Mexican food system     

Russell P 《Science (New York, N.Y.)》1983,219(4590):1276

  相似文献   

Identification and Discrimination of Pseudomonas syringae Isolates from Wild Cherry in England   总被引：1，自引：2，他引：1  

Joana G. Vicente  João P. Alves  Karen Russell  Steven J. Roberts 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(4):337-351

A survey of wild cherry (Prunus avium) woodland plantations and nurseries was carried out in 2000/01. Trees with symptoms of bacterial canker were found in 20 of the 24 plantations visited and in three of seven nurseries. Fifty-four Pseudomonas syringae isolates from wild cherry together with 22 representative isolates from sweet cherry and 13 isolates from other Prunus spp., pear and lilac were characterised by physiological, biochemical, serological and pathogenicity tests. Isolates from wild cherry were predominantly P. syringae pv. syringae (Pss), but P. syringae pv. morsprunorum (Psm) races 1 and 2 were also found. Physiological and biochemical tests discriminated Psm races 1 and 2 from other P. syringae isolates. Agglutination and indirect-enzyme-linked immunosorbent assay tests with three different antisera showed that Psm race 1 and race 2 were very uniform and indicated high variability amongst other P. syringae isolates. However, pathogenic Pss isolates could not be distinguished from non-pathogenic isolates of P. syringae on the basis of physiological, biochemical or serological tests. Pathogenicity tests on rooted lilac plants and on micropropagated plantlets of lilac and two wild cherry clones differentiated Pss and Psm isolates and demonstrated a range of aggressiveness amongst Pss isolates. Serological tests could be used as an alternative to the classical physiological and biochemical tests to increase the speed of detection and discrimination of isolates, but pathogenicity tests are still necessary to discriminate the pathogenic Pss isolates.  相似文献   

The effect of grain moisture on the biological activity of fenitrothion residues on maize in storage     

Peter R. Samson  Mervyn Bengston  Russell J. Parker  Julie A. Keating 《Pest management science》1987,19(2):135-144

The biological activity of freshly-applied fenitrothion on maize at a range of moisture contents was measured using adults of several species of Coleoptera. Activity declined by about ×15 as grain moisture increased from 10 to 24%, the greatest change occurring at moisture contents above about 14%. This occurred regardless of whether the grain was treated with fenitrothion when already moist or was moistened after treatment, and it was not reversed by drying the treated grain. These differences in activity could not be explained by differences in the chemical residues. The suggested mechanism is a reduction in the availability of fenitrothion for pick-up by insects.  相似文献   

Lentogenic Newcastle disease virus and respiratory disease in Australian broiler chickens     

Hooper PT  Russell GM  Morrow CJ  Segal Y 《Australian veterinary journal》1999,77(1):53-54

  相似文献   

One century of eel growth: changes and implications     

Françoise Daverat  Laurent Beaulaton  Russell Poole  Patrick Lambert  Håkan Wickström  Jan Andersson  Miran Aprahamian  Besma Hizem  Pierre Elie  Sukran Yalçın‐Özdilek  Aysun Gumus 《Ecology of Freshwater Fish》2012,21(3):325-336

Abstract – A cooperative effort gathered a large European length‐at‐age data set (N = 45,759, Lat. 36S–61N Long. 10W–27E) for Anguilla anguilla, covering one century. To assess the effect of global warming during the last century and habitat effects on growth, a model was fitted on the data representing the conditions met at the distribution area scale. Two GLMs were designed to predict eel log(GR): one model was fitted to the whole data and the other was fitted to the female data subset. A model selection procedure was applied to select the best predictors among sex, age class, five temperature parameters and six habitat parameters (depth, salinity and four variables related to the position in the catchment). The yearly sum of temperatures above 13 °C (TempSUP13), the relative distance within the catchment, sex, age class, salinity class and depth class were finally selected. The best model predicted eel log(GR) with a 64.46% accuracy for the whole data and 66.91% for the female eel data. Growth rate (GR) was greater in habitats close to the sea and in deep habitats. TempSUP13 variable had one of the greatest predictive powers in the model, showing that global warming had affected eel growth during the last century.  相似文献   

The role of commission VI during the last 50 years     

E.W. Russell 《Geoderma》1974,12(4):363-382

The work of Commission VI is primarily concerned with the principles of soil management on the farm itself. In the earlier years, interest was principally focussed on developing systems of farming that were better adapted to conserve soil and water than the existing systems, and on developing improved systems of field drainage. More recently, attention has shifted to developing improved systems of cultivation and of irrigation of land liable to salinity and alkalinity problems; and this has been accompanied by much greater attention being given to problems of root growth and functioning in the soil.Soil and water conservation was initially concerned with the reduction of s soil erosion, whether by water or by wind, and as a consequence improved methods for the control of water have been developed either by increasing the permeability of the surface soil or by allowing the safe shedding of surplus water off the soil surface. One of the central problems of soil cultivation research has been the development of methods that allow the optimum use to be made of the wide range of herbicides that are being introduced into farming practice. This work is closely linked to two other important problems, namely the reduction of soil compaction due to the passage of implements and tractors over the land, and the reduction of the number and cost of cultivations needed to prepare an adequate seedbed, to control weeds, and to maintain soil permeability.  相似文献   

Increased knowledge predicts greater adherence to the Mediterranean diet in Greek adolescents     

Tsartsali PK  Thompson JL  Jago R 《Public health nutrition》2009,12(2):208-213

  相似文献   

Barley adaptation and improvement in the Mediterranean basin     

A. Pswarayi  F. A. Van Eeuwijk  S. Ceccarelli  S. Grando  J. Comadran  J. R. Russell  E. Francia  N. Pecchioni  O. Li Destri  T. Akar  A. Al‐Yassin  A. Benbelkacem  W. Choumane  M. Karrou  H. Ouabbou  J. Bort  J. L. Araus  J. L. Molina‐Cano  W. T. B. Thomas  I. Romagosa 《Plant Breeding》2008,127(6):554-560

To study barley adaptation and improvement in the Mediterranean basin, a collection of 188 entries comprising landraces and old genotypes and current modern varieties from the Mediterranean basin and elsewhere was tested on moisture‐contrasted environments in seven Mediterranean countries, during 2004 and 2005 harvest seasons. The experimental design consisted of an unreplicated trial for all entries, augmented by four repeated checks to which a partial replicate containing a quarter of the entries was added. Best Linear Unbiased Predictions (BLUPs) representing adjusted genotypic means were generated for individual trials using a mixed model. BLUPs were used for genotype by environment interaction analysis using main effect plus genotype by environment interaction (GGE) biplots of yield ranked data and for comparisons of landraces, old and modern genotypes using analysis of variance. Mean yields ranged from near crop failure to 6 t/ha. Local landraces were better adapted to environments yielding below 2 t/ha, thus breeding has mostly benefited environments yielding above 2 t/ha where modern genotypes out yielded landraces and old cultivars by 15%. Current barley selection is leading to specifically adapted genotypes.  相似文献   

Sequencing of the Cultivated Tetraploid CottonGenome-Gossypium hirsutum     

YU Shu-xun  WANG Kun-bo  LI Fu-guang  KOHEL Russell J  PERCY Richard G  YU John Z 《棉花学报》2008,(Z1)

Cotton is an important cash crop in the world,and it plays an irreplaceable role in China's nationaleconomy.Cultivated upland cotton (Gossypium hirsutum L.) represents 95% of the world's cottonproduction,but it has a complex allotetraploid genome that contains at least 30000 genes in 2500 MbDNA.  相似文献   

Reproductive performance and mature gonad morphology of triploid and diploid Black Tiger shrimp (Penaeus monodon) siblings     

Melony Sellars  Andrew Wood  Brian Murphy  Greg Coman  Stuart Arnold  Russell McCulloch  Nigel Preston 《Aquaculture Research》2013,44(10):1493-1501

Sibling harvest age Black Tiger shrimp triploids and diploids of both sexes were reared to reproductive maturity, crossed with wild caught females and males, conditioned for spawning and a comprehensive reproductive performance trial was undertaken. Ovarian development, spawning frequency, fecundity, hatch rate, gonad morphology, male reproductive tracts and thelycum impregnation rates of the wild female × triploid male cross were assessed. After ablation, ovarian development and cycling between wild G₀ diploid and G₁ diploids was not significantly different, whereas G₁ triploids failed to show any signs of ovarian development and cycling, thus resulting in no G₁ triploid female spawnings. There were 10 G₀ diploid female × G₀ diploid male first‐spawnings and 9 G₀ diploid female × G₁ diploid male first‐spawnings, all of which produced viable nauplii. In comparison, there were 7 G₀ diploid female × G₁ triploid male first‐spawnings, none of which produced viable nauplii. The 26 wild G₀ diploid female spawnings had more eggs than the 1 G₁ diploid female spawning. Gonad morphology and male reproductive tract assessments showed impaired reproductive development in triploid gonadal tissues of both sexes (compared with sibling diploids and wild shrimp) to a point where complete maturation had not occurred. The thelycum of 16 wild G₀ diploid females crossed with G₁ triploid males had no visible spermatophore present, suggesting that G₁ triploid males are incapable of developing viable spermatophores and mating with females. This study demonstrates that the triploid females and males are incapable of producing viable gametes and are thus reproductively sterile.  相似文献