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991.
Two near-isogenic lines of the processing tomato cv. ‘IPA-5’, pheno-typically distinct from each other only in terms of the presence or absence of a jointless fruit pedicel, were used to estimate pleiotropic effects of the recessive gene j-2 on 15 processing and agronomic parameters. Total yield, total yield of mature fruit, total yield of green fruit, total number of fruit, total number of mature fruit, total number of green fruit, mean weight of mature fruit, mean weight of green fruit, mean weight of mature plus green fruit, soluble solids, fruit colour, pH, titratable acidity, sugar: acid ratio, and fruit firmness were compared in jointed (J-2/J-2) and jointless pedicel (J-2/J-2) lines. Statistically significant differences were detected between both isolines for the following parameters: total number of fruit, total yield, total yield of green fruit, and total number of green fruit. In all cases, smaller values were observed in the isoline with the genetic constitution J-2/J-2. These data reinforce the view that they j-2 gene may cause, in some specific tomato backgrounds, significant yield constraints. Furthermore, it was demonstrated that this gene cannot exert any important pleiotropic influence on any of the processing characteristics evaluated. 相似文献
992.
Many ordered intermetallic alloys have attractive high-temperature properties; however, low ductility and brittle fracture limit their use for structural applications. The embrittlement in these alloys is mainly caused by an insufficient number of slip systems (bulk brittleness) and poor grain-boundary cohesion. Recent studies have shown that the ductility and fabricability of ordered intermetallics can be substantially improved by alloying processes and control of microstructural features through rapid solidification and thermomechanical treatments. These results demonstrate that the brittleness problem associated with ordered intermetallics can be overcome by using physical metallurgical principles. Application of these principles will be illustrated by results on Ni(3)Al and Ni(3)V-Co(3)V-Fe(3)V. The potential for developing these alloys as a new class of high-temperature structural materials is discussed. 相似文献
993.
Summary The inheritance of resistance to the twospotted spider mite and of bitterness in cucumber has been studied in three sets of P1, P2, F1, F2, B11 and B12 of crosses between three bitter, resistant lines and one non-bitter, susceptible line. Resistance to the twospotted spider mite as measured by acceptance and oviposition appeared to be determined by several to many genes, which are inherited mainly in an additive fashion. Bitterness is basically governed by the gene Bi, which, contrary to earlier reports, is inherited in an intermediary way, while the expression of Bi is influenced by additively inherited intensifier genes. Whereas Bi and the bitterness intensifier genes are not related to the resistance factors acceptance and oviposition, they are related to resistance or tolerance as measured by the damage index. This relation is explained by linkage rather than by identity of the genes concerned. Changes in the test methods and breeding consequences are discussed. 相似文献
994.
995.
Performance of WATCOM (a numerical model) and CRPSM (a simple water balance model) were assessed in simulating root zone water
storage and water balance components under cowpea in Nigeria using a line source sprinkler system. Three sets of field data
were collected: the first was used for calibration and model parameters’ estimation and the other two for testing and comparisons.
The simulated soil water storage and crop evapotranspiration with WATCOM and CRPSM were in good agreement with field-measured
data though WATCOM performed significantly better (P < 0.05) under the stressed condition. The maximum average error between predicted and measured soil water storage was −0.95
and +1.47 mm for WATCOM and CRPSM, respectively, while that between measured and predicted actual crop evapotranspiration
was +2.7 and +11.38 mm, respectively, for the two models. WATCOM gave generally higher cumulative deep percolation and lower
evapotranspiration than that of CRPSM for all irrigation levels (P < 0.05), and values of deep percolation for WATCOM were in better agreement with field data than that of CRPSM. This suggests
that drainage below the field capacity needs to be included in CRPSM and that WATCOM will be a more useful management tool
when detailed soil parameter is required and under variable water regime. 相似文献
996.
Summary A serological survey was carried out in Paraguay to determine the prevalence of antibodies toAnaplasma marginale, Babesia bigemina andBabesia bovis. The results suggest that the parasites are widely distributed throughout the country with prevalence rates of 9w% forA. marginale, 79% forB. bigemina and 71% forB. bovis. Epidemiological studies on calves demonstrated that initial infection with the three blood parasites occurs in most animals within the first nine months of life. It is likely therefore that most of the country can be considered as being enzootically stable with respect to anaplasmosis and babesiosis.
Enfermedades Transmitidas For Garrapatas En Paraguay. I. Estudios Seroepidemiologicos De Anaplasmosis Y Babesiosis
Resumen Se llevó a cabo un estudio serológico en el Paraguay, para determinar la prevalencia de anticuerpos deAnaplasma marginale, Babesia bigemina yB. bovis. Los resultados sugieren que los parásitos se encuentran ampliamente distribuidos en todo el país, con tasas de prevalencia de 92% paraA. marginale, 79% paraB. bigemina y 71% paraB. bovis.Los resultados epidemiológicos en terneros demostraron que la infección inicial con los tres parásitos sanguíneos, ocurre durante los primeros nueve meses de vida en la mayoría de ellos. Es possible entonces inferir que la mayoría del país es estable enzoóticamente con respecto a anaplasmosis y babesiosis.
Maladies Des Bovins Transmises Par Les Tiques Au Paraguay. I. Etudes Seroepidemiologiques Sur l'Anaplasmose Et La Babesiose
Résumé Une enquête sérologique a été réalisée au Paraguay pour déterminer la fréquence des anticorps pourAnaplasma marginale, Babesia bigemina etBabesia bovis. Les résultats indiquent que les parasites sont largement répandus dans tout le pays avec des taux de prévalence de 92% pourA. marginale, 79% pourB. bigemina et 71% pourB. bovis. Les études épidémiologiques réalisées sur des veaux ont démontré que l'infection initiale avec les trois parasites sanguins se produit chez la plupart des animaux durant les neuf premiers mois de la vie. Il est donc vraisemblable que l'on peut considérer la majeure partie du pays comme enzootiquement stable pour ce qui concerne l'anaplasmose et les babésioses.相似文献
997.
On a farm with therapeutic problems and unsatisfactory management conditions, the occurrence of antibiotic resistance and transferable antibiotic resistance has been studied in E. coli isolated from calves which were 5 and 30 days old. Strains with resistance to up to seven antibiotics as well as transferable resistance against up to five antibiotics were recorded. On an average, 4.2 strains with different patterns and 4.0 different strains with transferable resistance were isolated from each calf. The corresponding figures previously found for healthy control calves were 1.6 and 1.1 strains, respectively. Resistance and transferable resistance were most common against sulphonamide and penicillin. 相似文献
998.
999.
Contact angles at the water–air interface have been measured for triturated preparations of clays and soils in order to assess changes in their hydrophobic properties under the effect of oil hydrocarbons. Tasks have been to determine the dynamics of contact angle under soil wetting conditions and to reveal the effect of chemical removal of organic matter from soils on the hydrophilicity of preparations. The potentialities of static and dynamic drop tests for assessing the hydrophilic–hydrophobic properties of soils have been estimated. Clays (kaolinite, gumbrine, and argillite) have been investigated, as well as plow horizons of soils from the Republic of Tatarstan: heavy loamy leached chernozem, medium loamy dark gray forest soil, and light loamy soddy-calcareous soil. The soils have been contaminated with raw oil and kerosene at rates of 0.1–3 wt %. In the uncontaminated and contaminated chernozem, capillary water capacity has been maintained for 250 days. The contact angles have been found to depend on the degree of dispersion of powdered preparation, the main type of clay minerals in the soil, the presence and amount of oxidation-resistant soil organic matter, and the soil–water contact time. Characteristic parameters of mathematical models for drop behavior on triturated preparations have been calculated. Contamination with hydrocarbons has resulted in a reliable increase in the contact angles of soil preparations. The hydrophobization of soil surface in chernozem is more active than in soils poorer in organic matter. The complete restoration of the hydrophilic properties of soils after hydrocarbon contamination is due to the oxidation of easily oxidizable organic matter at the low content of humus, or to wetting during several months in the absence of the mazut fraction. 相似文献
1000.
Kastelic JP Olson WO Martinez M Cook RB Mapletoft RJ 《The Canadian veterinary journal. La revue veterinaire canadienne》1999,40(3):173-178
Fifty-six cows received a norgestomet implant and an injection of norgestomet and estradiol valerate; half (n = 28) received 500 IU equine chorionic gonadotrophin (eCG) at implant removal, 9 d later. A third group (n = 25) received 2 doses of cloprostenol (500 micrograms) 11 d apart. Estrous rate was higher (P < 0.05) for cows given norgestomet and estradiol plus 500 IU eCG (75.0%) than for those receiving cloprostenol (44.0%); for those receiving norgestomet and estradiol alone, it was intermediate (67.8%). Pregnancy rates to artificial insemination (after estrus or timed) were higher (P < 0.05) for cows given norgestomet and estradiol than for those given cloprostenol (23 of 28, 82.1% vs 13 of 25, 52.0%), and intermediate (67.8%) for those given norgestomet and estradiol plus eCG. In a second experiment, for heifers treated with norgestomet and estradiol plus eCG (n = 15) or with 2 doses of cloprostenol (n = 16), estrous rates were 66.7% vs 56.2% (P > 0.5), ovulation rates were 100.0% vs 81.2% (P = 0.08), intervals from implant removal or cloprostenol treatment to estrus were 48.0 +/- 4.4 hours vs 61.3 +/- 7.0 hours (P = 0.12) and to ovulation were 70.4 +/- 4.4 hours vs 93.2 +/- 7.5 hours (P < 0.01), respectively; pregnancy rates were 41.7 and 35.7%, respectively (P > 0.5). Norgestomet and estradiol were as good as (heifers) or superior to (cows) a 2-dose cloprostenol regimen. In cows given norgestomet and estradiol, injecting eCG at implant removal did not significantly improve estrous or pregnancy rates. 相似文献