黄瓜离体子叶切块培养直接分化花芽

４８小时龄黄瓜幼苗的子叶切块接种于附加２．０ｍｇ／ＬＢＡ及１．０ｍｇ／ＬＡｇＮＯ３的修改ＭＳ培养基上,培养约６０天后在子叶切块的近轴端可直接形成雄花芽,其频率达７．７％。     

秋水仙碱诱导梨离体叶片再生多倍体

以二倍体梨(Pyrus communis L.) 品种'丰产'试管苗的离体叶片为外植体,研究了秋水仙碱处理对叶片不定梢再生及多倍体诱导率的影响.结果表明:(1)随秋水仙碱处理时间增加,叶片不定梢再生率下降,而多倍体诱导率增加;以0.4%的秋水仙碱溶液处理叶片48 h效果最好,多倍体诱导率为6.1%.(2)流式细胞仪(Flow cytometry)分析鉴定表明,获得的多倍体有三倍体、四倍体和混倍体;多倍体与二倍体的形态特征差异明显,多倍体比二倍体茎粗、节间短,叶形指数小,根粗而且短.     

Efficient Regeneration of Curcuma amada Roxb. Plantlets from Rhizome and Leaf Sheath Explants

Efficient and simple protocols were developed for conversion of embryos derived from microspores in rape. The frequency of embryo conversion was higher than 80% on improved media without pretreatments using ABA, GA₃ or desiccation, which had been required before embryos were transferred to solid media for conversion. While on basal media such as 1/2MS, the conversion frequency was no more than 32%. Two groups of embryos at different developmental stages, 7 mm embryos and 3 mm embryos, were used as material to select the most suitable medium. Different components were required for successful conversion of the two groups of embryos. For 7 mm embryos 1/2MS medium with Ca²⁺ concentration of 900 mg l^–1 was optimal, while for 3 mm embryos, 1/2 MS_N+V+Ca (half strength MS with 450 mg l^–1 CaCl₂·2H₂O, 100 mg l^–1 NH₄NO₃ and enhanced vitamins) was a suitable medium. The results indicate that calcium may play an important role in the conversion of embryos derived from microspores, and can replace, to some extent, the practice of drying and growth supplements, which have been widely used for maturation, and desiccation of embryos.     

Direct Differentiation of Shoot Buds from Leaf Explants of Cajanus Cajan L.

A protocol was developed for direct differentiation of multiple shoot buds from leaf explants of Cajanus cajan. In a modified Murashige and Skoog's medium supplemented with 2.22 µM benzyladenine (BA), 0.57 µM indole-3-acetic acid (IAA) and 41 µM adenine sulphate (AdS), the segments of basal halves of the first two leaves of a young seedling incubated on filter paper bridges in liquid medium took 20 – 25 d to differentiate shoot buds. The explants after transfer to solidified medium, with lower concentration of BA (0.22 M) resulted in fast growing healthy shoots. The developed shoots (measuring ca. 3 cm) were rooted in a medium supplemented with 1.42 µM IAA. They were subsequently grown in pots with soil with more than 80 % transplantation success.     

花生幼叶不定芽诱导与快速繁殖

以花生品种‘粤油7号’6~8 d龄幼叶为外植体进行植株再生研究。结果表明,外植体在MS+0.6 mg/L NAA+8 mg/L 6-BA+1 mg/L AgNO₃+3 mg/L Gln培养基上,诱导不定芽效果好,经两次继代培养出芽率达81.03%,每个外植体平均出芽数达5.79个。经伸长培养基MS+2 mg/L 6-BA+4 mg/L GA₃培养,不定芽伸长长度达1.0~2.0 cm。试管苗在培养基1/2 MS+0.5 mg/L NAA+3 mg/L IBA上生根率达86.15%,不定根粗而长,有侧根,移栽成活率达90%,结实率100%。     

Tissue 11In vitro Bud Formation on Explants from the Inflorescence of Nicotiana tabacum L.

Croes, A. F., Creemers-Molenaar, T., van den Ende, G., Kemp,A. and Barendse, G. W. M. 1985. Tissue age as an endogenousfactor controlling in vitro bud formation on explants from theinflorescence of Nicotiana tabacum L.—J. exp. Bot. 36:1771–1779. The in vitro formation of generative buds was studied on explantsfrom flower and fruit stalks and from internodes of the floralramifications of tobacco. A floral gradient was found to existalong the axis of the branch. The gradient concerns the numberof flower buds formed in vitro and is present in both typesof tissues. The number of flower buds is greater on tissuesfrom the apical than from the basal portion of the branch. Thecapacity to generate these buds is largely determined by tissueage at the moment of the excision. Consequently, the gradientmoves along the axis during the outgrowth of the inflorescence. The alternative possibility that some apex-derived stimuluspredetermines the morphogenetic capacity of the tissue priorto excision is excluded by the observation that the gradientremains virtually unaltered if the apex is removed one weekbefore the onset of culturing. Auxin affects the floral gradient Increasing the auxin concentrationin internode tissue culture causes a steeper gradient of flowerbud generation by almost completely abolishing bud formationon older tissues. Key words: Auxin, flower buds, gradient, tissue culture, tobacco     

In vitro Plant Formation from Stem Explants of Rape (Brassica napus cv. Zephyr)

Internodal segments from 6-weeks-old rape plants (Brassica napus L. cv. Zephyr) were induced to differentiate in vitro producing shoots or shoots and roots on synthetic nutrient medium under controlled conditions. Benzyladenine (BA) alone (5 × 10^?6 M) induced multiple shoot formation on all stem explants. Roots were induced on shoots when recultured on nutrient medium supplemented with auxins such as naphthalene-acetic acid (NAA) or indoleacetic acid (1AA) or when planted in vermiculite. Complete plant formation was obtained when NAA (2 × 1^?6, 5 × 10^?6 and 10^?5 M) was employed in conjunction with BA at 5 × 10^?6M. At higher concentrations (10^?5M) NAA retards the shoot development while 1AA suppresses it totally. Lower levels of auxins along with the cytokinin did not retard or inhibit shoot differentiation.     

Photo- and Gravitropic Bending of Potato Plantlets Obtained In Vitro from Single-Node Explants

Etiolated and light-grown plantlets obtained from potato shoot cultures were shown to perform vigorous tropic movements. Unilateral blue irradiation actively induced phototropic curvature of the shoots toward the light source, although etiolated plantlets required ten times longer stimulation than the light-grown plantlets to achieve a 90° angle. The fluence requirements for induction of second positive phototropism (PT) of light-grown plantlets spanned almost five orders of magnitude (~30–1.7?×?10⁵ μmol/m²). Upon responding to unilateral blue light by curving, plantlets entered the process of straightening after irradiation ended. Straightening also occurred in plantlets placed on a clinostat but it was of lower magnitude. Compared to early-morning and day-time hours, plantlets exhibited a significantly lower PT response in the late afternoon (5 p.m.) and gravitropic (GT) response at the end of the day (11 p.m.), suggesting that these responses may be under the control of circadian rhythms. GT was also recorded for both light-grown and etiolated plantlets. Ninety-degree stimulation, used to induce GT in etiolated plantlets, needed to be 50?% longer than stimulation used for light-grown plantlets to induce a similar response. Straightening was also recorded for the shoots that exhibited GT but was smaller when plantlets were placed on a clinostat compared to straightening exhibited by those plantlets left standing in an upright position for 2?h.     

Chemical constituents from Ailanthus altissima (Mill.) Swingle and chemotaxonomic significance

Sixteen compounds were isolated from the root barks of Ailanthus altissima (Mill.) Swingle, including thirteen lignans (1–13), two coumarins (14–15), and one chalcone (16). This is the first report on the occurrence of compounds 1–16 in the genus Ailanthus. Their structures were elucidated on the basis of NMR spectroscopic data. The plant distribution network of all isolated compounds was described to illustrate the significance of taxonomy. The presence of these congenetic lignans (1–13) and their biosynthetic relationships may be used for identification of Ailanthus genus.     

4-PU和6-BA对'汕油523'花生上胚轴愈伤组织诱导及不定芽发生的影响

以'汕油523'花生上胚轴为外植体,研究细胞分裂素4-PU和6-BA对愈伤组织诱导及不定芽发生的效应.结果表明,当MS培养基含有4-PU 0.1mg/L和6-BA4mg/L培育20d时,愈伤组织形成率为100%:0.1mg/L4-PU与适宜浓度的6-BA(1～4mg/L)共同作用,促进上胚轴不定芽发生,不定芽形成与芽伸长的适宜培养基配方分别为MS+4-PU 0.1mg/L+6-BA2mg/L和MS+4.Pu 0.1mg/L+6-BA 4mg/L;0.5mg/L4-PU对不定芽出芽率、芽数与长度的作用均大于其与不同浓度6-BA混合作用的效果.     

The Effect of Various Culture Media on the Formation of Embryo-like Structures in Cultures Derived from Explants Taken from Mature Larix decidua

The effect of various collection dates and nine different culture media on the formation of ‘embryo-like structures’ (ELS) in cultures derived from explants taken from a 42-year-old Larix decidua tree was studied. The best medium was AFC, a medium low in NH₄⁻, NO₃ ⁺, Mg²⁺ and SO₄²⁻ but high in PO₄³⁻ compared with the concentration of these elements in the other media. On AFC, ELS production reached a peak with collections made in late summer during the period when needle primordia are being initiated. For the other media, collection date had a lesser effect on ELS initiation.     

Flower Formation In vitro by Hypocotyl Explants of Cucumber (Cucumis sativus L.)

Hypocotyl explants of cucumber (Cucumis sativus L.) producedcallus when grown in Murashige and Skoog medium with 0.5 or1.0 µM benzyladenine and 1.5 or 5.0 µm 2, 4-D. Somaticembryos and adventitious buds were formed when callus was transferredto medium without growth regulators. Flowers that were formedin vitro were either staminate or pistillate. Cucumis sativus L, cucumber, embryogenesis, organogenesis, flowering in vitro     

Direct Adventitious Shoot Formation from Apical Shoot Explants of Euphorbia tirucalli

The induction of adventitious buds from apical shoot explants of Euphorbia tirucalli was studied. On average, 10.5 adventitious buds were efficiently induced in a ring on the segment from one apical explant on MS (Murashige and Skoog) medium supplemented with 0.5 mg l⁻¹ thidiazuron and 0.5 mg l⁻¹ benzylaminopurine. The adventitious buds could develop into adventitious shoots during subsequent cultures on hormone-free MS medium. For rooting, shoot clumps were cultured on half-strength MS medium containing 0.2 mg l⁻¹ α-naphthaleneacetic acid or indole-3-butyric acid. All the rooted plants survived establishment in soil within 2 months.     

Exogenous Calcium Enhances the Formation of Vegetative Buds,Flowers and Roots in Tobacco Pith Explants Cultured in the Absence of Exogenous Hormones

Pith explants excised from the apical stem internodes of vegetative, flowering, and fruiting tobacco plants were cultured on hormone-free medium in the presence or absence of CaCl₂ (3 mM). The aim was to determine the role of exogenous calcium (Ca²⁺), applied at the concentration normally present in the Murashige and Skoog (1962) medium, in organ formation obtainable in the absence of the exogenous hormonal input. Exclusive formation of vegetative buds was obtained from explants excised from vegetative plants (pure vegetative programme); vegetative buds and flowers (and occasionally roots) on the same sample were obtained from explants from flowering plants (mixed flowering programme); whereas roots, very occasionally associated with vegetative buds and flowers on the same sample, were obtained from explants from fruiting plants (mixed rooting programme). Histological analysis showed that the organs always exhibited indirect regeneration. Exogenous Ca²⁺ promoted the formation of meristemoids and the first phases of their growth into organs, but did not change the realization of the organogenic programme and did not affect callogenesis. Instead, the influence of exogenous Ca²⁺ changed with the programme, when considering the last phases of organ growth (i.e., macroscopic development and elongation), and the appearance of morphological anomalies in the organs.     

In vitro Regeneration of Gerbera jamesonii Bolus from Leaf and Petiole Explants

Regeneration of adventitious shoots from leaf and petiole pieces of Gerbera jamesonii has been obtained on Murashige and Skoog (MS) medium supplemented with different concentrations of auxins and cytokinins. About 75’77 per cent of the calli from both types of the explants produced 12’15 shoots per callus with 3 mg l^?1 SAP. Auxins and kinetin, separately failed to produce shoots. The shoots regenerated on the callus induction medium (elM). The regenerated shoots multiplied with 1 mg l^?1 SAP, were rooted on MS medium containing 1mg l^-1 BAP + 0.1 mg l^-1 IAA. The plants obtained were transferred to pots and acclimatized with 60’70 per cent success.     

Callus and Root Formation in Explants of Beta vulgaris

Callus from hypocotyl and petiole explants and anthers of Beta vulgaris L. was initiated on a defined agar medium containing IAA and kinetin. The cultures were kept in light (18 hours a day) at 27C for 5 weeks. Differences in dry matter production and root initiation were found between hypocotyl and petiole explants. No shoots were formed. Callus formation in anthers was very rare.     

In vitro Plant Regeneration of Melia azedarach L.: Shoot Organogenesis from Leaf Explants

In vitro regeneration of Melia azedarach L. was studied. Shoots were regenerated from calli initiated from leaflets of in vitro growing plants. The best medium for establishment of cultures was Murashige and Skoog (MS) medium with 4.44 μM benzylaminopurine (BAP) + 0.46 μM kinetin (KIN) + 16.29 μM adenine sulphate (ADE). Regenerated shoots were multiplied in MS + 0.44 μM BAP + 0.37 μM KIN + 3.26 μM ADE. Maximal rooting of 89 % was achieved by culture of regenerated shoots in MS + 12.26 μM indole-3-butyric acid for 3 d and subsequently in MS lacking growth regulators for 27 d. Rooted shoots were acclimatized and successfully transferred to soil. This revised version was published online in July 2006 with corrections to the Cover Date.     

试管植物器官微型化及结构特征

植物组织培养中的试管植物,其形态比自然形态要小得多,脱离试管后能恢复原形态大小,这种微型化和微型化解除是植物与环境相互作用的一个新命题.以试管马铃薯无性系微型薯为材料,在试管和花盆两种环境下发芽并长成植株,显微切片方法观察其组织结构特征,聚丙烯酰胺凝胶电泳(SDS-PAGE)方法分离不同处理植株的差异蛋白.研究发现,试管植株器官微型化的主要原因是细胞数量减少,其次是细胞体积减小,但试管植株的气孔则较大.在不同处理的植株中检测出单个和多个蛋白差异.结果说明,试管因子,包括营养和生长空间因子,能显著胁迫植物正常生长和形态建成,形态改变过程伴随有较大的生理变化.