bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. X. Some Mixed-Ligand Complexes of Group 2 Metal Halides With 2,2':6',2"-Terpyridine and Oxygen Donors
Authors: Waters AF , White AH
Published: November 2018

Room-temperature single-crystal X-ray structural characterizations are recorded for a variety of adducts of Group 2 metal halides with 2,2':6',2?-terpyridine ( tpy ) from various hydroxylic solvents. [Mg( tpy )2][Mg( tpy )(OH2)3] Br4.PriOH (1) is triclinic, Pī, a 19.352(6), b 12.852(5), c 11.463(3) Ǻ, α 110.95(3), β 99.04(2), γ 98.81(3)°, Z = 2 f.u .; conventional R on ׀ F ׀ at convergence was 0.056 for No 4398 independent 'observed' (I > 3σ(I)) reflections. In the [Mg( tpy )2]2+ ion, Mg-N(central; distal) are 2.099(9), 2.09(1); 2.152(9)-2.212(8) Ǻ, while in [Mg( tpy )(OH2)3]2+, Mg-N(central; distal) are 2.139(7); 2.206(9), 2.222(9) Ǻ, while Mg-O trans to these are 2.042(6); 2.082(9), 2.097(8) Ǻ. [Mg( tpy )(OH2)2( MeOH )] Cl2 (2) is triclinic, Pī, a 14.049(7), b 8.354(4), c 8.301(2) Ǻ, α 74.25(3), β 73.05(3), γ 80.37(4)°, Z = 2 f.u., R 0.064 for No 2417. In the cation, Mg-N(central; distal) are 2.125(4); 2.203(4), 2.218(4) Ǻ; Mg-O( MeOH ) is trans to Mg-N(central), being 2.013(4) Ǻ; Mg-O(OH2) are 2.067(4) and 2.063(4) Ǻ. [CaCl2( tpy )( dmf )2 (3) ( dmf = N,N- dimethylformamide ) is monoclinic, C2/c, a 23.27(2), b 11.225(6), c 16.517(8) Ǻ, β 109.56(5)°, Z = 4 centrosymmetric dimers, R 0.061 for No 985. The calcium atoms are linked by a pair of μ-chlorines, CaCl2Ca, and are seven-coordinate, N3Ca(μ-Cl )4 being broadly coplanar in the equatorial plane of a pentagonal bipyramidal array, with the other chlorine and the dmf oxygen trans and axial.
Structural and Solid-State Examination of Ca4Mn3O10 and Sr4Mn3O10
Authors: Rossell HJ , Goodman P , Bulcock S , March RH , Kennedy SJ , White TJ , Lincoln FJ , Murray KS
Published: November 2018

A comparative study of the manganates Ca4Mn3O10 and Sr4Mn3O10 shows them to belong to distinct structural classes, of Ruddlesden-Popper and Cs4Ni3F10 type respectively. Our determinations show both compounds to be orthorhombic, with Ca4Mn3O10 in space group Ccc2, with a = 5.240, b = 26.823, c = 5.276 Ǻ, and Sr4Mn3O10 in space group P2221, with the cell dimensions of a = 5.481(1), b = 6.237(1), c = 12.528(2) Ǻ. In addition, Ca4Mn3O10 is found to undergo a transition at 122 K, below which temperature there is evidence for antiferromagnetic ordering and for a sharp conductor-to-insulator transition. This appears to be a new form of giant magnetoresistance (GMR), differing from previous reports in that it occurs in an undoped , layered bulk perovskite.
Preparation and Reactivity of Some Phenyl-bismuth(III) Quinolin-8-olate Derivatives
Authors: Smith KA , Deacon GB , Jackson WR , Miller JM
Published: November 2018

The bimetallics [ PhBi (Ox)2( NaX )n] (Ox- = quinolin-8-olate: X = Cl , Br or I), containing variable amounts of sodium halides, have been prepared by reaction of PhBiX2 with Na(Ox) (mole ratio 1 : 2) or of Ph2BiX with Na(Ox) (mole ratio 1 : 1) in ethanol. A similar preparation has given [ PhBi ( MeOx )2( NaI )n] ( MeOx - = 2-methylquinolin-8-olate) . The bimetallics have been characterized by X-ray powder photography, f.a.b . mass spectrometry and 1H n.m.r. and electronic spectroscopy. Sodium halide-free PhBi (Ox)2 was obtained from the reaction of Ph2BiCl with Na(Ox) in the presence of 15-crown-5, or from treatment of PhBiI2 or Ph2BiI with NBu4(Ox). Reaction of equimolar amounts of PhBiI2 and Na(Ox) gives Bi(Ox)2I, which can also be obtained from BiI3 and Na(Ox) in a 1:1 or 1:2 stoichiometry. Treatment of PhBiI2 with M(0x) (M = Na or K) in a 1:3 mole ratio yields [ MPhBi (Ox)3] bimetallics, which appear to contain both chelating and unidentate Ox ligands from their electronic spectra.
Regiospecific Syntheses of the Monomethylated 3-Phenyldihydro-1,2,4-triazin-6(1H)-ones
Authors: Collins DJ , Hughes TC , Johnson WM
Published: November 2018

Unambiguous syntheses of four unreported monomethylated derivatives of 3-phenyldihydro-1,2,4-triazin-6(1H)-ones, namely, the 1-methyl (2), 2-methyl (3), 4-methyl (4) and the imidic O-methyl derivative (5), are described. Regioselectivity was achieved for the synthesis of (2) by addition of ethyl glycinate to the 1,3-dipolar nitrile imine derived from N- methylbenzohydrazonoyl bromide hydrobromide (8). The key step for the synthesis of (3) was addition of benzyl 3-methylcarbazate (14) to ethyl N-[ chloro (phenyl) methylene ] glycinate (15b). The 4-methyl compound (4) was prepared by cycloaddition of ethyl N-( thiobenzoyl ) sarcosinate (21) with hydrazine hydrate, and the O-methyl compound (5) was prepared by reaction of sodium methoxide with 6-chloro-3-phenyl-4,5-dihydro-1,2,4-triazine (23).
Benzonaphthyridine N-Oxides as 1,3-Dipoles
Authors: Zujewska T , Bachowska B
Published: November 2018

Benzonaphthyridine N-oxides give N-ylides with dimethyl acetylenedicarboxylate at room temperature, most probably by 1,3-dipolar cycloaddition followed by ring contraction to form an aziridine derivative, and ring opening.
Studies in the Cycloproparene Series: 3,8-Dioxa-1H-cyclopropa[b]anthracene
Authors: Cooney MJ , Halton B
Published: November 2018

The application of known methodology has provided 2,3-dimethylidene-2,3-dihydro-1,4-benzodioxin (12) as the essential precursor for preparation of the cyclopropa-fused dibenzodioxin 3,8-dioxa-1H-cyclopropa [b] anthracene (14). Cycloproparene (14) is both unstable and acid-sensitive, and readily dimerizes to a mixture of the dihydrotetraoxaheptacene (15) and its heptaphene analogue (16).
Substitution of Bridgehead Halogens by a Free-Radical Electron-Transfer Mechanism
Authors: Harsanyi MC , Lay PA , Norris RK , Witting PK
Published: November 2018

The reactions of 1-bromo-7-nitro- and 1-bromo-6-nitro-1,4-methanonaphthalene (2) and (3), and 9-bromo-2-nitro, 10-bromo-2-nitro-, 9,10-dibromo-2-nitro- and 9,10-diiodo-2-nitro-9,10-ethano-9,10-dihydroanthracene (4)-(7). respectively, with the sodium salt (1) of p-toluenethiol gave substitution products that were shown to be formed by an SRN1 or a related radical chain mechanism. In the relatively slow substitution reactions of the salt (1) with compounds (2)-(5). That contain bromine at bridgehead positions that are either meta- or para-benzylic to an aromatic nitro group, the rates of substitution in the isomers where the leaving group was meta- benzylic to the aromatic nitro group were slightly greater than those for the corresponding para-benzylic isomer. In compounds (6)and (7) the halogens are at bridgehead positions that are either meta- or para-benzylic relative to an aromatic nitro group within the same molecule. In the case of the reaction of the dibromide (6) with the thiolate (1), substitution was slow and occurred more rapidly at the benzylic -bridgehead position meta to the nitro group than at the corresponding para-benzylic position. In contast , the reaction of the diiodide (7) with the thiolate (1) gave substitution products which formed more rapidly than in the corresponding reaction of the dibromide (6) and the regioselectivity was reversed, with substitution occurring more readily at the bridgehead position para-benzylic to the nitro group than at the corresponding meta- benzylic position. The ratio of meta to para substitution products, determined for the reactions of compounds (2)-(6) with the salt (1), were in the range 1.15-2.5:1, while the reaction of (7) with the same nucleophile afforded a meta-to-para ratio of 1:2:3. These ratios contrast not only with each other, but also with the differences in reactivities determined for other nitrobenzylic systems, which are known to undergo SRN1 substitution reactions with the same nucleophile. The differences in first, the regioselectivity of substitution between the bridgehead systems, and secondly, the differences in the observed rates of regioselective substitution are compared with other simple nitrobenzylic halides. These differences are rationalized in terms of the effect of fixing the C-X bond at a bridgehead position to be orthogonal with the plane of the nitroaromatic group; this results in a reduction of the rate constants of intramolecular electron transfer, with significant consequences on the detailed overall mechanism for these reactions.
Experiments Directed Towards the Synthesis of Anthracyclinones. XXVIII. Titanium(IV)- and Tin(IV)-Mediated Cyclizations of ortho-Methallyl-Substituted Homochiral Dioxans
Authors: Cambie RC , Higgs KC , Rustenhoven JJ , Rutledge PS
Published: November 2018

Metal chloride cyclizations of the 4-demethoxy anthraquinonyl 1′,3'-dioxan (6) are highly diastereoselective , giving 9-chloro-9-methylanthracyclinones in high yield. The selectivity is inversely proportional to the strength of the Lewis acid, with the mild Lewis acid tin(IV) chloride/ dimethylformamide affording an 82% yield of the diastereomer (21). The predominant products have a (7S) configuration and a trans relationship between the C7 side chain and the 9-chloro substituent. Cyclization of the analogous dimethoxy 1′,3′-dioxan (4) with tin(IV) chloride/ dimethylformamide is considerably less selective, but the major product also has a (7S)-trans stereochemistry. Titanium(IV) chloride effects stereorandom cyclization of (4).
Mycalone: a New Steroidal Lactone From a Southern Australian Marine Sponge, Mycale sp.
Authors: Rochfort SJ , Gable RW , Capon RJ
Published: November 2018

Mycalone (1), a new steroid incorporating a novel six- membered lactone side chain, has been isolated fram a southern Australian marine sponge, Mycale sp. The gross structure for mycalone (1) was secured by spectroscopic analysis, and the stereochemistry established by a single-crystal X-ray structure determination.
Synthetic Approaches to the Hypothetical Lactone Intermediate in the Pyrolytic Conversion of 8-Methylcyclobuta[a]naphthalene-1,2-dione Into Acenaphthylene
Authors: Brown RFC , Eastwood FW , Wong NR
Published: November 2018

Synthetic approaches to the hypothetical lactone intermediate 8,8a-dihydro-2H-acenaphtho[1,8-bc]furan-2-one (2) based on intramolcular Diels -Alder reaction, and on intramolecular alkylation by diazoacetate groups, were not useful. Generation and pyrolysis of the 9-diazomethylnaphtho[1,2-c]furan-3(1H)-one (19) derived from the corresponding 9-formyl compound (15) gave products including acenaphthylene, consistent with the intermediacy of the lactone (2).
Structure Characterization of Sulfate and Oxysulfate Phases Formed During Sulfuric Acid Digestion of Ilmenites
Authors: Grey IE , Lanyon MR , Stranger R
Published: November 2018

Laboratory digestion of natural and upgraded ilmenites with concentrated sulfuric acid has been carried out under conditions simulating the sulfate-route pigment process. X-Ray diffraction studies on the solid digestion cakes led to the characterization of a number of different iron titanium sulfate and oxysulfate compounds, whose formation was dependent on the ilmenite composition and digestion conditions. Two different sulfate phases were identified, with structures related to those for Fe2(SO4)3 and H2O[ Zr (HPO4)2]. Four different iron titanium oxysulfates , ( Fe,Ti )(O,OH)SO4, were identified as major digestion products, three having structures related to those for β-NbOPO4, GeOHPO4 and lazulite , Mg[AlOHPO4], and the fourth being a new struture type. The structures of the oxysulfate phases were refined by the Rietveld method. Both the sulfates and the oxysulfates have three-dimensional framework structures formed by corner linking of ( Ti,Fe )O6 octahedra and SO4 tetrahedra, and containing channels or interlayer regions that can be occupied by cations such as H3O+ and Fe2+. The different structures have many features in common. Their structural relationships are discussed and mechanisms are proposed for the phase transformations encountered in the digestion studies.
A Shift-Lattice Interpretation of Structures in the Au4Mn Region of the Au-Mn System
Authors: Tilley RJD , Williams RP
Published: November 2018

The structures of a number of ordered phases in the Au-Mn system derived from the face- centred cubic structure of Au4Mn have been described in a systematic manner by use of shift-lattice distributions of the manganese atoms throughout the matrix of the alloys. The simplest structures are describable in terms of one-dimensional shift lattices, but many are best treated as two- or three-dimensional shift lattices. This approach has allowed structural correlations to be presented that have not been described previously and the variation in stoichiometry of these phases to be accounted for without recourse to defect populations. The diffraction patterns of such structures are also discussed, especially incommensurate patterns from materials with 'infinitely large' crystallographic unit cells.
New Structural Models for Anion-Excess Fluorite-Related Vernier Phases
Authors: Frit B , Laval JP , Strahle J
Published: November 2018

A great number of anion-excess fluorite-related phases MX2+y correspond to ordered distributions, within a fluorite matrix, of the same M6X14 columnar cluster generated by the insertion at the centre of six primitive cubes MX8 of an extra zigzag row of anions. They can therefore be formulated as Mm+6X2m+14 (0 ≤ m < ∞) or more generally as Mm′X2m′+2 (m′ = m+6). It has been shown that, among all these structures, some, in which the clusters are systematically aligned and directly connected along rows perpendicular to the densified anion layers, are classical vernier structures formulated as MnX2n+1 (n = m′/2 = integer). Some are new vernier structures that can be called shifted vernier structures since the M6X14 clusters are shifted, from one densified plane to the other, by a vector →T = p(→aF + →bF)/2 (p = integer) and for which non-integer values of n are possible. Bi7O5F11 constitutes the first isolated member (n = 3.5, m' = 7) of this new structural series. Some others are completely different structures like the K2NbF7 compound.
1,1-Diphenylbutane-1,3-diol: the First Structurally Characterized Example of an Intramolecularly Hydrogen-Bonded Open-Chain 1,3-diol
Authors: Carvalho CF , Arnold DP , Bott RC , Smith G
Published: November 2018

The crystal structure of the asymmetric 1,3-diol 1,1-diphenylbutane-1,3-diol has been determined and refined to a residual R of 0.039 for 795 observed reflections. Crystals are orthorhombic, space group P212121, with four molecules in a cell of dimensions a 9.625(4), b 16.002(3), c 8.834(3) Ǻ. The compound is unique among the known crystallographically characterized open-chain 1,3-diols in having only intramolecular hydrogen bonding involving the hydroxy groups [O-- -O 2.602(5) Ǻ].
The Yeast-Mediated Reduction of Nitrostyrenes in Organic Solvent Systems
Authors: Bak RR , Mcanda AF , Smallridge AJ , Trewhella MA
Published: November 2018

A range of nitrostyrenes have been reduced with dried baker's yeast in an organic solvent system. It was found that the reduction proceeded smoothly to give the corresponding nitroalkanes in good yield and with higher efficiency than the corresponding aqueous reaction system. No evidence for reduction of the nitro group was observed. In the case of β-methyl nitrostyrenes, racemic mixtures were formed, and it was shown that this is not due to racemization of the product.
Synthetic Routes to 3,9-Dimethylidene-1,5,7,11-tetrathiaspiro[5.5]undecane
Authors: Bromley MK , Gason SJ , Jhingran AG , Looney MG , Solomon DH
Published: November 2018

Spiro orthocarbonates ( SOCs ) have been widely studied, particularly as monomers which on polymerization undergo minimal shrinkage. Of particular interest has been the dimethylidene SOC because, unlike the parent SOC, it is amenable to free-radical polymerization. The incorporation of other hetero atoms, particularly sulfur, into the bicyclic structure offers the potential of polymers with improved refractive indices and mechanical properties. However, whilst literature methods are available for the spiro tetrathioorthocarbonates ( STOCs ),3 the synthesis of a methylidene derivative has not been reported. In this communication we report the synthesis of 3,9-dimethylidene-1,5,7,11-tetra-thiaspiro[5.5] undecane (DMSTOC) (1).
Managing glyphosate resistance in Australian cotton farming: modelling shows how to delay evolution and maintain long-term population control
Authors: Thornby David , Werth Jeff , Walker Steven
Published: November 2018

Glyphosate resistance is a rapidly developing threat to profitability in Australian cotton farming. Resistance causes an immediate reduction in the effectiveness of in-crop weed control in glyphosate-resistant transgenic cotton and summer fallows. Although strategies for delaying glyphosate resistance and those for managing resistant populations are qualitatively similar, the longer resistance can be delayed, the longer cotton growers will have choice over which tactics to apply and when to apply them. Effective strategies to avoid, delay, and manage resistance are thus of substantial value. We used a model of glyphosate resistance dynamics to perform simulations of resistance evolution in Sonchus oleraceus (common sowthistle) and Echinochloa colona (awnless barnyard grass) under a range of resistance prevention, delaying, and management strategies.
From these simulations, we identified several elements that could contribute to effective glyphosate resistance prevention and management strategies. (i) Controlling glyphosate survivors is the most robust approach to delaying or preventing resistance. High-efficacy, high-frequency survivor control almost doubled the useful lifespan of glyphosate from 13 to 25 years even with glyphosate alone used in summer fallows. (ii) Two non-glyphosate tactics in-crop plus two in-summer fallows is the minimum intervention required for long-term delays in resistance evolution. (iii) Pre-emergence herbicides are important, but should be backed up with non-glyphosate knockdowns and strategic tillage; replacing a late-season, pre-emergence herbicide with inter-row tillage was predicted to delay glyphosate resistance by 4 years in awnless barnyard grass. (iv) Weed species’ ecological characteristics, particularly seed bank dynamics, have an impact on the effectiveness of resistance strategies; S. oleraceus, because of its propensity to emerge year-round, was less exposed to selection with glyphosate than E. colona, resulting in an extra 5 years of glyphosate usefulness (18 v. 13 years) even in the most rapid cases of resistance evolution.
Delaying tactics are thus available that can provide some or many years of continued glyphosate efficacy. If glyphosate-resistant cotton cropping is to remain profitable in Australian farming systems in the long-term, however, growers must adapt to the probability that they will have to deal with summer weeds that are no longer susceptible to glyphosate. Robust resistance management systems will need to include a diversity of weed control options, used appropriately.
Changes in weed species since the introduction of glyphosate-resistant cotton
Authors: Werth Jeff , Boucher Luke , Thornby David , Walker Steve , Charles Graham
Published: November 2018

Weed management practices in cotton systems that were based on frequent cultivation, residual herbicides, and some post-emergent herbicides have changed. The ability to use glyphosate as a knockdown before planting, in shielded sprayers, and now over-the-top in glyphosate-tolerant cotton has seen a significant reduction in the use of residual herbicides and cultivation. Glyphosate is now the dominant herbicide in both crop and fallow. This reliance increases the risk of shifts to glyphosate-tolerant species and the evolution of glyphosate-resistant weeds.
Four surveys were undertaken in the 2008–09 and 2010–11 seasons. Surveys were conducted at the start of the summer cropping season (November–December) and at the end of the same season (March–April). Fifty fields previously surveyed in irrigated and non-irrigated cotton systems were re-surveyed.
A major species shift towards Conyza bonariensis was observed. There was also a minor increase in the prevalence of Sonchus oleraceus. Several species were still present at the end of the season, indicating either poor control and/or late-season germinations. These included C. bonariensis, S. oleraceus, Hibiscus verdcourtii and Hibiscus tridactylites, Echinochloa colona, Convolvulus sp., Ipomea lonchophylla, Chamaesyce drummondii, Cullen sp., Amaranthus macrocarpus, and Chloris virgata. These species, with the exception of E. colona, H. verdcourtii, and H. tridactylites, have tolerance to glyphosate and therefore are likely candidates to either remain or increase in dominance in a glyphosate-based system.
Cotton farming systems in Australia: factors contributing to changed yield and fibre quality
Authors: Braunack M. V.
Published: November 2018

This study was undertaken to identify factors in Australian cotton farming systems that influence yield and fibre quality of cotton and how these have changed with time after the wide adoption of Bollgard II® cultivars (containing the proteins Cry1Ac and Cry2Ab, providing easier control of Helicoverpa spp.) in the 2003–04 season. Data from Australian commercial cotton variety trials conducted from 2004 to 2011 were used to link management inputs, yield, and fibre quality.
Restricted (residual) maximum likelihood (REML) and regression analyses were used to determine which factors had a significant effect on yield and fibre quality. Results showed that lint yield was significantly influenced by cultivar and growing region, and the interaction between region and the amount of applied nitrogen and phosphorus (kg ha–1), plant stand (plants ha–1), in-crop rainfall (mm) and the number of irrigations, season length (days), and days to defoliation. Generally, the same factors also influenced fibre quality. Regression analysis captured 41, 71, 50, 30, and 36% of the variability in lint yield, fibre length, micronaire, fibre strength, and trash, respectively, for irrigated systems. For dryland systems the variability captured was 97, 87, 77 80, and 78%, respectively.
Changes in cotton farming systems from 2004 to 2011 have occurred with applied nitrogen fertiliser increasing under irrigation and decreasing under dryland systems. However, phosphorus fertiliser use has remained steady under irrigated and decreased under dryland systems, and the number of insect sprayings has decreased under both systems. Under irrigated systems, lint yield, fibre length, and trash levels increased while micronaire and fibre strength decreased. Under dryland systems, lint yield decreased while micronaire, fibre length, strength, and trash levels increased. All fibre quality parameters satisfied criteria that would not incur a penalty.
The results considering which factors are the most important and which are of lesser importance provide some insight to changes in management in both irrigated and dryland systems and the effect on lint yield and fibre quality and provide some basis for future investment in research and development and extension to the Australian cotton industry.
Rhizosphere properties in monocropping and intercropping systems between faba bean (Vicia faba L.) and maize (Zea mays L.) grown in a calcareous soil
Authors: Li Haigang , Zhang Fusuo , Rengel Zed , Shen Jianbo
Published: November 2018

The processes involving pH modification, carboxylate exudation and phosphorus (P) dynamics in the rhizosphere of crops grown in intercropping are poorly understood. Two groups of maize (Zea mays L.) or faba bean (Vicia faba L.) plants (monocropping) or one group of plant of each species (intercropping) were grown between three 1-mm-thick soil layers; the central soil layer is referred to as inter-rhizosphere, and the two outer soil layers are designated sole-rhizosphere. Faba bean intercropped with maize had an 11% increase in shoot biomass and a 15% increase in P uptake compared with monocropped faba bean. The cropping pattern did not significantly influence maize growth. After 4 weeks of growth, faba bean significantly decreased soil pH in both the sole- and inter-rhizosphere in monocropping, but no effects were apparent for the intercropping rhizosphere. The major carboxylates in the rhizosphere of faba bean were malate (18–45 nmol g–1 soil) and maleate (1.2–2.4 nmol g–1 soil). Only trace amounts of carboxylates were measured in the rhizosphere of monocropped maize. However, intercropped maize had a high concentration of malate (~11 nmol g–1 soil) in both sole- and inter-rhizosphere; the malate was likely exuded by faba bean and was then diffused to the sole-rhizosphere of intercropped maize. The amount of malate exuded by intercropped faba bean was 19% higher than with monocropped plants. The results indicate that diffusion of protons and carboxylates extended the interaction zone between maize and faba bean, and may have contributed to enhancements of P uptake in the intercropping system.
Detection of molecular markers associated with yield and yield components in durum wheat (Triticum turgidum L. var. durum) under saline conditions
Authors: Dura S. , Duwayri M. , Nachit M. , Al Sheyab F.
Published: November 2018

Durum wheat is one of the most important staple food crops, grown mainly in the Mediterranean region where its productivity is drastically affected by salinity. The objective of this study was to identify markers associated with grain yield and its related traits under saline conditions. A population of 114 F8 recombinant inbred lines (RILs) was derived by single-seed descent from a cross between Belikh2 (salinity-tolerant variety) and Omrabi5 (less salinity tolerant) was grown under non-saline and saline conditions in a glasshouse. Phenotypic data of the RILs and parental lines were measured for 15 agronomic traits. Association of 96 simple sequence repeat (SSR) loci covering all 14 chromosomes with 15 agronomic traits was analysed with a mixed linear model. In total, 49 SSR loci were significantly associated with these traits. Under saline conditions, 12 markers were associated with phenological traits and 19 markers were associated with yield and yield components. Marker alleles from Belikh2 were associated with a positive effect for the majority of markers associated with yield and yield components. Under saline condition, five markers (Xwmc182, Xwmc388, Xwmc398, Xbarc61, and Xwmc177) were closely linked with grain yield, located on chromosomes 2A, 3A, 3B, 4B, 5A, 6B, and 7A. These markers could be used for marker-assisted selection in durum wheat breeding under saline conditions.
Development and validation of molecular markers linked with stem rust resistance gene Sr13 in durum wheat
Authors: Periyannan Sambasivam K. , Qamar Zia U. , Bansal Urmil K. , Bariana Harbans S.
Published: November 2018

Stem rust resistance gene Sr13, found frequently in tetraploid wheats, was tested effective against Puccinia graminis f. sp. tritici pathotype Ug99 (TTKSK) and its derivatives. It remains a candidate for developing new cultivars with diverse combinations of stem rust resistance genes. To combine Sr13 with other genes that produce a similar phenotype, linked markers would be required. We used the AFLP approach to identify markers linked closely with Sr13. The STS marker AFSr13, derived from an AFLP fragment, mapped at 3.4–6.0 cM proximal to Sr13 across three mapping populations. Marker dupw167, previously reported to be linked with Sr13, mapped 2.3–5.7 cM distal to Sr13 in four F3 populations. Marker gwm427 mapped proximal to AFSr13 in two populations, and these markers were monomorphic on one population each. The map order dupw167–Sr13–AFSr13–gwm427 was deduced from the recombination data. Markers dupw167 and AFSr13 were validated on 21 durum wheat genotypes. Combination of dupw167 and AFSr13 would facilitate marker-assisted selection of Sr13 in segregating populations. At the hexaploid level, only gwm427 showed polymorphism and differentiated the presence of Sr13 in 10 of the 15 backcross derivatives carrying Sr13 from their Sr13-lacking recurrent parents.
QTL dissection of yield components and morpho-physiological traits in a durum wheat elite population tested in contrasting thermo-pluviometric conditions
Authors: Graziani M. , Maccaferri M. , Royo C. , Salvatorelli F. , Tuberosa R.
Published: November 2018

Dissection of the genetic basis of the adaptive response of durum wheat to unfavourable water and temperature regimes is an important prerequisite for the selection of genotypes less vulnerable to environmental constraints. An elite durum population of 249 recombinant inbred lines was tested across 16 Mediterranean environments characterised by contrasting thermo-pluviometric conditions and, consequently, a broad range of productivity (from 0.56 to 5.88 t  ha–1). Among the environmental variables investigated, soil moisture during grain filling showed the most consistent correlation with yield components and grain yield, whereas a weaker, albeit in some cases significant, association was noted with temperature at heading and thermal time during grain filling. Ear peduncle length appeared as a valid and easy-to-phenotype morphological proxy for the water available to the plant. In total, 76 quantitative trait loci (QTLs) were identified for yield components and for several morpho-physiological traits (peduncle length, the spectral reflectance index NDVI and leaf greenness at the milk-grain stage expressed in SPAD units) associated with the adaptive response of wheat to water and heat stresses. Although most of the QTLs were significant in only one or two environments, two major QTLs on chromosomes 2BL and 3BS showed consistent additive and epistatic effects on 1000-kernel weight, peduncle length, SPAD values and grain yield in half of the environments. In view of their strong phenotypic effects on kernel weight, these two QTLs are good candidates for positional cloning in order to gain a better understanding of the functional basis of their effect on the plasticity of grain weight and grain yield.
Corrigendum to: Crop-available water and agronomic management, rather than nitrogen supply, primarily determine grain yield of commercial chickpea in northern New South Wales
Authors: Elias N. V. , Herridge D. F.
Published: November 2018

Chickpea (Cicer arietinum L.) is considered an effective rotation crop in Australia's northern grains region; however, concerns exist that grain yields of commercial crops are reduced because of nitrogen (N) deficiency related to inadequate nodulation and N2 fixation. As part of a program to address these issues, we report on the monitoring of 22 commercial fields around Moree, northern NSW, during 2005–07 that were designated for chickpea, and an associated farmer survey (81 respondents). Our objectives were to determine whether the monitored crops were limited by N and to develop recommendations that would optimise productivity for farmers growing chickpeas. In 2005, only soil water and nitrate data were collected from the six fields designated for chickpea. In 2006 and 2007, almost complete datasets were assembled from the 16 chickpea fields or crops, including soil water and nitrate at sowing, row spacing, plant density, plant height, stubble cover, weed density and composition, shoot biomass, grain yield, nodulation and N2 fixation (%N derived from the atmosphere (%Ndfa) and total crop N fixed). The associated survey provided insights into farmer knowledge of, and practices related to, inoculation.
Field monitoring indicated moderate–high levels of soil nitrate at sowing (averages 114, 126 and 110kg N ha–1 to 1.2m depth for 2005, 2006 and 2007, respectively) and generally low plant nodulation (0.11–1.16g fresh wt plant–1) and N2 fixation (0–62%Ndfa and 0–87kg N ha–1). Grain yield varied between 0.53 and 2.91tha–1 across the 14 monitored crops, with averages of 1.89tha–1 in 2006 and 1.02tha–1 in 2007. Although total crop N and grain yields were highly correlated with total (i.e. soil+fixed) N supply, there was no evidence that the monitored chickpea crops were N-limited. Rather, we conclude that soil N and biologically fixed N were complementary in supplying N to the crops, the grain yields of which were primarily determined by the supply of plant-available water (PAW) and water-use efficiency (WUE). Simple and multivariate regression analyses showed that stubble cover during the fallow (positively correlated with sowing PAW) and sowing date (positively correlated with crop WUE) were significant determinants of grain yield. We conclude that farmers could improve inoculation practice by ensuring the time between seed inoculation and sowing is always
Improving water productivity in the Australian Grains industry—a nationally coordinated approach
Authors: Kirkegaard J. A. , Hunt J. R. , McBeath T. M. , Lilley J. M. , Moore A. , Verburg K. , Robertson M. , Oliver Y. , Ward P. R. , Milroy S. , Whitbread A. M.
Published: November 2018

Improving the water-limited yield of dryland crops and farming systems has been an underpinning objective of research within the Australian grains industry since the concept was defined in the 1970s. Recent slowing in productivity growth has stimulated a search for new sources of improvement, but few previous research investments have been targeted on a national scale. In 2008, the Australian grains industry established the 5-year, AU$17.6 million, Water Use Efficiency (WUE) Initiative, which challenged growers and researchers to lift WUE of grain-based production systems by 10%. Sixteen regional grower research teams distributed across southern Australia (300–700 mm annual rainfall) proposed a range of agronomic management strategies to improve water-limited productivity. A coordinating project involving a team of agronomists, plant physiologists, soil scientists and system modellers was funded to provide consistent understanding and benchmarking of water-limited yield, experimental advice and assistance, integrating system science and modelling, and to play an integration and communication role. The 16 diverse regional project activities were organised into four themes related to the type of innovation pursued (integrating break-crops, managing summer fallows, managing in-season water-use, managing variable and constraining soils), and the important interactions between these at the farm-scale were explored and emphasised. At annual meetings, the teams compared the impacts of various management strategies across different regions, and the interactions from management combinations. Simulation studies provided predictions of both a priori outcomes that were tested experimentally and extrapolation of results across sites, seasons and up to the whole-farm scale. We demonstrated experimentally that potential exists to improve water productivity at paddock scale by levels well above the 10% target by better summer weed control (37–140%), inclusion of break crops (16–83%), earlier sowing of appropriate varieties (21–33%) and matching N supply to soil type (91% on deep sands). Capturing synergies from combinations of pre- and in-crop management could increase wheat yield at farm scale by 11–47%, and significant on-farm validation and adoption of some innovations has occurred during the Initiative. An ex post economic analysis of the Initiative estimated a benefit : cost ratio of 3.7 : 1, and an internal return on investment of 18.5%. We briefly review the structure and operation of the initiative and summarise some of the key strategies that emerged to improve WUE at paddock and farm-scale.
Effect of climate warming on maize production in Timor-Leste: interaction with nitrogen supply
Authors: Bacon Samuel A. , Mau Raimundo , Neto Florindo M. , Williams Robert L. , Turner Neil C.
Published: November 2018

Climate change is predicted to decrease crop yields in semi-arid and subtropical regions of the world and this could negatively affect smallholder farmers in the developing world. Previous analysis has suggested that with low fertiliser input, yields of sorghum increased as temperatures increased. We used the wide range of tropical environments in the small mountainous island country of Timor-Leste to evaluate the impact of global warming on maize (Zea mays) yields with (i) no fertiliser input and (ii) increased nitrogen (N) supply. We calibrated the well-tested APSIM-Maize model for the cultivar of maize grown throughout Timor-Leste. We simulated maize yields at four locations with 8 years of reliable weather records, at present temperatures, +1.5°C and +3.0°C, with 0, 40 and 80 kg/ha of added N, with 1.2, 1.9 and 3.8% soil organic carbon (SOC), and with increased duration of the vegetative phase. With no added N, higher temperatures increased yields at the cooler, higher elevation sites and decreased yields at the warmest site near the coast. With fertiliser application, warming temperatures decreased yields or induced no change in simulated yield at all locations. Simulations with three levels of N supply for the four sites, which differed in temperature, showed a strong temperature × N supply interaction on yield. At maximum growing-season temperatures >31°C, yields decreased with increasing temperature at all levels of fertilisation. At maximum growing-season temperatures of 23−31°C, yields increased with increasing temperature with no added fertiliser, were unchanged with the application of 40 kg N/ha, and decreased with increasing temperatures with application of 80 kg/ha N. The changes in yield with temperature and N supply were associated with N uptake by the maize, which showed the same interaction with maximum temperature and N added. SOC acted as a source of N, so that changes in yield induced by temperature and N were similar whether the N was from an organic or an inorganic source. Increasing the duration of the vegetative phase resulted in lower or no change in yields at all sites. We conclude that global warming will increase the yield for low-input smallholder farmers growing maize at maximum growing-season temperatures <31°C, but that micro-dosing with N will increase yields at all locations with mean maximum temperatures of 20−35°C.
Use of 33P to trace in situ the fate of canola below-ground phosphorus, including wheat uptake in two contrasting soils
Authors: Foyjunnessa  , McNeill Ann , Doolette Ashlea , Mason Sean , McLaughlin Mike J.
Published: November 2018

Our understanding of the contribution of crop root residues to phosphorus (P) cycling is mainly derived from studies using excavated roots re-introduced to soil. This study aims to quantify total below-ground P (BGP) of mature canola in situ and to estimate directly the proportion accessed by subsequent wheat. 33P-Labelled phosphoric acid was fed by stem wick to canola (Brassica napus) grown in sand or loam in pots. Shoots were removed from all plants at maturity. Half of the pots were destructively sampled. After a 3-week fallow, wheat was grown for 5 weeks in the remaining undisturbed pots. At canola maturity, 23–36% of the 33P was partitioned in recovered roots and 34–40% in the soil. More 33P was recovered in the loam than the sand. Within the soil, 6–10% of the fed 33P was present in resin P and 3–5% was in hexanol-released P pools. Ratios of shoot P : BGP (8 : 1 in sand and 15 : 1 in loam) were much narrower than those of shoot P : recovered root P (17 : 1 in sand and 39 : 1 in loam). A greater proportion and amount of the mature canola BG33P was recovered by wheat grown in the loam (26%, 2.6 mg/plant) than in the sand (21%, 1.5 mg/plant). The majority of canola BG33P remained in the bulk soil. Input of P below-ground by mature canola and subsequent P benefit to wheat was greater in loam than sand. The P from canola below-ground residues contributed up to 20% of P uptake in wheat during the first 5 weeks of growth. Longer term benefits of P from below-ground residues require investigation.
Canopy application of film antitranspirants over the reproductive phase enhances yield and yield-related physiological traits of water-stressed oilseed rape (Brassica napus)
Authors: Faralli Michele , Grove Ivan G. , Hare Martin C. , Boyle Roger D. , Williams Kevin S. , Corke Fiona M. K. , Kettlewell Peter S.
Published: November 2018

Oilseed rape (Brassica napus L.) yield is strongly decreased by water deficit, and crop-management solutions are urgently required considering the emerging difficulties in breeding for drought-tolerant varieties. Film-forming antitranspirants (polymers) are agrochemicals that, applied to the crop canopy, mechanically block the stomata and decrease canopy transpiration. In this study, the drought-protection efficacy of an adaxial-surface application at the flowering stage of two film-forming treatments (poly-1-p-menthene and di-1-p-menthene) was investigated in pot-grown, droughted oilseed rape over two glasshouse experiments. Over the drought period, the two compounds reduced leaf stomatal conductance (P < 0.001), and as the soil moisture deficit increased, they sustained carbon assimilation and improved water-use efficiency with differing efficacy. Following the antitranspirant treatments, ABA concentration in leaves and reproductive organs was severely reduced and this was accompanied by significant improvements in leaf and flower–pod water potential. Drought significantly decreased the seed dry matter production of oilseed rape plants, by 39% on average. The treatments significantly increased seed dry matter by 13% (poly-1-p-menthene) and 17% (di-1-p-menthene), on average, compared with the unsprayed droughted plants, as a result of a significant increase in number of pods per plant, by 11% and 13%, respectively. The results suggest that film-forming compounds may be a useful crop-management tool to avoid severe drought-induced yield losses in oilseed rape by improving water-use efficiency and plant water status, thus alleviating ABA signalling under water deficit.
In-field film antitranspirant application shows potential yield protection from flowering-stage drought periods in winter canola (Brassica napus)
Authors: Faralli Michele , Grove Ivan G. , Hare Martin C. , Kettlewell Peter S.
Published: November 2018

Crop-management solutions that simulate plant water-saving strategies might help to mitigate drought damage in crops. Winter canola (Brassica napus L.) is significantly drought-sensitive from flowering to mid-pod development, and drought periods lead to significant yield losses. In this study, the drought-protection efficacy of different chemicals with antitranspirant activity applied just before key drought-sensitive phenological stages was tested on field-grown canola in two years. Drought was artificially imposed with rain shelters. The results suggest that in-field application of 1 L ha–1 of antitranspirant (Vapor Gard (VG), a.i. di-1-p-menthene) at GS6.0 (BBCH growth scale, initiation of flowering) mitigated drought-induced yield loss leading to a 22% seed-yield benefit on average over 2 years of experiments compared with the unsprayed unirrigated plots. No significant yield responses were found from application at GS7.0, with increasing VG concentrations (i.e. 2 and 4 L ha–1), or with an antitranspirant with short-lasting effectiveness. The data suggest that in field conditions where drought occurs during the flowering stage, application of 1 L ha–1 of VG just before the drought event can reduce yield loss. This result should encourage further work on water-saving management strategies during key drought-sensitive phenological stages as drought mitigation tools in canola and under different environments.
Molecular mechanisms of biogenesis of apoptotic exosome-like vesicles and their roles as damage-associated molecular patterns
Authors: Park Soo Jeong , Kim Jeong Mi , Kim Jihyo , Hur Jaehark , Park Sun , Kim Kyongmin , Shin Ho-Joon , Chwae Yong-Joon
Published: November 2018

Recent research has led to contradictory notions regarding the conventional theory that apoptotic cell death can evoke inflammatory or immunogenic responses orchestrated by released damage-associated patterns (DAMPs). By inducing IL-1β from bone marrow-derived macrophages in an effort to determine the inflammatory mediators released from apoptotic cells, we found that exosomal fractions called “apoptotic exosome-like vesicles” (AEVs) prepared from apoptotic-conditioned medium were the main inflammatory factors. These AEVs showed characteristics of exosomes in their size, density, morphology, and protein expression but had unique marker proteins, sphingosine-1-phosphate receptors 1 and 3 (S1PR1 and 3). Their biogenesis was completely dependent on cellular sphingosine-1-phosphate (S1P)/S1PRs signaling from multiple fine spindles of plasma membrane accompanied by F-actin, S1PR1, S1PR3, and CD63 at the early apoptotic phase and progressing to the maturation of F-actin–guided multivesicular endosomes mediated by G
βγ
subunits of S1PRs downstream. S1P-loaded S1PRs on AEVs were critical factors for inducing IL-1β via NF-κB transcriptional factor and p38 MAPK, possibly through the RHOA/NOD2 axis, in differentiating macrophages. The AEVs induced genes of proinflammatory cytokines, chemokines, and mediators in both in vitro and in vivo models. In conclusion, AEVs could be key inflammatory mediators, acting as DAMPs that could explain the pathogeneses of various chronic inflammations, autoimmune diseases, or cancers in the future.
Individual synaptic vesicles mediate stimulated exocytosis from cochlear inner hair cells
Authors: Grabner Chad Paul , Moser Tobias
Published: November 2018

Significance

Synaptic transmission is codetermined by presynaptic and postsynaptic neurons. Therefore, to understand how the inner hair cell (IHC) signals to spiral ganglion neurons at the first synapse in the auditory pathway, here we directly studied individual membrane fusion events by making cell-attached membrane capacitance recordings from IHCs, for which the quantal size is debated. The observed fusion steps in membrane capacitance are consistent with the quantal hypothesis of synaptic transmission in which individual synaptic vesicles undergo exocytosis independently from each other. This finding, in conjunction with previous work, raises the exciting possibility that action potential generation can be triggered by the release of a single vesicle at the IHC synapse.
N-cadherin signaling via Trio assembles adherens junctions to restrict endothelial permeability
Authors: Kruse Kevin , Lee Quinn S. , Sun Ying , Klomp Jeff , Yang Xiaoyan , Huang Fei , Sun Mitchell Y. , Zhao Shuangping , Hong Zhigang , Vogel Stephen M. , Shin Jae-Won , Leckband Deborah E. , Tai Leon M. , Malik Asrar B. , Komarova Yulia A.
Published: November 2018

Vascular endothelial (VE)–cadherin forms homotypic adherens junctions (AJs) in the endothelium, whereas N-cadherin forms heterotypic adhesion between endothelial cells and surrounding vascular smooth muscle cells and pericytes. Here we addressed the question whether both cadherin adhesion complexes communicate through intracellular signaling and contribute to the integrity of the endothelial barrier. We demonstrated that deletion of N-cadherin (Cdh2) in either endothelial cells or pericytes increases junctional endothelial permeability in lung and brain secondary to reduced accumulation of VE-cadherin at AJs. N-cadherin functions by increasing the rate of VE-cadherin recruitment to AJs and induces the assembly of VE-cadherin junctions. We identified the dual Rac1/RhoA Rho guanine nucleotide exchange factor (GEF) Trio as a critical component of the N-cadherin adhesion complex, which activates both Rac1 and RhoA signaling pathways at AJs. Trio GEF1-mediated Rac1 activation induces the recruitment of VE-cadherin to AJs, whereas Trio GEF2-mediated RhoA activation increases intracellular tension and reinforces Rac1 activation to promote assembly of VE-cadherin junctions and thereby establish the characteristic restrictive endothelial barrier.