高低镉积累棉花品种生理生化特性研究

为了探究不同浓度镉胁迫对棉花幼苗非蛋白巯基肽类(NPT)、植物螯合肽(PCs)、金属硫蛋白(MT)和谷胱甘肽(GSH)等含巯基类物质与镉胁迫毒理的内在联系,在漂浮育苗条件下,对镉(Cd)积累不同的棉花品种单16和11-20进行研究。结果表明,Cd处理提高了棉苗根、茎和叶中NPT和PCs含量。根中NPT含量11-20显著低于单16,茎中NPT含量则11-20显著高于单16,叶中NPT含量在镉处理浓度由150μmol/L提高到300μmol/L时,两品种根中NPT含量增加,茎中NPT含量略有下降,而在叶片中的NPT含量,表现为单16略增加,11-20略降低。棉苗根中GSH含量表现为先增后减,茎中则表现为先减后增,均为11-20品种GSH含量高于单16。棉苗各器官中PCs含量随着镉浓度的增加而增加。棉苗根和叶中PCs含量均为单16显著高于11-20,茎中PCs含量则相反。2个棉花品种NPT、PCs和GSH含量均表现为根茎叶。Cd处理显著提高了棉苗根、茎和叶中MT含量,均表现为叶茎根。11-20的MT含量显著高于单16,较高的镉浓度(300μmol/L)处理可诱导棉苗MT合成量增加。     

镉对小麦种子萌发、幼苗生长及抗氧化酶活性的影响

为了防止重金属毒害的发生和在环境监测中对重金属的评价,以小麦为试验对象,采用室内培养方法,研究了不同浓度镉胁迫对小麦种子萌发和幼苗生长、丙二醛及抗氧化酶系统的影响,结果表明,较低浓度镉胁迫对种子发芽率、发芽势、芽生长的抑制效应较小.随着镉胁迫浓度的提高,发芽指数、活力指数及根生长明显受抑制,且镉胁迫浓度越大,抑制作用越大.随着镉浓度的增加,幼苗根、芽中的MDA含量、G-POD明显增加,SOD活性呈现先增加后降低的趋势,其中根的SOD活性在1 000 μmol/L Cd胁迫下略低于对照,而CAT、APX活性总体呈下降趋势,且浓度越高下降幅度越大,表明遭受了氧化胁迫和膜脂过氧化损伤,这可能是镉胁迫下小麦幼苗根生长受阻的重要原因.     

施硒对黄芪生长、硒含量及转运的影响

为了解黄芪对硒的吸收转运能力,以黄芪为试材,采用根施和叶面喷施硒2种方式,探索施用不同浓度(0、5、10、50、100μmol/L)的硒酸钠和亚硒酸钠,对黄芪生物量、硒含量以及硒在植物体内的转运能力进行研究。结果表明,无论是以硒酸钠还是亚硒酸钠作为硒源均有利于黄芪地上部和根部干物重、硒含量的增加,随着硒浓度的增加干物重呈先升高后下降的趋势,黄芪地上部硒含量呈逐渐上升的趋势,根部硒含量与之相反。添加硒酸钠和亚硒酸钠处理时,在10μmol/L浓度处理时黄芪地上部和根部干物重最大,分别比CK增加了49.89%、60.87%和23.36%、60.00%。添加相同浓度的硒酸钠处理时,黄芪地上部和根部中硒含量高于施亚硒酸钠处理,在100μmol/L浓度处理下黄芪地上部硒含量最大为119.13μg/g,在5μmol/L浓度处理下黄芪根部硒含量最大为52.25μg/g。2种施硒方式下,根部施硒酸钠更有利于黄芪对硒的富集,且黄芪根部向地上部转运硒的能力随施硒浓度的升高逐渐增大。     

水杨酸提高水稻幼苗对镉胁迫的抗性

为了探讨水杨酸能否提高水稻对镉胁迫的抗性,在1/2浓度的木村B营养液内培养水稻幼苗后,添加CdCl2达500μmol/L,然后加入外源SA使最终浓度达300μmol/L。试验结果表明,镉胁迫使水稻叶片SOD,CAT,POD活性降低,叶绿素含量下降,细胞膜透性增加,MDA含量增多。而外源的SA加入后,能使镉胁迫条件下水稻叶片SOD,CAT,POD活性降低较少,活性氧的生成速率降低,使H2O2含量和MDA含量降低,在一定程度上减轻镉对叶绿素的破坏和提高叶片的光合能力。说明水杨酸对受镉胁迫的水稻抗氧化酶活性产生明显的影响,能提高水稻幼苗对镉胁迫的抗性。     

外源钙离子对镉胁迫下珠芽魔芋幼苗生长及生理特性的影响

为了探究镉胁迫对珠芽魔芋生长的影响及外源钙离子对镉毒害的缓解作用,本研究以珠芽魔芋为供试材料,分析不同镉浓度对珠芽魔芋根长、鲜重、叶绿素含量、抗氧化能力、叶片胞内镉含量及钙离子含量的影响。结果表明,随着供镉水平提高,珠芽魔芋表现出“低促高抑”现象。与对照相比,在200μmol/L的镉胁迫下,珠芽魔芋的鲜重、根长及叶绿素含量分别增加9.4%、10.6%及24.4%,而ROS、MDA及总抗氧化能力(ABTS)变化不显著。随镉浓度持续增,镉胁迫对珠芽魔芋的毒害作用逐渐加大,胞内钙离子的水平同时上调,在600μmol/L镉胁迫下植株胞内Ca²⁺含量较对照(CK)显著增加了336%。进一步的研究表明,外源添加5 mmol/L钙离子后,珠芽魔芋根长、鲜重、叶绿素含量分别较单一镉胁迫下增加了9.6%、102.7%及14%;ROS、MDA及镉含量显著减少17%、23.8%和42%。因而,高浓度镉胁迫会打破植株自身代谢平衡,对植株造成毒害,施加外源钙可一定程度缓解重金属镉对魔芋的氧化损伤。     

两个小麦新品种的耐盐性分析

为了研究不同浓度NaCl胁迫对小麦生理特性及TaNHX1基因表达的影响,以鲁原502和青麦6号2个小麦新品种为试验材料,50,100,150,200 mmol/L NaCl胁迫下测定2个小麦品种种子发芽率、幼苗鲜质量、根系活力、质膜透性、MDA含量、Na~+含量等生理指标,并通过荧光定量PCR方法对小麦耐盐基因TaNHX1在根部和茎基部的表达量进行了比较。结果表明,100 mmol/L以上浓度NaCl胁迫下青麦6号种子发芽率显著高于鲁原502;低浓度NaCl胁迫对青麦6号幼苗生长具有显著促进效应,150 mmol/L NaCl胁迫下青麦6号幼苗鲜质量显著降低,而鲁原502幼苗鲜质量在100 mmol/L NaCl胁迫下就开始显著降低;高浓度NaCl胁迫下鲁原502根系活力下降幅度显著大于青麦6号;相同浓度NaCl胁迫下鲁原502叶片质膜透性和MDA含量均显著高于青麦6号,说明NaCl胁迫对青麦6号叶片细胞质膜伤害较小;高浓度NaCl胁迫下青麦6号根部和茎基部Na+含量均显著高于鲁原502,说明青麦6号根部和茎基部的拒Na+能力显著大于鲁原502,可以有效限制Na+向地上部运输;鲁原502和青麦6号的TaNHX1基因分别在100,150 mmol/L NaCl胁迫下达到最高表达量。以上结果说明青麦6号比鲁原502更耐盐,鲁原502的最高耐盐浓度为100 mmol/L,青麦6号的最高耐盐浓度为150 mmol/L。     

镉胁迫对八角金盘生长及生理特性的影响

本研究通过对常用绿化植物八角金盘一年生实生苗进行不同浓度CdCl₂溶液[CK(0μmol/L Cd²⁺),Cd1(20μmol/L Cd²⁺),Cd2(40μmol/L Cd²⁺),Cd3(80μmol/L Cd²⁺)和Cd4(120μmol/L Cd²⁺)]处理,探究镉胁迫对八角金盘生长及生理特性的影响。结果显示,20μmol/L镉胁迫对八角金盘植株影响较小,表现为株高、叶片数、叶面积、最大光化学效率(F_v/F_m)、实际光化学效率(Y(Ⅱ))等变化不显著;40、80μmol/L镉胁迫处理下,其生长指标下降,丙二醛(MDA)含量上升,抗氧化酶活性和可溶性蛋白含量上升,说明此浓度下植株可通过自身抗氧化机制等来适应镉胁迫;120μmol/L镉胁迫下,植株株高、叶面积显著降低,叶绿素含量、F_v/F_m、Y(Ⅱ)、可溶性蛋白含量均显著下降至最低,MDA含量累积较高,说明在高浓度镉...     

盐胁迫下野大麦耐盐生理机制初探

以盐生植物野大麦、甜土植物中国春小麦为材料,研究了NaCl胁迫对野大麦、小麦幼苗叶片质膜透性、含水量、地上和根部离子含量、脯氨酸含量、磷酸烯醇式丙酮酸羧化酶(PEPCase)活性的影响。结果表明,随盐胁迫浓度增加,野大麦的细胞膜透性、Na 含量、脯氨酸含量、Na /K 、PEPCase活性增加,含水量、K 含量下降;但在相同盐胁迫条件下野大麦地上部和根部Na 含量明显低于小麦,而根中K 含量高于小麦,表明野大麦可能具有拒绝吸收Na 和维持高K 含量的能力;野大麦的脯氨酸含量增加幅度小于小麦,表明在盐胁迫下野大麦不是通过脯氨酸的积累来达到体内渗透平衡的;野大麦PEPCase活性增加明显高于小麦,说明提高光合效率可能是野大麦实现盐适应的主要措施之一。     

表油菜素内酯对重度镉胁迫下辣椒幼苗生理特性及抗逆基因的影响

为探究表油菜素内酯(EBR)对辣椒镉抗性的作用机制,以晋椒503为试验材料,在苗期进行高浓度镉(100μmol/L)胁迫,对喷施不同浓度EBR的辣椒幼苗各项生理性指标和抗逆相关基因进行了比较。结果表明,高浓度的镉离子可下调辣椒幼苗的生物量、光合色素含量、抗氧化物酶活性、抗坏血酸(AsA)-谷胱甘肽(GSH)循环的清除效率,上调辣椒DHAR、GR、MDHAR、CAT和WRKY25基因表达量;施加100μmol/L的EBR可以激活DHAR、MDHAR和WRKY25等基因的表达,增加辣椒幼苗的生物量,增加叶片中光合色素含量,提高过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、单脱氢抗坏血酸还原酶(MDHAR)、脱氢抗坏血酸还原酶(DHAR)和谷胱甘肽还原酶(GR)活性,提高AsA-GSH循环系统还原态与氧化态的比例,进而降低了O_2~(-·)产生速率和H_2O_2含量;高浓度的镉离子虽然可以激活GR、CAT和DHAR基因表达,但却抑制了相应酶的活性,阻碍了辣椒对重金属正常的响应路径,从而造成了严重的生理胁迫。适宜浓度的EBR可通过对转录因子和酶活性的调控有效缓解镉胁迫对辣椒幼苗的毒害,提升辣椒的耐镉能力。     

硅对小麦吸收镉、锌的影响及其生理效应

通过小麦水培试验,利用ICP等化学分析方法,研究硅对小麦吸收镉、锌的影响及其生理效应。根据试验结果可见,当硅浓度在90mg/L和60mg/L时能分别有效地控制镉、锌污染,提高小麦根、叶的生物学产量。通过小麦生理试验研究表明,硅在一定浓度条件下能提高小麦的根系活力、增加小麦叶片的叶绿素含量、降低小麦膜透性和提高小麦细胞膜抗重金属镉、锌的能力;而较高或较低浓度的硅抗重金属镉、锌的能力稍弱,使小麦的生物学产量、叶绿素含量和根系活力降低但膜透性升高。     

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.     

Evolution under domestication involving disturbance of genic balance

Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.     

Genetic variation for disease and nematode resistances and forage quality in perennial diploid and tetraploid lucerne populations (Medicago sativa L.)

Summary Twenty-five lucerne populations of the Medicago sativa complex, which were either diploid or tetraploid and wild or cultivated, were analysed for their resistance to four different fungal diseases and to stem nematode. Forage quality, including stem digestibility and saponin content, was also tested.Populations varied in susceptibility to the diseases caused by Colletotrichum trifolii, Verticillium albo-atrum, Sclerotinia trifoliorum and Pseudopezizza medicaginis, and to the nematode Ditylenchus dipsaci. Except for Sclerotinia rot, sativa and falcata subspecies differed in susceptibility, but this grouping of populations did not account for the full range of variation among them. However, the resistance to P. medicaginis was much lower in the sativa than in the falcata populations.Populations also varied significantly in stem fiber content and digestibility. Stem digestibility was negatively correlated to forage yield. Wild sativa and falcata populations had lower fiber content and higher digestibility than cultivated sativa populations. The medicagenic acid was the sapogenin responsible for the anti-nutritional effect of the lucerne measured by the yellow mealworm larvae Tenebrio molitor. The medicagenic acid content was lowest for the pure sativa populations, highest for the pure falcata populations, and intermediate for the French sativa varieties that have some traits originating from falcata germplasm. Some populations could be used in breeding programs to improve disease and nematode resistance, and forage quality.     

Review of Effects of Active Components of Gastrodiae Rhizoma on Central Nervous System

In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,...     

Effects of Pb on Rhizosphere Soil Enzyme Activity and Chemical Constituents of Achyranthes bidentata Blume

[Objectives]The purpose of this study was to investigate the effects of Pb on rhizosphere soil enzyme activity and chemical constituents of Achyranthes bidentat...     

不同P-Zn配比对小麦幼苗微量元素营养的影响

采用了螯合-缓冲营养液培养方法对小麦进行了苗期培养试验,在3个P水平(0,0.6,3.0 mmol/L)和3个Zn水平(0,3,30 μmol/L)的完全组合下对小麦苗期生长及Zn、Fe、Cu、Mn营养进行了研究,旨在为小麦微肥施用提供理论依据.结果表明,P、Zn的正常供应促进了小麦生长,二者的缺乏与过量均会抑制小麦发育,且这种影响在冠部表现得更为明显.在小麦苗期,Zn与Cu的吸收存在明显的拮抗作用,但供Zn则促进了Zn和Cu的转运,而Mn转运则受到了抑制;过量供Zn时,大量Zn被转运到冠部,同时明显抑制了(Fe+Cu+Mn)的吸收总量;P的供应显著地抑制了Fe的吸收,但P的供应提高了Zn、Cu、Mn的转运率;P、Zn在对Zn与Fe、Cu、Mn间吸收竞争的影响中,Zn本身的影响要比P的影响更为明显,供Zn明显促进了小麦幼苗对Zn的吸收;在小麦幼苗冠部,Zn与Fe的竞争中,供P利于Zn的吸收,缺P则利于Fe的吸收;而Zn与Cu以及Zn与Mn间的竞争中,缺磷时利于Zn的吸收,供磷后则利于Cu和Mn的吸收.总之,小麦幼苗Zn、Fe、Cu、Mn营养中,P、Zn的不同配比会不同程度地改变Zn与Fe、Cu、Mn的协同或拮抗效应.     

Isozyme variation between diploid and tetraploid cytotypes of Glycine tabacina (Labill.) Benth.

Summary Glycine tabacina (Labill.) Benth. is a wild perennial species related to the cultivated soybean, G. max (L.) Merr. It is composed of diploid (2n=40) and tetraploid (2n=80) cytotypes. Currently, to differentiate the cytotypes, plants are grown out in the greenhouse and chromosome counts made on pollen mother cells. It is a laborious and time consuming process. The objective of this study was to determine whether electrophoretic techniques could be utilized to separate the cytotypes. Electrophoretic examination of seven isozyme systems from seed of 67 G. tabacina accessions revealed banding patterns that could be used to differentiate between diploid and tetraploid cytotypes in the species. Among the tetraploid accessions, the number of bands observed were always greater than the diploids. Some tetraploid banding patterns consisted of bands similar to the diploid tabacina and/or additional bands previously identified in other Glycine species. The patterns of isozyme multiplicity and variation in the tetraploid tabacinas suggests more than one mode of origin for the tetraploids.     

Some physiological and photosynthetic characters of rice × sorghum and rice × wheat hybrids

Summary Some photosynthetic characters as-leaf anatomy, leaf photosynthetic rate and CO₂ compensation pointdistinguishing C₃ and C₄ plants and physiological characters as leaf area ratio, nitrogen content, leaf stem ratio and total shoot-to-root and deep root-to-shoot ratios have been studied in rice × sorghum and rice × wheat hybrids. Rice × sorghum 1. has lower values of photosynthetic rate, leaf nitrogen, total root and deep root-to-shoot ratio and CO₂ compensation point as of rice parent where as, rice × sorghym 2. is superior in all these characters. Both hybrids lack kranz anatomy. Though both rice × sorghum hybrids show characters of C₃ rice plant but rice × sorghum 2. has improved drought tolerance and leaf characters in relation to yield. Rice × wheat hybrid have higher assimilatory area and higher total root-to-shoot ratio. Grains of rice × wheat hybrids are identical to rice grain. However, as grains of rice × wheat hybrid does not contain seed coat, it could be exploited as novel rice germplasm after improvement.Abbreviations T CO₂ compensation point - T21 CO₂ compensation point at 21% O₂ - T2 CO₂ compensation point at 2% O₂ - dR/sR deep Root-to-shoot Ratio - LAR Leaf Area Ratio - CER photosynthetic rate - TR/SR Total Root-to-Shoot Ratio