首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13篇
  免费   2篇
农学   2篇
  6篇
水产渔业   1篇
畜牧兽医   1篇
植物保护   5篇
  2020年   1篇
  2017年   1篇
  2016年   1篇
  2013年   2篇
  2012年   1篇
  2011年   1篇
  2010年   2篇
  2008年   1篇
  2006年   2篇
  2004年   1篇
  2002年   2篇
排序方式: 共有15条查询结果,搜索用时 343 毫秒
1.
Hexaploid triticale (X Triticosecale Wittmack) (2n= 6x= 42, AABBRR) and wheat (Triticum aestivum L.) (2n= 6x= 42, AABBDD) differ in their R and D-genomes. This produces differences in both agronomic and end-use quality characteristics. Our objective was to determine how introgressions of individual chromosomes from the D-genome of wheat affect these characteristics of a winter triticale 'Presto'. We studied the effects of 18 D-genome chromosome substitution lines, 15 sib-lines as controls, and five check cultivars at Lincoln, NE in 1996, using a randomized complete block design with two replications. The experiment was repeated at Lincoln and Mead, NE in 1997 and 1998 with 15 substitution lines that survived the first winter in Lincoln, along with their 12 control sibs and five check cultivars. Few D-genome chromosomes had positive effects. Chromosomes 2D, 4D, and 6D significantly reduced plant height when substituted for 2R, 4B, and 6R, respectively. No grain yield increases were associated with any of the D-genome chromosomes tested, but three substitutions decreased the grain yield. Depending on the allele of the hardness gene present, chromosome 5D increased or decreased kernel hardness when substituted for 5R or 5A, respectively. Introgressions of chromosomes 1D and 6D improved end-use quality characteristics of Presto. These results suggest that apart from beneficial effects of individual loci located on the D-genome chromosomes, no major benefit can be expected from D-genome chromosome substitutions.  相似文献   
2.
Following a sustained spill-over event from dogs to foxes, fox rabies spread rapidly in the Aegean region, Turkey. In order to control the outbreak a program of oral vaccination of foxes against rabies was introduced. In the selected vaccination area three annual campaigns between 2008 and 2010 were undertaken during the winter months whereby the vaccine baits were distributed exclusively by plane using a density of 18 baits per km2. Subsequently, fox rabies cases were reported only from locations bordering the non-vaccinated areas. Hence, it was shown that fox rabies control by means of oral rabies vaccination is feasible in Turkey. However, for the progress towards the elimination of fox-mediated rabies in Turkey to be maintained, it is necessary that political and financial support is secured to extend oral vaccination where infected foxes remain.  相似文献   
3.
Common ragweed invasion poses serious risks to human health, biodiversity and agricultural production throughout the world. Although ragweed has an enormous potential to expand its range in Turkey, studies on ragweed have only concentrated on the Black Sea region. An exploratory survey was conducted to observe the level of ragweed occurrence on the nodes of predecided 10 × 10 km grids in the Thrace region of Turkey. Ragweed populations were observed in 44 out of 129 sites in a wide range of habitats, including roadsides, pastures, agricultural fields and non‐agricultural areas. The highest levels of ragweed infestation were recorded in the agricultural fields, followed by the roadsides. The most‐invaded crop was sunflower. The sunflower fields had the highest ragweed coverage as well and invasion even resulted in crop failure alongside the field borders. A spatial analysis of the data indicated that ragweed exhibited an aggregated pattern over the Thrace region. Ragweed distribution was not associated with the characteristics of the soils, which had a varying range of pH, electrical conductivity and texture. The results revealed that ragweed invasion can arise as a serious weed problem, interfering with the sustainability of sunflower production in Thrace and other sunflower‐producing regions of the country. A high degree of ragweed infestation also will contribute to the pollen level counts for the most crowded cities in the region, posing a serious danger to human health.  相似文献   
4.
Nineteen wild emmer wheat [Triticum turgidum ssp. dicoccoides (Körn.) Thell.] genotypes were evaluated for the grain concentrations of phosphorous (P), potassium (K), sulfur (S), magnesium (Mg), calcium (Ca), zinc (Zn), manganese (Mn), iron (Fe) and cooper (Cu) under five different environments in Turkey and Israel. Each mineral nutrient has been investigated for the (1) genotype by environment (G × E) interactions, (2) genotype stability, (3) correlation among minerals and (4) mineral stability. Among the macronutrients analyzed, grain concentrations of Ca (range 338–2,034 mg kg?1) and S (range 0.18–0.43%) showed the largest variation. In the case of micronutrients, the largest variation was observed in the grain Mn concentration (range 13–87 mg kg?1). Grain concentrations of Fe and Zn also showed important variation (range 27–86 and 39–115 mg kg?1, respectively). Accessions with higher nutrient concentrations (especially Zn and Fe) had also greater grain weight, suggesting that higher grain Zn and Fe concentrations are not necessarily related to small grain size or weight. Analysis of variance showed that environment was the most important source of variation for K, S, Ca, Fe, Mn and Zn, explaining between 44 and 78% of the total variation and G × E explained between 20 and 40% of the total variation in all the minerals, except for S and Zn where its effect accounted for less than 16%. Genotype was the most important source of variation for Cu (explaining 38% of the total variation). However, genotype effect was also important for Mg, Mn, Zn and S. Sulfur and Zn showed the largest heritability values (77 and 72%, respectively). Iron exhibited low heritability and high ratio value between the G × E and genotype variance components \( \left( {\sigma_{\text{GE}}^{2} /\sigma_{G}^{2} } \right) \), suggesting that specific adaptation for this mineral could be positively exploited. The wild emmer germplasm tested in the current study revealed some outstanding accessions (such as MM 5/4 and 24-39) in terms of grain Zn and Fe concentrations and environmental stability that can be used as potential donors to enhance grain micronutrient concentrations in wheats.  相似文献   
5.
Phyllonorycter apparella (Herrich-Schäffer, 1855) (Lepidoptera: Gracillariidae) is a new record for the Turkish fauna and a new trembling aspen(Populus tremula L.) pest for Turkey. Its biology, damage and infestation ratio were studied in Sankami?. (Kars), Turkey, during 1996 and 1997.P. apparella has one generation a year. The developmental stages of the pest are described briefly. P.apparella hibernates in the adult stage. At the beginning of June, the adults appear. Females deposit their eggs on both leaf surfaces, generally one by one, 7–10 days after emerging. The early instars (sap-feeding larvae) start to mine mostly from the underside of leaves. Each mine has one larva, and each leaf may have up to 26 mines. The last instar (tissue-feeding larva) begins to pupate in the mine after mid August. The adults emerge from mid September to the beginning of October, and move to the trunks of old pine trees, where they hibernate in bark crevices. The infestation level may be as high as 90% of the leaves on some trees.  相似文献   
6.
Data are presented on the occurrence of 43 species of the family Apionidae and two species of the family Nanophyidae in Turkey based on the material obtained mainly by beating stone-fruit trees in NE Turkey. The identity and information about the three species of Apionidae —Squamapion sp.cf.bifarium (Balfour-Browne),Protapion sp.cf.ruficrus (Germar),Catapion sp.cf.seniculus (Kirby) — must be revised. The faunistic data in the present paper on almost all species add to prior knowledge on their distribution in Turkey.Hypophyes aphyllae (Peyerímhoff),Ceratapion kasbekianum (Gerstaecker),Squamapion ottonis (Wagner),S. samarense (Faust),S. phocopus (Eppelsheim),Taeniapion rufulum (Wencker),Pseudoprotapion astragali (Paykull),P. ergenense (Becker),Stenopterapion intermedium (Eppelsheim) andOxystoma fausti (Desbrochers) are reported for the first time in the Turkish fauna. http://www.phytoparasitica.org posting Nov. 8, 2001.  相似文献   
7.
The present study was designed to compare the responses in freshwater fish Oreochromis niloticus exposed to a synthetic pyrethroid, cypermethrin (CYP); an essential metal, copper (Cu); and a nonessential metal, lead (Pb). Fish were exposed to 0.05 μg/l CYP, 0.05 mg/l Cu, and 0.05 mg/l Pb for 4 and 21 days, and the alterations in serum enzyme activities, metabolite, and ion levels were determined. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities increased in response to CYP, Cu, and Pb exposures at both exposure periods. While elevations in alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities and in cholesterol level were observed in pesticide-exposed fish at 4 and 21 days, they increased in Cu- and Pb-exposed fish at 21 days. Although metal-exposed fish showed increases in cortisol and glucose levels at 4 days followed by a return to control levels at the end of the exposure period, their levels elevated in pesticide-exposed fish at both exposure periods. Total protein levels decreased in Pb- and pesticide-exposed fish at 21 days. Na+ and Cl levels decreased in pesticide-exposed fish at both exposure periods and in Cu- and Pb-exposed fish at 21 days. The exposures of pesticide and metals caused an elevation in K+ level at the end of the exposure period. The present study showed that observed alterations in all serum biochemical parameters of fish-treated pesticide were higher than those in fish exposed to metals.  相似文献   
8.
One of the significant features of loess-derived soils in Kansas is the occurrence of clay-rich subsurface horizons above a layer enriched with pedogenic carbonates. In order to examine the extent of clay increase and pedogenic carbonate enrichment in a precipitation gradient, ten soil profiles from three different precipitation regions were studied using micromorphological and mineralogical techniques. The precipitation gradient was divided into three groups: 400–550 mm, 550–750 mm, and 750–1100 mm regions. The objectives were to (1) understand the cause of clay orientation in clay-rich horizons (2) investigate the reasons for the clay increase, and (3) observe the interaction of clay and pedogenic carbonate accumulation features along a precipitation gradient in Kansas. Although clay films were identified in the field for soils in the 400–550 mm regions, illuvial clay films were not observed in thin section analysis. The clay accumulations mostly occurred as grain coatings. The rest of the clay accumulations observed were very thin, striated, and mostly associated with voids. The argillic horizons had a granostriated b-fabric, which indicates stress orientation of micromass caused by high shrink–swell activity. Thick and continuous illuvial coatings were observed in the buried horizons of paleosols. In the other two regions where precipitation exceeds 550 mm, illuvial clay coatings with strong orientation were observed along with thin and striated stress-oriented clay. Both types of clay orientations exceeded 1% of the cross-sectional area for the thin section. Although illuvial clay features and pedogenic carbonates were observed in all soils at approximately the same depth, complete obliteration of clay coatings was not observed in these horizons. In-situ weathering of biotite was one of the reasons for the clay increase in all soil profiles. In all soils studied, the clay increase and cause of clay orientation cannot be attributed to a single genetic process or event. Both illuviation and shrink–swell activity were involved in the orientation of clay. Although orientation of clay and pedogenic carbonates were observed in all soils at approximately the same depth, the decomposition of clay coatings was not observed in these horizons.  相似文献   
9.
The objective of this study was to evaluate the relationship between clay mineralogy, specific surface area (SSA) and micromorphology in polygenetic Konza soil series. Physical, chemical and mineralogical analyses were performed on disturbed soil samples, and micromorphological investigations of selected horizons were done on undisturbed soil samples. X-ray diffraction indicated that lower part of each parent materials has more mectite and less clay mica content than that of the upper horizons in each parent material. Greater amounts of smectite can be attributed to transformation product of the clay mica in to smectite, eluviation from upper horizons or originated from parent material. Specific surface area of upper horizons in each parent material tended to increase to lower horizons. Clay content gradually increased from surface (21%) to the lower part (~48%) of the solum. Clay in Bt horizons had strong birefrengent, sharp boundary, and strong orientation pattern. SSA, clay content increase, clay mineralogy and oriented clay features agreed to one another. Therefore, this relationship gives opportunity to make predictions on extend of SSA and related soil processes by looking at one of these features.  相似文献   
10.
In the present study,Cnaemidophorus rhododactyla (Denis & Schiffermüller) (Lepo Pterophoridae) was noted for the first time as a pest ofRosa spp. in Turkey. The larva ofC. rhododactyla makes a cavity by feeding in the flower-bud and destroys at least 60% of the mass of the flower-bud. There are approximately 12 species ofRosa in Erzurum and Kars provinces, butRosa dumalis Bechst. andR. subcanina L. suffered more damage than the otherRosa species. One species of Tachinidae (Diptera) —Pseudoperichaeta palesoidea (Robineau-Desvoidy), and two species of Ichneumonidae (Hymenoptera) —Sinophorus turionus (Ratz.) andScambus brevicornis Gravenhorst, were reared as larval parasitoids ofC. rhododactyla. C. rhododactyla is a new host record for these parasitoids. Additionally,S. turionus is a new record for the Turkish fauna.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号