滴水珠珠芽发育过程研究

珠芽是滴水珠(Pinellia cordata)的营养繁殖结构,为揭示滴水珠珠芽发育过程中的特征,该研究以野外采集材料进行盆栽观察试验,通过形态观察法和石蜡切片方法,探索滴水珠叶片和叶柄处珠芽发育过程中的形态学和解剖学结构特征。结果表明:滴水珠珠芽发育过程在形态上分为叶柄无现象时期、早期珠芽结构分化和珠芽膨大成熟时期三个时期;相应的解剖学发育时期为珠芽原基启动期和形成期、原基分化期和膨大成熟期四个阶段。叶片和叶柄珠芽起始细胞均由叶柄腹面表皮下层薄壁细胞组织脱分化形成,起始细胞不断分裂形成细胞团最后发育成珠芽原基;在原基分化期的特征是生长点形成,最终分化形成芽原基和鳞片叶;膨大成熟期的特征是珠芽结构不断生长,生长点侧生分化鳞片叶增多。叶片和叶柄处珠芽成熟脱落时期为灰色椭圆形结构,测得平均直径分别为(2.79±0.40)mm和(2.69±0.36)mm,外部有鳞片包裹,内部含大量营养物质。在环境适宜条件下,珠芽遇土萌发,萌发率达75%。这表明滴水珠珠芽与同属植物半夏珠芽发育过程差别不大,都是无性克隆营养繁殖体结构。     

平陆百合鳞片组织培养中小鳞茎发生的条件及生物全息现象初探

本文研究了山西平陆百合在组织培养中鳞片分化形成小鳞茎的条件,其小鳞茎的发生符合生物全息理论。试验结果表明:百合鳞片小鳞茎的分化能力与外加植物激素的种类和浓度关系很大。在生长素类物质中,IRA 对鳞片分化小鳞茎效果最好,不仅数量多,而且小鳞茎的体积大,生活力强;NAA 从次之;而2,4-D 的诱导效果最差。细胞分裂素类(KT 或6-BA)与生长素类(IBA、     

大蒜气生鳞茎形态发生及其碳水化合物和内源激素含量以及相关基因表达的变化特征

以大蒜品种‘二水早’(早熟)、‘麻江红蒜’(中晚熟)和‘徐州白’(晚熟)为材料,采用石蜡切片技术结合显微观察探讨气生鳞茎形成过程中植株茎尖和花序轴形态变化,并测定了‘麻江红蒜’气生鳞茎形成过程中可溶性糖、蔗糖、淀粉和内源激素含量及相关基因表达变化,明确不同熟期各品种大蒜气生鳞茎形成进程和形态解剖学特征,以及碳水化合物和内源激素与大蒜气生鳞茎形成的关系,以探讨大蒜气生鳞茎分化的生理机制。结果表明:(1)依据茎尖生长点和花序轴的形态解剖特征,将气生鳞茎形成进程划分为启动期、气生鳞茎原基分化期(包括保护叶原基、贮藏叶原基分化)、气生鳞茎膨大期和气生鳞茎成熟期等4个时期;3个品种气生鳞茎在相同发育时期的形态解剖学特征相同,但分化时间不同,其分化顺序与大蒜品种成熟期表现一致;当总苞叶叶尖露出叶鞘,花器官原基分化时,花序轴周围分生组织区域产生小突起,标志着气生鳞茎原基分化的开始;外层保护叶由白色转为紫色时气生鳞茎进入成熟期。(2)气生鳞茎开始膨大后,其可溶性糖和蔗糖含量均显著降低,淀粉含量显著升高;ZR含量在启动期显著升高;IAA和MeJA含量在气生鳞茎原基分化期维持在较高水平,但IAA含量随着气生鳞茎膨大显著降低,并在成熟期降至最低。(3)果聚糖代谢相关基因1-SST、1-FEH分别在膨大初期、膨大中期表达量显著升高;细胞壁转移酶基因CWI相对表达量在气生鳞茎原基分化期显著升高;蔗糖信号转导基因T6P和生长素信号转导的关键转录因子ARF1相对表达量均在气生鳞茎分化期显著升高;茉莉酸信号调控途径中的负调控因子JAZ相对表达量在大蒜气生鳞茎原基分化期和膨大初期均维持一个较低水平。研究认为,大量可溶性糖及ZR在茎尖积累,可以启动气生鳞茎原基分化,促进气生鳞茎形态发生;高浓度IAA和MeJA可促进气生鳞茎原基分化;气生鳞茎膨大消耗可溶性糖,且低浓度IAA有利于气生鳞茎膨大;成熟的气生鳞茎积累大量淀粉。     

胭脂鱼眼早期形态发生研究

采用组织学方法观察了胭脂鱼(Myxocyprinus asiaticus) 眼的发生过程, 结果显示: 胭脂鱼眼的发育经历了眼原基形成期、眼囊形成期、视杯形成期、晶体板形成期、晶体囊形成期、角膜原基形成期、角膜上皮形成期、视网膜细胞增殖期、晶状体成熟期、眼色素形成期以及眼成型期等11个时期。视网膜发育最早, 起始于眼原基的形成, 直至眼成型期分化完成, 形成了厚度不一的8层细胞, 由内向外依次为神经纤维层、神经细胞层、内网层、内核层、外网层、外核层、视杆视锥层和色素上皮层, 且发育历时最长, 约264h。晶状体的发育在视网膜之后, 始于晶体板的形成, 于出膜前期成熟, 发育历时最短, 约74h。角膜发育最晚, 始于角膜原基的形成, 出膜1 d分化为透明的成熟角膜, 发育历时约96h。出膜4 d仔鱼眼色素沉积明显, 视网膜各层分化明显, 晶状体内部完全纤维化, 眼的形态结构基本发育完全。     

激素对风信子花序外植体分化形成小鳞茎的影响

用已长出地面的风信子(Hyacinthus orientalis L.)花序为试验材料。将花序分切成不同的部分,分别接种在附加不同量的NAA及BA的MS琼脂培养基上。在无激素的培养基上,除花序轴切段能形成极小的鳞茎原基以外,其余各种外植体都不能分化形成鳞茎原基。培养基中只加NAA或BA也不易分化生成小鳞茎。培养基中同时加入NAA及BA时,如NAA的用量较BA高得较多时,虽能很快形成愈伤组织,但也不易分化生成小鳞茎。如NAA的量小于BA,则花序不同部分的外植体都可形成大小不等的小鳞茎;但花被、子房较花序轴切片及花柄需要较高的激素用量。多年来,在生产上,风信子(Hyacinthus orientalis L.)是用从鳞茎上生出的小鳞茎,或是将基盘挖掉使鳞片上长出小鳞茎的方法繁殖。近年来,有些人用组织培养的方法,用鳞片或花序切段为外值体研究风信子的繁殖〔1—3〕。因风信子多种植在土中,用鳞片进行组织培养,灭菌较困难:而用长出地面的花序为材料不仅灭菌较容易,此外,原鳞茎还可保存下来,有利于以后的工作。本工作就是研究激素对花序的不同部分的分化形成小鳞茎的影响。     

狗牙根花序发育过程的形态学观察

对狗牙根(Cynodon dactylon‘C299’)花序发育过程中的形态学变化进行了观察。结果表明,‘C299’花序的整个发育过程可分为8个阶段,即营养生长期、穗轴发生期、苞叶原基分化期、小穗原基分化期、小穗分化期、小花分化期、颖片和内外稃发育期及花药和柱头形成期。其中,穗轴发生期(直立茎上有6~9片叶)是抑制花序形成和决定种子产量的关键时期。     

中国水仙花芽分化观察及储藏条件对花芽数的影响研究

以三年生中国水仙‘金盏银台’为材料,采用石蜡切片法观察其花芽形态分化过程。结果表明：中国水仙的花芽分化从7月上旬开始,到9月中旬形成雌蕊结束。其过程可分为叶芽时期、花序原基形成期、佛焰状总苞形成期、花原基形成期、花冠形成期、雄蕊形成期、雌蕊形成期7个时期。其中花冠形成期较长,20 d左右。花芽的外部形态变化上,分化后期芽的生长速度明显快于前期。对鳞茎球内花序数量的统计结果显示,高温储藏及烟熏法共同使用对中国水仙花序的形成具有很好的促进作用。     

长白落叶松生殖生物学特性研究：I.球花芽分化与早期发育

本文研究了长白落叶松大小孢子叶球的分化及其分布规律。获得如下结果：（１）６月下旬芽鳞形成期终止,７月初进入小孢子叶分化期,７月未至８月上旬小孢子叶分化期结束。８月上旬进入小孢子囊分化期,８月下旬出现造孢细胞,９月中旬形成小孢子母细胞。１０月底小孢子母细胞保持在细线期阶段,小孢子叶球进入冬季休眠期。（２）９月初苞片原基开始形成,９月中旬珠鳞原基形成;１０月上旬出现胚珠原始体,１０月下旬大孢子母细胞形     

暗期光间断条件下新铁炮百合花芽分化的形态学研究

在暗期光间断条件下采用石蜡切片技术对新铁炮百合花芽分化过程进行了研究.结果表明:新铁炮百合品种花芽或顶芽分化过程可分为营养生长期、花原基或花序原基分化期、花被分化期、雌雄蕊分化期和花序形成期,而对于新铁炮百合品种花器官的发生过程而言只具有前4个时期,而无花序形成期;暗期光间断处理下80％新铁炮百合花序形成所跨度的时间为25 d.研究结果可为新铁炮百合在生产上进行促花管理控制夜间光照天数提供有益参考.     

百合小鳞茎离体发生过程中内源多胺水平和多胺氧化酶活性的变化

以百合小鳞茎离体发生为实验系统,研究了鳞片(外植体)内多胺和多胺氧化酶活性的变化与小鳞茎发生之间的相关性。随着细胞脱分化、愈伤组织形成、小鳞茎发生等过程,内源腐胺、亚精胺和精胺的含量均失上升后下降,变化曲线为“钟形”,其含量达最高峰的时间为肉眼可见小鳞茎出现之前。多胺氧化酶活性在小鳞茎发生初期逐渐下降,6d后开始上升,并在小鳞茎突起时达最大值。由于内源多胺水平和多胺氧化酶活性的变化与小鳞茎发生有密切关系,可作为这一形态发生过程的生化指示。     

Effect of Auxins, Cytokinins, Gibberellins, Abscisic Acid and Ethephon on Regeneration and Growth of Bulblets on Excised Bulb Scale Segments of Hyacinth

The effect of various growth substances on regeneration and growth of bulblets on excised bulb scale segments of Hyacinthus orientalis L. cv. Pink Pearl was studied. Bulblet formation was promoted by the auxins IAA and IBA but was inhibited by NAA at high concentrations. IAA hardly affected bulblet weight, whereas IBA and NAA at high concentrations decreased it. Cytokinins had hardly any effect on bulblet regeneration and bulblet weight, Gibberellins inhibited both bulblet regeneration and bulblet weight; GA₄₊₇ acted much stronger than GA₃. ABA and ethephon decreased bulblet regeneration and bulblet growth.     

兰州百合组培鳞茎发育研究

该研究以兰州百合商品种球鳞片为外植体材料,通过组织培养诱导丛生芽萌发及高频增殖,再以丛生芽为材料诱导其发育形成小鳞茎,调节培养基对小鳞茎进行膨大发育培养,最终形成促进兰州百合组培鳞茎膨大发育的“三步”组培培养技术路线;对发育过程中形成的丛生芽、小鳞茎及膨大鳞茎进行淀粉含量测定与生长特征参数统计,分析各步培养对鳞茎形成发育过程中淀粉含量与形态变化的影响。结果表明：所建立的“三步”培养方案培育出的组培鳞茎直径、重量与鳞片数分别为1.66 cm、2.48 g和26.33片,有效地促进了鳞茎的膨大,并能诱导鳞茎主茎杆的形成发育;在培养进程中其淀粉含量呈现逐步增加的趋势,这表明与鳞茎膨大发育正相关,同时鳞茎大小、重量及鳞片数三者也表现为正相关性;当鳞茎所含鳞片数在26片以上时,其生长点易发育形成主茎杆。该文研究了兰州百合组培鳞茎的形成与膨大发育技术,所研发的“三步”培养组成的鳞茎膨大发育组培技术有效地促进了鳞茎的膨大发育,而膨大发育的鳞茎能有效地缩短田间生长周期,从时间上提高百合生产量,同时为实现兰州百合膨大的鳞茎种球规模化生产提供技术支撑。     

In vitro bulblet production of Lachenalia

In vitro bulblet formation and subsequent transplanting of bulblets to soil were studied in order to develop a cost-effective method for the mass production of three Lachenalia varieties. Clumps of adventitious shoots regenerated from leaf explants were used. Bulblet formation was initiated after 2 weeks when shoots were subjected to low temperature (4–15 °C). The size (age) of the adventitious shoot affected the bulblet size, and shoots shorter than 4 mm did not form bulblets. Larger bulblets formed on medium containing 6% sucrose compared to 3% sucrose. Following bulblet initiation, illumination was not necessary for the completion of bulblet formation. Bulblets went into dormancy 3–4 months after they had been initiated or when the culture medium dried out, and they were released from dormancy when the natural night temperatures started to decrease in the late summer. The survival rate of the bulblets after transplanting was directly correlated to the size of the bulblets.The most important factors influencing in vitro bulblet formation of Lachenalia were sucrose concentration, temperature and length of explant shoots. Received: 12 June 1998 / Revision received: 8 September 1998 / Accepted: 23 September 1998     

Bulblet Formation from Bulbscale Segments of Lilium Using Bioreactor System

In vitro bulblet formation was studied using solid, liquid and bioreactor culture (immersion and periodic immersion in liquid media using ebb and flood) in order to develop a cost effective method for the mass propagation of Lilium oriental hybrid ‘Casablanca’. Although the percent of bulblet formation was higher in solid culture, the increased growth rate and production of large number of bulblets in bioreactor makes it suitable for mass propagation. Four times per day and 15 min of medium supply was optimal for bulblet formation in ebb and flood bioreactor. Bulblet formation was also found to be effective in 16-h photoperiod. It was also observed that bulblet formation in the medium with 1.0 mg dm⁻³ BA and 0.3 mg dm⁻³ NAA was higher than in the medium without growth regulators, but formation of abnormal bulblets was higher in medium with BA and NAA. This revised version was published online in July 2006 with corrections to the Cover Date.     

Enhanced bud and bulblet regeneration from bulbs of<Emphasis Type="Italic"> Nerine sarniensis</Emphasis> cultured in vitro

Nerine (Nerine sarniensis) cv. Salmon Supreme in vitro-grown bulblets, 7-9 mm in diameter, were cut in half longitudinally and used for adventitious bud initiation following dissection of the roots and two-thirds of the upper part of the bulblets. The terminal apex was injured with a hot, sterile microscope dissecting needle. The highest number of buds formed (seven to nine buds per halved bulblet) on a semi-solid Murashige and Skoog (MS) basal salts medium supplemented with 3% sucrose and either 1 microM 6-benzylaminopurine (BA) and 1 microM alpha-naphthaleneacetic acid (NAA) or 0.5 microM BA and 0.1 microM NAA. Bulblet halves were cultured in the dark for 11-13 weeks with one subculture after 6 weeks. Anatomical studies indicated that the initiation of adventitious buds on the abaxial side of the inner scales of the halved bulblet was adjacent to the basal plate and started from the leaf primordium and a meristematic bulge. Buds developed directly into small bulblets after they were transferred to semi-solid MS basal salts medium supplemented with 6% sucrose, 10 microM indole-3-butyric acid (IBA) and 0.25% activated charcoal. Small bulblets cultured in liquid MS medium supplemented with additional KH(2)PO(4 )(170 mg l(-1)), 6% sucrose and 0.1 microM NAA under a 16/8-h (light/dark) photoperiod for 8 weeks grew into larger bulbs faster than those cultured on semi-solid medium. The bulbs were rooted on a semi-solid medium after 4 weeks and then transferred to the soil. As many as 18 bulblets developed and rooted from one in vitro-grown bulb after 25-27 weeks.     

In vitro bulblet production of Brunsvigia undulata from twin-scales

Many South African medicinal plants are over-collected for use in traditional medicines. This necessitates developing methods for increasing production. Micropropagation can be used as an alternative to conventional propagation methods. Twin-scales, cut from large parent bulbs, were cultured on MS medium (Murashige and Skoog, 1962) supplemented with 25 plant growth regulator combinations. Bulblets formed on twin-scales in 24 of the treatments. All explants formed bulblets on plant growth regulator-free medium. The effect of plant growth regulators, activated charcoal, explant orientation, explant origin and photoperiod on bulblet production was investigated. Bulblet formation was greatest when twin-scales were excised from the middle of the parent bulb, placed adaxial side down on plant growth regulator-free medium and kept in a 16 h photoperiod.     

Photoautotrophic culture conditions and photosynthetic photon flux influence growth of <Emphasis Type="Italic">Lilium</Emphasis> bulblets <Emphasis Type="Italic">in vitro</Emphasis>

Summary Lilium Asiatic hybrid ‘Mona’ bulblets were cultured in vitro for 100 d under photoautotrophic (CO₂-enriched conditions and without sucrose in the medium) and heterotrophic (non-enriched CO₂ conditions and sucrose-supplemented medium) methods and under various levels of photosynthetic photon flux (PPF). Bulblet growth and net photosynthetic rate (NPR) were analyzed. CO₂₋ and PPF-enriched conditions enhanced the overall growth of bulblets, scale leaves, and roots. Heterotrophic conditions enhanced bulblet growth but higher PPF levels were inhibitory to the development of scale leaves. These results indicate the CO₂₋ and PPF-enriched conditions (photoautotrophic conditions) are beneficial for the production of high-quality bulblets of Asiatic hybrid lilies in vitro     

Differential Effects of Paclobutrazol on the Bulblet Growth of Oriental Lily Cultured In Vitro: Growth Behavior,Carbohydrate Metabolism,and Antioxidant Capacity

Bulblet growth is crucial for global lily production, and the applications of plant growth regulators have proven effective but with poor understanding of mechanisms. The aims of this study were to identify the effects of paclobutrazol (PBZ) on tube lilies. Low PBZ concentrations (5 × 10⁻⁴ mM, LPBZ) stimulated bulblet biomass, whereas higher doses suppressed the growth of the leaves and roots. Soluble carbohydrate and starch contents increased significantly with increased PBZ dose. The activities of adenosine 5′-diphosphate glucose pyrophosphorylase (AGPase), granule-bound starch synthase (GBSS), and soluble starch synthase (SSS) increased dramatically in response to PBZ treatments at later growth stages (60 days after transplanting) when carbon starvation occurred. In contrast, GBSS activity was enhanced throughout the whole growth period, indicating that the starch increase was attributed mainly to amylose synthesis. Carbohydrates were utilized more efficiently following LPBZ, with a relative bulblet weight of approximately 77.07%, which potentially ensured the source-sink balance. Alternatively, more carbohydrates were stored in response to high PBZ concentration. Intriguingly, PBZ usage significantly increased the activities of ascorbate peroxidase, catalase and glutathione reductase at the early stages, implicating a possible role in the elimination of ROS to maintain homeostasis. Application of LPBZ resulted in the largest bulblet, which weighed 396 mg (2.5 times that of the control) and measured 10.70 mm in diameter. The detailed characterizations of the bulblet swelling mechanism using PBZ in vitro offer suggestions of future PBZ usage in other bulbous crops.

     

Effect of Photoperiod and Chlormequat on Apical Development and Growth in a Spring Wheat (Triticum aestivum) Cultivar

Spring wheat, cv. Timmo, was grown under three photoperiod regimes(16, 13 and 11 h) with and without treatment with the plantgrowth regulator chlormequat (applied at the glume primordiumstage of apical development) and the relationships between apicaldevelopment, primordium initiation and growth stage examined The effects of photoperiod were generally similar to those reportedfrom other studies; shorter photoperiod slowed the rate of apicaldevelopment, increased the duration of the primordium initiationphases and reduced the rate of primordium initiation. The finalnumber of spikelets was increased, but there was no effect onnumber of floret primordia per spikelet The number of tillersproduced was also higher in the shorter photoperiods. Chlormequattreatment had a similar effect to imposing short-days: floweringwas delayed and tiller production increased There were strong correlations between certain development eventsand the phasing of primordium initiation and growth stages andthese were not affected by photoperiod or chlormequat treatments.For example, the end of spikelet primordium initiation, i.e.terminal spikelet (TS) formation, coincided with the floret-stamenprimordium stage (of the most advanced spikelet) and the endof floret primordium initiation with the stigma tic branchesand hairs on ovary wall elongating stage. Similarly, rapid stemextension growth always started at TS formation while spikeextension and spike growth commenced at TS formation and thestigmatic branches stage, respectively. Tiller production alsoceased at TS formation, when rapid stem growth started Although the timing of the phases of primordium initiation andcertain growth events were linked to apical development, therate of apical development did not determine either the rateof spikelet primordium initiation or the rates of stem and eargrowth. However, there was a strong relationship between rateof development and rate of floret primordium initiation. Therewas also a strong relationship between spike length and apicaldevelopment stage Triticum aestivum, spring wheat, photoperiod, chlormequat, apical development, primordium initiation, stem and spike growth     

High frequency of shoot multiplication and bulblet formation of garlic in liquid cultures

In vitro shoot proliferation and bulblet production of garlic (Allium sativum L.) was studied in liquid cultures. Shoots grown in vitro were used as explants and were cultured in MS medium supplemented with 2% (w/v) sucrose and 0.5 mg l^–1 2-iP. Three culture methods (semi-solid, liquid-immersion and raft) were compared for shoot proliferation. Explants in liquid (immersion) culture exhibited an increased multiplication rate and fresh weight of shoots after 3 weeks of culture as compared with the other treatments. Bulblet formation and growth were studied in liquid medium with different concentrations of sucrose (2–13%). MS medium containing 11% (w/v) sucrose was optimal for bulblet development and bulblets developed in this medium within 9 weeks in culture. The highest multiplication rate was (135 bulblets/explant) found when explants were cultured in bulbing medium (MS medium containing 0.1 mg l^–1 NAA+11% (w/v) sucrose) supplemented with 10 M JA. Growth retardants CCC, B-9, ABA also promoted induction and growth of bulblets. Darkness promoted the bulblet induction and growth compared to light conditions (16-h photoperiod of 50 mol m^–2 s^–1). The dormancy of bulblets was broken by cold treatment at 4 °C for 8 weeks.