不同光周期下馥郁滇丁香 ‘香妃’的成花反应以及花芽分化进程的解剖学研究

以馥郁滇丁香品种‘香妃’扦插苗为试验材料,通过人工设置不同的光周期及采用迁光法对其进行处理,探讨不同光周期下馥郁滇丁香‘香妃’的成花反应,并采用石蜡切片法观察其花芽分化进程,以期为馥郁滇丁香‘香妃’的花期调控及商品化盆栽提供理论依据。结果表明：（1）馥郁滇丁香‘香妃’属于质性或专性短日照植物,临界日长约为14 h,适宜成花的日照长度为10～12 h,限界性诱导光周期为30 d短日照。（2）在诱导光周期下,花芽形态分化包括未分化期、总苞原基分化期、花序或小花原基分化期、花被原基分化期、雄蕊原基分化期及雌蕊原基分化期。在诱导光周期下处理16 d后,植株全部完成了成花转变;处理30 d后,所有植株的花芽分化处于花被原基发育形成期,并且成花决定达到稳定状态,移入非诱导光周期下不会发生成花逆转。（3）在4 h暗中断的非诱导光周期下,所有植株的芽一直处于营养生长的未分化期。     

光周期对青饲玉米耐高氮的调控效应

以光周期敏感型‘华农1号’青饲玉米为材料,在大田条件下,设置N1(75kg/hm2)、N2(225kg/hm2)、N3(375kg/hm2)3个氮素水平和3个光周期处理(16h、13h和10h),分析了其在不同光照长度条件下耐高氮胁迫的能力,探讨光周期对玉米氮高效相关的农艺性状和光合特性指标的影响。结果表明,(1)16h光照处理下,玉米植株的根长、根表面积、根体积分别比10h处理增加了113.19%、45.73%和97.71%,叶片叶绿素含量与净光合速率比10h处理分别提高97.90%和60.24%,且根长、根体积、叶绿素含量和净光合速率在16h和10h处理下差异极显著;16h处理与10h处理叶片数的平均相差值(12)显著,根系直径随光周期延长逐渐减小,但光周期对植株分蘖数无显著影响。(2)‘华农1号’青饲玉米地下部和地上部部分农艺性状指标,在16h长光照处理下随氮素水平的提高而增加,表现出耐高氮胁迫的生物学特征;在10h短光照处理下氮素水平过高相关性状指标反而下降。(3)随着光照时间逐渐延长,地上部生物量逐渐显著增加。研究发现,光周期敏感型‘华农1号’青饲玉米具有较强的耐高氮能力,长光周期促进了其植株营养生长阶段的生长发育,增强了其对高氮的适应能力。     

光周期诱导甘蔗花芽分化及成花逆转过程中生理代谢的变化

以两个在自然条件下难开花的甘蔗品种‘ROCl6’和‘ROC22’为材料,研究经光周期诱导甘蔗花芽分化和成花逆转过程中叶片碳水化合物和可溶性蛋白质含量的变化。结果表明,未分化前,两品种经光周期诱导后叶片可溶性总糖、淀粉和蛋白质含量与对照相比无明显变化;从花芽分化诱变期开始,两品种叶片可溶性总糖、淀粉和蛋白质含量迅速增加,明显高于对照（未分化）。随着花芽进一步分化,其叶片可溶性总糖、淀粉含量逐渐降低并低于对照,处在一个较低的水平,蛋白质含量始终高于对照。成花逆转植株在花芽分化前期叶片可溶性总糖、淀粉和蛋白质含量也高于对照,但低于正常抽穗开花植株;之后随着花芽分化的停止,其叶片可溶性总糖、淀粉含量一直保持较稳定的水平,仅蛋白质略有降低。说明甘蔗花芽分化期间大量的基因表达并且合成各种蛋白质的过程需要消耗大量的碳水化合物。     

长日照处理对牵牛开花抑制作用研究——Ⅰ.不同时间长日照处理对…

日本紫花牵牛子叶完全展开后,短日照诱导前、诱导后和两个短日照间的长日照处理对植株的花芽分化都有一定的抑制作用。双向凝胶电泳分析表明,长日照处理的牵牛子叶内存在着短日照处理子叶内没有的两种蛋白质。这些蛋白质可能与长日照抑制牵牛植株的花芽分化有一定关系。     

光周期和外源糖对新铁炮百合生长和内源糖含量的影响

糖类和光周期是植物成花启动中的重要因素,二者相互作用,共同调节植物成花。新铁炮百合(Lilium×formolongi)具有短生育期的特性,在适宜条件下,一年内可实现从播种到开花。为此,对新铁炮百合品种‘雷山三号’实生苗进行不同光周期和外施蔗糖的处理,探究其对内源糖、海藻糖-6-磷酸含量及对成花诱导的影响。结果表明:在长日照条件下外施蔗糖可以提高抽葶率,并缩短抽葶时间和可见花蕾出现的时间;同时提高植株体内蔗糖和海藻糖-6-磷酸的含量。植株体内葡萄糖含量受光周期影响较大呈现不同变化趋势,而果糖含量在四种不同处理中未表现出明显变化趋势,并且植株体内海藻糖-6-磷酸和蔗糖含量呈现显著正相关。综合而言,光周期是新铁炮百合成花启动的主要影响因素,外施蔗糖在长日照下对成花的促进作用更为明显。     

德国鸢尾‘常春黄’花芽分化的形态观察及两种代谢产物的动态变化

鸢尾是世界著名观赏花卉,为研究其花芽分化期的形态和生理指标变化情况,我们以德国鸢尾两季花品种‘常春黄’（Iris germanica cv. Lovely Again）为材料,运用扫描电镜（SEM）观察了德国鸢尾‘常春黄’的花芽分化过程。结果表明：整个形态分化过程可分为6个阶段：花序原基分化期、外轮花被分化期、雄蕊分化期、内轮花被分化期、雌蕊分化期、髯毛形成期。结合上述形态分化过程,分别取其二次花花芽分化时期的顶芽、根茎和叶片部位,以蒽酮比色法测定可溶性糖,以考马斯亮蓝G-250法测定蛋白质含量。结果表明：可溶性糖在花序原基分化的初始阶段含量最高,且在3个部位的含量大小关系始终是：根茎﹥叶片﹥顶芽;蛋白质含量呈先上升后下降的趋势,蛋白质含量的峰值出现于花序伸展初期。     

基于水分控制的切花百合生长预测模型

光合作用与干物质生产是观赏植物外观品质形成的基础。水分是影响植物光合作用与干物质生产的重要因子。为定量研究水分对切花百合光合作用与干物质生产的影响,以切花百合品种‘索邦’(Lilium‘Sorbonne’)为试验材料,于2009年3月至2010年1月在南京的连栋温室内开展了不同定植期和不同水分处理的栽培试验,以基于光温的温室花卉生长动态预测模型为基础,定量分析了不同定植期和不同水分处理条件下切花百合叶面积指数、光合速率和干物质生产的动态影响,并确定了切花百合正常生长的临界基质水势,建立了基质水势对切花百合光合速率和干物质生产影响的动态预测模型。结果表明,本文所建模型对切花百合叶片最大总光合速率和植株总干质量的预测效果较好,模型对叶面积指数、叶片最大总光合速率和植株干物质量的预测值与实测值之间的决定系数(r2)分别为0.97,0.96,0.94,相对根均方差(rRMSE)分别为7.12%、4.37%、11.14%。该模型能较好地预测水分对切花百合叶片最大总光合速率和植株总干质量的动态影响,可为进一步优化切花百合生产的水分管理提供决策支持。     

高温对番茄幼苗生长和花芽分化的影响

为了探讨高温胁迫对番茄幼苗生长和花芽分化的影响,该试验以‘中杂9号’番茄为材料,以25℃/15℃(昼/夜)为对照(CK),进行37℃/27℃(昼/夜)的高温处理,测定番茄幼苗生长和花芽分化相关指标。结果表明:从高温处理第3天开始番茄幼苗株高和节间长显著高于对照,而茎粗显著小于对照,即植株出现徒长;高温处理的番茄叶面积、根系表面积一直显著低于常温对照,而根系体积、根系总长和分根数也从第3天开始显著低于对照水平;高温处理的植株花芽分化进程从第1天起就明显加快,高温处理第9天时花芽分化数显著减少,而花芽大小高温处理后1～5 d大于对照,从第7天起高温处理植株的花芽大小显著低于对照。研究表明,高温抑制番茄幼苗营养生长,加快番茄花芽分化进程,减少花芽分化数,并减小花芽大小,最终导致产量降低。     

长日照处理对牵牛开花抑制作用研究 Ⅰ．不同时间长日照处理对花芽分化和子叶蛋白质的影响

日本紫花牵牛（Ｐｈａｒｂｉｌｉｓｎｉｌｃｖ．Ｖｉｏｌｅｔ）子叶完全展开后,短日照诱导前、诱导后和两个短日照间的长日照处理对植株的花芽分化都有一定的抑制作用。双向凝胶电泳分析表明,长日照处理的牵牛子叶内存在着短日照处理子叶内没有的两种蛋白质（ｐＩ４．１,ＭＷ１６．５ｋＤ;ｐＩ４．２,ＭＷ１６．５ｋＤ）。这些蛋白质可能与长日照抑制牵牛植株的花芽分化有一定关系。     

光周期对春石斛开花及多胺含量的影响

以春石斛为试材,研究光周期对其开花及多胺（腐胺、亚精胺和精胺）含量的影响,以期了解春石斛开花的光周期特性以及期间能源物质多胺的变化规律。结果显示,春石斛短日照处理植株开花较长日照处理的提前约18d,为称量性短日照植物;同时,短日照处理植株的花芽多,开花量犬,花径较长日照大。不同光周期诱导开花过程中,春石斛叶片内腐胺含量最高,波动较大,短日照处理下基本维持比长日照高的水平。亚精胺含量其次,且随生长发育逐渐升高,短日照处理下一直保持比长日照高的水平。精胺含量最低,变化不大,短日照下保持与长日照相同或略高的水平。由此推测,春石斛为称量性短日照植物,高水平的腐胺和亚精胺可能与春石斛花芽的形成有关。     

疏花对富士苹果光合同化物分配的外部调节和生理表现

在盛花期,利用对树冠不同部位疏除花序的试验。对富士苹果树体内同化物的调配及其生理表现进行了研究。结果表明,苹果平均单果重和平均单果叶面积之间关系呈线性正相关。该相关关系在不同处理之间无差异（r=0.91),充分说明在苹果树体内存在一个可自由流动的碳水化合物库或者说树体对结果具有光合调节作用,疏花可以从外部调节光合同化物分配的方向。对每株苹果树未结果部位和结果部位短枝及延长枝叶片净光合速率测定表明。结果和未结果部位光合速率没有显著差异。虽然疏花没有显著影响苹果单株枝条生长量和叶面积,但是,苹果树树冠全部疏除花序的一侧 或主枝的平均枝条生长量和叶面积去比该树其它结果部位分别平均高出153.5cm和8900cm^2,差异极为显著。苹果树疏除花序1/2或3/4的数量使苹果平均单果重比不疏花分别显著增加了33g或79g。而果实钙浓度每百克鲜重分别降低了1.62mg或2.66mg,充分说明当疏花显著地影响果实大小时,果实内钙浓度也会明显地发生相应的变化,虽然在疏花处理之间不同部位疏除花序没有影响单株花芽总数量,但是,每株树前一年春季疏花的部位比未疏花,结果的部位极显著地增加了花芽数量（SED=11.6)。     

In vitro photoinduction of leaf tissue ofStreptocarpus nobilis

Leaf expiants from vegetative plants of the short-day plantStreptocarpus nobilis (C. B. Clarke) developed flower budsin vitro when cultured in 8 h photoperiods. Tn non-inductive photoperiods only vegetative buds were formed.In vitro photoinduction was demonstrated by giving the expiants short-day (SD) cycles and then transferring them to non-inductive photoperiods for expression of flowering. On medium containing 6-benzylaminopurine (BAP) organogenesis was initiated during the photoinductive treatments. Photoinduction of leaf tissue without adventitious bud development was obtained on medium without BAP. The photoinductive state of the leaf tissue was fairly stable, being expressed after 2–3 weeks in non-inductive photoperiods when adventitious buds were formed. The quantitativein vitro flowering response to the endogenous floral stimuli, resulting from photoinduction, could provide the basis of a bioassay for presumptive flower inducing chemicals.     

温度对叶用莴苣春化的影响

为了探讨温度对叶用莴苣春化的影响,进而明确其春化类型,本试验选用两个易抽薹叶用莴苣品种GB-30和GB-31为试材,分别进行20 d的4、20和25 ℃处理,然后均进行高温胁迫促进抽薹,采用石蜡切片观察茎尖花芽分化进程,并结合后期抽薹开花情况来判断是否进行春化,并确定其春化类型.结果表明:两个品种在前期经过3种温度处理后,在高温胁迫第8天时均有不同程度的抽薹.两个品种不同温度处理下花芽均进行了分化,前期4 ℃处理并没有使其花芽分化明显提前,后期的高温胁迫可以明显促进花芽分化进程.两品种间在不同温度处理下完成各发育阶段所需天数存在差异,两品种各处理从催芽到开花以及从高温到开花的有效积温也存在差异.前期未经低温处理的叶用莴苣也进入花芽分化、抽薹、现蕾及开花阶段,表明叶用莴苣为非低温春化型植物,后期高温处理能明显促进其抽薹开花,而且从催芽开始只有有效积温达到约2500 ℃·d才能开花.     

6-BA、GA3调控春石斛花芽分化的效应

调查了春石斛假鳞茎封顶和增粗的生长情况,并以不同浓度6-BA、GA₃溶液进行灌根处理,观测其对花芽分化的效应。结果表明,假鳞茎的增粗阶段在9月15日至10月10日,经过约50 d增粗生长,假鳞茎粗度迅速增加。其间,6-BA、6-BA+GA₃处理对春石斛花芽分化有促进作用。3种6-BA浓度作用效果明显,最佳为400 mg/L;6-BA添加低浓度GA₃,对花芽分化有增效作用,其中以6-BA 200 mg/L添加GA₃ 50 mg/L效果最佳。GA₃作用效果不稳定,浓度为25 mg/L时叶片脱落不明显,高于50 mg/L则叶片大量脱落。     

DAYLENGTH AND LIGHT RESPONSES IN GROWTH AND FERTILITY OF GLOSSOPHORA KUNTHII (PHAEOPHYTA,DICTYOTALES) FROM PACIFIC SOUTH AMERICA1

Excised ligulae of Glossophora kunthii (C. Ag.) J. Ag. were cultured in photoperiods of 4–24 h and photon fluence rates of 10–75 μmol.m^?2.s^?1. Daylength interacted with irradiance on the growth of the ligulae. Maximal growth of primary ligulae occurred in long-day regimens with high irradiances suggesting an effect of irradiance on photosynthesis and growth. In contrast, growth of secondary ligulae was greatest in short-day regimes. Differences were significant at the highest irradiance tested. Differentiation of tetrasporangia on the ligulae is a short-day photoperiodic response. Daylengths of 8.5 h or less induced a sharp increase in numbers of fertile ligulae and tetrasporangia attaining maturity. Interruptions of the dark period decreased the development of tetrasporangia; the number of interruptions had a cumulative inhibitory effect. Differentiation of reproductive structures was influenced by interactions of photoperiod and irradiance. Maximum numbers of tetrasporangia were formed at short-day regimes and low irradiances; differentiation was completely inhibited at long-day conditions and high irradiance.     

不同光周期对西红花开花和花丝品质的效应比较

为筛选促进西红花开花和提高花丝品质的最佳光周期,以3种不同规格(20~25 g、25~30 g、30~35 g)西红花种球为材料,设置4种光周期处理(8 h/16 h、10 h/14 h、12 h/12 h、14 h/10 h),考察光周期对西红花种球鲜重变化、主芽生长、展叶数量、开花后营养物质含量以及花朵性状和花丝品质的效应。结果表明:(1)光周期8/16 h最有利于促进西红花主芽生长、增加展叶的种球数量。(2)光周期8 h/16 h和12 h/12 h下的西红花花朵直径大且前5 d开花数量多。(3)不同光周期对西红花苷含量、花丝干重、鲜重、折干率、含水量等花丝品质无显著影响。(4)西红花开花后种球中可溶性糖、淀粉、可溶性蛋白等营养物质含量在光周期8 h/16 h处理下较高,而在光周期12 h/12 h和14 h/10 h处理下较低。研究认为该试验条件下适合西红花生长的最佳光周期是8 h/16 h(昼/夜),此光周期有利于西红花生长、促进初期提前开花,然而对花丝品质无明显影响。     

Winter bud content according to position in 3-year-old branching systems of 'Granny Smith' apple

An investigation was made of the number of preformed organs in winter buds of 3-year-old reiterated complexes of the 'Granny Smith' cultivar. Winter bud content was studied with respect to bud position: terminal buds were compared on both long shoots and spurs according to branching order and shoot age, while axillary buds were compared between three zones (distal, median and proximal) along 1-year-old annual shoots in order 1. The percentage of winter buds that differentiated into inflorescences was determined and the flowers in each bud were counted for each bud category. The other organ categories considered were scales and leaf primordia. The results confirmed that a certain number of organs must be initiated before floral differentiation occurred. The minimum limit was estimated at about 15 organs on average, including scales. Total number of lateral organs formed was shown to vary with both bud position and meristem age, increasing from newly formed meristems to 1- and 2-year-old meristems on different shoot types. These differences in bud organogenesis depending on bud position, were consistent with the morphogenetic gradients observed in apple tree architecture. Axillary buds did not contain more than 15 organs on average and this low organogenetic activity of the meristems was related to a low number of flowers per bud. In contrast, the other bud categories contained more than 15 differentiated organs on average and a trade-off was observed between leaf and flower primordia. The ratio between the number of leaf and flower primordia per bud varied with shoot type. When the terminal buds on long shoots and spurs were compared, those on long shoots showed more flowers and a higher ratio of leaf to flower primordia.     

Changes in organ growth ofChenopodium rubrum due to suboptimal and multiple photoperiodic cycles with and without flowering effect

The growth changes of cotyledons, leaves, hypocotyls and roots due to photoperiodic induction in short day plantChenopodium rubrum were investigated in relation to flowering. Six-day old plants were induced by photoperiods with a different number of dark hours. We found that the degree of inhibition which occurred during induction in the growth of leaves, cotyledons and roots similarly as the stimulation of hypocotyl is proportional to the length of dark period. The photoperiods with 12, 16 and 20 dark hours bring about marked inhibition of growth and at the same time induce flowering in terminal and axillary meristems. The inhibitory effect of critical period for flowering,i.e. 8 dark hours, is not apparent in all criteria used and even the flower differentiation is retarded. The photoperiods of 4 and 6 dark hours did not affect growth and were ineffective in inducing flowering even if their number has been increased. The experiments with inductive photoperiod interrupted by light break have clearly shown that growth pattern characteristic for induced plants can be evoked in purely vegetative ones. Such statement did not exclude the possible importance of growth inhibition as a modifying factor of flower differentiation. We demonstrated that the early events of flower bud differentiation are accompanied by stimulation of leaf growth. The evaluation of growth and development of axillary buds at different nodes of insertion enabled us to quantify the photoperiodic effect and to detect the effects due to differences in dark period length not exceeding 2 hours.     

The Role of Light in Leaf and Flower Bud Break of the Peach (Prunus persica)

The effect of light on peach leaf and flower bud break was examined. It was found that leafless dormant shoots were light-perceptive organs. Darkness, after light preconditioning during dormancy, reduced leaf bud opening; however, light was obligatory when the shoots were preconditioned in the dark. Relatively short exposures to light were sufficient to stimulate leaf bud break. Terminal buds were less inhibited by darkness than were laterals. Flower bud break was inhibited in light after dark preconditioning. The red region of the spectrum was found to be active; the phytochorome system seems to be involved in the light reactions, as the red light effect was reversible with subsequent far-red illumination. Supplementary light, producing long-day conditions, could partly compensate for insufficient chilling. A possible sequence of reactions in the plant is suggested.