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91.
J. D. LOZIER N. J. MILLS P. J. PALSB
LL G. K. RODERICK 《Molecular ecology resources》2005,5(3):499-501
Hyalopterus pruni is an invasive aphid pest in California. To study the population biology of this pest both in California and its native Mediterranean region, we have developed 11 di‐ and tri‐nucleotide repeat microsatellite markers. Each locus amplified in individuals representing the full range of geographical regions and host plants where Hyalopterus is found. Polymorphism was high, ranging from six to 22 alleles per locus in the individuals screened. These loci represent the first microsatellites developed for Hyalopterus and they should be of great value in studying the invasion biology and population structure of this insect pest. 相似文献
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Six novel metal-organic complex assemblies constructed from a conformation-flexible ligand - pyridine-4-acetamide (PAT) and inorganic CuII and CoII salts have been synthesized and structurally characterized by single crystal X-ray diffraction analysis. Crystal structure analysis reveals five types of architectures by variation of metal salts. In {[Cu(PAT)2Cl2]}n (1) and {[Co(PAT)2Cl2]}n (3), PAT ligands bridge metal centers to form one-dimensional chains. The chains are extended to three dimensions with the aid of two types of hydrogen bonded motifs () and (12)). {[Cu(PAT)2(NO3)](NO3)(THF)}n (5) which exhibits two-dimensional coordinating layers forms open channels filled with solvent molecules. In [Cu(PAT)2Cl2] (2), [Co(PAT)2Cl2] (4) and [Co(PAT)4(H2O)2](NO3)2(THF)2 (6), PAT is observed as a monofunctional ligand. Complex 2 forms one-dimensional hydrogen bonded chains. Crystal structure of complex 4 has a two-dimensional infinite hydrogen-bonded network with and motifs formed by complementary amide-amide hydrogen bonds. [Co(PAT)4(H2O)2](NO3)2(THF)2 (6) crystallizes in centrosymmetric I41/a space group. Complex 6 forms chiral channels which are filled with twisted solvent helices and anion helices. Within each channel the solvent helix and the anion helix have the same handedness; and adjacent channels have opposite handedness. Complexes 1, 2 and complexes 3, 4 illustrate examples of conformational supramolecular isomerism in {[Cu(PAT)2Cl2]}∞ and {[Co(PAT)2Cl2]}∞, respectively. In these complexes, changes of PAT conformations and coordination geometry of metal center induced the structural versatility. 相似文献
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Hari D Upadhyaya Sangam L Dwivedi Michael Baum Rajeev K Varshney Sripada M Udupa Cholenahalli LL Gowda David Hoisington Sube Singh 《BMC plant biology》2008,8(1):106
Background
Plant genetic resources (PGR) are the basic raw materials for future genetic progress and an insurance against unforeseen threats to agricultural production. An extensive characterization of PGR provides an opportunity to dissect structure, mine allelic variations, and identify diverse accessions for crop improvement. The Generation Challenge Program conceptualized the development of "composite collections" and extraction of "reference sets" from these for more efficient tapping of global crop-related genetic resources. In this study, we report the genetic structure, diversity and allelic richness in a composite collection of chickpea using SSR markers, and formation of a reference set of 300 accessions. 相似文献98.
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Suppose a finite set X is repeatedly transformed by a sequence of permutations of a certain type acting on an initial element x to produce a final state y. For example, in genomics applications, X could be a set of genomes and the permutations certain genome ‘rearrangements’ or, in group theory, X could be the set of configurations of a Rubik’s cube and the permutations certain specified moves. We investigate how ‘different’ the resulting state y′ to y can be if a slight change is made to the sequence, either by deleting one permutation, or replacing it with another. Here the ‘difference’ between y and y′ might be measured by the minimum number of permutations of the permitted type required to transform y to y′, or by some other metric. We discuss this first in the general setting of sensitivity to perturbation of walks in Cayley graphs of groups with a specified set of generators. We then investigate some permutation groups and generators arising in computational genomics, and the statistical implications of the findings. 相似文献
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Three species of dwarf, prostrate willow ( Salix arctica , S. rotundifolia and S. herbacea ) were subjected to experimental summer warming in high arctic Canada, arctic Alaska, and subarctic Sweden, respectively, as part of the International Tundra Experiment. Phenological and growth responses of these species were compared for the second season of the experiment. Stigmas became receptive and pollen dispersal occurred significantly earlier for S. rotundifolia and S. herbacea in the ITEX open-top chambers, but not for S. arctica . Warming had no effect on the timing of seed dispersal, leaf yellowing, or leaf senescence. The length and dry weight of the largest leaves were greater for warmed plants, and was significant for S. rotundifolia . The number of catkins/plot did not differ among species or treatments, but the fruit : flower ratio was reduced in the experimental plots. 相似文献