平均3.00;基因多样性指数在0.08~0.79之间,平均为0.44;23份亲本品种的遗传距离在0.09~0.81之间,平均为0.46。新育成品种遗传多样性低于其亲本品种。  相似文献   

19.
Genetic diversity of wheat wild relatives in the Near East detected by AFLP   总被引:3,自引:0,他引:3  
In order to reveal the molecular genetic diversity of wheat wild relatives, an AFLP analysis was conducted with 16 accessions of five Triticum andAegilops species originating from the Near East. Variation within population was studied with at least seven individuals per accession. Four primer combinations were used for selective amplification. Based on the scored bands, we estimated percentage of polymorphic bands, 1 – proportion of shared bands (1-psb) and nucleotide diversity (π). Of the five species used in this study, Ae. speltoides had the highest level of `within population' variation. This species had also the highest value of the variation among populations. As for Triticum species, the level of variation within population was low in diploid species (T. urartu and T. boeoticum),whereas two tetraploid species (T. dicoccoides and T. araraticum) had relatively high levels of variation within population. While the two diploid Triticum indicated a clear interspecific divergence, the two tetraploid wild wheats were not clearly divergent in this study. The variance portioning analysis indicated that the variation detected for diploid Triticum species was mainly composed of `between species' variation, on the other hand that for tetraploid Triticum was mostly composed of `within population' variation. In conclusion, AFLP analysis reveals molecular variation in all accessions used in this study, suggesting a potential genetic diversity of the wheat wild relatives in natural populations. These results have implications for the design of strategies to maintain genetic diversity within genebank collections. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

20.
Three major types of B subunits of glutenin patterns were detected among 240 durum wheat lines collected from eleven countries by the one-step one-dimensional SDS-PAGE procedure. Most commercial durum lines had the LMW-2 type while extensive variation of other banding patterns was found for lines particularly from North African and Mediterranean region. A total of 281 wild and less-cultivated tetraploid wheat lines (var. dicoczoides, Triticum dicoccum and T. polonicum) were also studied for the variation of low molecular weight glutenin subunits and extensive variation was found. The complexity of banding patterns observed among the T. turgidum species indicate a rich source of glutenin variation with a potential value to be used for quality improvement of cultivated wheat when their functional properties have been tested.  相似文献   

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