Genetics of colour traits in common vetch (Vicia sativa L.)     

Doza M.S. Chowdhury  Jane M. Rathjen  Max E. Tate  Glenn McDonald 《Euphytica》2004,136(3):249-255

Five parents of common vetch (Vicia sativa L.) having orange/beige cotyledon colour, brown/white testa colour, purple/green seedling colour and purple/white flower colour were crossed as a full diallele set. The inheritance patterns of cotyledon, testa or seed coat colour, flower and seedling colour, were studied by analyzing their F₁, F₂, BC₁ and BC₂ generations. The segregation pattern in F₂, BC₁ and BC₂, showed that cotyledon colour was governed by a single gene with incomplete dominance and it is proposed that cotyledon colour is controlled by two allelic genes, which have been designated Ct₁ and Ct₂. Testa colour was governed by a single gene with the brown allele dominant and the recessive allele white. This gene has been given the symbol H. Two complementary genes governed both flower and seedling colours. These flower and seedling colour genes are pleiotropic and the two genes have been given the symbols S and F.  相似文献   

Polar bears in the Beaufort Sea: A 30-year mark-recapture case history     

S. C. Amstrup  T. L. McDonald  I. Stirling 《Journal of Agricultural, Biological & Environmental Statistics》2001,6(2):221-234

Knowledge of population size and trend is necessary to manage anthropogenic risks to polar bears (Ursus maritimus). Despite capturing over 1,025 females between 1967 and 1998, previously calculated estimates of the size of the southern Beaufort Sea (SBS) population have been unreliable. We improved estimates of numbers of polar bears by modeling heterogeneity in capture probability with covariates. Important covariates referred to the year of the study, age of the bear, capture effort, and geographic location. Our choice of best approximating model was based on the inverse relationship between variance in parameter estimates and likelihood of the fit and suggested a growth from ≈ 500 to over 1,000 females during this study. The mean coefficient of variation on estimates for the last decade of the study was 0.16—the smallest yet derived. A similar model selection approach is recommended for other projects where a best model is not identified by likelihood criteria alone.  相似文献   

Illinois Soil Nitrogen Test Method Optimization for Analysis of Temperate Mineral Grassland Soils     

Noeleen T. McDonald  Miguel A. Dionisio Fernández  David P. Wall 《Communications in Soil Science and Plant Analysis》2016,47(22):112-121

ABSTRACT

A reliable and practical test that can provide timely measurements of the levels of mineralizable nitrogen (MN) in soil is critical for improving the accuracy of N fertilizer applications for grassland and crops. The Illinois soil N test (ISNT) is considered to be a good estimate of MN, once soils are grouped according to soil characteristics such as the drainage type and sampling depth. To date, development and evaluation of the ISNT method has been conducted using arable soils mainly in North America where, in general, soils have lower levels of soil organic matter (SOM) compared to temperate grassland soils. We evaluated the effects of two pre-treatment soil aggregate sizes of <1 mm and <2 mm on the yield and recovery of MN (1) across temperate grassland soil types, and (2) across a 6-h interval diffusion period. No significant difference existed in the concentrations of ISNT-N between the two soil aggregate sizes of each soil type. For both aggregate sample sizes, the recovery of spiked amino sugar-N glucosamine from a temperate grassland soil was generally linear until hour 5, after which the quantities of recovered N diminished. Although N recovery after 6 h of diffusion at 50°C (±1°C) was less than 100% in both aggregate size samples, the response models indicated that the standard ISNT protocol using a 5-h diffusion period is appropriate for temperate grassland soils. The incomplete recovery of N in these mineral soils suggested that the protocol could be further optimized for temperate soils with high organic matter content and additional evaluation of the temperature during diffusion within an enclosed environment may be required using N (spiked glucosamine-N) recovery studies.  相似文献   

Relationships Between Radionuclide Content and Textural Properties in Irish Sea Intertidal Sediments     

Clifton  J.  McDonald  P.  Plater  A.  Oldfield  F. 《Water, air, and soil pollution》1997,99(1-4):209-216

Intertidal sediments from a range of depositional environments in the eastern Irish Sea have been analysed with regard to their radionuclide content, particle size distribution and magnetic properties. Concentrations of²⁴¹Am and¹³⁷Cs are highly influenced by the abundance of sediment finer than 32μm in fine-grained sedimentary environments, whilst radionuclide activity in coarser sediments is less dependent on particle size. Investigation of the magnetic properties of these sediments highlights a similar association between this size fraction and magnetic remanence, the latter being shown to offer strong potential as a grain size proxy in monitoring¹³⁷Cs concentrations in fine-grained sediments. Analysis of particle size fractions indicates the extent to which¹³⁷Cs may be enriched in the clay size fractions of both tine and coarse sediments.  相似文献   

Study on Flying Behavior of Tiphia popilliavora Rohwer in Two Types of Inter-Cropping Fields     

CHEN Hong-yin  CHEN Chang-feng  WANG Shu-ying  LUO Yi-zhen  McDonald R C 《中国农业科学(英文版)》2003,2(6)

A study was conducted in corn-peanut and sweet potato-peanut fields on the flying behavior of the white grub parasitoid Tiphia popitliavora Rohwer wasps. Observation on the first three times of flying,after the wasps being released, revealed that the first flying was an escape style and not showed preference to land on any special crops. 81.82 % wasps landed on corn leaves at the second flying but stayed for just about 3min. In the sweet potato-peanut field, 51.43 % wasps landed on sweet potato in contrast with 48.57 % landed on peanuts and in the afternoon 33.53 % on sweet potato compared with 76.4 % landed on peanut field. Majority preferred landing on peanut field on the third flying in both type fields of inter-cropping. Behavior of flying was different between morning and afternoon. The time length between two flies showed that wasps were more active in the morning than in the afternoon.  相似文献   

The gene for enhancer binding proteins E12/E47 lies at the t(1;19) breakpoint in acute leukemias   总被引：17，自引：0，他引：17  

J D Mellentin  C Murre  T A Donlon  P S McCaw  S D Smith  A J Carroll  M E McDonald  D Baltimore  M L Cleary 《Science (New York, N.Y.)》1989,246(4928):379-382

  相似文献   

Cloned gene of Rickettsia rickettsii surface antigen: candidate vaccine for Rocky Mountain spotted fever   总被引：15，自引：0，他引：15  

G A McDonald  R L Anacker  K Garjian 《Science (New York, N.Y.)》1987,235(4784):83-85

Two major protective antigens of Rickettsia rickettsii have been previously described. In this study, we cloned the gene encoding one of these antigens into Escherichia coli and tested the effectiveness of the recombinant-made product as a vaccine for Rocky Mountain spotted fever. A clone bank of R strain R. rickettsii DNA was made in E. coli K-12 by using the plasmid vector pBR322. Transformants were screened for their ability to make rickettsial antigens by reactivity with rabbit antibodies to R. rickettsii. One of the transformants, EM24(pGAM21), made a product reactive with two monoclonal antibodies that recognize a 155-kilodalton protein of R. rickettsii. One of the monoclonal antibodies was a member of a class of antibodies that react to heat-sensitive epitopes and protect mice injected with a potentially lethal dose of viable R. rickettsii. The cloned product contained this protective heat-sensitive epitope. In order to obtain enhanced expression, the gene was subcloned downstream of the lactose promoter on the plasmid vector pUC8. A sonic lysate of E. coli harboring the pUC8 subclone was used successfully as a vaccine to protect mice injected with a lethal dose of the viable R. rickettsii.  相似文献   

Maintenance of resting potential in anoxic guinea pig ventricular muscle: electrogenic sodium pumping   总被引：5，自引：0，他引：5  

T F McDonald  D P MacLeod 《Science (New York, N.Y.)》1971,172(983):570-572

Anoxic ventricular muscle maintained a normal resting potenitial despite a large loss of potassium. The resting potential was separated into two components: one that depended on the potassium distribution, and one that depended on the activity of an electrogenic sodium pump.  相似文献   

Voyager 1 explores the termination shock region and the heliosheath beyond     

Stone EC  Cummings AC  McDonald FB  Heikkila BC  Lal N  Webber WR 《Science (New York, N.Y.)》2005,309(5743):2017-2020

Voyager 1 crossed the termination shock of the supersonic flow of the solar wind on 16 December 2004 at a distance of 94.01 astronomical units from the Sun, becoming the first spacecraft to begin exploring the heliosheath, the outermost layer of the heliosphere. The shock is a steady source of low-energy protons with an energy spectrum approximately E(-1.41 +/- 0.15) from 0.5 to approximately 3.5 megaelectron volts, consistent with a weak termination shock having a solar wind velocity jump ratio r=2.6(-0.2)(+0.4). However, in contradiction to many predictions, the intensity of anomalous cosmic ray (ACR) helium did not peak at the shock, indicating that the ACR source is not in the shock region local to Voyager 1. The intensities of approximately 10-megaelectron volt electrons, ACRs, and galactic cosmic rays have steadily increased since late 2004 as the effects of solar modulation have decreased.  相似文献   

Aedes aegypti: origin of a "new" chromosome from a double translocation heterozygote   总被引：1，自引：0，他引：1  

P T McDonald  K S Rai 《Science (New York, N.Y.)》1970,168(936):1229-1230

An apparent enhancement of crossing-over occurs in the region common to two translocated chromosomes derived from two different reciprocal translocations in the yellow-fever mnosquito, Aedes aegypti. A "new" chromosome containing parts of all three linkage groups is created through crossing-over. In a reversible process, two haploid translocated sets in the double translocation heterozygote produce a new, normal chromosome. set and vice versa in alternating generatiots.  相似文献