防风体细胞胚发生发育中的淀粉体和多糖动态

以防风体细胞胚的发生体系为材料,通过半薄切片技术研究了培养物中淀粉体的组织化学定位,并采用分光光度法测定了不同培养阶段的多糖含量.结果发现在胚性细胞内积累了大量的淀粉体;含4%蔗糖的培养基中的胚性愈伤组织阶段多糖含量最高.研究表明糖类物质的活跃代谢为胚性细胞的分化和发育直接提供了物质和能源;大量淀粉体的存在可作为胚性细胞分化的标记.     

防风悬浮培养中的体细胞胚发生

将防风（Ｓａｐｏｓｈｎｉｋｏｖｉａ ｄｉｖａｒｉｃａｔａ （Ｔｕｒｃｚ．） Ｓｃｈｉｓｃｈｋ．）试管苗幼根接种在含０．５ ｍ ｇ／Ｌ ２,４－Ｄ 的ＭＳ培养基上诱导出愈伤组织,继而在含１０％ 椰子乳和０．５ ｍ ｇ／Ｌ ２,４－Ｄ的ＭＳ液体培养基中振荡分散建立了细胞悬浮物。至胚性细胞团产生后转至无激素培养基中形成体细胞胚。观察了从单细胞直到球形胚发生的显微及超微结构的变化。在胚性细胞团阶段细胞内出现周质内质网,它的出现可能与细胞团向原胚过渡时的特殊代谢相联系。从单细胞至原胚各阶段细胞内均含有圆球体,到原胚时数量大增,而且其中央电子致密的基质变小变浅,周边部分扩大并更加透明,暗示圆球体在胚胎发生早期起着贮藏蛋白或脂蛋白的作用,后来消耗于原胚的建成而衍生为脂滴。球形胚阶段,在很多细胞的液泡中出现团块状的液泡蛋白。此外还观察到,悬浮培养时单细胞的聚集能促进体细胞胚的发生     

磁场对防风体细胞胚发生发育和亚显微结构的影响

近年来,关于防风的离体培养国内学者相继进行了研究,余绍华等（１９８５）用幼叶诱导愈伤组织分化出根芽;慈忠玲和陈惠民（１９９５,１９９６）通过悬浮培养诱导体细胞胚发生及再生植株,对单细胞至球形胚形成的各阶段作了显微及超微结构观察,并对其培养过程中的染色体变异进行了分析;盛世红和陈惠民（１９９０）用原生质体培养获得了再生植株。但目前还未见磁场对防风胚状体发生和发育影响方面的报告。关于生物磁学在植物组织培养中的应用,赵成章（１９８０）研究了磁场对水稻花粉愈伤组织诱导和分化的影响;王曼丝和李鸣镝（１９９…     

矮牵牛叶片体细胞胚胎发生发育的组织学观察

以矮牵牛生根试管苗的叶片为外植体,在培养基MS NAA0.1mg/L 6-BA1.6mg/L上诱导体细胞胚胎直接发生。从接种后第一天开始观察叶片愈伤组织发生、发育的外部形态变化,从接种后第七天开始,每隔3天取变化明显的叶片组织块切片观察其胚状体的组织细胞学连续变化。组织切片观察表明,矮牵牛叶片体细胞胚胎发生类似于合子胚的发育过程;矮牵牛体细胞胚起源于叶肉细胞,胚性细胞与非胚性细胞染色明显不同,体细胞胚胎与周边其它组织有明显界线;体细胞胚胎的发育经历胚性细胞、多细胞原胚、球形胚、梨形胚、心形胚、鱼雷胚、类子叶胚等几个阶段。     

枣树体细胞胚发生和组织学研究

以临泽小枣子叶切块为外植体,在附加０．２mg/L IBA 1．0mg/L 6-BA的ＭＳ培养基上１周后切块边缘可诱导出白色胚愈伤组织,继续培养１个月后愈伤组织中产生体细胞胚。体细胞胚发生不同步,经历球形胚、心形胚、子叶胚等阶段,与合子胚发育途径相似。组织切片表面胚性愈伤组织细胞体积小,细胞核大、细胞质浓,细胞排列紧密;而非胚性愈伤组织细胞体积大、细胞核小、细胞质稀薄,子叶胚时期体细胞胚内部出现维管束,并观察到螺纹导管。     

芹菜体细胞胚胎发生及干化体细胞胚的研究

以芹菜无菌苗为材料,在ＭＳ附加ＫＴ ０．５ｍｇ／Ｌ,ＡＢＡ０．２５ｍｇ／Ｌ,脯氨酸５００ｍｇ／Ｌ,ＣＨ５００ｍｇ／Ｌ的培养基上,采用静止与震荡交替进行的培养方式,可获得大量健壮的子叶期胚状体（体胚）。干燥可以提高贮茂后体胚的转换率,特别是在低温,高湿中缓慢干燥,并在干燥前用ＡＢＡ预处理效果更好。通过干燥和不干燥体胚扫描电镜观察和电导值及脱氢酶的比较,发现干燥体胚有助于贮藏期间细胞结构及膜系统的保持     

防风愈伤组织的玻璃化法超低温保存及再生

为避免连续继代造成的愈伤组织变异,探索新的种质资源保存方法,对防风愈伤组织进行了超低温冷冻保存及植株再生研究。以关防风3周龄的愈伤组织为材料,单一变量法研究适宜的玻璃化法超低温保存程序。结果显示:(1)防风愈伤组织超低温保存的最佳方案为:4℃条件下于MS+1.0mg/L 6-BA+1.0mg/L NAA+5%DMSO的继代培养基中预培养3d,60%PVS2常温装载20min,100%PVS2于2℃脱水45min后直接投入液氮。(2)防风愈伤组织经超低温保存后的相对存活率最高为79.24%,其中预培养和脱水是实现超低温冻存的关键环节,且1.0mol/L蔗糖的MS溶液洗涤、暗培养14d以上有助于冻后愈伤组织恢复生长。研究表明,玻璃化超低温冻存可以作为防风愈伤组织的保存方法,冻后愈伤可以恢复生长并再生成完整植株。     

关防风根腐病拮抗细菌筛选与鉴定

【背景】由木贼镰刀菌[Fusarium equiseti(Corda)Sacc.]引起的关防风根腐病,是近年来导致关防风产量及质量下降的主要土传病害之一。生物防治因其对环境安全及人畜无害等优势,成为目前植物病害防治的一种有效手段。【目的】挖掘关防风根际土壤中对木贼镰刀菌具有良好拮抗作用的生防菌株。【方法】采用稀释平板法分离根际土壤细菌;用滤纸片法和牛津杯法对拮抗细菌进行筛选和抑菌谱检测;用抗生素标记法标记拮抗细菌并测定其定殖能力;通过盆栽实验研究其对关防风根腐病的防效;通过形态学、生理生化特征及16S rRNA基因序列确定分类学地位。【结果】从健康关防风根际土壤中分离纯化了157株细菌,筛选获得对关防风根腐病菌具有显著抑菌作用的拮抗细菌SC-119,无菌滤液的抑菌率可达68.53%,而且兼具广谱抑菌能力和良好的定殖能力;盆栽实验表明,菌株SC-119对关防风根腐病的防治效果达到67.39%,其相对防效较接种哈茨木霉菌剂、枯草芽胞杆菌菌剂和代森锰锌分别提高了29.03%、32.26%和16.13%;对菌株SC-119进行分类学鉴定,确定其为萎缩芽胞杆菌(Bacillus atrophae...     

Comparative study of somatic embryogenesis from immature and mature embryos and organogenesis from leaf-base of Triticale

Immature and mature zygotic embryos of hexaploid, Triticale var. DT-46 formed an embryogenic callus, with subsequent somatic embryo formation upon subculture to MS (Murashige and Skoog, 1962) or N₆ (Chu et al., 1975) nutrient medium supplemented with various concentrations (9.0–22.5 M) of 2,4-dichlorophenoxyacetic acid (2,4-D). Of the two types of explants, embryogenic tissue from immature embryos responded at a higher frequency, to form somatic embryos over the callus surface. Leaf-base segment cultured on to 2,4-D-containing medium formed a tissue which did not form somatic embryos and instead differentiated into shoot-buds. N₆ medium proved to be more effective than MS in support of somatic embryogenesis or shoot-bud formation. Regeneration of plantlets occurred on 2,4-D-free basal medium. These in vitro-formed plantlets were successfully transferred to soil and set seed.     

Induction of somatic embryogenesis in Azadirachta indica

A modified culture protocol has been developed for the induction of somatic embryogenesis in Azadirachta indica (neem). Embryogenic calluses were initiated from cotyledons or hypocotyls using a Murashige and Skoog (MS) agar medium supplemented with 0.5 mg l⁻¹ α-napthaleneacetic acid (NAA), 1 mg l⁻¹ 6-benzylaminopurine (BA), 1 g l⁻¹ casein hydrolysate, and 50 g l⁻¹ sucrose. The calluses, when transferred to a liquid medium similar to the agar medium but with NAA replaced by 0.5 mg l⁻¹ indole-3-acetic acid (IAA), formed globular structures which further developed a rudimentary root, after 4 to 5 weeks incubation. Subsequently, these highly differentiated tissues when transferred into a hormone-free MS medium containing 1 g l⁻¹ casein hydrolysate and 50 g l⁻¹ sucrose, active embryo masses started to appear after 1 to 2 weeks. The embryo production was found to improve more than 2 fold by adding 0.2 mg l⁻¹ zeatin to the medium. This revised version was published online in June 2006 with corrections to the Cover Date.     

渗透剂对白刺花体细胞胚成熟及萌发的影响

该研究以蔗糖、麦芽糖、山梨醇及PEG(6000)为渗透剂,探讨了不同渗透剂对白刺花体细胞胚发育、胚成熟及萌发的影响。结果表明:白刺花下胚轴形成的胚性愈伤组织接种至MS+2,4-D 0.2 mg·L~(-1)+NAA 1.0 mg·L~(-1)+6-BA 2.0 mg·L~(-1)+TDZ 1.0 mg·L~(-1)+蔗糖40 g·L~(-1)+谷氨酰胺100 mg·L~(-1)+植物凝胶3g·L~(-1)的培养基上,体细胞胚发生率高达66. 21%,总胚数为79个; 7%蔗糖可使体细胞胚成熟率高达64.36%,同时也可提高多子叶畸形胚形成; 2%麦芽糖+2%山梨醇+4%蔗糖组合使体细胞胚成熟率最高达88.89%,畸形胚比例最低; 30 g·L~(-1)PEG培养时,体细胞成熟率最高,为82.35%;鱼雷期的体细胞胚最合适转接,可使体胚萌发率达90.58%,复合糖上培养得到的成熟体细胞胚生根率最高,为87.47%。这为实现白刺花体细胞胚育苗奠定了理论基础,并提供了可行的方案。     

温度和水分对不同基因型小麦未成熟胚体细胞胚胎发生以及分化能力的影响

对小麦未成熟胚盾片组织离体再生途径中,未成熟胚发育时期以及不同小麦品种的体细胞胚发生能力和体细胞胚的分化能力进行了研究,在所 试的14个小麦品种中,筛选出具有很强的体细胞胚发生能力和体细胞胚分化能力的4个品种,西农1376、盐2号、85＋1－3和宝丰7228。为进一步给小麦离体遗传操作打下基础,研究还对温度的影响进行了分析。通过低温手段解决了胚性愈伤组织随继代天数的延长体细胞胚分化能力快速降低的问题,同时研究还首次分析了干燥处理对小麦体细胞胚转换能力的影响,建立起一套高效的小麦离体培养再生体系,而且该体系从接种未成熟胚到再生植株移至土壤只需10－12周时间,避免了长期培养过程中存在的体细胞变异问题。     

In vitro somatic embryogenesis and plant regeneration in Acacia arabica

In vitro somatic embryogenesis and subsequent plant regeneration was achieved in callus cultures derived from immature zygotic embryos of Acacia arabica on semi-solid Murashige and Skoog (MS) basal salts and vitamins supplemented with 8.88 MBA, 6.78 M2,4-D and 30 g l^–1 (w/v) sucrose. Somatic embryos proliferated rapidly by secondary somatic embryogenesis after transfer to MS medium supplemented with 6.66 M BA, 6.78 M 2,4-D. The maximum number of somatic embryos per callus was 72.6 after 8 weeks of culture on medium containing 6.66 M BA and 6.78 M 2,4-D. The isolated somatic embryos germinated on half-strength basal MS salts and vitamins supplemented with 0.04 M BA, 0.94 M ABA and 2% (w/v) sucrose. The embryo-derived plantlets were acclimatized in the greenhouse and subsequently showed normal growth.     

植物体细胞胚胎发生的调控网络

植物体细胞胚胎发生是一个极其复杂而有序的过程,受到多种内外因素的影响与调控。其中基因的表达与调控是影响体细胞胚胎发生最重要和最根本的因素。这些基因包括PLANT GROWTH ACTIVATOR系列基因、LEAFYCOTYLEDON家族基因、BABY BOOM基因、SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE基因和PICKLE基因等,它们相互作用构成了一个复杂的调控网络。以下结合作者对PLANT GROWTH ACTIVATOR 37等基因的研究,对这一调控网络进行了介绍,并探讨了未来体细胞胚胎发生的研究方向。     

Developmental pathways of somatic embryogenesis

Somatic embryogenesis is defined as a process in which a bipolar structure, resembling a zygotic embryo, develops from a non-zygotic cell without vascular connection with the original tissue. Somatic embryos are used for studying regulation of embryo development, but also as a tool for large scale vegetative propagation. Somatic embryogenesis is a multi-step regeneration process starting with formation of proembryogenic masses, followed by somatic embryo formation, maturation, desiccation and plant regeneration. Although great progress has been made in improving the protocols used, it has been revealed that some treatments, coinciding with increased yield of somatic embryos, can cause adverse effects on the embryo quality, thereby impairing germination and ex vitro growth of somatic embryo plants. Accordingly, ex vitro growth of somatic embryo plants is under a cumulative influence of the treatments provided during the in vitro phase. In order to efficiently regulate the formation of plants via somatic embryogenesis it is important to understand how somatic embryos develop and how the development is influenced by different physical and chemical treatments. Such knowledge can be gained through the construction of fate maps representing an adequate number of morphological and molecular markers, specifying critical developmental stages. Based on this fate map, it is possible to make a model of the process. The mechanisms that control cell differentiation during somatic embryogenesis are far from clear. However, secreted, soluble signal molecules play an important role. It has long been observed that conditioned medium from embryogenic cultures can promote embryogenesis. Active components in the conditioned medium include endochitinases, arabinogalactan proteins and lipochitooligosaccharides.