基于主成分分析法的干旱区典型绿洲土壤盐分特征分析——以新疆第二师31团为例

为研究新疆典型绿洲土地盐分特征及分布特征,以新疆第二师31团为例,采用GPS对研究区域进行定点采样(N=66),采样深度为100 cm,采样层数为5层,对土壤盐分离子进行化验检测,运用SPSS软件对数据进行描述性、离子间相关性及离子主成分分析。结果表明:不同土壤层中各离子处于中等以上变异程度,各土壤层的pH=8.11,各土壤层中Cl^-、K⁺+Na⁺与SO₄^2-离子含量大于HCO₃^-、Ca²⁺与Mg²⁺离子;Cl^-、K⁺+Na⁺、SO₄^2-、Ca²⁺、Mg²⁺之间的相关系数较高,呈现极显著相关性。各土壤层的第一主成分主要包含Cl^-、SO₄^2-、Ca²⁺、Mg²⁺、K⁺+Na⁺离子信息,第二主成分与第三主成分主要包含HCO₃^-离子信息。以第一主成分、第二主成分及第三主成分所表征不同信息为基准,分析了研究区不同位置不同土壤层的盐渍化程度及碱度,该研究区域受盐碱影响较大。     

艾比湖盐基离子的空间异质性研究

为了反映艾比湖地区不同程度盐渍化的空间分布,以野外调查和实地数据为基础,对艾比湖盐渍土的土壤盐分和盐基离子进行描述性统计分析、相关性分析和地统计分析,结果表明,土壤含盐量和盐基离子均近似服从正态分布,盐分表聚强烈,空间变异性显著。表层土壤盐分、Cl^-、Mg²⁺、Na⁺均属于强空间变异,HCO₃^-、Ca²⁺、SO₄^2-和K⁺均属于中等强度的空间变异。HCO₃^-、Ca²⁺、Mg²⁺、SO₄^2-和K+属于强空间相关性。含盐量、Cl^-和Na⁺属于中等程度空间相关性。通过分析盐分和盐基离子的空间变异性,有益于土壤盐渍化的快速诊断,可为提高土地利用效率和农田精细管理提供决策依据。     

渭-库河绿洲植棉土壤不同土层盐分相关性分析

为渭-库河绿洲植棉土壤盐渍化的治理、改良及合理利用提供一定的理论基础和科学依据,笔者通过筛选渭-库河绿洲植棉土壤上典型的野外考察路线、GPS定点、取样测定,并对植棉土壤不同土层总盐、盐离子含量以及盐离子间进行相关性分析。研究结果表明：植棉土壤不同土层盐分含量分别：0~ 10 cm 1.555%,10~30 cm 0.454%,30~50 cm 1.082%;pH：0~10 cm pH 8.09,10~30、30~50 cm pH 8.59左右;平均含盐量分别为15.549、4.548、10.821 g/kg。不同深度土层的盐分含量从大到少顺序依次为0~ 10 cm＞30~50 cm＞10~30 cm,属于盐化土壤。相关性分析结果表明：在研究区植棉土壤不同土层的全盐量、pH、HCO₃^-、Cl^-、Ga²⁺、SO₄^2-、K⁺+Na⁺、Mg²⁺之间的相关性基本上呈显著到极显著正相关,尤其是表层土壤中SO₄^2-与K⁺+Na⁺的相关系数达到了0.98,硫酸物在表层土壤积聚强烈,盐分以向上运行为主。     

龟裂碱土地下水年际动态变化特征研究

旨在为龟裂碱土改良利用水盐调控提供理论依据,本研究对龟裂碱土用绳测法测地下水埋深、电导率仪测定矿化度、多参数测试仪测定pH值和滴定法测定盐分离子,对比分析龟裂碱土地下水埋深、矿化度、pH值和盐分离子年际变化规律。结果表明：地下水埋深和矿化度横向变化较大,变异系数分别为22.2%和38.9%,盐分离子Na⁺、Cl^-和HCO₃^-横向变异较大,Ca²⁺和K⁺横向变异较小;地下水盐分离子主要以Na⁺、Cl^–、SO₄^2-和 HCO₃^-为主;地下水埋深逐年变浅,pH值、矿化度逐年变小。本研究结果为龟裂碱土改良利用水盐调控提供依据,以及对干旱地区的环境保护和农业灌溉具有重要的科学价值。     

盐渍土壤生境中大果沙枣成年树离子吸收、运输和分配特征研究

为揭示盐渍土壤中大果沙枣(Elaeagnus angustifolia Linn.)树体矿质离子分布规律,保障大果沙枣高效种植和丰产栽培,以不同盐度土壤中生长的成年大果沙枣树为材料,测定并分析了其根、枝、叶中Na⁺、K⁺、Mg²⁺和Ca²⁺的吸收、运输和分配特征。结果表明：盐土土壤环境中,大果沙枣叶片对Ca²⁺和Mg²⁺具有较强的选择吸收能力,低盐（I~II级）土壤环境中,叶内Na⁺含量明显上升,而至高盐（III~IV级）中,根部对Na⁺的吸收量明显高于枝和叶。随着林地土壤盐度的升高,K⁺、Ca²⁺、Mg²⁺在枝部和叶部的积累量明显增大,矿质离子由根部向枝、叶部运输的能力在I~III级盐度土壤环境中逐渐增大,并在IV级盐度土壤环境中受抑。同时,根和枝中K⁺/Na⁺和Mg²⁺/Na⁺值均是先增大后减小,叶中K⁺/Na⁺、Mg²⁺/Na⁺变幅较小,根和叶中Ca²⁺/Na⁺变幅较大。大果沙枣成年树的盐适应机制主要是通过根对Na⁺的聚积作用,叶对K⁺、Mg²⁺和Ca²⁺的选择性吸收能力增强来实现的,同时也与枝中相对稳定的K⁺、Na⁺、Mg²⁺和Ca²⁺的选择性运输能力有关。     

燕麦对碱胁迫的阳离子响应机制

以耐碱性燕麦品种Vao-9和碱敏感性品种白燕5号为试验材料,采用盆栽法,用25、50、75、100 mmol L^-1碱浓度(Na₂CO₃和NaHCO₃按摩尔比1∶1混合)进行短期(14 d)和长期(28 d)胁迫处理,观测两品种根、茎、叶中Na⁺、K⁺、Ca²⁺、Mg²⁺吸收及分配特点,并从离子平衡吸收与分配角度,探讨燕麦对碱胁迫的生理适应机制。胁迫处理14 d后,燕麦体内Na⁺增加,K⁺下降,Ca²⁺和Mg²⁺变化不大,且两品种间各器官中4种离子的分配比例差异不显著。胁迫处理28 d后,两品种各器官中Na⁺增幅较大,K⁺、Ca²⁺和Mg²⁺降幅较大。Vao-9植株体内Na⁺、Ca²⁺含量大于白燕5号,但K⁺、Mg²⁺含量与白燕5号无显著差异,但两品种间各器官中4种离子的分配特点不同;当胁迫浓度达到100 mmol L^-1时,与白燕5号相比,Vao-9叶片中少分配5.9个百分点Na⁺,多分配13.5个百分点K⁺、28.9Ca²⁺、10.9Mg²⁺,茎中多分配5.4个百分点Na⁺,少分配9.8个百分点K⁺,根中少分配28.9个百分点Ca²⁺、10.9Mg²⁺,因而Vao-9叶片中Na⁺ /K⁺、Na⁺ /Ca²⁺、Na⁺ /Mg²⁺值较白燕5号低。可见,燕麦通过提高阳离子选择吸收及器官分配能力以适应碱胁迫。     

盐胁迫下水稻叶绿素荧光特性与离子积累的相关性分析

以4个北方常规粳稻品种为材料,于孕穗期施加80 mmol/L的NaCl胁迫测定了水稻叶片叶绿素荧光参数及体内离子含量的变化,以揭示盐胁迫下水稻离子积累与叶绿素荧光特性的相关性。结果表明盐胁迫下水稻叶片最大荧光(Fm)、最大光化学量子效率(Fv/Fm)、光系统Ⅱ的实际光合效率(PhiPSⅡ)、表观光合量子传递效率(ETR)和光化学猝灭(qP)均呈下降趋势最小初始荧光(Fo)和非光化学猝灭(qN)呈升高趋势。盐胁迫导致水稻体内Na⁺、Cl^-积累显著增加,K+积累显著下降,SO₄^2-、PO₄^3-和NO3-含量较对照差异不显著。盐胁迫下水稻叶绿素荧光参数与Na⁺、Cl^-和SO₄^2-含量呈显著负相关,与K+和PO₄^3-含量呈显著正相关,与NO3-含量相关性不显著。以上结果表明水稻体内有害离子在盐胁迫下会过量积累这是导致水稻叶片光合结构破坏和光合作用效率下降的重要原因。     

田菁改良重度盐渍化土壤的效果分析

为评价田菁改良重度盐渍化土壤的效果,试验设置4个处理：（1）只种植田菁(T);（2）种植田菁,施用二铵450 kg/hm²(TA);（3）种植田菁,施用磷石膏2250 kg/hm²(TG);（4）不种植田菁的空白处理作对照(CK)。结果表明：施用磷石膏能够显著促进田菁生长(P<0.05),TG处理地上部、地下部生物量较T、TA处理分别增加了14.24%、24.77%和8.32%、12.39%,施用二铵对田菁生长的促进作用不显著。种植田菁能够显著降低重度盐渍化土壤含盐量、容重,提高土壤速效氮、速效钾、水溶性有机质(DOC)含量,及土壤大团聚体含量、平均重量直径(MWD)、总孔隙度(P<0.05),TG处理改良效果最大。相关分析表明,盐渍化土壤含盐量、Na⁺含量、DOC、有机质是维系盐渍化土壤结构的关键性状,降低土壤含盐量、Na⁺含量,提高DOC、有机质含量是盐渍化土壤改良方向。种植田菁,同时施用磷石膏是一种快速提升重度盐渍化土壤肥力的有效方法。     

有机物料配施菌剂对设施次生盐渍化土壤的修复效果

设施土壤次生盐渍化已成为制约设施农业发展的主要问题,为验证施用有机物料对次生盐渍化设施土壤的修复效果,本研究采用田间小区试验,以河北永清典型次生盐渍化设施土壤为研究对象,选择牛粪和生物炭两种有机物料并结合微生物菌剂作为外源有机物料,处理包括不施用有机物料(CK)、单施牛粪(DM)、单施生物炭(BC)、牛粪配施菌剂(DM+MI)、生物炭配施菌剂(BC+MI),通过分析各处理土壤的水溶性盐分总量、各盐分离子以及植株生长状况,探讨了有机物料对设施土壤次生盐渍化的改良效果。结果表明：施用有机物料和微生物菌剂可以不同程度的减轻土壤次生盐渍化。与对照相比,对降低土壤盐分效果最显著的为DM+MI处理,最高可降低土壤可溶盐总量18.26%,以及Na⁺、Ca²⁺与Mg²⁺含量24.1%、18.75%、24.29%,其他降盐效果表现为DM处理>BC+MI处理>BC处理。施用有机物料对辣椒植株的生长有一定的促进作用,至第10周时显著增加株高与茎粗达10.40%~16.00%和19.50%~21.30%。对辣椒植株生长与土壤水溶性盐分含量的相关性分析表明,在设施次生盐渍化土壤中,辣椒植株生长与土壤中Ca²⁺和Mg²⁺的含量呈显著负相关关系。综上,有机物料配施微生物菌剂能改善土壤条件,降低土壤含盐量,缓解设施土壤次生盐渍化状况,并促进辣椒正常生长。     

8种耐盐植物与脱硫石膏对河套灌区盐碱土水稳定性团聚体的影响

为了探究种植不同耐盐植物配合施用脱硫石膏对河套灌区盐碱土水稳定性团聚体的影响,本研究在内蒙古河套灌区硫酸盐盐碱土上种植8种典型的耐盐植物,配合施用脱硫石膏,比较种植前后土壤水稳定性团聚体特征,以期筛选出适宜的耐盐植物。结果表明,种植耐盐植物后,<0.01 mm团聚体质量分数降低了44%~65%,而>0.25 mm和0.25~0.053 mm团聚体显著增加了95%~203%和21%~66%,0.053~0.01 mm团聚体质量分数没有发生显著的变化;各级团聚体有机碳和全氮显著提高,尤其是>0.25 mm水稳性团聚体,有机碳和全氮含量分别增加了13%~90%和75%~179%。不同耐盐植物存在明显的差异,其中多年生豆科植物的效果更为明显。>0.25 mm和0.25~0.053 mm团聚体质量分数与土壤pH、EC值、Na⁺、Mg²⁺、SO₄^2-和Cl^-含量呈显著的负相关关系,但与有机碳和全氮含量呈极显著的正相关关系,而<0.01 mm团聚体质量分数则与之相反。可见,盐分离子决定小团聚体,而大团聚体取决于有机质含量,种植耐盐植物由于降低盐分含量,同时提高有机质含量,从而促进盐碱土矿质土粒团聚作用,形成较大的水稳定性团聚体,多年生耐盐植物柳枝稷、紫花苜蓿、草木犀等效果更好,可有效地改良本地区盐碱土。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

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.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

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.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

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.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

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.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

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.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

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).     

Screening techniques and sources of resistance to parasitic angiosperms

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.