北方白菜型冬油菜的膜脂脂肪酸组分和ATPase活性对温度的响应

为了解北方白菜型冬油菜膜脂脂肪酸和ATPase活性与抗寒性的关系,以抗寒性强的冬油菜品种陇油7号和抗寒性弱的品种天油2号为材料,研究了不同温度处理(25°C、10°C、2°C、–5°C)后叶片和根系膜脂脂肪酸组分和ATPase酶活性的变化。结果表明,低温胁迫下2个冬油菜品种叶片和根系膜脂脂肪酸组分相同,叶片中不饱和脂肪酸以亚麻酸为主,根系不饱和脂肪酸以亚油酸为主。随处理温度的降低,2个冬油菜品种叶片不饱和脂肪酸含量呈先降低(10°C,2°C)后增加(–5°C)的趋势;陇油7号根中不饱和脂肪酸含量逐步增加,天油2号则逐步降低;在低温条件下(2°C,–5°C),陇油7号膜脂U/S比值、IUFA值高于天油2号;ATPase活性表现为陇油7号逐渐高于天油2号。说明2个冬油菜品种的膜脂在低温响应上存在一定差异,低温下不饱和脂肪酸含量和ATPase活性的提高是强抗寒冬油菜品种在北方旱寒区严酷环境条件下能安全越冬的重要原因。     

水分胁迫对玉米幼叶质膜ATPase活性影响及其与钙调素和渗透调节的关系

０．５ＭＰａＰＥＧ－６０００胁迫２４ｈ明显刺激三叶期玉米幼苗，第三叶质膜ＡＴＰａｓｅ活性提高，并且Ｖｍａｘ增加近一倍，而Ｋｍ值却降低；水分胁迫下渗透调节因子脯氨酸累积，Ｋ含量则呈现先上升后下降的趋势，渗透调节的起动与质膜ＡＴＰａｓｅ活性上升可能无直接关系。实验也表明质膜ＡＴＰａｓｅ活性被三氟拉嗪（ＴＦＰ）促进而受钙调素抑制，由此推断质膜ＡＴＰａｓｅ在钙调素参与的磷酸化后活性降低。     

Effect of Nickel on Membrane Integrity,Lipid Peroxidation and Fatty Acid Composition in Wheat Seedlings

The influence of 50 and 100 μm Ni on membrane integrity, hydrogen peroxide content, lipid peroxidation as well as total fatty acid composition was studied in shoots and roots of wheat seedlings. In both organs, treatment with Ni led to significant increase in electrolyte leakage reflecting the metal‐induced enhancement of membrane permeability. In the shoots, it was accompanied by significant increase in lipid peroxidation. Accumulation of hydrogen peroxide, more pronounced in the shoots, was also found in Ni‐treated wheat. Exposure of wheat seedlings to Ni altered the total fatty acid composition, leading to decrease in their unsaturation, which was indicated by reduction in double bond index. In both organs, a significant decrease in linolenic acid (C18 : 3) content was observed. It was accompanied by increased linoleic (C18 : 2) and oleic (C18 : 1) acid contents in shoots and roots, respectively. In the shoots, parallel increase in palmitic acid (C16 : 0) and decrease in palmitoleic acid (C16 : 1) were found at the end of the experiment. Our results suggest that modification of fatty acid profile in Ni‐treated wheat seedlings is partly related to lipid peroxidation and increased electrolyte leakage and may reflect damage of cells caused by the metal.     

Influence of Warm Intervals on the Effects of Vernalization and the Composition of Phospholipid Fatty Acids in Seedlings of Winter Wheat

Excised embryos of winter wheat were submitted to a different number of vernalization (2 °C) and devernalization (20 °C) cycles of different lengths. In all treatments sum of cold and warm intervals was 50 and 10 days, respectively. The influence of different temperature conditions of seedling growth on the effectiveness of vernalization and correlations between effectiveness of vernalization and final content of phospholipid fatty acids were analyzed.
All indexes of generative development of plants (length of vegetative phase, % of generative plants, number of side shoots) showed the most effective was uninterrupted vernalization beginning immediately after excision of embryos. Increasing the number of 2 ° C/20 °C cycles rapidly depressed effectiveness of vernalization, which reached the minimum with the 8.3 days at 2 °C and 2 days at 20 °C cycle and then improved again as cycles became shorter and more numerous.
Correlations between indexes of generative plant growth and indexes describing composition of fatty acids in seedlings showed that from 50 % to 60 % of variability in the composition of phospholipid can be associated with changes in the degree of generative induction. A higher degree of generative induction was associated with a higher share of < 16, 16: 0 and 18:2 acids and a lower share of 18: 3 acid and also with a lower value of the 16: 0/< 16 ratio of phospholipids.
The relation between the generative induction of plants and the composition of phospholipid fatty acids may however be blurred when induction proceeds under conditions of alternate short spells of vernalization and devernalization temperatures.     

镉对鸡卵巢发育及卵巢组织ATP酶活性的影响

【研究目的】为了探讨镉对性未成熟鸡卵巢发育的毒性机制，从分子水平阐述镉中毒的发病机理，增强人类环境保护意识，避免畜、禽镉中毒的发生。【方法】在饲料中加入140mg/kgCdCl2 、210mg/kgCdCl2建立亚慢性镉中毒模型，分别在试验20d、40d、60d取卵巢称重，进行Na+-K+-ATPase，Mg2+-ATPase和Ca2+-ATPase活性检测。【结果】对照组卵巢组织内Na+-K+-ATPase，Mg2+-ATPase和Ca2+-ATPase活性随日龄增加呈上升趋势，各时间点酶活性比较差异不显著；加镉组卵巢组织内Na+-K+-ATPase，Mg2+-ATPase和Ca2+-ATPase活性随日龄增加呈降低趋势，与对照组比较差异显著或极限著，且呈一定的时间-剂量效应。【结论】镉能够抑制性未成熟鸡卵巢发育，降低卵巢组织ATPase活性，二者存在一定相关性。     

Ca^2＋,BR对玉米呼吸器官耐冷性的影响

研究了外源Ｃａ２＋、ＢＲ对低温下玉米胚芽呼吸速率、膜透性以及对线粒体呼吸控制比、ＳＯＤ活性和ＭＤＡ含量的影响。结果表明，Ｃａ２＋、ＢＲ处理，相应提高了种苗胚芽的呼吸速率，降低膜透性。低温下经Ｃａ２＋、ＢＲ处理的玉米种苗，其线粒体有较高的呼吸控制比。Ｃａ２＋处理的线粒体中ＳＯＤ活性比对照高；ＭＤＡ含量比对照低。Ｃａ２＋和ＢＲ可能是在低温下通过维持膜系统的正常结构和功能来提高玉米种苗的耐冷性的     

玉米根系生态型及生理活性与抗旱性关系的研究

利用盆栽洗根法对玉米根系各参数进行了系统研究。结果表明，不同基因型玉米在形态、解剖及生理活性上的差异是形成其抗旱性不同的原因之一；根系参数与玉米抗旱性的关系密切。在抗旱性鉴定时应加强使用。     

细胞色素氧化酶活力及线粒体膜脂脂肪酸组分与玉米抗冷性的关系

细胞色素氧化酶活化转折点温度与玉米芽期抗冷性密切相关,是反映植物抗冷性的一个较好指标,其统计数据可用于玉米芽期抗冷级别的化分.线粒体膜脂脂肪酸不饱和指数和亚油酸/棕榈酸也可作为玉米芽期抗冷性指标.膜脂不饱和脂肪酸的摩尔百分含量是否可作为玉米芽期抗冷性的指标,有待于进一步的研究.玉米芽期抗冷性潜力很小.     

多胺对玉米种子吸胀期间耐冷性和种子发芽能力的影响

以玉米耐寒自交系黄C和低温敏感自交系Mo17为材料, 研究了亚精胺(Spd)和精胺(Spm)引发对玉米种子吸胀中的耐冷性和种子发芽能力的影响。种子经0.25 mmol L^-1的Spd和Spm引发72 h后, 在5℃下低温吸胀不同时间(12、24、36和48 h)。结果表明, Spd和Spm引发提高了胁迫期间两自交系胚内过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性, 以及可溶性蛋白质和脯氨酸(Pro)含量, 降低了胚渗出液的核苷酸含量, 同时显著提高发芽率, 并显著缩短平均发芽时间。低温吸胀48 h后, 与对照相比, Spd和Spm处理分别提高两自交系种子的平均发芽率18.5%和14.0%, 分别缩短平均发芽时间1.21 d和1.14 d。黄C在种子吸胀期间的耐冷性强于Mo17。总之, Spd和Spm处理能提高玉米种子吸胀期间的耐冷性, 提高低温胁迫下种子发芽能力。     

杂交玉米的丛生芽的诱导、植株再生和转化

本文研究了大面积推广的4个玉米杂交品种正大619、农大108、临奥1号和登海l号的丛生芽的诱导和植株再生.在A型诱导培养基上,四个玉米品系芽尖均不能形成丛生芽.在B型诱导培养基上,除登海1号外,正大128、农大108、临奥1号的芽尖能够形成丛生芽和分化苗.结果表明,品系和植物激素的组合对丛生芽和分化苗有显著的影响.利用该组培体系只是成功地对正大619和农大108进行了转化,说明该转化系统仍然有玉米基因型特异性的局限.     

渗透胁迫对玉米幼苗叶片不同形态多胺含量的影响

用高压液相色谱法，研究了玉米品种农大108（抗旱性较强）和掖单13（抗旱性较弱）幼苗叶片中游离态(free, f)、酸可溶性共价结合态(AS-conjugated)和酸不溶性共价结合态(AIS-bound) 多胺（polyamine, PA）与渗透胁迫的关系。结果发现，渗透胁迫7 d，农大108的fSpd和fSpm的含量显著(P＜0.05)上升，而掖单13的fPut的升幅显著(P＜0.05)。用S-腺苷蛋氨酸脱羧酶（SAMDC）抑制剂甲基乙二醛-双（鸟嘌呤腙）（MGBG）处理农大108，显著抑制了渗透胁迫诱导的fSpd和fSpm的增加，并且加重了渗透胁迫伤害，用外源Spd处理掖单13，则显著促进了渗透胁迫诱导的fSpd和fSpm的增加，并且减缓了渗透胁迫的伤害。渗透胁迫下，农大108幼苗叶片中AS-conjugated-PA和AIS-bound-PA的上升幅度都显著大于掖单13。用转谷氨酰胺酶（TGase）抑制剂菲咯啉(o-Phen)处理，则抑制了渗透胁迫诱导的AIS-bound-PA含量的上升，并加重了渗透胁迫的伤害。上述结果说明，玉米幼苗叶片中的fSpd、fSpm、AS-conjugated-PA和AIS-bound-PA的升高有利于增强幼苗的抗渗透性。     

玉米花粒期群体光合性能与高产潜力研究

对两个高产潜力不同的玉米品种，在两种肥力条件下的研究表明：高产潜力大的玉米品种和高肥处理的植株，花粒期群体光合速率下降慢，高值持续期长。高产品种群体呼吸速率亦高，但群体呼吸占群体光合的百分数低，群体干物质净积累率高。     

种子处理对玉米幼苗抗低温能力的影响

在10℃的冷环境中,6-BA处理的玉米种子的幼苗SOD酶活性、可溶性蛋白含量都较高,而MDA含量较低.PEG处理的玉米种子的幼苗SOD酶活性和MDA含量较低,而可溶性蛋白含量较对照略高.人工老化2d的种子幼苗叶片中SOD酶活性较对照下降明显,但其MDA含量高,可溶性蛋白含量较低,且变化幅度大.种子老化降低了玉米幼苗对低温的抵抗力,而能改善种子活力的各种处理均可提高其幼苗对低温的抵抗力.     

The Effect of Chilling Temperature on the Permeability of Membranes to K+, Mg2+, Ca2+ ions and on the Electric Potential of Leaves in the Seedlings of Maize (Zea mays L.)

The relations between the extent of injuries in seedlings caused by a few day-long exposures to chill (5°C) and the leakage of K⁺, Mg²⁺ and Ca²⁺ ions from the leaves as well as the electric potential in seven maize hybrids, were investigated. The permeability of cells to ions was defined based on their absolute concentration in a water diffusate (C_t) and concentration expressed in relation to the total ion content in the leaves (IL index).
At lowered temperature the hybrids of higher resistance to chilling temperature were characterized by a lower value of the IL index for K⁺ and Mg²⁺ ions than the chill-sensitive hybrids. On the other hand, absolute concentration of the ions (C_t) Mg²⁺ and Ca²⁺ leaking from the leaves before chill exposure of the seedlings was positively and highly correlated with the extent of injuries in hybrids caused by 4 day-long exposures to chill. This observation is evidence that the chill injuries were predetermined through increased cell permeability to the mentioned ions at room temperature.
Changes in the electric potential of leaves in conditions of lowered temperature preceded the injuries of leaves, which became apparent after a longer period of exposure to chill. Thus, as the leakage of Mg²⁺ and Ca²⁺ ions occurs, changes in the electric potential may supply early information about the predisposition of the particular maize hybrids to chilling injuries. Leakage measurements of Mg²⁺ and Ca²⁺ ions from the leaves at room temperature may find application in the selection of chill-tolerant maize genotypes.     

抗逆增产剂10号对低温干旱胁迫下玉米幼苗生长与代谢的影响

以3叶期玉米幼苗为材料,研究叶面喷施抗逆增产剂10号（简称抗10）对低温干旱双重胁迫下玉米植株的生长与光合、呼吸、蒸腾、荧光等生理代谢特性的影响。结果表明：抗10处理提高了玉米植株的鲜重、株高、净光合速率,促进暗呼吸速率增加,表观量子效率增加,气孔导度减小,蒸腾速率下降,胞间CO2浓度降低,同时还促使叶绿素a荧光量子产额下降（未达到显著水平）,但是提高了PSII的光化学转化效率和潜在活性。这些参数变化表明抗10主要通过诱导保护机制提高玉米幼苗在双重逆境胁迫下的生长与净光合速率。     

高温胁迫对早稻根系质膜ATPase活性及NH+4吸收的影响

选用高温耐性品种农大228、082和高温敏感品种茉莉占、协青早B，比较研究了高温胁迫对根系质膜ATPase活性和NH4^＋吸收速率的影响。结果表明，高温胁迫下，农大228和082根系质膜H^＋-ATPase和Ca^2＋-ATPase活性均比对照提高，而茉莉占和协青早B分别比对照大幅度下降，品种间差异显著（Duncan’s法检验）。根系质膜蛋白含量在高温胁迫后均表现下降。082的NH4^＋吸收速率不受高温影响，热敏感型品种NH4^＋吸收速率受高温胁迫明显下降。     

渗透胁迫对玉米幼苗类囊体膜上结合态多胺含量的影响

研究了渗透胁迫下,玉米品种农大108(抗旱性较强)和掖单13(抗旱性较弱)幼苗类囊体膜上非共价结合态(Noncovalently conjugated,NCC)多胺(Polyamines,PAs)和高氯酸不溶性共价结合态(Perchloric acid insoluble covalently con-jugated,PISCC)多胺(PA)含量的变化。发现渗透胁迫下,抗旱性弱的掖单13的NCC-亚精胺(Spermidine,Spd)、PISCC-腐胺(Putrescine,Put)和PISCC-Spd下降幅度明显大于抗旱性强的农大108;掖单13的NCC-Put含量明显上升,NCC-精胺(Spermine,Spm)含量明显下降,而农大108的NCC-Put和NCC-Spm含量变化不明显。外源Spd处理明显抑制了渗透胁迫下掖单13类囊体膜上NCC-Spd含量的下降,也提高了掖单13玉米幼苗的抗性;Spd生物合成的专一性抑制剂——MGBG处理,则明显促进了渗透胁迫下农大108类囊体膜上NCC-Spd含量的下降,也降低了农大108玉米幼苗的抗性。PISCC-PAs生物合成的专一性抑制剂——o-phen处理,促进了渗透胁迫下玉米幼苗类囊体膜上PISCC-PAs含量的下降,而且明显降低了玉米幼苗的抗性。表明玉米幼苗类囊体膜上NCC-Spd、PISCC-Spd和PISCC-Put在胁迫条件下的稳定有利于增强玉米幼苗适应渗透胁迫的能力。     

玉米自交系耐铝性评价及根系形态解剖特征

采用营养液培养方法,对9个玉米自交系的耐铝性进行了评价,并对其中两个耐铝性不同的典型自交系的根系形态和解剖特征进行了比较。结果表明,玉米自交系在含铝营养液中的耐铝性评价结果与酸性土壤上的耐酸性筛选结果基本一致。耐铝基因型具有苏木精着色程度较低、种子根相对伸长率和植株相对生物量较高的共同特点。种子根相     

The Effect of Short Warm Breaks during Chilling on Water Status, Intensity of Photosynthesis of Maize Seedlings and Final Grain Yield

The effects of short-term exposure of seedlings to suboptimal temperature (14 °C for 1 or 4 h in 24 h cycles) during chilling (5 °C for 12 days) on the water status and intensity of photosynthesis of tolerant (TG) and chilling-sensitive (SG) maize genotypes were studied. Daily warming for 1 or 4 h resulted in a decrease in the hydration of the seedlings to 31.1 % and 61.5 % (SG) and 14.8 % (TG) and 39.1 % (SG), respectively, in comparison with the continuously chilled control. During warming for 4 h, both genotypes absorbed water from soil in amounts that partly compensated for its loss through transpiration, after the plants had been moved to the lower temperature. A protective effect of shorter warming (1 h) on the hydration of the seedlings was a result of a strong, stomatal limitation of transpiration during the initial days of chilling. Warming for 1 or 4 h also increased the ability of TG stomata to close in reaction to water deficit in chilling conditions. The effect of increased temperature delayed the decrease of P_N in leaves and limited RGR inhibition of the seedling mass caused by chilling. Daily warming of plants at the seedling phase (14 and 20 °C for 1 or 4 h) reduced the unfavourable effect of chilling (5 °C for a period of 8 days) on the final yield, the filling of caryopses and their number in a cob after growth in natural conditions.