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1.
河西走廊土壤钾素变化的定位连作试验研究 总被引：4，自引：0，他引：4
连续4a定位试验研究表明，小麦／玉米带田作物年均携带走钾素404．3－502．0kg/hm^2，小麦、玉米单作年均携钾量227．4－297．2kg/hm^2和385．2－483．1kg/hm^2，携带量大于归还量是土壤钾素减少的直接原因；单作田缓效钾年均减少1．1％－6．8％，速效钾年均减少8．0％－10．8％，带田耗钾强烈，缓效钾平均 每年减少9．4－10．8％，速效钾平均下降6．％－10．5％。年投入化学钾素187kg/hm^2或土粪75t/hm^2均不能保持带田土壤钾素，在土粪基础上增加化学钾素用量方可保持土壤钾平衡；带田土壤缓效钾消耗速率大于速效钾，单作栽培速效钾消耗速率大于缓效钾；当土壤缓效钾＜700mg/kg，速钾＜133mg/kg时，带田作物表现出缺钾反映。 相似文献
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3.
独山地区人工草地钾素供应状况及肥效研究 总被引：1，自引：0，他引：1
通过对贵州独山地区人工草地黄壤农化样品与剖面样品的养分含量以及土壤对钾素的固定性能的分析测定,结果表明,该地区人工草地土壤速效钾（Ｋ）含量为３８．５－１２４．４ｍｇ／ｋｇ,缓效钾（Ｋ）含量为９６．８－３２０．５ｍｇ／ｋｇ。土壤交换性镁钾比例较高,以致交换性钾饱和度较低,导致土壤钾素供应不良,土壤对施入外国纱具有较强的固定能力,固钾量与施钾量呈显著正相关,其要关系数γ为０．８８９,而固钾百分率与施钾 相似文献
4.
ASI土壤养分状况系统研究法在棉田上的应用 总被引：2，自引：1，他引：1
应用化学分析、吸附反应和生物诊断方法，系统研究了两种棉田土壤速效养分的丰缺状况。结果表明，土壤对磷、硫、铜、锰的吸附曲线呈近似的指数曲线，低浓度时，吸附强烈，随浓度增加，土壤的吸附能力下降。在吸附液浓度＜２０ｍｇ·Ｌ－１，加入的锰几乎全部被土壤吸附固定。在吸附液浓度＜７．５ｍｇ·Ｌ－１时，对锌的吸附强度较大，在吸附液浓度＞７．５ｍｇ·Ｌ－１时，吸附强度减少。盆栽生物效应试验证明，所有土壤均缺氮，另外扶沟潮土的磷、钾，南阳黄褐土的磷、钾、硫，是主要的养分限制因子。在剖析养分吸附特性的基础上按适宜的比例补充营养元素后，棉花产量及净收益显著提高。 相似文献
5.
北京郊区潮土中镁素释放特点及对作物的有效性 总被引：2，自引：0，他引：2
通过室内模拟试验、生物耗竭试验和连续流动交换试验,研究了昌平、大兴两处潮土中镁释放特点。尽管两处土壤中交换态镁含量较高。但随种植茬数增加,交换态镁含量,六茬植物镁的总吸收量中,非交换态镁的贡献率将近５０％。大兴处土壤镁释放能力好于昌平处土壤,释放量高。６００min内用０．５mol/Ｌ中性,ＣＨ４ＡＣ连续流动交换镁释过程,以抛物线扩散方程拟合最好。 相似文献
6.
以长江流域下游棉区的12个棉花主栽品种为研究材料,在人工气候室水培和田间种植条件下进行棉花苗期耐低钾能力筛选指标研究。结果表明,低钾会放大棉花苗期关于钾素吸收利用和光合碳同化等生理特性上的品种间差异幅度。土壤严重缺钾时会显著降低棉花铃数、铃重及衣分,其中铃数响应土壤缺钾最为敏感,而在铃重组成中纤维质量对土壤缺钾的响应幅度大于棉子质量。通过对比基于棉花苗期不同生理指标和最终产量与品质指标的筛选结果,发现综合考虑棉花苗期叶片SuSy活性、SPAD值和单株叶片生物量3项指标的低钾胁迫系数对棉花最终产量与品质的耐低钾能力具有较好的预测效果。通过试验筛选出低钾敏感型棉花品种泗杂3号和耐低钾型棉花品种泗棉3号,二者可作为进一步研究低钾环境下棉花产量、品质形成机理的理想试验材料。 相似文献
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8.
长期秸秆与氮磷肥配施对土壤钾素形态的影响 总被引：2，自引：0，他引：2
以山东省黄河冲积平原低肥力潮土为供试土壤,经18a盆栽土培定位试验后,采用化学形态分析方法对土壤的钾素形态进行了研究。结果表明,长期秸秆还田并配施适量的化肥,能明显提高潮土缓效钾和速效钾的释放效应,对矿物钾的有效化也有一定效果。在秸秆还田量分别为2250、4500、6750kg/hm2范围内,土壤水溶性钾、非特殊吸附钾、特殊吸附钾、非交换钾与秸秆还田量呈显著正相关;与矿物钾呈显著负相关。长期秸秆还田土壤钾素年度变化规律：非交换钾、特殊吸附钾呈逐年上升趋势;水溶性钾、非特殊吸附钾、矿物钾呈逐年下降趋势。 相似文献
9.
施钾对棉花苗期叶片内源激素与氧自由基代谢的影响 总被引：9，自引：0，他引：9
在大田条件下,研究了钾素对棉花苗期叶片内源激素与氧自由基代谢的影响。结果表明,施钾有利于提高棉花功能叶片中生长素(IAA)、玉米素核苷(ZR)、赤霉素(GA3)的含量,降低脱落酸(ABA)的含量,有利于提高IAA/ABA,ZR/ABA,GA3/ABA之比,延缓棉花功能叶片的衰老。同时,适量施钾肥有利于提高棉花叶片中SOD活性,降低POD活性,减少过氧化物的产生和累积,有利于降低MDA含量,减轻活性氧对细胞膜的伤害。但过量施钾对氧自由基代谢不利。 相似文献
10.
研究施用白云石粉与氧化镁肥对植烟土壤交换性钙、镁含量和烟叶钙、镁等营养元素的影响,为烟区优化施肥措施提供科学支撑。在植烟土壤交换性钙、镁偏低的典型区域,采用随机区组试验设计,设置不同白云石粉、氧化镁肥施用量,通过田间小区试验,测定各处理烟草不同生育期土壤交换性镁、交换性镁、速效氮磷钾与烟叶钙、镁、氮、磷、钾的含量,观测最大叶长、最大叶宽、株高、茎围、节距等农艺性状。结果表明,施用3000 kg/hm2白云石粉在烟叶生长48、68 d和烟叶收获后的土壤交换性镁含量均显著高于其他处理,在烟叶收获后的土壤交换性钙含量显著高于其他处理,该处理在烟叶收获后上部烟叶和中部烟叶的镁含量、上部烟叶的钙含量也高于其他处理。针对植烟土壤交换性钙、镁偏低的区域,施用白云石粉3000 kg/hm2有利于提升植烟土壤交换性钙、交换性镁和烟叶钙、镁含量。 相似文献
11.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
12.
Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts 总被引：7，自引：0，他引：7
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed. 相似文献
13.
Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
14.
C. J. Spurr D. A. Fulton P. H. Brown R. J. Clark 《Journal of Agronomy and Crop Science》2002,188(4):275-280
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality. 相似文献
15.
Chunli TANG Fengxian ZHAO Hongxia CHEN Jiabao MA Jiangcun WEI Meiyan QIU Zhen XIE 《Medicinal Plant》2019,(6):60-65
[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination... 相似文献
16.
D. A. Bond G. J. Jellis G. G. Rowland J. Le Guen L. D. Robertson S. A. Khalil L. Li-Juan 《Euphytica》1993,73(1-2):151-166
Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses. 相似文献
17.
Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed. 相似文献
18.
[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho... 相似文献
19.
E. Keep 《Euphytica》1986,35(3):843-855
Summary Cytoplasmic male sterility (cms) is described in the F1 hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf
1) and recessive for the other (Rf
2).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph
3(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf
1(one of two dominant additive genes controlling early season leafing out) indicated that Rf
1and Rf
2were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf
1, and 0.15 for Lf
1-Sph
3were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph
3.It is suggested that competitive disadvantage of lf
1-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph
3. Poor performance of lf
1- (and possibly lf
2-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off). 相似文献
20.
Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques. 相似文献