Consequences of 1BL/1RS translocation on agronomic and physiological traits in wheat

The 1BL/1RS wheat-rye translocations had been used in wheat breeding programs worldwide. The objective of this study was to determine the effect of the 1BL/1RS translocation in SeriM82 /Babax recombinant population. 167 lines of this population were assayed under well-irrigated, terminal drought, heat and a combination of heat and drought stress conditions in two years. 5S rDNA and Iag95 markers were used to differentiate genotypes with or without the1BL/1RS translocation. Presence of 1BL/1RS translocation reduced grain yield (YLD), grain per spike (GSP) and grain per m2 (GM2). QTLs in 1 BL/1RS segments indicated increased thousand-grain weight (TGW), chlorophyll content, spikelet per spike (SPLS), spike compactness (SCOM) and awn length (AWL) but reduced YLD, GSP and GM2. The 1BL/1RS carrying lines’ response varied between assayed environments. Plants of drought trials were more affected by 1BL/1RS compared to others. Differences in the effects of 1BL/1RS and QTLs suggest that gene expression at translocation loci is restricted to specific environmental conditions. In general, the 1BL/1RS translocation could not be a suitable source of genetic diversity for enhancing grain yield under heat and drought stresses

Exploiting a wheat EST database to assess genetic diversity

Expressed sequence tag (EST) markers have been used to assess variety and genetic diversity in wheat (Triticum aestivum). In this study, 1549 ESTs from wheat infested with yellow rust were used to examine the genetic diversity of six susceptible and resistant wheat cultivars. The aim of using these cultivars was to improve the competitiveness of public wheat breeding programs through the intensive use of modern, particularly marker-assisted, selection technologies. The F2 individuals derived from cultivar crosses were screened for resistance to yellow rust at the seedling stage in greenhouses and adult stage in the field to identify DNA markers genetically linked to resistance. Five hundred and sixty ESTs were assembled into 136 contigs and 989 singletons. BlastX search results showed that 39 (29%) contigs and 96 (10%) singletons were homologous to wheat genes. The database-matched contigs and singletons were assigned to eight functional groups related to protein synthesis, photosynthesis, metabolism and energy, stress proteins, transporter proteins, protein breakdown and recycling, cell growth and division and reactive oxygen scavengers. PCR analyses with primers based on the contigs and singletons showed that the most polymorphic functional categories were photosynthesis (contigs) and metabolism and energy (singletons). EST analysis revealed considerable genetic variability among the Turkish wheat cultivars resistant and susceptible to yellow rust disease and allowed calculation of the mean genetic distance between cultivars, with the greatest similarity (0.725) being between Harmankaya99 and Sönmez2001, and the lowest (0.622) between Aytin98 and Izgi01

Genetic studies on salt tolerence in Barley (Hordeum vulgare L.)

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN007880 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Evaluation of Drought Resistance Criteria in Some Cumin (Cuminum cyminum L.) Landraces

Cumin is one of the most important herbal drug crops of Iran and used in traditional foods. It needs low water for growth cycle, and grows in arid and semi-arid regions of Iran. For evaluation of drought resistance of some cumin landraces of Iran, two experiments as under drought stress and normal condition were conducted. The parameters of leaf water potential, osmotic potential, harvest index and stress susceptibility index (SSI) were studied on cumin landraces. Sarvestan-e Fars, Tabriz and Sabzevar landraces were distinguished as arought tolerant landraces. Cluster analysis using single linkage method, classified the genotypes into three groups. Sabzevar, Sarvestan-e Fars, Tabriz and Khorasan2-374 landraces made the first group, Zirkoh-e Quen, Qunabad and Ferdous landraces, included in the second group, and  Kerman landrace, alone, was located in the third group

Unidirectional Curved Surface Plasmon Polariton in a Radially Magnetized System

Dynamic manipulation of the surface plasmon polariton (SPP) and wave steering are important in plasmonic applications. In this work, we excite a curved SPP in topological continua by applying a radial magnetic bias. We believe that it is a new technique to create a unidirectional SPP traveling along a curved trajectory. We also derive a Greens function model for radially-biased plasma, applicable to curved SPPs. We compare the properties of unidirectional curved SPPs with the usual case when an axial bias is applied

Insights from the Echinacea purpurea (L.) Moench transcriptome: Global reprogramming of gene expression patterns towards activation of secondary metabolism pathways

Echinacea purpurea (L.) Moench is an important medicinal plant with a wide range of therapeutic potentials that is extensively applied in pharmaceutical industry. The molecular bases and regulatory mechanisms of active compounds in E. purpurea, are yet to be fully described. In the study, to explore genome-wide transcriptional and metabolic changes, seedlings elicited by methyl jasmonate (MeJA) were analyzed by integrative transcriptome sequencing and quantitative chemical profiling. The plants exposed to MeJA significantly increased accumulation of phenolic compounds content as well as phenylalanine ammonia-lyase (PAL) activity, compared with control plants. The assembly of the clean reads generated 85,736 unigenes, in which more than 52% were annotated. Transcriptome analysis revealed that MeJA induces major transcriptional changes, especially metabolic, and signal transduction pathways. Overall, 5538 differentially expressed genes were identified after MeJA application that some of them were assigned to transcription factors (TFs), protein kinases (PKs), and transporters involved in phenolic secondary metabolite biosynthesis. Moreover, core genes in the pathways of phenylalanine and phenylpropanoid were affected by MeJA. A transcriptional regulatory network from transcriptome profiles of TFs and genes involved in phenolics biosynthesis pathway were constructed that identified hub genes which might play central regulatory roles in secondary metabolite biosynthesis. The current study provides a comprehensive genomic dataset that can serve as a resource to better understanding of the phenolic biosynthesis and improveing metabolic engineering strategies for overproduction of bioactive metabolites in Echinacea industry.Ahmad Tahmasebi, Esmaeil Ebrahimie, Hassan Pakniyat, Mansour Ebrahimi, Manijeh Mohammadi-Dehcheshme