河北省小麦品种基于农艺性状的遗传多样性分析

为明确河北省小麦品种遗传多样性的基础和历史演变,本研究以所收集的该省近60年来审(认)定的125个小麦品种为研究材料,以8个农艺性状为基础进行了遗传多样性分析.结果表明:河北省小麦品种农艺性状变异比较丰富,以每穗不孕小穗数的变异系数最高(52.63%),其次为单株粒重和有效分蘖数,每穗小穗数的变异最小;多样性指数从20世纪70年代的1.62增加到目前的1.89,平均值为1.76,但略低于其他省份.在上述分析基础上,用最长距离法可将125份材料聚为3大类,其中80.8%(101个)的品种归入第3大类,主要为20世纪90年代以后的品种.这说明该省小麦品种遗传多样性在逐步提高的同时,其遗传基础仍需进一步拓宽.     

QTL Mapping of Diffuse Reflectance Indices of Leaves in Hexaploid Bread Wheat (Triticum aestivum L.)

Russian Journal of Plant Physiology - Quantitative trait loci (QTL) mapping of diffuse reflectance indices of laminas in bread wheat (Triticum aestivum L.) has been first performed under controlled...     

Development and Characterization of a New TILLING Population of Common Bread Wheat (Triticum aestivum L.)

Mutagenesis is an important tool in crop improvement. However, the hexaploid genome of wheat (Triticum aestivum L.) presents problems in identifying desirable genetic changes based on phenotypic screening due to gene redundancy. TILLING (Targeting Induced Local Lesions IN Genomes), a powerful reverse genetic strategy that allows the detection of induced point mutations in individuals of the mutagenized populations, can address the major challenge of linking sequence information to the biological function of genes and can also identify novel variation for crop breeding. Wheat is especially well-suited for TILLING due to the high mutation densities tolerated by polyploids. However, only a few wheat TILLING populations are currently available in the world, which is far from satisfying the requirement of researchers and breeders in different growing environments. In addition, current TILLING screening protocols require costly fluorescence detection systems, limiting their use, especially in developing countries. We developed a new TILLING resource comprising 2610 M(2) mutants in a common wheat cultivar 'Jinmai 47'. Numerous phenotypes with altered morphological and agronomic traits were observed from the M(2) and M(3) lines in the field. To simplify the procedure and decrease costs, we use unlabeled primers and either non-denaturing polyacrylamide gels or agarose gels for mutation detection. The value of this new resource was tested using PCR with RAPD and Intron-spliced junction (ISJ) primers, and also TILLING in three selected candidate genes, in 300 and 512 mutant lines, revealing high mutation densities of 1/34 kb by RAPD/ISJ analysis and 1/47 kb by TILLING. In total, 31 novel alleles were identified in the 3 targeted genes and confirmed by sequencing. The results indicate that this mutant population represents a useful resource for the wheat research community. We hope that the use of this reverse genetics resource will provide novel allelic diversity for wheat improvement and functional genomics.     

部分耐盐小麦品种(系)SSR位点遗传多样性研究

选择有多态性的32对SSR引物对80个小麦耐盐品种(系)进行遗传差异研究,共检测出155个等位变异,平均每个位点上有4.75个等位变异;供试80份耐盐小麦品种(系)来源广泛,遗传基础丰富,表现出较高的遗传多样性,遗传相似系数范围在0.26～0.81;聚类分析结果显示,冬性小麦品种(系)聚为一大类;春性小麦品种(系)也聚为一大类;一些系谱相同或相近的品种(系)遗传相似系数较大;A、B、D基因组中SSR位点平均等位变异差异不大,以B基因组较高.     

Biolistic Genetic Transformation of a Wide Range of Chinese Elite Wheat (Triticum aestivum L.) Varieties

<正>Wheat(Triticum aestivum L.)is a major staple food crop worldwide.It is economically important because it can be grown in a wide range of climates and geographic regions,and it has made an enormous contribution to the increase in global food production over the past four decades(Dixon et al.,2009).Wheat is produced on more than 18%of the arable land in the world,and is the most cultivated crop after maize     

不同处理条件下小麦胚芽鞘长的遗传分析

以小麦双单倍体(DH)群体(旱选10号×鲁麦14)的150个株系及其亲本为材料,对不同处理条件下的胚芽鞘长、幼苗株高和幼苗生物学产量进行遗传分析,以探讨胚芽鞘长、幼苗株高及幼苗生物学产量的遗传基础及其相关性.结果表明:(1)随着播种深度的增加,胚芽鞘长、幼苗株高显著增加,16.1%PEG-6000处理条件下的幼苗株高显著低于对照,干旱胁迫条件下的幼苗生物学产量显著低于正常供水对照;(2)胚芽鞘长、幼苗株高、幼苗生物学产量的遗传力分别为92.5%、90.3%和78.1%;(3)胚芽鞘长、幼苗株高及幼苗生物学产量均受多基因控制,决定各性状的基因估计数目分别为7、8和14对;(4)根据对性状偏度和峰度系数的估算结果,控制这3个性状的多基因之间均有互补作用;胚芽鞘长与幼苗株高、生物学产量及成熟期株高之间呈显著正相关.     

Seed Storage Protein Profiles of Seven Indian Wheat (Triticum aestivum L.) Varieties

Seed storage protein profiles, Including triticin, gliadin and glutenin, of seven Indian wheat varieties were Investigated using sodium dodecyl sulfate-polyacrylamide gel eletrophoresis (50S-PAGE). A strategy was developed for half-seed analysis of the three seed storage protein classes. The results are presented In the form of a key for Identification of these varieties based on their seed protein composition. A minimum of 10 seeds of each variety were analysed to check for possible intravarietal heterogeneity, and all the varieties except HUW-12 were homogeneous. The HUW-12 was a mixture of two ‘biotypes’ with respect to the low molecular weight (LMW) glutenin subunits coded by the Glu-A3 locus. The varieties were also analysed for the presence of rye chromatin using a rye-specific repetitive DNA probe (pAW-161), and two of the recently released varieties HUW-206 and HUW-318 were found to possess rye chromatin. Based on the DNA dot-blot results, presence of rye secalins and the absence of chromosome 1 B-speclflc gliadlns It was concluded that these two varieties possess 1BL-1RS wheat-rye translocation. Both of these varieties also have high molecular weight (HMW) glutenin subunits 5 + 10 which may be necessary for compensating the loss of dough strength associated with the wheat-rye translocations.     

河北省冬小麦品种SSR标记遗传多样性分析

利用79对多态性较高的SSR引物,对河北省1997-2007年间审定的冬小麦品种及国家小麦区试抗旱对照品种晋麦47和洛旱2号,共计87个冬小麦品种进行遗传多样性分析。79对SSR引物共检测出175个等位变异位点,每对引物可产生1~6条等位变异位点,平均2.215条。标记位点多态性信息含量(PIC)变幅为0.824~0.998,平均为0.941;有效等位基因数(Ne)变幅为1.644~20.333,平均4.708;香农指数(H’)变幅为0.148~1.102,平均为0.544,说明河北省冬小麦品种SSR遗传多样性较低。品种间遗传相似系数(GS)变幅为0.184~0.899,平均为0.418,其中河农826与石家庄8号间的遗传相似性最高,GS高达0.899,71-3与藁优9618间的遗传相似性最低,GS为0.184。不同育种单位培育的小麦品种平均遗传相似系数存在较大差异。UPGMA遗传相似性聚类表明,石家庄市小麦新品种新技术研究所培育的小麦品种与其他单位品种存在较大的遗传差异。     

不同小麦品种愈伤组织诱导和再生体系建立

为了筛选适合组织培养的小麦基因型,建立一套有效的小麦诱导再生体系,以24个小麦品种的幼胚为研究材料,选用4种诱导培养基和3种分化培养基,研究了影响小麦组织培养的各种因素。结果表明：①培养基之间存在显著差异,MM2培养基的诱导效果最好,平均诱导率为98．5％,M5B培养基的分化效果最佳,平均分化率为39．8％。②不同品种在诱导愈伤和分化再生上都有显著的基因型差异。③愈伤组织诱导率和分化率之间无显著相关性。     

小麦异交群体连续歧化选择的RAPD分析

利用太谷核不育基因构建的遗传变异丰富的基础群体DNS2,进行了连续5轮歧化选择。本论文从不同的世代中,选择了10个子群体进行RAPD分析。采用7个引物扩增出116个位点,从基因频率和表型带两个角度的分析都表明,群体具有丰富的遗传变异。整个群体总的多态位点百分率达88.79,总杂合度为0.3143。子群体内（间）遗传距离的结果显示：子群体内的遗传差异小于子群体间的遗传差异;各选择子群体与未选群体间都有较大的遗传距离;随着选择轮次的增加,株高选择子群体间的遗传距离逐渐增大;对同一性状进行选择的子群体间世代内（间）平均遗传距离小于对不同性状进行选择的子群体内（间）的遗传距离。RAPD分子聚类结果显示出对同一性状进行选择的子群体聚在一起,反映了对株高选高的选择效果比较明显。 Abstract:A base population was established through multi-parent random crossing by using Taigu dominant male-sterile wheat,and then five cycles of 2-way selection for four quantitative characters were conducted.The dynamic changes of genetic structures in the open-pollinated wheat population were examined by RAPD technique.Seven primers in RAPD analysis amplified 116 sites.The results of gene frequencies and phenotypic bands showed abundant genetic variations existed in the population.The percentage of polymorphic loci was 8879,and the average heterozygosity was 0.3143 in the whole population.The genetic distance of RAPD showed as follows :① The genetic distance within a subpopulation was lower than that between every two subpopulations.② Each subpopulation had considerable divergence compared with unselected population.③ The genetic distances between the subpopulations which were selected for plant height gradually increased accompanied with the selection.④The genetic distance between subpopulations which were selected for the same character was lower than that were selected for different characters both in the same generation and among different generations.The cluster results of RAPD genetic distance demonstrated that the subpopulations selected for the same character going to one cluster.It also showed that the selective effect of increasing plant height was obvious.     

小麦体细胞无性系SSR位点的遗传变异特性分析

研究结果表明:(1)小麦体细胞无性系SSR位点变异类型有:扩增片段迁移率的变大或变小、扩增片段缺失以及新的扩增片段;(2)变异特点为:变异频率与基因型有关,不同染色体组上的SSR位点变异频率不同,而不同无性系后代的SSR位点变异频率也不同;(3)同一SSR位点的变异类型在同一基因型的无性系后代中变异表现一致,在不同基因型无性系后代中的变异表现不同,有的SSR位点在无性系后代中表现出一致的变异,而有的则不一致。     

The Morphology and Development of Cross Veins in the Leaves of Bread Wheat (Triticum aestivum L.)

In the leaves of bread wheat Triticum aestivum L. the longitudinalvascular bundles are linked by small transverse bundles Pairsof similar small vascular bundles also link the upper ends ofminor longitudinal bundles to their neighbours in a Y-shapedarrangement The cross-vein procambial strands arise from unexpanded cellsof one layer of the mesophyll tissue. Lines of these cells connectone longitudinal procambial strand to the next The procambialcells subsequently undergo two tangential divisions to producecells which differentiate to form the conducting and parenchymatouselements of the mature cross veins. Anomalous cross veins are sometimes found. possible modes oforigin of these anomalous cross veins are considered.     

Free Polyamines in Senescing Wheat(Triticum aestivum L.)

The free polyamine content of flag leaves, peduncles, rachis,glumes, and grains of wheat (Triticum aestivum L., cv. Castell)plants, ripening under field conditions, has been investigatedduring three consecutive growing seasons. Putrescine was quantitativelythe most important of all polyamines detected in these organs.Concentrations were highest in the grains, glumes and flag leaves.No correlation was found between polyamine content and the onsetof senescence of flag leaves and other organs. Excised primaryleaves, however, showed a decrease in polyamine content in thedark and also in light/dark cycles, but in the latter case onlyafter an initial increase. Sink removal of otherwise intactwheat plants caused an accumulation of putrescine in flag leavesat the later stages of senescence, whereas removal of all otherleaves was without any significant effect. Putrescine was alsorecovered in phloem-exudate samples collected throughout theperiod of grain development. In both grains and glumes, peakconcentrations of polyamines were found early during seed development. Key words: Triticum aestivum, polyamines, ripening, senescence     

Genetic Diversity and Population Structure of Cucumber (Cucumis sativus L.)

Knowing the extent and structure of genetic variation in germplasm collections is essential for the conservation and utilization of biodiversity in cultivated plants. Cucumber is the fourth most important vegetable crop worldwide and is a model system for other Cucurbitaceae, a family that also includes melon, watermelon, pumpkin and squash. Previous isozyme studies revealed a low genetic diversity in cucumber, but detailed insights into the crop''s genetic structure and diversity are largely missing. We have fingerprinted 3,342 accessions from the Chinese, Dutch and U.S. cucumber collections with 23 highly polymorphic Simple Sequence Repeat (SSR) markers evenly distributed in the genome. The data reveal three distinct populations, largely corresponding to three geographic regions. Population 1 corresponds to germplasm from China, except for the unique semi-wild landraces found in Xishuangbanna in Southwest China and East Asia; population 2 to Europe, America, and Central and West Asia; and population 3 to India and Xishuangbanna. Admixtures were also detected, reflecting hybridization and migration events between the populations. The genetic background of the Indian germplasm is heterogeneous, indicating that the Indian cucumbers maintain a large proportion of the genetic diversity and that only a small fraction was introduced to other parts of the world. Subsequently, we defined a core collection consisting of 115 accessions and capturing over 77% of the SSR alleles. Insight into the genetic structure of cucumber will help developing appropriate conservation strategies and provides a basis for population-level genome sequencing in cucumber.     

Floret Initiation and Development in Spring Wheat (Triticum aestivum L.)

The number and developmental stages of florets were determinedin each spikelet of the spike in the main shoots of spring wheat.Samples were taken frequently from plants grown in a phytotronand in a nitrogen application field-test. Ten stages of development,from floret initiation until anthesis, were recognized and described. Inter-spikelet variation in the total number of initiated floretswas rather small. However, the number of florets at advancedstages of development, as well as the number of grains, washighest in the central spikelets in which florets initiatedfirst. Floret initiation did not proceed beyond spike emergence,whereafter the distal florets and the spikelet apex degenerated.Grain-set was restricted to florets which had developed at leastto the stage of visible anther lobes at spike emergence. Thenumber of these florets was increased significantly by nitrogenapplication. Wheat, Triticum aestivum L., spikelet, floret, grain set, nitrogen