Novel genotypes of the subtropical grass Eragrostis curvula for the study of apomixis (diplospory)     

S. Cardone  P. Polci  JP. Selva  M. Mecchia  S. Pessino  P. Hermann  V. Cambi  P. Voigt  G. Spangenberg  V. Echenique 《Euphytica》2006,151(2):263-272

The aim of this work was to obtain a series of genetically related lines of Eragrostis curvula with different ploidy levels and reproductive modes, which can be used for the discovery of genes associated to diplospory. E. curvula is a widely cultivated forage grass native to Southern Africa that reproduces naturally by obligate diplosporous apomixis (asexual reproduction by seeds) of the Antennaria type. In vitro culture of immature inflorescences of the apomictic cultivar Tanganyika led to the regeneration of a diploid plant with a particular morphology (plant UNST1122). Embryo sac analysis and progeny tests determined that plant UNST1122 reproduces by sexuality. UNST1122 was cloned by dividing its tillers and a R ₁ generation was obtained from seeds after open pollination among the diploid clones. A set of 500 seeds from a diploid R ₁ plant was treated with colchicine and two plants showing a duplicated chromosome number (2n = 4x = 40) were obtained (plants UNST1112 and UNST1131). Progeny tests using RAPDs indicated that these plants reproduce also by sexuality. The availability of sexual tetraploid genotypes of E. curvula will allow the production of hybrids with new interesting combinations of agronomic traits and the developing of mapping populations segregating for diplospory. Besides, these genetically related plants with different reproduction modes constitutes an excellent model for the identification of gen(es) involved in diplosporous apomixis by mRNA profiling as well as to study the genomic rearrangements and gene expression alterations associated to changes at ploidy levels.  相似文献   

Genetic variance of six agronomic characters in three lentil (Lens culinaris Medic) crosses     

N. I. Haddad  T. P. Bogyo  F. J. Muehlbauer 《Euphytica》1982,31(1):113-120

Summary Three lentil (Lens culinaris Medic) crosses (cross 1 = Chilean × PI 297784; cross 2 = Tekoa × PI 212611; cross 3 = Precoz × PI 212611) were advanced in a hierarchal design from the F₂ generation to the F₅ generation and tested in replicated field experiments. The purpose was to estimate the genotypic variances and covariances for several characters and to partition these into components due to additive, dominance, and additive × additive variances.Additive genetic variance was the major component of variance in cross 2 for all characters, except plant height and seed weight. Unexpectedly, estimates of dominance variance appeared to be high in crosses 1 and 3. Estimates of the additive × additive component seemed very small in all three populations. The dominance variance component estimates were consistently high for plant height in the three crosses and for seed weight in crosses 2 and 3. Where parental means were close, additive variance estimates were often low and in many cases negative. The unexpected high ratio of dominance variance to additive variance indicated that dominance variance was important in the crosses we studied.Cooperative investigations of Agricultural Research Service, US Department of Agriculture and the College of Agriculture, Washington State University, Pullman, Washington 99164, Work sponsored by Fellowship from Univ. of Jordan, Amman, Jordan. Scientific paper no. 5825.Formerly: Department of Agronomy and Soils, Washington State University, Pullman, WA., USA. Presently: Department of Plant Production and Plant Protection, University of Jordan, Amman, Jordan.Statistical Services, Washington State University, Pullman, WA 99164, USA.US Department of Agriculture, Agricultural Research Service, Washington State University, Pullman WA 99164, USA.  相似文献   

SPORE series winner. Making Earth science data accessible and usable in education     

Ledley TS  Dahlman L  McAuliffe C  Haddad N  Taber MR  Domenico B  Lynds S  Grogan M 《Science (New York, N.Y.)》2011,333(6051):1838-1839

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The Importance of Having Zinc During In Vitro Maturation of Cattle Cumulus–Oocyte Complex: Role of Cumulus Cells     

JM Anchordoquy  JP Anchordoquy  MA Sirini  SJ Picco  P Peral‐García  CC Furnus 《Reproduction in domestic animals》2014,49(5):865-874

The aim of this study was to investigate the influence of zinc (Zn) on the health of cumulus–oocyte complex (COC) during in vitro maturation (IVM). Experiments were designed to evaluate the effect of Zn added to IVM medium on: DNA integrity, apoptosis, cumulus expansion and superoxide dismutase (SOD) activity of cumulus cells (CC). Also, role of CC on Zn transport during IVM was evaluated on oocyte developmental capacity. DNA damage and early apoptosis were higher in CC matured with 0 μg/ml Zn compared with 0.7, 1.1 and 1.5 μg/ml Zn (p < 0.05). Cumulus expansion did not show differences in COC matured with or without Zn supplementation (p > 0.05). Superoxide dismutase activity was higher in COC matured with 1.5 μg/ml Zn than with 0 μg/ml Zn (p < 0.05). Cleavage and blastocyst rates were recorded after IVM in three maturation systems: intact COCs, denuded oocytes with cumulus cells monolayer (DO + CC) and denuded oocytes (DO). Cleavage rates were similar when COC, DO + CC or DO were matured with 1.5 μg/ml Zn compared with control group (p > 0.05). Blastocyst rates were significantly higher in COC than in DO + CC and DO with the addition of 1.5 μg/ml Zn during IVM (p < 0.01). Blastocyst quality was enhanced in COC and DO + CC compared with DO when Zn was added to IVM medium (p < 0.001). The results of this study indicate that Zn supplementation to IVM medium (i) decreased DNA damage and apoptosis in CC; (ii) increased SOD activity in CC; (iii) did not modify cumulus expansion and cleavage rates after in vitro fertilization; (iv) improved subsequent embryo development up to blastocyst stage; and (v) enhanced blastocyst quality when CC were present either in intact COC or in coculture during IVM.  相似文献   

Behavioural and EEG changes in sheep in response to painful acute electrical stimuli     

RM ONG  JP MORRIS  JK O'DWYER  JL BARNETT  PH HEMSWORTH  IJ CLARKE 《Australian veterinary journal》1997,75(3):189-193

Objective To measure acute pain in sheep, based on a human pain model, and examined changes in both electroencephalogram frequency spectrum and behavioural responses to increased electrical stimulation in sheep. Design Analysis of variance (treatment and animal effects) for stimulus intensity where each animal received each electric shock treatment given in the order 0, 5,10 and 20 mA. Procedure Eight sheep with electrodes implanted over the surface of the brain were examined for escape-avoidance and electroencephalogram responses to four levels of electrical stimulation from 0–20 mA. Results With increasing stimulus intensity at the time of feeding, the sheep were more hesitant to return to the feeder or remain near the feeder following stimulation. There was little difference between the 0 and 5 mA stimuli for any of the behaviour variables (P > 0.05). However, there were marked increases in the time taken to re-approach the feeder after receiving an electric shock of 5 mA and of 20 mA (P < 0.05; mean values 3 and 119 s, respectively) and remaining near the feeder for 5 s (P < 0.001; mean values 10 and 167 s, respectively). Following the stimulus, there was an overall increase in the electroencephalogram power spectrum in the first four seconds, which then rapidly returned to normal. In particular, the 20 mA stimulus resulted in higher absolute power values than in the control (0 mA) treatment for delta 2 (P < 0.001), theta 1 (P < 0.05), theta 2 (P < 0.05), alpha 1 (P < 0.001), alpha 2 (P < 0.001) and beta 1 (P < 0.01) band-widths. Similarly, for the 10 mA stimulus, the absolute power values were greater than the control treatment for delta 2 (P < 0.05), alpha 1 (P < 0.01), alpha 2 (P < 0.001) and beta 1 (P < 0.01) bandwidths. Conclusion The experiment suggests that a human acute pain model is applicable to sheep and that these electroencephalogram changes may provide a good measure of acute pain in sheep.  相似文献   

Effect of adjuvants on antibody responses of sheep immunised with recombinant pili from Dichelobacter nodosus     

AK WALDUCK  JP OPDEBEECK 《Australian veterinary journal》1996,74(6):451-455

Objective To compare the effects of two oil emulsion adjuvants (incomplete Freunds adjuvant and a proprietary oil adjuvant), DEAE-dextran, L-tyrosine particles and Quil A on the humoral immune responses of sheep immunised with recombinant pili of Dichelobacter nodosus (strain A).
Procedure Antibody titres were studied for up to 32 weeks and were measured by bacterial agglutination and ELISA. The relative avidity of antibodies for pili was determined and the incidence and severity of adverse reactions at the site of injection of vaccines were recorded.
Results The oil emulsion adjuvants and Quil A were more effective than either DEAE-dextran or L-tyrosine at stimulating antibodies in sheep. The incidence and severity of adverse reactions was lower in sheep which received vaccines containing either Quil A or DEAE-dextran than in sheep which received vaccines containing oil emulsion adjuvants. L-tyrosine had no adverse effects.
Conclusion Quil A was as effective as oil adjuvants at stimulating high levels of antibodies against recombinant pili in sheep and had the significant advantage of being less irritant after subcutaneous injection.  相似文献   

The environmental impacts of humans on groundwater in Lebanon     

K. Khair  N. Aker  F. Haddad  M. Jurdi  A. Hachach 《Water, air, and soil pollution》1994,78(1-2):37-49

The execution of most large water projects in Lebanon has been continuously postponed, due to political reasons for the period preceding 1975 and to the civil war after that date. The accumulated impacts of mismanagement and shortage in water supplies forced population to drill their private wells and extract groundwater to meet their increasing needs. This uncontrolled action has significantly deteriorated the quality of groundwater, reflected in the increasing salinity of extracted water from coastal aquifers, and in the contamination of many wells and springs by improperly disposed waste water. The overexploitation of the aquifers has led to considerable decline in the discharge of springs and rivers amounting 18.8% between the 1960's and early 80's, irrespective of rainfall fluctuations. This study shows that the water budget in early 1980's has decreased appreciably, relative to 1960's budget. In Mount Lebanon basin the amount of precipitation dropped from 2700 to 2214 m³ yr^?1, the rivers, discharge declined from 1320 to 834 Mm³ yr^?1, and the recharge to groundwater decreased from 733 to 601 Mm³ yr^?1.  相似文献   

The isolation and identification of Edwardsiella tarda from a diseased native Australian eel (Anguilla reinhardtii)     

LE EAVES  PJ KETTERER  IG ANDERSON  JP BEUMER † 《Australian veterinary journal》1990,67(9):336-337

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Efficacy of closantel against infestations of screw-worm fly Chrysomya bezziana     

JP SPRADBERY  IL OWEN 《Australian veterinary journal》1990,67(9):340-340

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Concentrations of gentamicin in serum, milk, urine, endometrium, and skeletal muscle of cows after repeated intrauterine injections     

N S Haddad  W M Pedersoli  R L Carson  W R Ravis 《American journal of veterinary research》1986,47(7):1597-1601

Healthy mature cows (n = 6) were injected intrauterinally (IU) with gentamicin (50 ml of a 5% injectable solution) daily for 3 consecutive days. Venous blood and milk samples were collected at postinjection (initial) hours (PIH) 1, 3, 6, 9, 12, 24, 28, 31, 34, 37, 48, 51, 54, 57, 60, and 71, and endometrial biopsies were performed at PIH 6, 25, 48, 73, 95, and 119. Skeletal muscle biopsy samples were taken at PIH 25 and 73, and urine was collected every 1 or 2 hours during 12 consecutive hours after the first IU injection. Serum, milk, urine, and tissue concentrations of gentamicin were measured by radioimmunoassay. The highest mean serum concentration of gentamicin occurred during the 3 hours after each injection (2.49 +/- 1.46, 6.60 +/- 5.47, and 4.98 +/- 2.70 micrograms/ml). The mean peak concentration of gentamicin in milk occurred 3 to 6 hours after each injection. Mean peak urine concentration of gentamicin (256.8 +/- 127.9 micrograms/ml) was measured at PIH 6. The mean percentage of the first dose of gentamicin excreted in the urine within 12 hours was 14.78 +/- 3.56. The highest concentration of gentamicin in endometrial tissue (639.16 +/- 307.22 micrograms/g) was measured at PIH 6, decreasing to 9.64 +/- 3.55 micrograms/g before the next IU dose. Gentamicin was still detectable in endometrial tissue (0.86 +/- 0.43 microgram/g) 71 hours after the 3rd (last) IU injection.  相似文献