Propagation in vitro of the apple rootstock M4: effect of phytohormones on shoot quality

The quality of shoots in cultures of the apple rootstock, M4, was used as a criterion for the selection of an optimum medium. The frequency of shoots in defined shoot clases was monitored for each of five media, which differed in the type and concentration of phytohormone. Media containing BA (1.15 mg l^-1) and IBA (either 0.15 or 0.20 mg l^-1) produced the maximum number of shoots that were desirable for transplantation and acclimatization.     

Micropropagation ofPenstemon serrulatus and iridoid formation in regenerated plants

A method for the micropropagation ofPenstemon serrulatus Menz. from shoot tips or nodal segments was developed. Multiple microshoot cultures (up to 20 shoots from a single explant) were obtained by maintenance of shoot tip explants on Schenk & Hildebrandt medium (SH) supplemented with 4.4 µM benzyladenine (BA) or 8.9 µM BA and 0.57 µM indole-3-acetic acid (IAA). Microshoots developed into numerous, normal shoots when explants were transferred to SH medium containing 2.9 µM IAA or 2.5 µM indole-3-butyric acid (IBA). Shoot cultures were also established from nodal segments (max. 6.8 shoots per segment) when they were placed on SH medium with 0.49 µM IBA and 2.2 µM BA. Rooting of shoots was better on SH medium containing auxin (IBA, NAA or IAA) than on SH medium without growth regulators. The plantlets were then transferred to pots and grown in the greenhouse. Four-month-old regenerated plants demonstrated similar iridoid content (leaves contained 3.83% dry wt. penstemide and 1.8% dry wt. serrulatoloside) as the original plants.     

A simplified protocol for micropropagation of guayule (Parthenium argentatum gray)

Summary A simple, efficient protocol for in vitro micropropagation of guayule is reported. Shoot cultures were maintained on MS (Murashige and Skoog, 1962) medium supplemented with 1.0 mg l⁻¹ (4.4 μM) 6-benzylaminopurine and 0.025 mg l⁻¹ (0.3 μM) α-naphthaleneacetic acid. Excised shoots were treated for 14–18 h with 100 mg l⁻¹ (492.1 μM) indole-3-butyric acid in 0.5 x MS salts to induce rooting. The shoots were subsequently inserted into cellulose plugs which were packed in sterile, ventilated plastic culture vessels and moistened with 0.5 x MS medium without growth regulators. Use of cellulose plugs, liquid medium and ventilated culture vessels facilitated acclimation. Rooted shoots were transplanted into potting medium and acclimated to greenhouse conditions by covering with a cloche for 2 d, followed by daily watering for the first week. Any mention of trade names or commercial products in this report is for informational purposes only and does not imply endorsement by the U.S. Department of Agriculture or the Agricultural Research Service.     

发酵液中添加物对气含率的影响

气含率是史定气液接触面积和传质系数的重要因素,也是表示气液两相流体力学特征的重要参数。发酵液中添加物对气含率的影响,过去虽有一些研究,但范围非常狭窄．仅局限于部分无机或有机小分子添加物．与实际发酵过程存在着一定的差异．特别对天然营养物质的影响尚未有研究。同时由于气含率对物性的高度敏感性．使现有的气含率关联式已不能适用于发酵液中的所有添加物。Shah⑴则建议,鉴于气含率容易测量,根据某一特定体系进行的小试结果将比任何已知关联式所预测的要好。本文研究发酵过程中常用添加物对气含率的影响．并从理论上推导得出气含率的关联式。对研究发酵液中不同组分与氧传递速率的关系以及前文⑵中氧传质系数的计算均有重要意义。     

Cometabolic degradation of trichloroethylene in a bubble column bioscrubber

A bubble column bioreactor was used as bioscrubber to carry out a feasibility study for the cometabolic degradation of trichloroethylene (TCE). Phenol was used as cosubstrate and inducer. The bioreactor was operated like a conventional chemostat with regard to the cosubstrate and low dilution rates were used to minimize the liquid outflow. TCE degradation measurements were carried out using superficial gas velocities between 0.47and 4.07 cm s(-1) and TCE gas phase loads between 0.07 and 0.40 mg L(-1) Depending on the superficial gas velocity used, degrees of conversion between 30% and 80% were obtained. A simplified reactor model using plug flow for the gas phase, mixed flow for the liquid phase, and pseudo first order reaction kinetics for the conversionof TCE was established. The model is able to give a reasonable approximation of the experimental data. TCE degradation at the used experimental conditions is mainly limited by reaction rate rather than by mass transfer rate. The model can be used to calculate the reactor volume and the biomass concentration for a required conversion. (c) 1995 John Wiley & Sons Inc.     

覆土栽培对高节竹笋品质的影响

为了生产高品质高节竹笋,提高竹林经济效益,该研究通过调查并测定了覆土1a、覆土2a和不覆土栽培的高节竹林竹笋外观形态和营养物质、呈味物质、氨基酸含量,分析了覆土栽培对高节竹笋品质与适口性的影响。结果表明:覆土栽培1a和2a的高节竹笋个体重量及可食率分别较未覆土栽培高节竹笋提高了107.58%、165.73%及8.77%、13.63%,而且高节竹笋个体重量及可食率覆土栽培年限之间差异显著;覆土栽培高节竹笋长度总体显著高于未覆土栽培高节竹笋,且覆土栽培年限之间并无显著差异;高节竹笋基茎则为覆土栽培1a与未覆土栽培之间无显著差异,且均显著低于覆土栽培2a的高节竹笋。覆土栽培高节竹笋蛋白质、单宁、草酸、总酸、纤维素、木质素和各类氨基酸含量及氨基酸总量总体上有明显降低,而脂肪、可溶性糖含量和糖酸比则明显提高;鲜味、甜味和芳香类氨基酸比例有所升高,而苦味氨基酸比例则有所降低。综合分析表明,覆土栽培能明显改善高节竹笋外观形态质量,增加香味和甜味,减少酸涩味和粗糙度,竹笋品质和适口性明显提高,且覆土栽培2a的影响作用更为明显。     

The effect of light on the production of Heimia alkaloids

Alkaloid extracts obtained from light- and dark-grown shoot cultures of Heimia salicifolia were partially fractionated and semi-quantitatively analysed for phenyl- and biphenylquinolizidine alkaloids. The concentrations of the two structural types of alkaloids in extracts of shoots grown with illumination increase over a 4 week culture period. In extracts obtained from shoots grown in darkness for 4 weeks, however, we observed substantial decreases in the concentrations of both the phenyl- and biphenylquinolizidine alkaloids. We observed that growth in the dark for periods of up to 9 weeks resulted in a further reduction in the levels of biphenyl alkaloids relative to those of the phenylquinolizidinols.     

Somatic embryogenesis from cultured epicotyls and primary leaves of soybean [Glycine max (L.) Merrill]

Summary Regeneration of several varieties of soybean [Glycine max (L.) Merrill] by somatic embryogenesis from cultured epicotyls and primary leaves has been demonstrated. Somatic embryogenesis was induced from epicotyls and primary leaves when cotyledon halves with the intact zygotic embryo axes were cultured on Murashige and Skoog (MS) medium supplemented with 10 mg 1⁻¹ (45.2 μM) 2,4-D. Stable, continuously proliferating globular embryo cultures (GEC) were established from small groups of somatic embryos on MS medium supplemented with 20 mg 1⁻¹ (90.5 μM) 2,4-dichlorophenoxyacetic acid (2,4-D). Rapid multiplication of shoot tips from germinating somatic embryos was achieved on Cheng’s basal medium (CBO) containing 2.5 mg 1⁻¹ (11.3 μM) 6-benzyladenine. Fertile plants were obtained from individual somatic embryos and in vitro propagated adventitious shoot bud cultures.     

Morphological differentiation in callus cultures of lavandin: a role of ethylene

The involvement of ethylene in shoot formation in vitro was studied in one year old lavandin (Lavandula officinalis Chaix x Lavandula latifoliaVillars) callus. A peak in ethylene evolution characterized thenon-regenerating leaf callus line, as compared to the shoot-forming calyxcallus line, on the growth medium provided with 2,4-dichlorophenoxyacetic acid (1 mg dm-3) and kinetin (0.5 mg dm-3). After one year in culture, calyxcallus attained the capacity to grow on auxin-reduced media, showing decreased ethylene production and faster shoot bud emergence, when transferred onto the regeneration medium, supplemented with 10 mg dm^-3 benzyladenine. Shoot formation was also inhibited by addition of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid, indicating an involvement of ethylene in the failure of regeneration. This revised version was published online in July 2006 with corrections to the Cover Date.     

聚酰胺树脂纯化竹壳类黄酮工艺的研究

采用聚酰胺吸附树脂对竹笋壳黄酮类化合物分离纯化,确定了聚酰胺吸附树脂对竹笋壳黄酮分离纯化的最佳工艺条件:制备5mg/mL的竹笋壳黄酮提取液90mL,调节pH=5,用1.8mL/min的流速上样后,用160mL的去离子水冲洗大量杂质,随后用120mL的60%乙醇溶液洗脱120mL。在此条件下,竹笋壳黄酮的纯度为58.4%,与大孔树脂纯化方法相比,该方法更具有良好的分离纯化效果。     

Nickel hyperaccumulation in shoot cultures of Alyssum markgrafii

Shoot cultures of Alyssum markgrafii O.E. Shulz, endemic nickel hyperaccumulating species of central Balkan, were established and maintained on Murashige and Skoog medium supplemented with 0.2 mg dm^–3 benzyladenine (BA). Nickel in form of NiCl₂ . 6 H₂O was supplemented at 22 different concentrations ranging from 0.0001 to 15 mM but none of them was lethal to cultures. High Ni²⁺ concentrations (10 mM or more) arrested shoot growth which, upon transfer to Ni-free medium, commenced via axillary bud proliferation. Shoots that developed from axillary buds through the subculture manifested increased tolerance to Ni²⁺ expressed as shoot elongation. Shoot multiplication and dry biomass production decreased with increase of Ni²⁺ in medium. Only the accumulation of Ni²⁺ in tissues increased with Ni²⁺ content of the medium. Apart from shoot cultures, high Ni²⁺ accumulation was registered in undifferentiated callus cultured on medium with 0.5 mg dm^–3 BA and 0.5 mg dm^–3 naphthylacetic acid. Highest content of accumulated Ni was 2.37 g g^–1 (d.m.) in shoots and 2.65 g g^–1 (d.m.) in callus, both measured on medium with 15 mM Ni²⁺.     

油橄榄叶中橄榄苦苷的分离纯化

考察了6种不同大孔树脂对橄榄苦苷的吸附,筛选出吸附选择性好的D101大孔吸附树脂为实验材料.得到的D101大孔树脂的最佳吸附条件:试样上样质量浓度41.06[J].,流速5 mL/min,50％乙醇溶液洗脱,洗脱液用量260mL,树脂可以反复使用.经大孔树脂富集后,橄榄苦苷的纯度可达55％以上,再经葡聚糖凝胶精纯化后,可达76％以上.     

Miconazole: An effective antifungal agent for plant tissue culture

Miconazole at concentrations between 5 and 20 mgl^-1 inhibited hyphal growth and sporulation in a wide range of fungi commonly associated with plants. These fungi included 4 Oomycetes, 11 Deuteromycetes, 4 Ascomycetes and 4 common airborne contaminants of plant tissue culture. The phytotoxicity of 20 mgl^-1 miconazole was also tested against a wide range of in vitro plant cultures. Shoot cultures from 15 species showed either no response or a slight growth reduction in the presence of miconazole. Although the growth of shoot cultures in 2 other species was significantly reduced by miconazole, a positive growth rate was maintained. Callus and hairy root cultures from 5 species were more sensitive to miconazole than shoot cultures, although they also retained a positive growth rate in the presence of the antifungal agent. Reconstruction experiments demonstrated the effectiveness miconazole had for the rescue of plant material from in vitro cultures contaminated from fungi.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - BA 6-benzylaminopurine - EBI ergosterol biosynthetic inhibitor - IAA indole-3-acetic acid - MZ miconazole - NAA -naphthaleneacetic acid