排序方式： 共有10条查询结果，搜索用时 171 毫秒
1
1.
Seven potassium (K) rates (0, 50, 150, 350, 450, 550, and 650 kg K/ha) were used to determine the optimum rate of K for turf‐type perennial ryegrass during the winter based on turf growth, quality, and winter hardiness. Turf density, color, growth, and winter hardiness were increased as the rate of K application increased up to 350 kg K/ha. However, there were no beneficial effects of K application beyond that rate. Potassium content of the whole plant was 1.72% of the dry matter at the 350 kg K/ha rate. Calcium and Mg contents of the plant were reduced as the result of K application, and a reduction in growth and K content was detected at the higher K application rates. It is suggested that the optimum K rate for perennial ryegrass is about 350 kg K/ha under our experimental conditions in the winter, and that the K content should be about 1.72% of dry weight of whole plant. 相似文献
2.
Perennial ryegrass (Lolium prenne L.) has been introduced to Japan as a cool season turfgrass. In spite of relatively mild winter in most parts of the country, it still goes to winter dormancy. A well‐balanced fertility ratio and rate may prevent such dormancy without causing winter injury. Therefore, this experiment was designed to find a balanced rate and ratio among nitrogen (N), potassium (K), and phosphorus (P) fertilizers in order to prevent winter dormancy and promote growth during the winter in Japan. Yorktown 2 perennial ryegrass was used in this experiment. Nitrogen and K application rates were 50, 150, 250, 350, 450, 550, and 650 kg K/ha; whereas P rates were 50, 150, and 250 kg P/ha. These rates were applied in 30 different ratios. Growth, color, and density of the turf were estimated and used as the parameters for finding a suitable rate and ratio for these three major nutrients. Color, density, and growth were increased as the rate of N fertilizer increased, but there was no visual response to P or K rates. It is suggested that increases in color, density, and growth were function of N rates, whereas K and P rates maintained the cold hardiness of the turf when high N rates were applied under the conditions of this experiment. Fertility ratio and the rates of 450 kg N/ha, 250 kg K/ha, and 50 kg P/ha were sufficient to prevent dormancy, promote growth, and produce good quality turf throughout the winter. Thus, it is concluded that fertility ratios and rates are the main factors limiting growth and quality of perennial ryegrass in transitional zones similar to Japan. 相似文献
3.
An established two‐year‐old stand of ‘Apollo’ alfalfa (Medicago saliva L.) was used to determine the alfalfa yield and macronutrient contents response to potassium (K), sulfur (S), boron (B), and molybdenum (Mo) fertilization under a high yield environment. A split, split block field design was used with nine micronutrient treatments (0, 50, and 100 g Mo ha‐1 and 0, 1, and 2 kg B ha‐1) in a factorial arrangement (32) as the subplots and three K levels (150, 300, and 600 kg K ha‐1) as the main plot in three replications. Two levels of S (0 and 240 kg S ha‐1) fertilization were applied in strips across the main plots (K levels) resulting in the split, split block design. Alfalfa yield and macronutrient contests were determined. Increased in K or S rate increased K contents of the plants, however, the differences between the K or S rates were not significant and B or Mo application did not have a marked effect on alfalfa K levels. Alfalfa calcium (Ca), magnesium (Mg), or phosphorus (P) content was not significantly affected by K, S, B, or Mo fertilization. Potassium, S, B, or Mo fertilizer application also did not have a marked effect on alfalfa yield during this study. Combinations of K, S, B, and Mo fertilizer had variable effects and the effects were dependent on the combination of fertilizer, sources, and levels. With a few exceptions, there was lack of alfalfa yield and nutrient contents response to K, S, B, and Mo applications which was due to the effect of low available soil moisture as a result of low incident rainfall during the study on these nutrients availability, uptake, and alfalfa growth. 相似文献
4.
Background: Several methods have been developed for detection of sequence variation in genes and each has its advantages and disadvantages. A disadvantage of them is that the simpler, cost-effective methods are commonly perceived as being less sensitive in their detection of sequence variation, whereas those with proven sensitivity have a requirement for complex or expensive laboratory equipment. In this context, we undertook improvements to the conformation sensitive gel electrophoresis (CSGE) method which provides a cost-effective approach to mutation detection and compared the results with scanning carried out using denaturing high performance liquid chromatography (DHPLC) which utilises a dedicated analyser. Methods: We designed PCR primers to amplify the seven protein-coding exons of the human SPP2 gene which encodes secreted phosphoprotein 24 (spp24) such that the amplified products included the immediately-adjacent intronic regions. Five improvements were made to the CSGE method that was used to the scan the PCR-amplified DNA. The scanning was then repeated using DHPLC and the results were compared. Results: Using CSGE, a single nucleotide polymorphism was discovered in exon 2 and another in intron 2 of the gene. Re-scanning of the same regions by DHPLC detected no additional sequence polymorphisms. Conclusion: With modification of the original protocol, CSGE is capable of providing a simple and cost-effective approach to the detection of DNA sequence polymorphisms that appears to be comparable in sensitivity to DHPLC. 相似文献
5.
6.
Khorshid Mahdieh Oustan Shahin Najafi Nosratollah Khataee Alireza 《Archives of Agronomy and Soil Science》2016,62(10):1474-1485
The objective of this research was to assess the hexavalent chromium (Cr(VI)) reducing efficiency of sulfur-based inorganic agents including calcium polysulfide (CPS), iron sulfide (FeS), pyrite (FeS2) and sodium sulfide (Na2S) in three soils. An alkaline soil (soil 1), a neutral soil (soil 2) and a slightly acid soil (soil 3) constituted the investigated soils. The soils were spiked with two levels of Cr(VI) (100 and 500 mg Cr(VI) kg?1 soil) and incubated at field capacity (FC) for one month. Then, CPS, FeS, FeS2 and Na2S were added at 0, 5 and 10 g kg?1 and the concentrations of exchangeable Cr(VI) were measured after 0.5, 4, 48 and 168 h in a batch experiment. The pH and organic carbon content of the soils played predominant role in Cr(VI) self-reduction by the soil itself. Complete self-reduction of Cr(VI) from soils 1, 2 and 3 was achieved at maximum Cr(VI) levels of 1, 50 and 500 mg kg?1, respectively. Therefore, the concentration of Cr(VI) should not exceed the given levels in order to ensure that Cr(VI) is not released into the environment from contaminated sites. Moreover, decreasing pH in the alkaline soil caused significant increase of Cr(VI) reducing efficiency. Na2S, CPS and FeS, in contrast to FeS2, were efficient Cr(VI) reducing agents in all three soils. For all added amendments the following order of Cr(VI) reducing capacity was observed: Na2S > CPS > FeS > FeS2 in soil 1, Na2S ? CPS ~ FeS > FeS2 in soil 2 and Na2S ? FeS > CPS ~ FeS2 in soil 3. 相似文献
7.
Hamid Mohammadiazarm Milad Maniat Khorshid Ghorbanijezeh Negar Ghotbeddin 《Aquaculture Nutrition》2021,27(1):252-260
In this study, the effect of spirulina meal (Spirulina platensis) as a feed additive on growth and physiological response of Oscar fish,Astronotus ocellatus, was assessed using four diets including control without spirulina supplementation, 13.75 g/kg spirulina (SP1), 27.50 g/kg spirulina (SP2) and 55 g/kg spirulina (SP3). One hundred and twenty fish (10.41 ± 0.25 g) were disturbed to twelve aquariums and fed to apparent satiation three times a day for 8 weeks. The result showed that the SP3 treatment had statistically better growth performance, feeding parameters, total protease activity, total protein and lipid contents than the control. Moreover, haemoglobin, haematocrit, mean erythrocyte haemoglobin and mean erythrocyte haemoglobin concentrations were improved considerably in the SP3 treatment compared with the control. The SP3 treatment showed higher total protein and albumin levels, but lower triglycerides, cholesterol levels and liver enzyme activities than the control. Also, serum complements (C3, C4), lysozyme activity and total carotenoid contents in fish skin significantly increased in the SP3 treatment compared with the control. The results of this study suggest that spirulina powder at the level of 55 g/kg of the diet can be used as a functional natural feed additive to improve the performance of Oscar fish. 相似文献
8.
Khorshid Razmjoo Takayuki Imada Junko Sugiura Seiji Kaneko 《Journal of plant nutrition》2013,36(12):1667-1679
Quality (color and density) of tall fescue (Festuca arundinacea Schreb.) as a turfgrass is reduced during both the winter and summer in Japan. Seasonal variations in nutrient and carbohydrate levels of six cultivars of tall fescue were measured to determine if these changes are related to the reduction in the turf quality. There were significant differences among the cultivars in nutrient and carbohydrate levels. The nutrient and carbohydrate levels of tall fescue cultivars changed seasonally. Levels of calcium (Ca) and zinc (Zn) were below the sufficiency, but the concentrations of other nutrients were sufficient during the summer suggesting that the reduction in the quality of tall fescue cultivars during the summer in Japan may not be related to the lack of these nutrients in the plant tissues. The nitrogen (N), Ca, magnesium (Mg), phosphorus (P), Zn, iron (Fe), and copper (Cu) levels in the plant tissues were below the adequate range in the spring which could be attributed to high growth rate since no deficiency symptom was observed. With exception of Ca content, plants contained sufficient or more than sufficient nutrients in their tissues during the fall. Though concentrations of other nutrients were sufficient in the plant tissues in the winter, levels of N, Ca, Mg, P, molybdenum (Mo), Zn, and Cu were lower than plant's requirement which could be due to low temperature since availability of the nutrients reduces under low temperature. There were no deficiency symptoms of these nutrients, but lack of N in the plant tissue could be the cause of the reduction in the color of the tall fescue cultivare in winter. Levels of glucose, fructose, sucrose, fructan, and starch in the summer were higher or equal to those carbohydrate levels in the spring or fall suggesting that decline in tall fescue quality in Japan during the summer may not be related to carbohydrates shortages. Though starch levels were lower in the winter than other seasons, other carbohydrate levels were equal or higher than the levels in the spring and the total carbohydrate content was much higher in the winter than other seasons, suggesting that reduction in tall fescue quality in Japan during the winter may not be related to carbohydrates shortages. 相似文献
9.
Zahid Khorshid Abbas 《Archives of Agronomy and Soil Science》2016,62(6):745-758
Two cultivars of wheat (Triticum aestivum L.) with differential salinity tolerance were compared by evaluating the growth attributes, pigment composition and accumulation of Na+, K+, Zn2+, Fe 2+, Mn 2+ and proline. Wheat cultivars Al-Moiaya (AM) (salt tolerant) and Habbe-Druma (HD) (salt sensitive) were subjected to four levels of salinity (1.21 dS m?1, 4.4 dS m?1, 8.8 dS m?1 and 13.2 dS m?1) in factorial combinations with three drought stress (FC 30%, FC 60% and FC 90%) treatments in a randomized complete block design. Plant dry weight, leaf area ratio (LAR), soluble protein and total chlorophyll (Chl) content were higher in AM than HD. Salt-tolerant AM maintains a higher K+/ Na+ ratio and thereby is able to grow better than the salt-sensitive HD under both the stresses. The lower foliar Na+ in AM resulted in retention of higher Chl content, reflected in the strong positive correlations between plant ion status and Chl contents (Na+-Chl r2 = 0.83; Chl- Fe2+ r2 = 0.76; Zn2+ r2 = 0.93 and Mn2+ r2 = 0.88). In conclusion, our results suggested that the K+/Na+ ratio, exclusion of Na+ and ion homeostasis play much more important roles in the tolerance to salinity and drought stress than the compatible osmolyte, proline. 相似文献
10.
Mohammad Mobin Mohammad Nasir Khan Zahid Khorshid Abbas Habib Rahman Ansari Khalid Awad Al-Mutairi 《Archives of Agronomy and Soil Science》2017,63(2):288-295
A sand culture experiment was carried out to study the effects of sulfur deprivation on heat stress tolerance of two cluster bean (Cymopsis tetragonoloba L. Taub) cultivars (GC-1 and Pusa Nau Bahar (PNB)). Three weeks old sulfur-starved and sulfur-supplemented plants were subjected to heat stress (45°C/35°C) treatment for 24 h. Total dry weight, chlorophyll content, Chlorophyll a:b ratio, electrolyte leakage, malondialdehyde (MDA) accumulation, H2O2 content, sugar, glucose-6-phosphate (G-6-P), fructose-6-phosphate (F-6-P), ascorbate and glutathione concentrations and antioxidant enzyme activity (superoxide dismutase (SOD) and catalase (CAT)) were monitored, at the end of the heat stress treatment. Heat stress enhanced and sulfur starvation depleted the contents of sugar metabolites, but the accumulation of sugar, G-6-P and F-6-P were not related with heat stress tolerance. Antioxidant enzyme activities of SOD and CAT were influenced significantly more by sulfur starvation than heat stress. The results showed that under heat stress, the addition of sulfur helps to mitigate the oxidative damage in both the cultivars. However, GC-1 was more heat tolerant as it was characterized by significantly higher total dry weight, chlorophyll content, ascorbate and glutathione content and lower H2O2, MDA, electrolyte leakage than PNB. 相似文献
1