硝态氮和铵态氮对墨兰生长发育的影响

以无土栽培的方法研究不同氮水平的硝态氮和铵态氮对墨兰［Ｃｙｍｂｉｄｉｕｍｓｉｎｅｎｓｅ（Ａｎｄｒ．）Ｗｉｌｌｄ．］生长发育和某些生理特性的影响。１ｍｍｏｌ／Ｌ和１０ｍｍｏｌ／Ｌ的硝态氮和铵态氮处理都促进叶芽和叶片正常生长,前者似乎比后者好一些。５０ｍｍｏｌ／Ｌ的两种形态的氮均使叶片生长缓慢,尤其是铵态氮。１和１０ｍｍｏｌ／Ｌ硝态氮处理则正常开花,而５０ｍｍｏｌ／Ｌ则例外。铵态氮处理各种浓度均不形成花芽。建议墨兰营养生长期施用１ｍｍｏｌ／Ｌ的硝态氮或铵态氮,但生长后期则应施１—１０ｍｍｏｌ／Ｌ硝态氮,以利花芽分化。作者认为,墨兰生长缓慢与光合速率极慢和硝酸还原酶活性极低有关,墨兰开花与否和Ｅ／Ｎ比大小有关。     

不同钾水平对钾饥饿墨兰碳水化合物和蛋白质含量的影响

墨兰（Ｃｙｍｂｉｄｉｕｍｓｉｎｅｎｓｅ（Ａｎｄｒ．）Ｗｉｌｌｄ）植株经过钾饥饿后,无上栽培于不同钾浓度的培养液中．随着钾浓度的升高（５ｍｍｏｌ／Ｌ）,体内可溶性糖、淀粉、纤维素和蛋白质含量比对照分别增加１２５、１１７、１２７和４１％,而还原糖和游离氨基酸含量则比对照分别下降４４％和２４％．假球茎是贮藏还原糖、可溶性糖、淀粉、游离氨基酸和蛋白质的主要器官,叶片是纤维素最多的器官．钾供应充足时,叶片丙酮酸激酶活性明显加强（比对照强１５倍）,而硝酸还原酶活性也加强（比对照强０．８倍）．本文对钾促进墨兰生长发育和抗病等原因加以讨论．并初步提出诊断墨兰体内钾状况的三种生理指标．     

兔血管平滑肌延迟整流钾通道研究及其与克隆Kv1.5通道的电生理特性比较

本文用膜片箝全细胞技术比较了研究了单个兔肺动脉血管平滑肌细胞上延迟整流钾通道与克隆Ｋｖ１．５通道的电生理及药理学特性。将平滑肌细胞箝制在－４０ｍＶ,以１０ｍＶ的步跨阶跃去极化（０￣６０ｍＶ）可产生一系列快速上升的外向电流,几无衰减,其激活曲线的Ｖ１／２为２７．２ｍＶ。灌流液中加入１００ｍｍｏｌ／Ｌ和ＴＥＡ １ｍｍｏｌ／Ｌ ４ＡＰ,电流幅度均明显减小,细胞外Ｃａ＾２＋水平由１．５ｍｍｏｌ／Ｌ降至０．     

草酸对氧化胁迫下水稻叶片中核酮糖—1,5—二磷酸羧化酶／加氧 …

以杂交稻（汕优６３）为试验材料,在木村Ｂ营养液中培养至三叶期,用草酸５ｍｍｏｌ／Ｌ预处理水稻２ｄ,再处以氧化胁迫（用０．１ｍｍｏｌ／Ｌ浓度的活性氧诱发剂甲基紫精处理）。结果表明：ＭＶ诱发的氧化胁迫下,Ｒｕｂｉｓｃｏ及其它可溶性蛋白快速降解。草酸预处理可明显缓解Ｒｕｂｉｓｃｏ及其它可溶性蛋白的降解,降解速率分别降低１／３和１／２左右,植株经草酸处理后其叶片中几种抗氧化酶如ＡｓＡ－ＰＯＤ、ＳＯＤ、ＣＡ     

细胞外Mn^2＋对内向整流钾通道（IRK1）的阻断作用

目的和方法：采用双微电极电压钳（ＴＥＶ）法研究细胞外Ｍｎ＾２＋对非洲爪蟾卵母细胞表达的内向整流钾通道（ＩＲＫ１）的阻断作用。结果：细胞外Ｍｎ＾２＋浓度分别为１、１．２５、２．５、５、１０和２０ｍｍｏｌ／Ｌ,Ｋ＾＋浓度为９０ｍｍｏｌ／Ｌ,可见Ｍｎ＾２＋对ＩＲＫ１的瞬间电流（旋加电压后２ｍｓ）具有Ｍｎ＾２＋浓度依赖性和电压依赖性阻断作用;细胞外加Ｍｎ＾２＋浓度较高时强;细胞外Ｋ＾＋浓度为９０ｍｍｏｌ／     

多胺对裸大麦离体叶片活性氧代谢的影响

裸大麦离体叶片分别在光照和暗诱导下,以腐胺、亚精胺和精胺等３种多胺,分别用２ｍｍｏｌ／Ｌ,０．５ｍｍｏｌ／Ｌ,和０．２ｍｍｏｌ／Ｌ３种浓度处理,均使丙二醛累积减少,延缓过氧化氢酶和ＳＯＤ活性的下降。以ＣａＣｌ２（５ｍｍｏｌ／Ｌ）＋Ｓｐｄ（０．５ｍｍｏｌ／Ｌ）处理,可降低Ｓｐｄ（０．５ｍｍｏｌ／Ｌ）的效应,因此多胺延缓离体叶片衰老与活性氧代谢有关,并且进入细胞时,与Ｃａ发生竞争。     

钙对生长素诱导的玉米胚芽鞘切段延长生长的影响

１０μｇ／ｇ的ＩＡＡ溶液强烈地促进玉米胚芽鞘切段的延长生长和质子分泌,但这两种效应的启动时间有别．Ｃａ２＋在高浓度下（２—５ｍｍｏｌ／Ｌ）强烈抑制ＩＡＡ诱导的延长生长,但在低浓度下（０．５ｍｍｏｌ／Ｌ）则有轻微的促进作用．ＩＡＡ增大质膜相对透性,而Ｃａ２＋则有稳定膜的作用,且适宜的浓度较低（０．５ｍｍｏｌ／Ｌ）．     

水稻叶片中过氧化氢与核酮糖—1,5—二磷酸羧化酶／加氧酶降解 …

甲基紫精（ＭＶ）处理水稻植株能快速诱导核酮糖－１,５－二磷酸羧化酶／加氧酶（Ｒｒｂｉｓｃｏ,ＥＣ４．１．１．３９）及其它可溶性蛋白的降解。ＭＶ浓度越高,降解速率越高。ＭＶ能诱发叶片内源Ｈ２Ｏ２迅速积累。光合电子传递抑制剂ＤＣＭＵ（１５０μｍｏｌ／Ｌ）能显著抑制ＭＶ（１００μｍｏｌ／Ｌ）诱导的Ｒｕｂｉｓｃｏ及其它可溶性蛋白的降解;活性氧清除剂抗坏血酸（５ｍｍｏｌ／Ｌ）、甘露醇（１０ｍｍｏｌ／Ｌ）、苯     

水杨酸对黄瓜叶片抗氧化剂酶系的调节作用

分析了水杨酸（ＳＡ）对黄瓜（ＣｕｃｕｍｉｓｓａｔｉｖｕｓＬ．）叶片抗氧化剂酶系活性及活性氧水平的调节作用。不同浓度的ＳＡ（０．５ｍｍｏｌ／Ｌ、１ｍｍｏｌ／Ｌ、２．５ｍｍｏｌ／Ｌ、５ｍｍｏｌ／Ｌ）均能显著地提高被处理叶片超氧化物歧化酶（ＳＯＤ）和过氧化物酶（ＰＯＤ）活性,而且还能诱导同株的非处理叶片中ＳＯＤ和ＰＯＤ活性增加。用１ｍｍｏｌ／ＬＳＡ处理第一片真叶,在处理后６～７２ｈ,ＰＯＤ活性增加了２２％～６７％,同株非处理的第二片真叶ＰＯＤ活性增加了１４％～８６％,但是,在ＳＡ处理后３ｈ之前以及处理９６ｈ之后,ＰＯＤ活性没有变化。ＳＡ能够显著降低超氧物阴离子含量和提高过氧化氢水平,但它对过氧化氢酶（ＣＡＴ）活性的抑制作用很弱,表明ＳＡ提高体内过氧化氢含量的原因主要是通过提高ＳＯＤ活性而不是抑制ＣＡＴ活性。同工酶分析表明,ＳＡ不能诱导新的ＳＯＤ同工酶,但可以诱导新的ＰＯＤ同工酶。     

黑鹅膏菌（Amanita fuliginea）毒素的HPLC初步分离鉴定

本文了用反相高效液相色谱法（ＨＰＬＣ）分离黑鹅膏实体内几种鹅膏毒素的结果,采用Ｃ１８液相柱,以不同浓度的０．０２ｍｏｌ／Ｌ乙酸铵－乙腈混合液为流动相,从黑鹅膏子产体中分离并鉴定出了６种毒素,每公斤干重含量分别为（ｍｍｏｌ）：α－毒伞肽：５．１９ｍｍｏｌ;β－毒伞肽;１．１７ｍｍｏｌ;ｐｈａｌｌｏｉｄｉｎ;１．５ｍｍｏｌ;ｐｈａｌｌａｃｉｄｉｎ;０．４０ｍｍｏｌ;ｐｈａｌｌｉｓｉｎ;０．２６ｍｍｏｌ     

Rice Resistance to Brown Spot Mediated by Nitrogen and Potassium

This study was undertaken to investigate the effects of both nitrogen (N) and potassium (K) rates on rice resistance to brown spot, caused by the fungus Bipolaris oryzae. Rice plants (cultivar ‘Metica 1’) were grown in soil corrected with 0, 25, 50, 75 and 100 mg of N / kg (as NH₄NO₃) of soil as well as with 25, 50, 75, 125 and 150 mg of K / kg (as KCl) of soil. Thirty‐three‐day‐old plants were inoculated with a suspension of Bipolaris oryzae conidia and the incubation period (IP), number of lesions (NL) per cm² of leaf area and disease severity was evaluated. Disease severity was scored at 24, 48, 72, 96, 120 and 144 h after inoculation and data were used to obtain the area under brown spot progress curve (AUBSPC). Soil plant analysis development (SPAD) index, plant dry weight and concentration of N and K in leaf tissues were also determined for both non‐inoculated (NI) and inoculated (IN) plants. Concentration of N in leaf tissue increased as the N rates in the soil increased. Concentration of K in leaf tissue increased sharply as the K rates in the soil increased for both NI and IN plants. Concentration of K in leaf tissue was not affected by N rates. The IP increased as the N rates increased, but was somewhat less impacted by increasing K rates. The NL decreased as the N rates increased. The NL dramatically declined at the highest K rates. The AUBSPC dramatically declined as the N and K rates in the soil increased. SPAD index values increased as the N and K rates in the soil increased for both NI and IN plants. Plant dry weight increased as the N and K rates in the soil increased for both NI and IN plants. Results from this study suggest that combining high N and K rates may contribute to reducing the intensity of brown spot in rice while improving plant development.     

NaCl胁迫下高纬度移植桐花树幼苗的生理生态效应

通过砂培试验,研究了不同浓度NaCl(0、100、200、300和400 mmol·L-1)处理对高纬度移植桐花树幼苗生物量、离子吸收、碳氮代谢、叶片光合色素和叶片抗氧化系统的影响.结果表明:100 mmol·L-1NaCl处理对桐花树生长有轻微的促进作用,当NaCl浓度达到300mmol·L-1时,桐花树根、茎、叶器官的干鲜质量、根冠比、株高和基径均显著下降.高盐胁迫抑制了叶片抗氧化系统中超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性,提高了丙二醛含量,降低了叶片中叶绿素、类胡萝卜素总量以及根茎叶的可溶性总糖和游离氨基酸总量.不同浓度NaCl胁迫下,桐花树根茎叶中Na+含量快速上升,K+含量相对下降,K+/Na+快速下降,导致各器官中离子平衡失调.当NaCl浓度高于300 mmol·L-1时,桐花树根茎叶的碳氮代谢运转失调,抑制了植株的正常生长,导致各器官的生物量显著下降.     

不同氮营养水平下草莓叶片光合作用对高CO2浓度的适应

研究了不同氮素水平（12mmol／L,4mmol／L,0、4mmol／L）下生长的‘丰香’草莓在富C02（700μL/L）和大气CO（390μL/L）下的光合作用。结果表明,高氮（12mmol／L）下,在富CO2环境中生长的‘丰香’草莓叶片未出现光合作用下调,富CO2下草莓叶片的净光合速率、最大羧化速率（Vc.max）、最大电子传递速率（Jmax）、碳同化的电子传递速率（Jc）和光化学猝灭系数（qp）等均显著提高;而在中氮（4mmol／L）、低氮（0．4mmol／L）下,富CO2下生长的草莓叶片的上述参数均出现不同程度的下降。富CO2下,无论氮素水平如何,草莓叶片的光呼吸电子传递速率（Jo）均降低高氮草莓叶片的非光化学猝灭系数（qN或NPQ）降低,光抑制降低,而低氮则相反。上述结果说明,氮素供应不足时草莓叶片在富CO2下光合作用出现下调,因此生产上进行CO2施肥时应适度增加氮素的供应。     

Effect of Substrate Moisture and Potassium on Water Relations and C, N and K Distribution in Vigna Radiata

The Vigna radiata L. plants were grown in greenhouse at moisture content of sand (SMC) of 12.0 ± 0.5 %. At flower bud initiation stage, i.e. 45 - 50 d after sowing, the SMC was decreased to 3.5 ± 0.5 %, and the effects of applied potassium (0, 2.56 and 3.84 mmol dm-3) were studied. During water stress, K-fed plants maintained higher leaf water potential and relative water content (RWC) of leaves and nodules and lower osmotic potential as compared to untreated plants. The proline content was higher in nodules than in leaves showing their difference in degree of stress. A partial recovery was found after re-irrigation. When subjected to drought, carbon was accumulated in the leaves and declined in nodules and roots. K-fed plants showed higher C and N content in stem, roots and nodules than untreated plants. The content of K significantly increased in stem and nodules in K-fed plants, irrespective of SMC. Dry masses of different plant parts were also increased in K-fed plants. This revised version was published online in July 2006 with corrections to the Cover Date.     

转HAL1基因番茄的耐盐性

利用农杆菌介导的叶盘法,把HAL1 基因转入番茄,Southern杂交检测得到转基因植株.耐盐实验表明, T1代转基因番茄在150 mmol/L的NaCl胁迫下仍有43%的发芽率,200 mmol/L的NaCl胁迫下发芽率为6%,而对照种子在100和150 mmol/L的NaCl胁迫下发芽率分别为11.0%和0.转基因番茄的电解质相对外渗率小于对照,而根冠比和叶绿素含量大于对照,转HAL1基因显著提高了番茄的耐盐性.盐胁迫下Na 、K 的累积状况表明,转基因番茄根、茎、叶的K /Na 均有所提高,根系的SK/Na增大,茎、叶的RSK/Na和RLK/Na减小,说明根系对K /Na 离子的选择吸收和运输能力加强.不但选择吸收K /Na ,而且表现出整株水平上的有利于耐盐的K /Na 区域化分配.     

滇池流域富磷区不同土壤磷水平下植物叶片的养分化学计量特征

滇池流域是我国典型的富磷区, 分析该区域内不同土壤磷含量下主要植物的化学计量特征, 有助于理解该区域的生态环境特点和生态恢复的特殊性。该研究测定了滇池流域滇中地区75种常见植物叶片的碳(C)、氮(N)、磷(P)及钾(K)含量, 综合分析了该区域不同土壤磷水平(富磷和正常)下不同生活型植物叶片的C、N、P和K的计量特征。结果表明, 研究区域植物叶片C、N和K含量的算术平均数分别是441.42、16.17和13.57 mg·g^-1, P含量的几何平均数为1.92 mg·g^-1, 植物叶片的N、P和K含量之间呈显著的正相关; 富磷区域植物叶片的P和K含量显著高于正常区域, N/P、K/P显著低于正常区域。无论是富磷还是正常区域, 草本植物的N、P和K含量均高于木本植物, 乔木与灌木差异不明显。植物叶片的P含量及N/P与土壤磷水平呈显著相关; 叶片N/P分析结果表明, N是影响滇池流域植物生长和群落恢复的主要限制元素。研究指出, 在滇池流域增加陆地植物群落及生态系统的氮素来源是进行生态修复和面源污染防治的重要切入点。     

盐地碱蓬二型性种子及其幼苗对盐渍环境的适应性

研究了盐地碱蓬二型性种子中离子含量与刚萌发幼苗耐盐性之间的关系,以及盐分对砂培盐地碱蓬二型性种子的幼苗生长、离子含量及光合特性的影响.棕色种子中离子含量显著高于黑色种子.与对照相比,100和400 mmol/L NaCl对棕色种子幼苗伸长没有抑制作用,却显著抑制黑色种子幼苗的伸长.NaCl处理下棕色种子的幼苗地上部分干重和主茎一级分枝数比黑色种子幼苗高,但二型性种子的幼苗叶片中离子含量、叶绿素含量及光合放氧速率却没有明显差异.上述结果说明盐地碱蓬棕色种子较高的离子含量可能是棕色种子刚萌发幼苗耐盐性较强的重要原因.棕色种子幼苗较高的生物量可能与其较多的分枝数有关.二型种子的这些特征可能决定了其在群落建成中所起到的不同作用.     

Effects of nitrogen supply on the anatomy and chemical composition of leaves of four grass species belonging to the genus Poa, as determined by image-processing analysis and pyrolysis–mass spectrometry

Previous experiments have shown that the anatomy and chemical composition of leaves of inherently fast- and slow-growing grass species, grown at non-limiting nitrogen supply, differ systematically. The present experiment was carried out to investigate whether these differences persist when the plants are grown at an intermediate or a very low nitrogen supply. To this end, the inherently fast-growing Poa annua L. and Poa trivialis L., and the inherently slow-growing Poa compressa L. and Poa pratensis (L.) Schreb. were grown hydroponically at three levels of nitrate supply: at optimum (RGR_max) and at relative addition rates of 100 and 50 mmol N (mol N)^?1 d^?1 (RAR₁₀₀ and RAR₅₀), respectively. As expected, at the lowest N supply, the potentially fast-growing species grew at the same rate as the inherently slow-growing ones. Similarly, the differences in leaf area ratio (LAR, leaf area:total dry mass), specific leaf area (SLA, leaf arear:leaf dry mass) and leaf mass ratio (LMR, leaf dry mass:total dry mass) disappeared. Under optimal conditions, the fast-growing species differed from the slow-growing ones in that they had a higher N concentration. There were no significant differences in C concentration. With decreasing N supply, the total N concentration decreased and the differences between the species disappeared. The total C concentration increased for the fast-growing species and decreased for the slow-growing ones, i.e. the small, but insignificant, difference in C concentration between the species at RGR_max increased with decreasing N supply. The chemical composition of the leaves at low N supply, analysed in more detail by pyrolysis–mass spectrometry, showed an increase in the relative amounts of guaiacyl lignin, cellulose and hemicellulose, whereas those of syringyl lignin and protein decreased. The anatomy and morphology of the leaves of the four grass species differing in RGR_max were analysed by image-processing analysis. The proportion of the total volume occupied by mesophyll plus intercellular spaces and epidermis did not correlate with the amount of leaf mass per unit leaf area (specific leaf mass, SLM) at different N supply. The higher SLM at low N supply was caused partly by a high proportion of non-veinal sclerenchymatic cells per cross-section and partly by the smaller volume of epidermal cells. We conclude that the decrease in relative growth rate (and increase in SLM) at decreasing N supply is partly due to chemical and anatomical changes. The differences between the fast- and slow-growing grass species at an optimum nutrient supply diminished when plants were growing at a limiting nitrogen supply.