青海高原矮嵩草和珠芽蓼的光合适应性比较(英文)

对生长在两个海拔地带 (3 2 0 0m ,3 980m)的矮嵩草 (KobresiahumilisSerg.)和珠芽蓼 (PolygonumviviparumL .)叶片的叶绿素荧光特性及其叶绿体超微结构进行了比较研究。海拔升高 ,矮嵩草和珠芽蓼叶片的Fv/Fo、Fv/Fm和Rfd值均增大 ,且矮嵩草的Fv/Fo、Fv/Fm 和Rfd值均大于珠芽蓼。叶绿体超微结构的结果显示 ,海拔升高 ,珠芽蓼和矮嵩草的叶绿体都表现出一定程度的变形 ,但珠芽蓼的叶绿体变形和类囊体膜肿胀现象更为显著。研究表明 ,矮嵩草和珠芽蓼光合作用对高山胁迫环境具有很强的适应性 ,且矮嵩草的适应能力比珠芽蓼强。     

运用叶绿素a荧光诱导动力学技术检测水稻生产潜力

运用叶绿素a荧光诱导动力学技术,检测水稻叶片和叶绿体的PSII原初光转化效率(F_v/F_m)或与此相关可代表PSII潜在活性(F_v/F_o)的参数,结果表明,不同产量水平的水稻品种之间,其叶片和叶绿体的F_v/F_m(或F_v/F_o)的比值,以及光合电子传递速率均有明显差异.此外,在外源Mg~(2+)的存在下,高产水稻品种叶绿体有更高的原初光能转化效率,同时Mg~(2+)对高产品种叶绿体PSII和PSI之间激发能分配的调节能力也较低产品种者高.实验说明Chl a荧光诱导动力学的技术,能够作为一种快速、灵敏和简便的有效方法用于早期检测水稻(或其他作物)的生产潜力.     

青海高原不同海拔珠芽蓼叶绿体超微结构的比较

 用电子显微镜技术观察研究了生长于青海高原3个海拔地带(2500m、3200m、3980m)的珠芽蓼(polygonum viviparum L．)叶绿体的超微结构,发现随着海拔的升高,叶绿体结构呈现显著的变化趋势。2500m和3200m处叶绿体形状规则,分布在细胞边缘。3980m处叶绿体膨大变形,且分布在整个细胞当中。海拔升高,类囊体膜减少,膜垛叠程度减小。不同海拔珠芽蓼叶绿体的类囊体膜结构差异较大,特点显著。随海拔升高,珠芽蓼叶绿体破坏程度增加。主要表现为类囊体膜肿胀、类囊体膜溶解和叶绿体破裂。许多破裂的叶绿体中残留有发达的基粒和大而多的淀粉粒。珠芽蓼叶绿体的这些结构特征,既是环境胁迫的结果,又是植物适应性的表现。     

不同海拔地区紫外线B辐射状况及植物叶片紫外线吸收物质含量的分析

对不同海拔地区的太阳 UV- B辐射和植物叶片的光学特性进行了比较研究。结果表明 :位于高海拔地区的海北高寒草甸生态系统定位站 ,太阳 UV- B辐射明显高于相近纬度的西宁、兰州和南京地区。UV- B辐射与总辐射和 PAR的日变化规律相似 ,都受太阳高度角的直接影响 ,在当地太阳正午时最高。UV- B/Q的日变化也为单峰曲线 ,海北站地区的 UV- B/Q高于西宁的同期测定结果。对珠芽蓼等植物的研究表明 ,生长于海北站地区的珠芽蓼 ,其叶片中紫外线吸收物质的含量明显高于西宁的同种植物 ,也略高于海拔较高的达坂山和小达坂山山顶的同种植物。叶绿素含量以海北站珠芽蓼最低 ,达坂山和小达坂山的同种植物最高。珠芽蓼叶片中类胡萝卜素的含量以西宁最低 ,海北站、达坂山和小达坂山依次升高。海北站矮嵩草与从海北站移植到西宁生长 4年的同种植物相比 ,叶片中紫外线吸收物质、叶绿素、类胡萝卜素的变化与生长于两地区的珠芽蓼相同     

水分胁迫对牛心朴子叶片光合色素及叶绿素荧光的影响

研究了水分胁迫对牛心朴子叶片光合色素及叶绿素荧光动力学参数的影响。结果表明,在长期的水分胁迫中,牛心朴子叶片的叶绿素a(Chl a)、叶绿素b(Chl b)和类胡萝卜素(Car)含量没有下降或下降不明显。直到处理末期才显著下降;叶片叶绿素荧光动力学参数Fo、Fm、Fv、Fv／Fm变化不大,在处理末期各处理Fo降低,轻度、重度水分胁迫的Fm、Fv、Fv／Fm升高。说明K期水分胁迫后牛心朴子的光合功能受到影响,但牛心朴子仍表现出较强的适应干旱的能力。     

Growth and photosynthetic activity of micropropagated strawberry plants inoculated with endomycorrhizal fungi (AMF) and growing under drought stress

The plants produced by in vitro methods are free of any microflora contrary to natural systems where plants are colonized by symbiotic fungi. The present paper reports the experiments carried out to evaluate the role of arbuscular endomycorrhizal fungi in development of micropropagated strawberries and their photosynthetic activity (measured by chlorophyll fluorescence) under drought conditions. Mycorrhization strongly affected growth and tolerance to water deficiency of the plants cultivated in greenhouse. Wilting of not-mycorrhized plants was accompanied by drastic increase of Fo and Tfm and decrease of Fm. At the same time, the value of these parameters for mycorrhized plants did not change. Drastic decrease in the value of parameters Fv/Fm, Fv/Fo and Fo/Fm for plants without AMF appeared at the end of dry period. Rise of Fs and decrease Rfd was noted only for not-mycorrhized plants. The plants colonized by fungi, fully recovered their photosynthetic activity when watering was restored.     

干旱胁迫对不同葡萄砧木光合特性和荧光参数的影响

干旱胁迫导致葡萄砧木实生苗叶片光合能力下降.在正常供水和轻度干旱下,砧木的P_n 以3309C最高,其次是1103P,420A较低,各砧木的G_s和T_r差异不显著;中度干旱下,则以1103P的P_n最高,3309C最低;而严重干旱胁迫下,1103P的P_n比3309C高出124%,水分利用效率是3309C的1.95倍.干旱胁迫下,3种砧木的共同趋势是可变荧光 (F_o) 升高,最大荧光 (F_m)、实际光能转化效率 (ФPSⅡ）和可变荧光与最大荧光比 (F_v/F_m) 降低,但品种变幅不同.中度干旱使3309C的F _o升高17.1%,F_v/F_m降低了8.5%,而1103P的F_o升高6.8%,F_v/F_m降低了5.8%;严重干旱则使3309C的F_o升高36.2%,F_v/F_m降低了20.1%,而1103P的F_o升高9.9%,F_v/F_m降低了10.2%.干旱胁迫对不同葡萄砧木光合和荧光参数的影响与其抗旱性密切相关,其中F_v/F_m和P_n的相关系数最大（r=0.9883）.     

不同剂量^137Cs-γ辐射对毛竹幼苗叶片叶绿素荧光参数的影响

利用不同剂量的137Cs-γ射线对毛竹（Phyllostachys heterocycla ‘Pubescens’）种子进行辐射, 测定实生苗叶片中的光合色素含量和叶绿素荧光参数等指标, 探讨辐射对毛竹幼苗生长的影响, 为筛选有利的突变单株奠定良好基础。结果表明：30或60 Gy的137Cs-γ射线辐射后, 毛竹幼苗的光合色素含量以及最大荧光强度（Fm）、可变荧光强度（Fv）、PSII最大光化学效率（Fv/Fm）、PSII的潜在活性（Fv/Fo）、PSII实际光化学效率（Yield）和表观光合电子传递速率（ETR）等荧光参数值均高于90 Gy辐射处理, 说明较低剂量辐射后PSII反应中心的能量捕获效率高, 且具有较强的光合能力; 而90 Gy的137Cs-γ射线辐射对毛竹的影响则与之相反。不同处理剂量之间叶片光能耗散程度以及表观光合电子传递速率-光合有效辐射（ETR-PAR）响应曲线的分析结果也进一步证实了以上结论。     

外源Ca2＋对高温强光胁迫下灌浆期小麦叶片光合机构运转的影响

灌浆期叶面喷施10mmol·L-1 CaCl2对高温强光胁迫下小麦叶片光合电子传递、放氧速率、叶绿素荧光参数和D1蛋白的影响结果表明,Ca2＋预处理可保护D1蛋白,削弱其降解,提高光系统I（PSI）和光系统Ⅱ（PSⅡ）子传递速率、全链电子传递速率、净光合速率（Pn）、PSII最大光化学效率（Fv/Fm）、PSII实际光化学效率（ΦPSⅡ）和光化学猝灭（qp）,维持较低的Fo,最终导致小麦适应高温强光的能力提高。     

外源甜菜碱对盐胁迫下枸杞光合功能的改善

研究了外源甜菜碱对盐胁迫下枸杞扦插苗叶片光合功能的影响。结果表明,外源甜菜碱能使盐胁迫下的枸杞叶片叶绿素荧光动力学参数Fo、Fm、Fv、Fv／Fm、Fm／Fo和Fv／Fo增高,使光合色素叶绿素a(Chla)、叶绿素b(Chlb)和类胡萝卜素(Car)含量明显增加,叶绿素a与b的比值(Chla／Chlb)升高,类胡萝卜素与叶绿素的比值(Car／Chl)降低,说明外源甜菜碱有利于植物对光能的捕获、吸收、传递和转换,提高叶片的光合活性,降低盐胁迫对植物的抑制作用。     

青藏高原不同海拔矮嵩草抗逆性的比较研究

主要对生长在海拔４００ｍ（大坂山）,３２００ｍ（海北部）和２２００ｍ（西宁）的地区同矮嵩草的生理生态适应特性进行了比较研究。结果表明：生长在３个不同海拔地区的矮嵩草其生长发育和干物质和积累具有明显差异,随着海拔高度的增加,植株高度明显变低,叶面积、叶绿素含量和干物质积累减少;类胡萝卜素和类黄酮含量增加;光合速率、光饱和点和补偿点提高;光呼吸强度减弱。在花果前期,海拔４０００ｍ处植株地上组织的蔗糖、     

热带林下人工种植阳春砂仁的生长与果实产量动态

调查了西双版纳不同海拔热带沟谷雨林和次生林下的阳春砂仁生长和果实产量动态.结果表明,西双版纳热带林下阳春砂仁自身年龄增长、林下光照不足和旱季水分胁迫影响阳春砂仁果实产量.随种植期增加,阳春砂仁果实产量和成熟植株密度降低.当林下光照水平在全日照的35%以下时,阳春砂仁果实产量随林下日照水平变化呈线性增加(P<0.05).沟谷下方阳春砂仁果实产量显著高于上方(P<0.05).海拔600～1000m,由于阳春砂仁的主花期从干热季3～4月推迟到雨季5月,果实产量显著增加.沟谷雨林和次生林下阳春砂仁果实产量差异不显著.因此,在海拔800～1000m沟谷中轮歇地次生林下有计划种植阳春砂仁,代替在沟谷雨林下种植阳春砂仁,既能解决沟谷雨林下光照和当地旱季水分不足对阳春砂仁果实产量的影响,又有利于热带沟谷雨林的保护.     

Photoinhibition in Shaded Cotton Leaves After Exposing to High Light and the Time Course of Its Restoration (in English)

Chlorophyll fluorescence emission, pigment composition and photosynthetic rate of shade-grown cotton (Gossypium hirsutum L.) plants were measured immediately after suddenly exposing to full sunlight and at regular intervals there after within 15 d. Photoinhibition occurred in shade-grown cotton leaves immediately after exposed to full sunlight. The chlorophyll fluorescence parameter Fv / Fm and ΦPSⅡ , which reflect the efficiency of PSⅡ, obviously decreased in shade-grown leaves, much lower than that of the full sunlight-grown leaves. On the contrary, Fo value was sharply increased. Neither of these parameters could completely recover till next morning. The photoinhibition was chronic and continued for about 4 d, while the Fv / Fm and the net photosynthetic rate ( Pn ) continued to decline, then began to increase gradually 6 d later and turned stable after 10-12 d, appearing as an acclimation phenomenon. However, the final value of Fv / Fm and Pn did not reach the level as in those leaves grown in the full sunlight ever before. The final Pn was higher by 60% than that before exposure, but lower for more than 40% than that of the full sunlight-grown leaves. The most notable response of chloroplast pigment composition was a pronounced increase in the pool size of carotenoids in xanthophyll cycle over a period of 3 d. The results indicated that when shade-grown cotton seedlings were suddenly transferred to the full sunlight, the decline of Fv / Fm and Pn might associate with the damage of the PSⅡ reaction center. During the light acclimation, photoprotective mechanisms such as the xanthophyll cycle-dependent energy dissipation were increased, so that photodamage in leaves transferred from low to high light might be reduced.     

微量元素营养对桉树无性系苗木叶绿素及荧光参数影响

研究了不同微量元素营养液,对栽培的三种桉树无性系苗木叶绿素及荧光参数变化。结果表明:各无性系苗木在全部测试性状的差异表现出极显著。在六个测试的微量元素因子中,Fe(B)显著地影响苗木的Fo、Fm、Fv/Fo、Fv/Fm,Zn(C)显著地影响Fo、Fv/Fm,Mn(D)显著地影响叶绿素含量(SPAD值),Mo(F)显著地影响叶绿素含量、Fo,B(G)显著地影响叶绿素含量Fo、Fv/Fo、Fv/Fm。相关分析表明Fm与Fo、Fv/Fo与Fo、叶绿素含量与Fo、Fm、Fv/Fm与Fv/Fo均存在显著的相关性。随着微量元素Fe、Zn、Cu、Mo、B浓度增大,Fo、Fv/Fm均呈增大趋势,但在不利的高浓度环境下,Fv/Fm降低。对三个无性系叶绿素荧光比较,U₆与DH_32-29具有高的Fo、Fm和低的Fv/Fm、Fv/Fo,DH_201-2却具有低的Fo、Fm和高的Fv/Fm、Fv/Fo。对微量元素浓度变化,DH_32-29较敏感。因此,叶绿素荧光参数可作为诊断植物微量元素营养状况的指标之一。     

Dirunal leaf movement, chlorophyll fluorescence and carbon assimilation in soybean grown under different nitrogen and water availabilities

Diurnal heliotropic leaf movements, photosynthetic gas exchange, and the ratio of variable fluorescence to maximum fluorescence (Fv/Fm) of unrestrained and horizontally restrained leaves from soybean (Glycine max cv. Cumberland) plants grown in two different water and two different nitrogen treatments were measured. Leaves of plants grown in low water or low nitrogen availability treatments displayed more pronounced diaheliotropism (solar tracking) in the afternoon and a longer period of paraheliotropism (light avoiding) at midday relative to those of well-watered, high-nitrogen-grown plants. Photosaturated photosynthetic rates and the photon flux required to saturate photosynthesis were reduced by water stress and nitrogen deficiency. Compared to horizontal leaves, irradiance on orienting leaves was nearer to the breakpoint of the photosynthetic light response curve, where photosynthesis is co-limited by ribulose biphosphate regeneration and carboxylation. This would increase the carbon return on investments of nitrogen into photosynthesis. A positive linear relationship between Fv/Fm and quantum yield of photosynthesis was measured. Leaves of low-nitrogen-grown plants had earlier and more prolonged reductions in Fv/Fm at midday compared to leaves of high nitrogen grown plants of the same water treatment. Within the same water and nitrogen treatment, horizontally restrained leaves had lower midday Fv/Fm in relation to orienting leaves. Nitrogen deficiency and water stress enhanced this difference such that horizontally restrained leaves of low water and low nitrogen grown plants had earlier and longer midday depressions in Fv/Fm.     

Effects of Strong Light and Active Oxygen on Photosynthesis in Soybean

With the use of chlorophyll fluorescence technique, it was found that the net photosynthetic oxygen evolution rate decreased after strong light (2 000 μmol· m-2·2-1 ) treatment for two hours in soybean ( Glycine max L. ) leaves. The chlorophyll fluorescence parameters, Fm/Fo, Fv/Fm, ФPSII, qp and qN decreased along with the increase of light intensity. In strong light, exogenous active oxygen H202、·OH and 'O2 were harmful to soybean leaves. The destruction of 'O2 and·OH to leaves was most evident, as was shown that Fv/Fm and PS H decreased significantly. The antioxidants DABCO, mannitol, ascorbate and histidine protected the leaves, but weakly, from strong light. In darkness, the SOD inhibitor sodium diethyldithiocar- bamate (DDC) had no significant effect on Fm/Fo and Fv/Fm, but NAN,, the ascorbate peroxidase (APX)inhibitor, significantly decreased Fm/Fo, Fv/Fm and ФPS II. In strong light, however, beth DDC and NaN3 reduced the above-mentioned fluorescence parameters, but NaN3 was more effective than DDC. The results suggested that photoinhibition did take place in soybean leaves under strong light, and it was related to active oxygen in vivo.     

水分胁迫与复水对地枫皮生理生态特性的影响

以岩溶特有药用植物地枫皮为材料,研究土壤水分胁迫及复水条件下,其叶片光合参数、叶绿素荧光参数及光合色素含量的变化特性,进而探讨其对水分胁迫的生理生态适应性。结果表明:停止供水10 d,水分胁迫地枫皮叶片的P_n(净光合速率)、C_i(胞间CO_2浓度)、G_s(气孔导度)和L_s(气孔限制值)均下降,气孔限制是P_n降低的主要原因;停止供水15 d,水分胁迫地枫皮叶片的P_n日变化呈逐渐下降趋势,上午9:30以后全天的P_n值均接近零,非气孔限制成为P_n下降的主要因素;而对照地枫皮叶片的P_n日变化呈"双峰型",中午P_n下降的主要原因依然是气孔限制。水分胁迫下,地枫皮叶片叶绿素含量降低和Chl_(a/b)升高,减少了叶片对光能的捕获,减轻了光合机构遭受光氧化的破坏,而Car/Chl_(a+b)升高增强了光保护能力。水分胁迫下,地枫皮叶片的初始荧光(F_o)显著增大,最大荧光(F_m)、光系统Ⅱ(PSⅡ)潜在活性(F_v/F_o)和最大光化学效率(F_v/F_m)均显著降低,表明水分胁迫对地枫皮叶片的PSⅡ反应中心和电子传递造成了一定的破坏,从而使其PSⅡ的潜在活性和最大光化学效率降低。复水5 d后,地枫皮的上述生理生态参数均能恢复到对照水平,表明其复水后的生理修复能力很强。     

高温胁迫对柑橘光合速率和光系统Ⅱ活性的影响

用红外CO2分析仪和叶绿素荧光仪测定了温州蜜柑和脐橙叶片的净光合速率(Pn)、初始荧光(Fo)、最大光能转换效率(Fv／Fm)及电子传递速率(ETR)．结果表明,与常温(25℃)相比,高温胁迫(38～40℃)使温州蜜柑和脐橙叶片的Pn、Fv／Fm及ETR下降,Fo升高．胁迫25d后温州蜜柑和脐橙叶片的Pn分别下降55．6％和39．8％．Fv／Fm下降22．0％和6．7％,ETR下降55．0％和41．5％,Fo分别上升了113．8％和14．9％．柑橘经高温胁迫后,在25℃下处理10d,叶片的Pn、Fv／Fm、Fo及ETR恢复明显．这些结果说明柑橘的光合速率下降与PSⅡ反应中心失活有关．     

矮嵩草光合作用与环境因素关系的比较研究

 以青海高原不同海拔地区生长的矮嵩草(Kobresia humilis)为材料,研究高山植物光合作用随海拔梯度的变化特征及对生长环境和低温胁迫的反应。随海拔升高矮嵩草叶绿素含量有降低的趋势,而叶绿素a／b值和类胡萝卜素含量则随海拔升高而增高。生长地区海拔越高矮嵩草光合速率、光补偿点、光饱和点越高;而光合表观量子产额则随海拔升高而降低。光呼吸强度有随海拔升高而降低的趋势。矮嵩草光合作用特性受生长环境因素的影响。低温胁迫导致矮嵩草光合速率、表观量子产额降低,低温下的光照加剧了光合作用抑制的程度。     

木棉叶片叶绿素荧光参数和SPAD值对干旱胁迫的响应

采用盆栽控水干旱法模拟干旱逆境,对1年生木棉(Bombax ceiba)盆栽苗进行不同程度的胁迫处理,测定干旱胁迫时其叶片叶绿素SPAD值和荧光参数动态变化。结果表明,干旱胁迫下,木棉叶片叶绿素相对含量逐渐降低;初始荧光(Fo)随着干旱程度的加剧而呈上升趋势,而最大荧光(Fm)、潜在光化学效率(Fv /Fo)、最大光化学效率(Fv /Fm)、光化学淬灭系数(qP)和表观光合电子传递速率(ETR)下降,在中度和重度干旱胁迫时差异显著(P＜0.05);非光化学淬灭系数(NPQ)变化不显著。干旱胁迫导致木棉植株出现光抑制,植株可通过降低光化学淬灭、增加热耗散的形式增强对干旱的适应能力。