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Chromosome pairing was analysed in F[sub 1] hybrids of the wheat cultivar ‘Chinese Spring’ (CS) and its ph1b mutant (CS ph1b) with Dasypyrum villosum. On average, 1.61 chromosomes per cell paired in the hybrid CS × D. villosum, but 14.43 in the hybrid CS ph1b × D. villosum. Genomic fluorescence in situ hybridization (GISH) revealed three types of homoeologous association between wheat (W) and D. villosum (D) chromosomes (W-D, D-W-W and D-W-D) in pollen mother cells of the CS ph1b × D. villosum hybrid, and only one type (W-W), in the CS × D. villosum hybrid. Both F[sub 1] hybrids were self-sterile. The seed set of the backcross of CS × D. villosum with CS was 6.67% and that of CS ph1b × D. villosum with CS or CS ph1b was only 0.45%. The chromosome number of BC[sub 1] plants varied from 48 to 72. Translocations of chromosome segments or entire arms between wheat and D. villosum chromosomes were detected by GISH in the BC[sub 1] plants from the backcross of CS ph1b × D. villosum to CS ph1b. [ABSTRACT FROM AUTHOR]

This paper presents the capability of a numerical code, isis-cfd, based on the solution of the Navier-Stokes equations, for the investigation on the hydrodynamic characteristics of a marine propeller in open water. Two propellers are investigated: the Istituto Nazionale per Studi ed Esperienze di Architectura Navale (INSEAN) E779A model in straight-ahead flow and the Potsdam Propeller Test Case (PPTC) model in oblique flow. The objectives of this study are to establish capabilities of various turbulent closures to predict the wake propeller and to predict the instability processes in the wake if it exists. Two Reynolds-averaged Navier-Stokes (RANS) models are used: the k-ω shear stress transport (SST) of Menter and an anisotropic two-equation explicit algebraic Reynolds stress model (EARSM). A hybrid RANS-large eddy simulation (LES) model is also used. Computational results for global flow quantities are discussed and compared with experimental data. These quantities are in good agreement with the measured data. The hybrid RANS-LES model allows to capture the evolution of the tip vortices. For the INSEAN E779A model, the instability of the wake is only predicted with a hybrid RANS-LES model, and the position of these instabilities is in good agreement with the experimental visualizations. [ABSTRACT FROM AUTHOR]

Lodging (LD) is a major constraint limiting the yield and forage quality of barley. Detailed analyses of LD component (LDC) traits were conducted using 246 F2 plants generated from a cross between cultivars ZQ320 and 1277. Genetic relationships between LD and LDC were evaluated by unconditional and conditional quantitative trait locus (QTL) mapping with 117 simple sequence repeat markers. Ultimately, 53 unconditional QTL related to LD were identified on seven barley chromosomes. Up to 15 QTL accounted for over 10% of the phenotypic variation, and up to 20 QTL for culm strength were detected. Six QTL with pleiotropic effects showing significant negative correlations with LD were found between markers Bmag353 and GBM1482 on chromosome 4H. These alleles and alleles of QTL for wall thickness, culm strength, plant height, and plant weight originated from ZQ320. Conditional mapping identified 96 additional QTL for LD. Conditional QTL analysis demonstrated that plant height, plant height center of gravity, and length of the sixth internode had the greatest contribution to LD, whereas culm strength and length of the fourth internode, and culm strength of the second internode were the key factors for LD-resistant. Therefore, lodging resistance in barley can be improved based on selection of alleles affecting culm strength, wall thickness, plant height, and plant weight. The conditional QTL mapping method can be used to evaluate possible genetic relationships between LD and LDC while efficiently and precisely determining counteracting QTL, which will help in understanding the genetic basis of LD in barley.

The goal of this study is to understand the evolution relationship of the members of B-hordein gene family in hull-less barley by analysis of their structure and to explore their utility in grain quality improvement. Six copies of B-hordein gene (Hn1-Hn3, Hn7-Hn9) were cloned from six hull-less barley cultivars collected from Qinghai-Tibet Plateau and molecularly characterized. Comparison of their predicted polypeptide sequences with the published suggested that they all share the same basic protein structures. In addition, we found that the C-terminal end sequences of all B-hordeins shared a similar feature. In the six clones and the other three published (Hn4, Hn5 and Hn6) from hull-less barley, Hn2 and Hn7 contained identical C-terminal end sequence DIMPVDFWH, Hn3, Hn4, Hn5, Hn8 and Hn9 also shared the common sequence DIMPPDFWH, which was similar to that of a B-hordein reported previously. Both Hnl and Hn6 exhibited differences in their C-terminal end sequences, and they clustered into different subgroups. The B-hordeins with identical C-terminal end sequences were clustered into a same subgroup, so we believe that B-hordein gene subfamilies possibly can be classified on the basis of the conserved C-terminal end sequences of predicted polypeptide. Phylogenetic analysis also indicated that there is a relatively weak identity between our predicted B-hordeins and those reported from H. chilense and H. brevisubulatum. All of our nine predicted B-hordeins were clustered together and other B-hordeins formed another cluster. The possible use of these genes in relation to the barley quality is discussed.