超声波对白术幼苗生长的影响（简报）

中药白术种子经超声波处理后,发芋率及幼苗生长高度、叶面积和根系长度均受到明显的促进     

光照度对豚鼠屈光发育的影响

目的探讨豚鼠在不同光照度照明条件下(10 000,500,5 lx,白色光,色温6000 K)的屈光发育状况,以比较光照度对豚鼠屈光发育的影响。方法 30只3周龄的豚鼠(英国种三色豚鼠),随机分为强光组10只、对照组10只和弱光组10只,分别置于10 000、500、5 lx三种光照度环境下,光照周期为12/12 h(早6:00～晚6:00)。于实验前及光照12周末分别用带状检影计、A超测定仪、角膜曲率计对豚鼠右眼重复进行眼球的生物学测量(包括屈光度、眼轴、角膜曲率)。光照12周结束后处死豚鼠取右眼球行高效液相色谱分析,对不同时间点的组间测量数据采用单因素方差分析,以P<0.05为差异有统计学意义。结果光照前不同组间生物学测量参数差异无显著性(P>0.05)。光照12周后,强光组屈光度为(4.03±1.59)D,同光照前相比发生(0.45±1.65)D的变化,对照组屈光度为(2.15±2.01)D,发生(2.28±0.66)D的变化,强光组同对照组相比远视度数偏高约1.50 D,两者差异有显著性(P<0.05);强光组眼轴增长(0.54±0.10)mm,对照组为(0.76±0.05)mm,强光组较对照组眼轴长度延长较慢,差异有显著性(P<0.05);光照后不同组角膜曲率半径均增加,但组间变化差异无显著性(P>0.05);强光组视网膜多巴胺含量平均为(148.70±22.44)nmol/g,对照组为(44.50±12.45)nmol/g,两者差异有显著性(P<0.001)。光照12周后弱光组较对照组相比,无论是屈光度、曲率、眼轴以及视网膜多巴胺含量均无统计学差异(P>0.05)。结论强光可以引起豚鼠眼球眼轴增长减缓,正视化进展减慢,屈光度数偏远视,弱光对豚鼠的屈光发育没有影响。强光照射后可以引起豚鼠视网膜多巴胺含量增加,可能为强光引起豚鼠正视化进展减缓的机制之一。     

青霉素对几种作物种子发芽率和幼苗生长的影响（简报）

青霉素可提高玉米、水稻、黄瓜的种子发芽率、发芽指数、活力指数、幼苗长度及干重,可溶性糖含量、淀粉酶和抗坏血酸氧化酶活性。     

不同光照强度对小球藻生长的影响

【目的】优化小球藻的培养与提高资源化利用效率,得到不同光照强度对小球藻生长的影响规律。【方法】通过室内控制实验,设置0、1 000、3 000、5 500、7 000、9 000 lx共6组光照强度,在温度为20°C和曝气强度为20%的条件下,采用BG-11培养基培养小球藻(Chorella vulgaris)至稳定生长,研究不同光照强度对小球藻生长的影响,建立光照强度与最大光密度ODmax、最大比增长率μmax之间的抛物回归曲线。【结果】不同光照强度下,小球藻生长差异较大,培养初期叶绿素a浓度迅速增加直至峰值,后期迅速降低,其中5 500 lx强度下小球藻生长最好。藻类生长对溶解性总磷的消耗比溶解性总氮更大。【结论】光照强度(x)与ODmax的拟合方程为:ODmax=-1E–07x~2+0.001 6x+0.105 5(R~2=0.987 2,0≤x≤9 000 lx),光照强度(x)与μmax的拟合方程为:μmax=-2E–08x~2+0.000 3x-0.004 2(R~2=0.998 6,0≤x≤9 000 lx)。     

不同培养基对杜氏藻（DunaliellaSalina）生长和无机离子含量的影响

培养在Ｊｏｈｎｓｏｎ培养液、Ｊｏｈｎｓｏｎ＋０．３％ＮａＣｌ培养液、海水和卤水中的杜氏藻,其生长速度有区别,在Ｊｏｈｎｓｏｎ＋０．３％ＮａＣｌ培养液中生长较好,Ｊｏｈｎｓｏｎ培养液和卤水次之,海水中生长较差。杜氏藻生沃的盐度范围为０～１２％,当培养基中ＮａＣｌ浓度超过１２％时,细胞数几乎不增加,甚至略有降低。在不同培养基中藻细胞Ｈ￣＋含量较稳定,而积累ｃａ￣（２＋）,在Ｊｏｈｎｓｏｎ＋０．３％ＮａＣｌ培养液中,杜氏藻细胞Ｎａ￣＋含量增加;而在含高浓度Ｎａ￣＋的海水和卤水中杜氏藻细胞中Ｎａ￣＋的含量低于培养液。     

盐碱对黑麦草发芽和幼苗生长的影响（简报）

黑麦草种子在Na_2SO_4混合盐溶液中萌发较好,而在NaCl混合盐和Na_2CO_3盐溶液中萌发则不及对照。在三类盐中的萌发极限分别为4.5％,2.5％和0.8％。在克诺普培养液中加入Na_2SO_4时,黑麦草幼苗生长较好,加NaCl或Na_2CO_3则受抑并有盐害,前者极限浓度和致死浓度分别为1.0％和4.0％;后者分别为0.3％和1.3％。     

多效唑（PP333）对苦荞植株生长的影响（简报）

在土壤肥力水平高的条件下,在苦荞分枝始期喷施多效唑能不同程度地提高光合强度,降低叶片氨基氮和茎尖可溶性糖含量,降低株高,增加每穗的花朵数和饱粒数,提高产量。     

生长调节物质对西洋参种胚生理后熟的影响（简报）

正交试验结果表明,经２００ｍｇ／ＬＧＡ３浸泡３６ｈ后于低温下处理２０ｄ的西洋参裂口种子可完成生理后熟,６－ＢＡ效果次之,ＩＢＡ次之,ＩＢＡ无效。２００ｍｇ／Ｌ６＝ＢＡ＋２００ｍｇ／ＬＧＡ３,２００ＭＧ／Ｌ６－ＢＡ＋１００ｍｇ／ＬＧＡ３,２００ｍｇ／Ｌ６－ＢＡ＋５０ｍｇ／ＬＧＡ３浸泡３６ｈ后置于室温下不再作低温处理,其形态后熟种子也可萌发。     

烯效唑对油菜秧苗生长和产量的影响（简报）

油菜苗期喷施浓度为50、100、150mg·L(-1)的烯效唑后，秧苗高度降低，幼茎增粗，叶片小而厚，叶柄短而粗，单株绿叶数、叶绿素含量与根冠比均提高，因而秧壮。移栽于大田后有效分枝位高度降低，有效分枝数及单株角数增加，从而获得增产。     

不同光强对薇甘菊生长及光系统的影响

为了控制薇甘菊的生长和危害,对不同照度条件下薇甘菊的生长及光系统进行了测定.分别采用光强40μmol·m-2·s-1(处理Ⅰ);上午自然光,下午照度为40μmol·m-2·s-1(处理Ⅱ);全自然光(处理Ⅲ)处理薇甘菊.结果表明对薇甘菊处理2个月后,处理Ⅰ条件下,薇甘菊生长差,生物量积累少,光系统Ⅰ和光系统Ⅱ的光能转换效率和潜在活性较低,可溶性糖和蛋白质含量较低,细胞膜脂脂肪酸组成中不饱和脂肪酸含量相对较高;在处理Ⅱ和处理Ⅲ条件下,则生长茂盛,生物量积累多,光系统Ⅰ和光系统Ⅱ的光能转换效率和潜在活性较高,可溶性糖和蛋白质含量较高,细胞膜脂脂肪酸组成中不饱和脂肪酸含量相对较少.这些结果说明光照多方面影响薇甘菊光系统功能的形成,从而影响其生长.     

The Effect of Light Intensity on Stem and Leaf Growth in Broad Bean Seedlings

THE final mean size, cell number, and cell size of the threelower internodes and of a leaflet of the three lower true leaveshave been determined from seedlings grown in darkness or inlight intensities of 0.1, 1, 10, 100, or 1,000 f.c. The results indicate that the effect of light may be dividedinto two phases, a sensitive effect on cell multiplication anda less sensitive one on cell enlargement. Growth in 0.1 f.c.results in an increase in leaf area over that attained in darknessmainly due to an increase in the number of cells. Further andmore marked increases in area at 100 and 1,000 f.c. are dueto an effect on cell size. Low intensities also greatly reduceinternode length, again owing to an effect on cell multiplication.Both internode length and the number of cells are graduallyfurther reduced as the intensity is raised to 1,000 f.c. Celllength is reduced in the first (basal) internode by 10 f.c.and above, but in the second is reduced only at 1,000 f.c. Inthe third internode the cells are longer at all intensitiesthan those in the etiolated seedling. It is suggested that the basic effect of light is modified bydifferences between the successive leaves and internodes alreadypresent in the ungerminated seed, and also by a factor tendingto promote growth of the leaves and upper internodes. This factoris taken to be growth substances produced under the action oflight, or an increased supply of raw materials as a consequenceof the suppression of the lower internodes and the beginningof photosynthesis. Cell multiplication and cell enlargement are possibly controlledthrough two distinct pigment systems, with peaks of maximumefficiency in the red and blue regions of the spectrum respectively.     

Heterotrophic Growth of Blue-Green Algae in Dim Light

A unicellular blue-green alga, Agmenellum quadruplicatum, and a filamentous blue-green alga, Lyngbya lagerheimíi, were grown heterotrophically in dim light with glucose as major source of carbon and possibly energy. The dim-light conditions did not support autotrophic growth. The two blue-green algae appeared to have the same metabolic block, namely an incomplete tricarboxylic acid cycle, as has been found in other obligately phototrophic blue-green algae. Under dim-light conditions, glucose made a greater contribution to cell constituents (amino acids) of A. quadruplicatum and L. lagerheimii than under high-light conditions.     

Effect of Light Intensity during Growth on Photoinhibition of Intact Attached Bean Leaflets

In the study reported here, two different photoinhibitory phenomena were compared within a single plant species. Bean plants were grown in three different light intensities to simulate sun and shade environments. The effects of photoinhibitory treatments on in vivo CO₂ assimilation rates and in vitro chloroplast electron transport reactions were investigated and the extent to which carbon metabolism served to prevent photoinhibition was characterized. It was shown that the photoinhibition which follows exposure of intact leaflets of low light-grown bean plants to high light intensity in normal air is essentially similar to that which occurs when leaflets of plants grown in full sunlight are illuminated in the absence of CO₂ at low O₂ partial pressures.     

The Effect of Light Quality on Shoot Extension Growth in Three Species of Grasses

The effect of light quality on the extension growth of vegetativeshoots and on the final size of their leaves was investigatedin plants of Lolium multiflorum, Sporobolus indicus and Paspalumdilatatum. Three experimental approaches were used, (a) redor far-red end-of-day irradiations of sunlight-grown plants,(b) different red/far-red ratios of white light in a growthroom and (c) sunlight enrichment with radiation of differentred/far-red ratios or with different amounts of far-red lightduring the photoperiod. Plants treated with end-of-day far-redor low red/far-red ratios throughout the photoperiod developedlonger leaves and, as a result, longer shoots. This effect wasmore marked in leaf sheaths than in blades. Tiller extensionand leaf sheath length increased with the amount of far-redadded to sunlight in a simple hyperbolic relationship. Theseresults show that vegetative grass shoots respond to light qualityin a way similar to internodes of dicotyledonous plants. Lolium multiflorum Lam., Sporobolus indicus (L.), Paspalum dilatatum (Poir.), leaf growth, tiller growth, photomorphogenesis     

Effect of Light Intensity on Growth of Natural Populations of Dactylis glomerata L.

The growth of two natural populations of cocksfoot from contrastingclimatic regions, Norway and Portugal, was studied in two photoperiodsat three temperatures with three levels of light energy (48,144, and 240 W m^–2 in the wavelength interval 400–700nm). There was a consistent increase in relative growth-rate(RGR) in response to increased light energy up to 144 W m^–2,but above this energy level there was either no change, or,in some treatments, a decline. Net assimilation rate (NAR) increased,whilst leaf area ratio decreased from the lowest to the highestenergy level in most treatments. The decrease of LAR with increasedlight energy could be attributed to a decrease of both leafweight ratio (LWR) and specific leaf area (SLA), a greater proportionof dry matter being distributed to plant parts other than leaf.This effect occurred although there was a positive relationshipbetween light energy and relative leaf growth-rate (RLGR). Populationdifferences in these growth attributes were most marked in thetreatments with low-temperature and short-day conditions. Theefficiency of energy conversion of visible radiation declinedfrom 3–4 per cent at the lowest energy level to 1–2per cent at the highest energy level.     

The Effect of Light Intensity on the Release of Ethylene from Leaves

When leaf discs of Xanthium strumarium L. a C₃ plant, or Zeamays L. a C₄ plant, are incubated in 1-aminocyclopropane-l-carboxylicacid (ACC) in closed flasks, ethylene is released. The rateof ethylene release appears to be dependent on the levels oflight and CO₂ available for photosynthesis in the tissues. In Xanthium the rate of ethylene release is lower in the lightthan in the dark regardless of the presence or absence of addedbicarbonate as a source of CO₂. The inhibition of ethylene releaseis most apparent in the absence of added bicarbonate (i.e. atthe CO₂ compensation point), and at light intensities sufficientto saturate photosynthesis (had the CO₂ level in the test flaskbeen maintained). In contrast, light dramatically promotes therate of ethylene release from Zea leaf tissue when the CO₂ levelis maintained above the CO2 compensation point. The rate ofethylene release from either Xanthium or Zea, incubated withor without added bicarbonate, does not appear to be alteredby further increasing the light intensity above the minimallevels sufficient to saturate photosynthesis. In the closed system used in these studies and at a light intensitysufficient to saturate photosynthesis, Xanthium and Zea leaftissue both appear to release comparable amounts of ethylenefrom ACC when the data is expressed on a chlorophyll basis.However, in Xanthium the rate of ethylene release is similarin light and dark, while in Zea the rate in the light is muchgreater than in the dark when the data is expressed either ona leaf area or on a chlorophyll basis. It is suggested thatthe different responses of these tissues to light/dark transientsmay reflect differences in their ability to metabolize ACC and/ordifferences in their ability to retain and metabolize ethyleneitself.     

生长光强对4种热带雨林树苗光合机构的影响

于雾凉季研究了西双版纳热带雨林 4种植物幼苗对光抑制及光破坏的防御。发现不同光强下生长的玉蕊和滇南红厚壳日间光抑制均较团花树和滇南插柚紫重 ,在中光强下还发生了长期光抑制。中光强下生长的团花树和滇南插柚紫叶绿素含量降低 ,光合能力升高 ,同时增加热耗散量 ,维持光能平衡 ,避免了光破坏的发生。中光强下玉蕊和滇南红厚壳减少光能吸收、提高热耗散的同时 ,发生了光系统II光化学量子产量长期下调。中光强下生长的 4种植物叶片的类胡罗卜素的绝对含量并不高 ,但单位叶绿素的类胡罗卜素含量显著升高 ,相对保护作用增强。先锋树种团花树类胡罗卜素含量低于另 3种植物 ,这与其较低的热耗散速率相一致 ,光合能力的提高对其光破坏的防御有重要的作用