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951.
赵杨 《湖南农业大学学报(自然科学版)》2013,39(2):176-178
采用Williams鉴别系统的4个鉴别寄主(2 个芜菁甘蓝品种Laurentian和Wilhelmsburger,2 个结球甘蓝品种Jersey Queen和Badger Shipper),于2011—2012年连续2年对采自黑龙江、吉林、辽宁的11个大白菜根肿病主要发病区域的病原菌进行了生理小种鉴定。结果表明,东北地区大白菜根肿病菌主要种群均为4号生理小种。 相似文献
952.
以蓖麻品种淄5号和秀蓖2号的成熟种子胚轴为外植体,在含0.25 mg/L 苯基噻二唑基脲(TDZ)的改良MS(蔗糖20 g/L、琼脂9 g/L)固体培养基上诱导生芽。结果显示:淄5号和秀蓖2号平均每个外植体可产生4个不定芽,2品种间产生不定芽的数量没有明显差异;不定芽经伸长、诱导生根能发育成完整的植株,2品种在根分化能力上没有明显差异。综合分析,这2个蓖麻品种基因型对体外再生体系的建立没有明显影响。 相似文献
953.
小麦条锈病是小麦生产中的重要病害之一,为了明确中草药苍耳和黄瑞香提取液对小麦条锈病的抑制作用,分别以两种中药水浸液测定其对小麦条锈病菌的抑制作用,以及对小麦条锈病的防治效果。结果显示,不同浓度的苍耳、黄瑞香提取液对小麦条锈菌孢子萌发和菌丝生长均有抑制作用,在浓度为0.50 g/mL条件下对其孢子的萌发抑制率分别为69.29%和64.44%,对其菌丝生长的抑制率分别为55.44%和44.77%。两种中药浸提液叶面喷施试验结果显示,两种中药浸提液对小麦条锈病都具有显著的防治效果。 相似文献
954.
955.
《Communications in Soil Science and Plant Analysis》2012,43(12):1465-1475
ABSTRACTUtilizing the proper techniques of plant residue composting can play a significant role in reducing the adverse environmental impacts of chemical fertilizers. Herein the effects of commercial poultry manure (CPM) and composted pistachio residues (CPR) on nutrient availability and saffron daughter corms behavior in a calcareous soil were evaluated as a greenhouse experiment based on completely randomized design arranged in factorial with three replicates. In this study, CPM rates (0, 3, 6, and 9 t ha?1) and CPR levels (0, 20, 40, and 60 t ha?1) were assigned as the first and the second experimental factors, respectively. From the results, CPM or CPR application caused a significant increase in small (≤5 g), mid (5.1–10 g) and large-sized (10.1–15 g) daughter corms number. The highest N (P) concentration in small, mid and large-sized daughter corms was recorded when 9 t ha?1 CPM was applied along with 60 t ha?1 CPR. Soil organic carbon content increased with increasing CPM or CPR levels. The same trend was also observed for soil available N, P, K, and electrical conductivity. By contrast, CPM or CPR levels caused a significant reduction in soil pH. According to the results, pistachio compost can be considered as an eco-friendly alternative to chemical fertilizers to improve soil fertility in saffron farms. 相似文献
956.
《Communications in Soil Science and Plant Analysis》2012,43(3):221-240
Abstract The effects of nitrogen fertilization and age of regrowth on a number of indices for assessing the sulphur status of the perennial tropical pasture grass Panicum maximum var. trichoglume (green panic) have been examined in pot experiments. A non‐rectangular hyperbola regression model has been used as an aid in deriving critical sulphur concentrations and evaluating their confidence limits. The merits and limitations of this model together with problems associated with other methods of deriving critical nutrient concentrations are discussed. Results indicate that critical total S concentrations in whole plant tops declined markedly with age of regrowth. Critical sulphate S concentrations were more stable with age of regrowth, concentrations in excess of 0.012% being indicative of adequate sulphur for maximum plant yield. It is also suggested that plants have adequate sulphur when more than 12% of their total S content is in the sulphate form. N:S ratios may provide a useful guide for assessing sulphur status but should be treated with caution when the nitrogen supply to the plants is high. 相似文献
957.
《Communications in Soil Science and Plant Analysis》2012,43(9):883-895
Abstract Five levels of S (as gypsum) were topdressed on to a pasture containing subterranean clover. Yield responses by the clover fraction of the pasture were measured, together with the total S concentration, the sulphate S concentration and the N:S ratio in young clover plants collected in autumn prior to the fertilizer application, and in plants from the control plots collected in winter and in spring. As there were irregular changes in analytical values from autumn through winter to spring, a more detailed series of samples was taken in the second year. Therein, values for total S and sulphate S in clover plants from each treatment rose during the winter and fell during the spring, so that the critical concentration of sulphur or sulphate varied during the growing period. However, the critical N:S ratio was relatively stable, and in view of previously demonstrated correlations with response to added S, appears to be the more useful index for both diagnosis and prognosis. 相似文献
958.
《Communications in Soil Science and Plant Analysis》2012,43(1):115-123
Abstract The technique of simultaneous quantitative determination of mineral N soil forms (nitrates, exchangeable and non‐exchangeable ammonium, and total amount of these compounds) and sample pretreatment for the analysis of 15N:14N ratio is suggested. The technique is based on the selective association of NH4 +‐ions into indophenol complex and subsequent ethyl‐acetate extraction of this complex from solution. The mineralization of indophenol is carried out in alkaline medium with simultaneous NH3 distillation into H2SO4 titrant. The application of given technique allows us to shorten significantly the time required for analysis and to increase the accuracy of analytical determination. 相似文献
959.
Ahmed Mohamed Mahdy 《植物养料与土壤学杂志》2012,175(4):560-571
A greenhouse experiment was conducted to investigate the immediate effect of application of mono‐ammonium phosphate (MAP), single superphosphate (SSP), and triple superphosphate (TSP) fertilizers containing varying concentrations of Cd on (1) chemical speciation of Cd and Zn in soil solution by chemical‐equilibrium calculations (MINEQL+4.6 model), (2) growth of barley plants, (3) concentrations of Cd, P, and Zn in soil solution and plant tissue, as well as total plant accumulation of Cd, P, and Zn, and (4) monitoring pH and element changes during incubation periods following phosphate application. Results show that, in general, the pH of soil solution increased during the first 40 d of incubation, then declined. Also, at the end of incubation period, pH of soil solution was affected by fertilization source and fertilization rate. The concentration of Cd in soil solution changed with time. Phosphate fertilization (p < 0.05) or fertilizer source (p < 0.05) showed consistent effects. Also, the application of phosphate fertilizers with three rates significantly increased Zn concentrations in soil solution during the first half (0–30 d) of incubation period and then decreased but still more than in the control. In general, application of different sources of phosphate at 100 g kg–1 did not change the dominant forms of Cd in soil solution during all incubation time intervals. Speciation of Zn in the control after 30 d of incubation had changed, in comparison to 10 d of incubation, and the dominant forms were Zn2+, ZnOH+, ZnHCO3, ZnCO3(aq), and Zn(OH)2(aq). Adding phosphate fertilizer significantly increased both shoot and root dry weight compared to control, indicating P was a growth‐limiting factor in the control plants. The Zn concentrations in shoot and root were lower in the TSP‐ and SSP‐fertilizers treatment than those in the MAP and fertilizer treatments at all rates of fertilization. Adding phosphate increased the Cd : Zn and P : Zn ratios in the shoot and root tissue, with the effect being greater with increasing fertilization rate. Phosphate fertilization greatly increased the total accumulation of Cd of barley compared with the control plants (p < 0.001), with the effect being greater with increasing fertilization rate. Source and rate of fertilizers, and their interactions had significant effect (p < 0.05) on Cd accumulation in the whole plant. 相似文献
960.
巢式群体可以利用多个亲本解析复杂性状的遗传机制。本研究利用1个共同亲本与6个基础亲本所配置巢式组合F2:3家系的种子脂肪含量数据,分析了花生脂肪含量的遗传模型,旨在探明不同的基础亲本组合中脂肪含量性状的遗传差异,为制定脂肪含量遗传改良的亲本选配和后代选择策略提供依据。6个组合的共同亲本为高脂肪含量的普通型大果品种豫花15号,其他6个基础亲本为不同脂肪含量和不同植物学类型的品种。结果表明,在不同杂交组合中脂肪含量的遗传模式有所不同,6个组合分别符合无主基因模型、1对主基因加性显性模型和2对主基因等显性模型3种遗传模式。各种遗传效应的估计值也各不相同,主基因遗传力从32%到80%,说明不同杂交组合中,控制脂肪含量的基因位点差异及其重组和分离方式不同。高脂肪含量双亲杂交后代的高脂肪含量个体较多,但主基因遗传力较低,不宜在早代实施表型选择;双亲脂肪含量差异较大的后代脂肪含量变异幅度更大,能够选择到不同脂肪含量的类型。本研究也表明,巢式组合具有较丰富的脂肪含量变异类型,揭示出脂肪含量性状遗传的复杂性和多基因调控的特点,为较全面地了解脂肪含量的遗传提供了基础。该巢式群体也将有助于进一步开展脂肪含量的QTL定位研究。 相似文献