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1.
The yield response of Chinese cabbage to phosphate fertilizer and manure was studied. The effect of over-application of phosphate fertilizer and manure on plant total phosphorus content and phosphorus accumulation in soil was also investigated. The experiment was arranged in a plastic barrel in the field for two years. Application of phosphate fertilizer at the rates of 150–600 mg·kg−1 gave a yield increase of 14.9%–21.5% of Chinese cabbage. Application of manure at the rates of 33.3–-133.2 g·kg−1 gave a yield increase of 18.2%–25.9%of the crop. There was no significant difference of yield response at the rates of 150, 300 and 600 mg·kg−1 phosphate fertilizer, and no significant yield response to the application of phosphate fertilizer after applying manure. The total P content in Chinese cabbage was increased gradually with the rate increase of phosphate fertilizer and manure. Phosphorus was absorbed luxuriously by the plant with over-application phosphate fertilizer and manure. The content of total-P, Olsen-P, water-soluble P, biological available P in the soil was increased with the rate of phosphate fertilizer and manure. Organic phosphorus in the soil was increased by the application of manure. Olsen-P had high correlations with water-soluble-P and biological available-P, but there was a poor relationship between Olsen-P and organic-P. __________ Translated from Scientia Agricultura Sinica, 2006, 39(10): 2147–2153 [译自: 中国农业科学]  相似文献   

2.
3.
In the present study, the spatial variability of some soil physical and chemical properties in a 0.8 ha apple orchard were studied. Sixty soil samples were taken from two sampling depths: 0–0.3 m and 0.3–0.6 m. The soil samples were analyzed for the following soil properties: soil texture, pH, cation exchange capacity and NO3–N, NH4–N, P, K, Na, Ca, Mg, Fe, Zn, Mn, Cu, B and organic matter content. Data analysis indicated that most of the nutrients were at sufficient levels. The site-specific application map for N was created based on the amount of N that was removed from the soil with the yield of the previous year. By applying N site-specifically, 38% of N could be saved compared to uniform application.  相似文献   

4.
The effect of technological factors (varieties, fertilizers, and sowing rate) and weather conditions of the Middle Volga Region of the Russian Federation on variability of the quality of soft spring wheat grain is analyzed on the basis of long-term investigations (2003–2008).  相似文献   

5.
【目的】调查油松Pinus tabulaeformis胚性愈伤组织增殖培养阶段不同因素对于褐化产生的影响,并结合增殖率对培养基进行调整优化以降低褐化率,提高利用率。【方法】以3个年份的9个细胞系的油松胚性愈伤组织为材料,利用单因素试验设计对放置不同数量愈伤块、pH、植物凝胶含量、糖种类和含量以及培养时间的褐化率和增殖率进行测定计算。采用正交试验选出最佳培养条件。【结果】单因素试验结果表明,褐化率在不同基因型间差异显著,且与增殖继代年龄显著正相关;在培养皿中放置6~7块愈伤组织、pH 5.8~6.0、培养基中添加2.0~3.0 g·L~(-1)植物凝胶、添加10 g·L~(-1)蔗糖能保证较低的褐化率和较高的增殖率,且蔗糖优于葡萄糖和麦芽糖。【结论】结合正交设计,90 mm培养皿中放置7块愈伤组织,培养基中添加2.5 g·L~(-1)植物凝胶、10 g·L~(-1)蔗糖,调节pH为5.9时,褐化率、增殖率和利用率最理想。  相似文献   

6.
Under controlled conditions in a growth chamber, we studied the mortality of pepper seedlings caused by Phytophthora capsici. The results showed that soil temperature and soil water content were important factors affecting their infection with P. capsici and the optimum condition for infection was found to be a soil temperature of 22°C–28°C and a soil water content of 40%. The relationships of pepper seedling mortality caused by P. capsici along with soil temperature, soil water content and their interactions can be described by mathematical models. Field observations suggested that the Gompertz model was the best one for describing the epidemiological dynamics of the disease. The incidence of pepper phytophthora blight was significantly related to the initial incidence of pepper phytophthora blight, soil temperature, soil water content and air temperature. A forecasting model for pepper phytophthora blight in the field was developed. __________ Translated from Chinese Journal of Applied Ecology, 2007, 18(5): 1061–1065 [译自: 应用生态学报]  相似文献   

7.
The development of genomics and bioinformatics offers new tools for comparative gene mapping. In this paper, an integrated QTL map for sugarcane mosaic virus (SCMV) resistance in maize was constructed by compiling a total of 81 QTL loci available, using the Genetic Map IBM2 2005 Neighbors as reference. These 81 QTL loci were scattered on 7 chromosomes of maize, and most of them were clustered on chromosomes 3 and 6. By using the method of meta-analysis, we identified one “consensus QTL” on chromosome 3 covering a genetic distance of 6.44 cM, and two on chromosome 6 covering genetic distances of 16 cM and 27.48 cM, respectively. Four positional candidate resistant genes were identified within the “consensus QTL” on chromosome 3 via the strategy of comparative genomics. These results suggest that application of a combination of meta-analysis within a species with sequence homology comparison in a related model plant is an efficient approach to identify the major QTL and its candidate gene(s) for the target traits. The results of this study provide useful information for identifying and cloning the major gene(s) conferring resistance to SCMV in maize. __________ Translated from Hereditas (Beijing), 2008, 30(1): 101–108 [译自: 遗传(北京)]  相似文献   

8.
Malate dehydrogenase (MDH) ubiquitously exists in animals, plants and microoganisms, and catalyzes the interconversion from oxaloacetate to malate. Cytosolic NAD-dependent MDH gene (cyMDH) encodes a key enzyme crucial for malic acid synthesis in the cytosol which has not been extensively characterized in plants. In this study, a full-length cDNA of cyMDH was isolated from apple fruits with RT-PCR as well as 3′ and 5′ rapid amplification of cDNA ends, and designated as Mal-cyMDH (GenBank accession No. DQ221207). It contained a 996-bp ORF and its sequence analysis shows a high similarity to other plant cyMDHs. Phylogenetic analysis indicated that almost all the cyMDHs could be clustered into the same group and it was likely to represent the original MDH. A roughly 37-kDa fused protein was obtained by the recombinant prokaryotic expression and its enzyme activity assay showed that it mainly catalyzed oxaloacetate to malate. It was also discovered that the enzyme activity of cyMDH exhibited remarkable difference between the high-and low-acid apple germplasm. __________ Translated from Acta Horticulturae Sinica, 2008, 35(2): 181–188 [译自: 园艺学报]  相似文献   

9.
A benchmark question in contemporary food regimes scholarship is how to theorize agriculture’s incorporation into the WTO. For the most part, it has been theorized as an institutional mechanism that facilitates the ushering in of a new, so-called ‘third food regime’, in which food–society relations are governed by the overarching politics of the market. The collapse of the Doha Round negotiations in July 2008 makes it possible, for the first time, to offer a conclusive assessment as to whether this is the case. Using a broadly conceived world-historical framework, this article contends that the WTO is more appropriately theorized as a carryover from the politics of the crisis of the second food regime, rather than representing any putative successor. The Doha Round’s collapse in Geneva in July 2008 should put an end to speculation of a WTO-led transformation of global food politics towards unfettered market rule; the supposed basis for a neo-liberalized ‘third food regime’. Consequently, it is through analysis of the factors that framed the Doha Round’s collapse, rather than in the WTO itself, that provide insights into the defining elements of a new global politics of food.  相似文献   

10.
The advantage of fall soil tillage by loosening with an experimental chisel implement to a depth of 40–42 cm compared with moldboard plowing with a share plow to a depth of 25–27 cm is shown. Original Russian Text ? V.I. Pyndak, V.F. Loboiko, V.N. Pavlenko, 2009, published in Doklady Rossiiskoi Akademii Sel’skokhozyaistvennykh Nauk, 2009, No. 2, pp. 54–55.  相似文献   

11.
Factors influencing vegetative growth and spore germination of strain F603 of Epicoccom sp., an antagonistic fungus for Phytophthora infestans (Mont) de Bary, were studied. Among the different growth media tested, Rye agar was the best medium for its vegetative growth. The range of temperature and pH value for mycelial growth was 5–35°C and 2–12, respectively, with the optimum 25°C and 6–9, respectively. The fungus grew better in Czapek medium with maltose and dextrose as carbon sources and peptone, KNO3, and NaNO3 as nitrogen sources. The range of temperature for spore germination of strain F603 was 5–35°C, the optimum was 20°C. The range of temperature for sporulation was 10–30°C, and the optimum was 15–18°C.  相似文献   

12.
The contents of soil organic C (SOC), total N (TN), total P (TP), dissolved N (DN), Olsen-P, and microbial biomass C, N, P (BC, BN, BP) of 254 paddy soils (0–18 cm in depth) in a hilly red soil region of subtropical zone of China were studied. The results showed that the contents of SOC, TN, BC, BN and DN of paddy soils at the bottom of hills were 14.6%, 13.6%, 24.6%, 20.4% and 95.8% higher than those at the foothill, respectively. The Olsen-P content of paddy soils at the foothill was 33.3% higher than that at the bottom of hills. However, the differences in TP, BP and available P (the sum of BP and Olsen-P) contents were not significant between the two positions. In addition, the ratios of soil C/P, BC/BP and BC/SOC of paddy soils at the bottom of hills were 12.7%, 28.5% and 8.2% higher than those at the foothill, respectively, but the differences in ratios of soil C/N, BC/BN, BN/TN and BP/TP were not statistically significant between various positions. __________ Translated from Plant Nutrition and Fertilizer Science, 2007, 13(1): 15–21 [译自: 植物营养与肥料学报]  相似文献   

13.
This paper reports the process of fertilization in Brassica campestris ssp. pekinensis and the duration of each stage. The results are as follows: (1) Pollen germinates on stigma 2–3 h after pollination. (2) 4–8 h after pollination, pollen tube grows in the style. (3) 8–14 h after pollination, pollen tube grows in the ovary and gets into the ovule via the micropyle. (4) 16 h after pollination, one sperm nucleus moves to the egg and enters it. (5) The sperm nucleus adheres to the nuclear membrane of the egg 18 h after pollination. (6) 20 h after pollination, it enters the egg nucleus and male chromatin gradually disperses and 24 h after pollination, a male nucleolus appears. A large female nucleolus and a small male nucleolus occur in the nucleus of the fertilized egg, and zygote formed. The dispersing of sperm chromatin in the egg nucleus takes about 4 h. (7) 32–34 h after pollination, the division of zygote begins. The dormancy stage of the zygote lasts for about 8–10 h. (8) The pair polar nuclei lie in the chalazal end of the egg before fertilization, which may fuse into a secondary nucleus or not. (9) 16–18 h after pollination, the sperm nucleus moves to the polar nuclei or the secondary nucleus. 18 h after pollination, the sperm nucleus adheres to the nuclear membrane of the polar nuclei or that of the secondary nucleus. (10) 20 h after pollination, the sperm nucleus enters one of the polar nuclei or the secondary nucleus and a triple fusion takes place. The process of fusion is similar to the karyogamy but faster. The dispersing of the sperm chromatin in the polar nucleus or secondary nucleus takes about 2 h. (11) 22 h after pollination, the primary endosperm nucleus formed. The female and male nucleoli cannot fuse with each other before mitotic division of the primary endosperm nucleus. (12) 24 h after pollination, the division of the primary endosperm nucleus actually takes place. __________ Translated from Acta Horticulturae Sinica, 2005, 32(5): 812–817 [译自: 园艺学报]  相似文献   

14.
The lowest level of selenium is established in muscle tissue of moose, badger, and squirrel (64–101 μg/kg fresh weight) and the highest in that of Manchurian wapiti, Manchurian roe deer, reindeer, wild boar, and fox (216–269 μg/kg), as well as birds: pheasant, duck, goose (210–249 μg/kg). The content of the trace element in muscle tissue of cattle and pigs is 86–90 μg/kg.  相似文献   

15.
It is found that the 70-year application of fertilizers in a grain-sugar beet crop rotation in the forest steppe of the Central Chernozem Region changes considerably the biochemical indices of leached chernozem fertility and increases the activity of urease by 17.4–26.9%, catalase by 5.6–36.5%, protease by 23.2–54.2%, cellulose-decomposing activity by 96.2–154.2%; phosphatase activity decreased by 65.7–105.1%. The phytotoxicity of soil against a high fertilizer dose background increased 85.7%.  相似文献   

16.
A molecular map of melon (Cucumis melo L.) was constructed with SRAP (Sequence-Related Amplified Polymorphism) markers using a population consisting of 114 F2 individuals derived from the cross of 4G21 (C. melo var. chinensis) and 3A832 (C. melo var. saccherinus). Twenty-nine primer pairs were used and 187 polymorphic loci were produced. The map consists of 12 linkage groups that include 152 genetic markers and cover 2077.1 cM with an average genetic distance of 13.67 cM. Every linkage group has 6–32 genetic markers with average genetic distance of 9.72–19.19 cM. The length of linkage group is 85.3–496.1 cM. __________ Translated from Acta Horticulturae Sinica, 2007, 34(1): 135–140 [译自 : 园艺学报]  相似文献   

17.
生长调节剂对降香黄檀营养生长与生殖生长的影响   总被引:1,自引:0,他引:1  
【目的】研究生长调节剂对降香黄檀Dalbergia odorifera营养生长与生殖生长的影响,为不同经营目标的降香黄檀人工林生产提供技术支撑。【方法】以10年生降香黄檀为研究材料,采用随机区组试验设计,通过叶面喷施3种不同浓度的赤霉素(GA3)、多效唑(PP333)和6-苄氨基嘌呤(6-BA),测定盛花期内一年生新梢、花、叶的形态生长和干质量变化,再运用统计分析软件,对各种生长调节剂处理后营养生长和生殖生长的变化规律进行分析。【结果】不同种类和不同浓度的生长调节剂对降香黄檀营养生长和生殖生长的影响差异均达显著水平(P0.05)。叶面喷施200、100 mg·L~(-1)的GA3和500 mg·L~(-1)的6-BA均能显著促进降香黄檀的营养生长,抑制其生殖生长;其中,200 mg·L~(-1)的GA3对生殖生长的抑制效果最理想,施用后其营养枝率比对照显著提高140.84%,花序数显著降低79.41%;100 mg·L~(-1)的GA3对营养生长效果显著,施用后其营养枝枝长、直径、复叶数和单叶干质量分别比对照提高218.08%、120.70%、132.38%和217.33%,且均达显著水平。1 500、2 000 mg·L~(-1)的PP333和50 mg·L~(-1)的6-BA均能显著促进降香黄檀的生殖生长,以2 000 mg·L~(-1)的PP333作用效果较好,处理后其花枝率、花序数量和花序径依次比对照提高73.50%、50.37%和31.30%,且均达显著水平。【结论】降香黄檀人工林培育中,叶面喷施200或100 mg·L~(-1) GA3能显著抑制生殖生长、促进营养生长,有利于大径级木材培育,2 000 mg·L~(-1)的PP333则有利于生殖生长,有利于良种壮苗生产。  相似文献   

18.
One approach to the application of site-specific techniques and technologies in precision agriculture is to subdivide a field into a few contiguous homogenous zones, often referred to as management zones (MZs). Delineating MZs can be based on some sort of clustering, however there is no widely accepted method. The application of fuzzy set theory to clustering has enabled researchers to account better for the continuous variation in natural phenomena. Moreover, the methods based on non-parametric density estimation can detect clusters of unequal size and dispersion. The objectives of this paper were to: (1) compare different procedures for creating management zones and (2) determine the relation of the MZs delineated with potential yield. One hundred georeferenced point measurements of soil and crop properties were obtained from a 12 ha field cropped with durum wheat for two seasons. The trial was carried out at the experimental farm of CRA-CER in Foggia (Italy). All variables were interpolated on a 1 × 1 m grid using the geostatistical techniques of kriging and cokriging. The techniques compared to identify MZs were: (1) the ISODATA method, (2) the fuzzy c-means algorithm and (3) a non-parametric density algorithm. The ISODATA method, which was the simplest, subdivided the field into three distinct classes of suitable size for uniform management, whereas the other two methods created two classes. The non-parametric density algorithm characterized the edge properties between adjacent clusters more efficiently than the fuzzy method. The clusters from the non-parametric density algorithm and yield maps for three seasons (2005–2006, 2006–2007 and 2007–2008) were compared and agreement measures were computed. The kappa coefficients for the three seasons were negative or small positive values which indicate only slight agreement. These results illustrate the importance of temporal variation in spatial variation of yield in rainfed conditions, which limits the use of the MZ approach.  相似文献   

19.
Germination conditions are determined by hydraulic, thermal and mechanical properties of the soils. In heterogeneous fields, the most favourable seeding depth varies spatially. To investigate the influence of seeding depth on emergence and grain yield of corn, corn was planted in depths of 40, 50, 60, 70, 80 and 90 mm in three experimental years (2006–2008). The apparent soil electrical conductivity was measured with an EM38. The apparent electrical conductivity was used as a proxy for soil texture, top-soil thickness, effective root zone thickness, soil water content and soil structure. The spatial dependencies among emergence, yield and apparent electrical conductivity were considered by including spatial models into the statistical analysis. The results showed significant correlations of the apparent soil electrical conductivity, of the experimental year, and of the seeding depth with the emergence of corn. Deeper planted corn (80 or 90 mm) resulted in more emergence than shallow planted corn (+4.4% in 2006, +1.2% in 2007 and +1.5% in 2008). The emergence decreased with increasing apparent soil electrical conductivity values. The corn grain yield was significantly affected by the soil electrical conductivity, by emergence and by the experimental year. Increasing apparent soil electrical conductivity values were correlated with decreasing yield (from 7.5 to 3.4 Mg ha−1 in 2006, from 10.8 to 5.3 Mg ha−1 in 2007 and from 8.4 to 2.9 Mg ha−1 in 2008). Increasing emergence resulted in increasing yield.  相似文献   

20.
In order to study the effect of cell mediated immunity regulation of duck IFN-α eukaryon expression plasmid (pcDNA-SDIFN-α) on duck plague virus (DPV) attenuated vaccine in ducks, pcDNA-SDIFN-α was administered to 28-day-old ducks at doses of 1, 3 and 6 μg per duck, respectively, by gene-gun. PBS and empty vector pcDNA were used as control. Fifteen days later, all ducks were injected with DPV attenuated vaccine and blood samples were collected at 3, 7, 14, 21, 28, 35, 49, 63 and 84 days after injection. T-lymphocyte proliferation tests (MTT) were used to detect the T-lymphocyte proliferation in the peripheral blood (PBL) of ducks. Blood samples collected at 7, 14, 21, 28, 35 and 49 days after injection were detected by fluorescence-activated cell sorter (FACS) for recording the number of CD3 + T-lymphocytes of ducks. Results were as follows: (1) Reaction of T-lymphocytes in PBL to ConA (OD value) of ducks treated with pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups in 3–84 days. There were highly significant differences between the 1 μg per duck group and the two control groups in 3–84 days (P ⩽ (0.01), between the 3 μg per duck group and the two control groups in 3–84 days (P ⩽ 0.01, P ⩽ 0.05), and between the 6 μg per duck group and the two control groups in 7–49 days (P ⩽ 0.01, P ⩽ 0.05). The significant difference was also present between the groups of 1, 3 and 6 μg per duck in 3–35 days (P ⩽ 0.05). However, there was no significant difference between the 3 and 6 μg per duck groups (P ⩾ 0.05). The pcDNA control group was higher than PBS control group, but no difference was detected (P ⩾ 0.05). (2) Change of the number of CD3 + T-lymphocytes in ducks administered with different doses of pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups in 7–49 days. The change in the 1 μg per duck group was significantly higher than that in PBS and pcDNA control groups in 14–49 days (P ⩽ 0.01). There were significant differences between the 3 μg per duck group and the two control groups in 21–49 days (P ⩽ 0.01, P ⩽ 0.05) and between the 6 μg per duck group and the two control groups in 7–49 days (P ⩽ 0.01, P ⩽ 0.05). However, no significant differences among the groups of 1, 3, and 6 μg per duck groups (P ⩾ 0.05) and between the two control groups (P ⩾ 0.05) were found. The results indicated that pcDNA-SDIFN-α administered 15 days before injection of DPV-attenuated vaccine could significantly enhance cellular immunity induced by DPV-attenuated vaccine. pcDNA-SDIFN-α is an excellent DPV-attenuated vaccine molecular adjuvant and the best result can be obtained with the dose of 1 μg per duck of pcDNA-SDIFN-α inoculated by gene-gun. __________ Translated from Acta Veterinaria et Zootechnica Sinica, 2007, 38 (10): 1066–1071 [译自: 畜牧兽医学报]  相似文献   

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