Influence of ventilation and sucrose on growth and leaf anatomy of micropropagated potato plantlets

Potato single nodes were cultured in vessels containing MS medium supplemented with 10, 20 and 30 g/l of sucrose. Vessels were closed with a clear polypropylene lid with or without 10 mm microporous polypropylene membrane. Sucrose concentration significantly increased plantlet height, shoot fresh weight and chlorophyll a content. Plantlets grown in ventilated vessels were significantly shorter, had lower shoot fresh weight and higher shoot dry weight than those in non-ventilated vessels. The highest leaf chlorophyll a content (21.83 mg/g fresh weight) was found in plantlets grown in ventilated vessels using MS medium with 20 g/l of sucrose, whereas those grown on medium with 10 g/l of sucrose had the highest chlorophyll b content (24.00 mg/g fresh weight). Total chlorophyll content was significantly higher when plantlets were grown in ventilated vessels containing medium with 10 or 30 g/l sucrose than in non-ventilated vessels. There was no significant difference in total chlorophyll content among plantlets grown in ventilated vessels with different concentrations of sucrose. Stomatal density was significantly lower when plants were grown under ventilated conditions. Leaf replica examination showed that stomata under non-ventilated condition were spherical with wide openings whereas, those in ventilated vessels were elliptical with narrow openings. Plantlets grown in non-ventilated vessels had thinner leaves and failed to build up a distinct defined upper epidermis, palisade parenchyma layer and spongy cells. On the other hand, leaves under ventilated conditions showed comparatively well organized layers with small intercellular space. The vascular system of leaves under the ventilated conditions demonstrated very well developed xylem unlike leaves under non-ventilated conditions. Thus, ventilated vessels with the 20 g/l of sucrose under ambient CO₂ in the growth room could successfully promote photomixotrophic culture and produce healthy plantlets.     

蓝叶类型玉簪叶片表皮蜡质对光合生理的影响

为探究阴生植物玉簪叶片表皮蜡质在光的适应性中发挥的作用，以蓝叶类型‘翠鸟’（Hosta ‘Halcyon’）和‘婴儿睡袋’（Hosta‘Baby Bunting’）为试材，通过盆栽试验，在自然光照下，分别测定正常覆有蜡质的叶片和人工除去蜡质的叶片在0、7、14 d后的光合日变化、叶绿素含量和叶绿素荧光参数以及相对电导率、丙二醛含量等生理指标。结果表明：正常叶片净光合速率、水分利用效率、最大光化学效率高于去蜡质的叶片，而蒸腾速率低于去蜡质的叶片。‘翠鸟’玉簪叶片净光合速率分别在8：00和16：00时出现峰值，而‘婴儿睡袋’玉簪峰值分别出现在10：00和14：00时，说明‘婴儿睡袋’比‘翠鸟’对强光的适应性更强。在光照强度较高的条件下，正常叶片温度比去蜡质的低。随着处理天数的增加，各种处理的玉簪叶片相对电导率和MDA含量均增加且在7 d后达到最大，之后明显下降。本研究结果说明，在强光照下，叶片表皮蜡质具有减少光抑制、降低叶片温度、减少蒸腾失水等保护作用。     

慈姑叶片结构的光学显微镜和扫描电镜观察

在光学显微镜和扫描电镜下,对慈始异形叶——沉水叶、浮叶和挺水叶叶表皮特征及解剖结构进行了观察。观察结果显示,沉水叶气孔量少且闭合,有大量气腔,仅由几层细胞构成,结构简单,机械组织不发达;浮叶和挺水叶都有较多开放气孔,具有完整的栅栏组织、海绵组织、疏导组织和机械组织,但浮叶气孔不规则,表面蜡质颗粒多,挺水叶气孔器大小一致,蜡质颗粒少。慈始沉水叶到挺水叶的结构变化反映了植物对环境的适应性,体现了沉水植物到陆生植物的发育过程。     

Culture method and photosynthetic photon flux affect photosynthesis,growth and survival of Limonium ‘Misty Blue’ in vitro

Microcuttings (shoots each with two leaves) of Limonium ‘Misty Blue’ were cultivated in vitro for 28 days under photoautotrophic (sucrose-free culture medium; CO₂ and photosynthetic photon flux (PPF) enriched conditions), photomixotrophic (medium with 30 g l⁻¹ sucrose; CO₂ and PPF enriched conditions) and heterotrophic (medium with 30 g l⁻¹ sucrose; CO₂ non-enriched conditions) methods. Several growth variables were measured during and at the end of cultivation: shoot fresh and dry weight, percentage of shoot dry matter, root fresh weight, number of leaves, leaf area, chlorophyll and sugar content of leaves, stomatal density and size, net photosynthetic rate (NPR) and percent survival of plantlets ex vitro. Plantlets grown in photoautotrophic and photomixotrophic methods had more leaves, high chlorophyll and sugar contents, high NPR, and showed high percent survival. However, these plantlets possessed less number of stomata per square millimeter. In contrast, the plantlets grown by the heterotrophic method showed decreased values of these growth variables except for the number of stomata per square millimeter. These results indicate that CO₂ enrichment for plantlets in vitro at a relatively high PPF would promote photosynthesis and hence growth of chlorophyllous explants/plantlets in vitro. The resulting plantlets were acclimatized better and sooner on ex vitro transplantation.     

盐胁迫对三色苋叶片气孔分化及开闭的影响

以三色苋（Amaranthus tricolor L.）为材料,研究了不同浓度（0、50、150、300、500 mmol · L^-1）NaCl 处理后气孔的应答反应和300 mmol · L^-1 NaCl 长时间处理后对不同叶序叶片气孔开闭和分化的影响。结果表明,盐处理后三色苋的气孔不同程度地迅速关闭,气孔开放率在处理3 h 后达到最低,之后小幅回升。24 h 后除50 mmol · L^-1 NaCl 处理外,仍有多数气孔处于关闭状态。长时间盐胁迫使基层的叶片气孔密度略有增加;上层新叶的气孔密度显著降低。长时间盐胁迫使气孔的开放率也降低,越是新分化的叶片盐胁迫对其气孔影响也越大。     

空气湿度对东方百合生长和切花品质的影响

 以东方百合(Lilium spp. ) 品种‘凝视星空’和‘巴希亚布兰卡’为材料, 种植于温室进行不同湿度栽培试验, 设置60%、75%和90%相对湿度水平。结果表明: 湿度对两个东方百合品种的植株生长和发育有显著影响, 高湿度增加了叶面积, 但是推迟了开花期, 缩短了切花瓶插寿命, 加速了叶片衰老。高湿度下气孔增大, 密度减小, 叶片气孔导度和蒸腾速率提高, 气孔在叶片失水后的反应迟钝, 关闭速度慢于低湿度下生长的叶片。高湿度下植株茎流也慢, 水分吸收少于低湿度植株。高湿度下生长的百合切花在瓶插期发生了纸叶病。     

辣椒幼苗叶片解剖特征及光合特性对弱光的响应

 以弱光适应性不同的4个辣椒(Capsicum annuum L. )基因型（甜味型和辣味型）为试材，在人工气候室内研究了弱光（75~100 μmol·m^-2·s^-1）条件下辣椒幼苗叶片显微结构、叶绿体超微结构、气孔特征特性，以及光合特性的适应性变化。结果表明，弱光下辣椒幼苗叶片变薄，栅栏组织/海绵组织比值增加，'伏地尖'（辣味型）和'上海园椒'（甜味型）具有较高的栅栏组织/海绵组织比值；叶绿体数目减少，但叶绿体变大，基粒数、基粒厚度和基粒片层增加，淀粉粒增大、增多，2个辣味型材料比2个甜味型材料具有较高的叶绿体数和基粒数。辣椒（甜味型）展叶过程中下表皮气孔密度下降，而展叶14 d以后的气孔指数和单片叶气孔数变化不大。弱光下叶片气孔密度、气孔指数和单片叶气孔数减小，但气孔变大，其中'上海园椒'气孔纵轴、横轴较正常光照下增加，'20078'则横轴显著增加；弱光环境中叶片表皮细胞变大并发生扭曲皱褶，气孔与表皮平齐或略显外突，保卫细胞角质层上可观察到明显的环状褶皱。弱光下辣椒幼苗的光饱和CO₂同化速率(Asat)、暗呼吸速率(Rd)、夜间呼吸速率(R_n)、光呼吸速率(R_p)、光补偿点(LCP)、光饱和点(LSP)、CO₂补偿点(Г)、CO₂饱和点(CSP)、羧化效率(CE)以及RuBP最大再生速率下降，表观量子效率(Фi)上升；辣味型较甜味型材料Asat下降幅度较小，并且具有较低的LCP 、LSP 及其Rd 、Rn和Rp。弱光下各基因型辣椒的光合启动时间均有所延长，弱光敏感性材料表现更为明显。     

Morpho-physiological disorders in in vitro culture of plants

The special conditions during in vitro culture results in the formation of plantlets of abnormal morphology, anatomy and physiology. Tissue culture conditions that promote rapid growth and multiplication of shoots often results in the formation of structurally and physiologically abnormal plants. They are often characterized by poor photosynthetic efficiency, malfunctioning of stomata and a marked decrease in epicuticular wax. Qualitatively also, the waxes present on the surface of the leaves of in vitro cultured plants may vary. The conditions under which most laboratories done tissue culture is high relative humidity and low light, no supplemental CO₂, high sucrose and nutrient containing medium may contribute to a phenotype that cannot survive the environmental conditions when directly placed in a greenhouse or field. Understanding these abnormalities is a prerequisite to develop efficient transplantation protocols. The present review summaries the major abnormalities in in vitro culture of plants and also highlight the current and developing methods that are satisfactory for acclimatization of in vitro cultured plantlets.     

葡萄试管苗在移栽过程中叶解剖和根系活力的变化

葡萄试管苗通过分步驯化后,能够高频率的成活。观察和测定了各驯化阶段叶解剖结构和根系活力的变化,结果表明,试管苗叶片薄,组织稀疏,气孔突起,开口大,根系活力极低。通过分步炼苗,叶片逐渐向旱生结构变化,根系活力迅速增强。这是试管苗逐渐适应低湿和自然光照的解剖和生理变化。     

无蜡质芥蓝突变型叶表面蜡质超微结构观察

以亮叶无蜡质紫色芥蓝突变型紫.中花芥蓝和多蜡质紫色芥蓝野生型为试材,对芥蓝叶片发育过程中最外层的表面蜡质进行系统地观察,并对无蜡质突变型紫.中花芥蓝、多蜡质野生型芥蓝和普通绿色芥蓝(CK)的干物质量、VC、可溶性糖、粗纤维、蛋白质、花青苷等主要营养成分含量进行测定分析。结果表明:在叶片发育过程中,多蜡质野生型芥蓝的叶面蜡质明显多于无蜡质突变型紫.中花芥蓝;野生型芥蓝和紫.中花芥蓝叶片背面的蜡质均明显多于叶片腹面;野生型芥蓝叶片背面的蜡质退化速度明显慢于叶片腹面。无蜡质突变型紫.中花芥蓝的VC含量高于野生型芥蓝,而粗纤维(DW)含量低于野生型芥蓝,说明紫.中花芥蓝有利于改良现有芥蓝的营养品质,有望育成高VC含量、高花青苷含量、以生食为主的芥蓝品种。芥蓝叶片的无蜡质性状对多蜡质表现为隐性遗传,紫色对绿色表现为显性遗传。     

Effect of the culture environment on stomatal features, epidermal cells and water loss of micropropagated Annona glabra L. plants

Shoots of Annona glabra L. were rooted in vitro under three levels of irradiance and two closure systems (conventional and natural ventilation) of the culture vessels. Once the shoots had been rooted, we studied how the manipulation of the culture environment affects the stomata features and water loss through leaf tissues after the plants are removed from the vessel. The stomata frequency increased significantly in the leaves of plants grown under high (300 μmol m⁻² s⁻¹) compared to low (50 μmol m⁻² s⁻¹) or intermediate (150 μmol m⁻² s⁻¹) irradiance, with higher effect under natural ventilation. Irrespective of the culture environment, leaves developed in vitro attained a higher stomata frequency than those grown in vivo. Under high irradiance and natural ventilation, the leaves presented functional stomata of characteristically elliptical shape and the epidermal cells were smaller and had slightly sinuous anticlinal walls. Besides, water loss through leaves of plants grown under high irradiance and natural ventilation was drastically reduced if these plants were exposed to an environment with low relative humidity thereafter. Our results indicate that an increased light availability and the use of natural ventilation improve the regulatory capacity of water loss in micropropagated A. glabra L. plants and can favor the plants’ survival and growth after transference to the natural environment.     

苗期夜间低温对番茄叶片气孔开张度日变化及叶片超微结构的影响

以15℃夜温为对照,研究了6℃夜间低温对番茄叶片气孔开张度日变化及叶片结构的影响。结果表明:处理7d时,处理植株叶片气孔器大小和叶面积显著小于对照,气孔密度显著大于对照。表皮厚度极显著大于对照。叶片厚度大于对照,但与对照差异不显著。处理植株番茄叶片气孔张开程度一天中皆小于对照,气孔张开率上午与对照差异不显著,14:00显著小于对照。16:00极显著小于对照;恢复7d时,夜低温处理番茄叶片气孔器显著大于对照。气孔密度、每叶气孔数及单叶叶面积、气孔张开率皆小于对照,叶片气孔开口程度、叶片表皮厚度及厚度大于对照,但差异都不显著;夜间低温处理后叶片栅栏组织显得更紧密,恢复7d后无显著差异。     

苹果叶片离体培养中秋水仙素加倍效应的研究

用不同浓度的秋水仙素溶液处理苹果的栽培品种嘎拉试管苗的离体叶片，发现以０．５％的秋水仙素溶液处理４ｄ效果最佳，诱变频率达５６．１％。诱变后获得的四倍体植株在形态学和细胞学上均发生了明显变异。与对照株比较，变异株茎矮、粗壮、节间短、叶片厚、叶色浓绿；叶背面的气孔体积增大，单位面积气孔数目减少、茸毛数量增加；染色体数目加倍，２ｎ＝４ｘ＝６８（对照２ｎ＝２ｘ＝３４），细胞核核仁数目增加。梢端组织学切片证明，变异株中同质突变体的频率达７３％。     

Effects of suboptimal low temperatures on plant architecture and flowering in muskmelons Cucumis melo L.

Summary

The effects of suboptimal cold temperatures were investigated in an array of vegetative, reproductive and leaf characters in 34 cultivars, both open pollinated and hybrid, of melons, Cucumis melo. The cultivars were grown in two treatments: (i) a heated greenhouse (T1) that produced temperatures similar to those used in commercial cultivation in winter; and (ii) an unheated greenhouse (T2) that produced significantly lower night-time temperatures than T1. Plants grown in T1 had significantly longer main stems and internode lengths, more nodes and more potassium in their leaves but less leaf biomass than plants grown in T2. Plants from T2 also had more green and yellow leaf colour than plants from T1. Open pollinated cultivars had significantly longer main stems, more nodes and more green and yellow leaf colour than hybrid cultivars. Significant differences were found among the cultivars in all traits.     

甘蓝无蜡粉突变体叶表皮蜡质超微结构观察

运用扫描电子显微镜对结球甘蓝无蜡粉突变体及野生型材料不同生长时期的叶表皮蜡质发育
状况进行比较观察。结果表明：甘蓝无蜡粉突变体也有蜡质晶体存在,但蜡质发育不完全,整个生长期以
颗粒状晶体结构为主;野生型不同生长时期表现出不同的蜡质晶体结构,苗期以颗粒状和片状为主,结球
期以圆柱状和片状为主,成熟期以片状和线状为主。     

不同栽培基质对吊兰气孔参数的影响

通过对营养液水培、陶粒浇灌营养液、珍珠岩浇灌营养液、蛭石浇灌营养液、土培5种栽培条件处理下吊兰气孔参数的研究，结果表明，试验中所观察的吊兰叶片气孔呈圆型或椭圆型，保卫细胞半月形。靠近叶尖和叶中部位的气孔分布较叶缘和叶基的多，叶基部位气孔分布相对较少，从叶基到叶尖气孔密度逐渐增大，表现为：叶尖〉叶中〉叶基。不同栽培基质中吊兰叶片中段下表皮气孔参数相比较：土培处理的叶片中段气孔指数最大为41．63％，极显著地高于蛭石浇灌营养液、营养液水培、陶粒浇灌营养液处理；土培单个气孔面积最小，为896．98μm^2，极显著地低于蛭石浇灌营养液、营养液水培、陶粒浇灌营养液处理。     

红肉脐橙等5个柑橘品种气孔器结构的比较研究

以卡拉卡拉红肉脐橙(Citrus sinensis)、玫瑰橙(C.sinensis)、稻叶温州蜜柑(C.unshiu)、春见(C.reticulatax C.sinensis)和HB柚(C.grandis)等的春梢嫩叶(1/2伸展)与完全伸展叶片为材料,结合常规石蜡切片、超薄切片与透射电镜技术、扫描电镜技术以及改良的临...     

Higher than optimum temperature under CO2 enrichment influences stomata anatomical characters in rose (Rosa hybrida)

There is little available information on the effects of temperature and CO₂ enrichment on stomata anatomical characteristics of plants. Effect of these two microclimates was studied on five rose (Rosa spp.) cultivars, viz. ‘First Red’ (used as check), ‘Arjun’, ‘Raktima’, ‘Raktagandha’ and ‘Pusa Pitamber’. Budded, single-stemmed rose cultivars having five lateral buds were grown in controlled environment growth cabinets under enriched CO₂ (1000 μmol mol⁻¹) and optimum (28/18 °C, T₀) or high (35/25 °C, T₁) temperature for 50 days. All observations were made on the abaxial leaf surface. Significant increases in stomatal density (68.7%), index (29.6%) and epidermal cell density (37.3%) were recorded in plants grown at high temperature over control with CO₂ enrichment. The cultivars responded differently in terms of length and width of guard cell and stoma (pore) under high temperature, however, the values averaged over treatments showed a significant reduction in these parameters. Further, number of stomata per leaf was higher (28.3%) in plants grown at high temperature, except First Red. A reduction in mean leaf area (26.7%) and dry mass (32.0%) was recorded at high rather than optimum temperature. The specific leaf area was maximum in Arjun (87%) while in First Red, a 14% reduction was noted at high temperature.     

5-氨基乙酰丙酸对弱光下甜瓜幼苗光合作用和抗冷性的促进效应

 5-氨基乙酰丙酸(ALA)10 mg·L 处理能够明显提高弱光下生长的甜瓜幼苗叶片净光合速率(Pn)，而低温胁迫明显降低甜瓜幼苗叶片光合能力。经ALA处理过的甜瓜幼苗光合表观量子效率、羧化效率、气孔开度、叶片叶绿素(特别是叶绿素b)和可溶性糖含量均显著增加。在ALA处理3 d之后将幼苗转移到8℃低温条件下4 h，对照叶片光合能力基本丧失，而ALA处理叶片仍能维持一定的光合能力，并在20 h内基本恢复至对照水平。若幼苗在低温下处理6 h，对照植株完全死亡，而ALA预处理植株仅出现少量伤害症状。本研究结果表明，ALA处理可以提高植物耐弱光性和抗冷性。