Plant Regeneration from Mesophyll Protoplasts of Echinacea Purpurea

An efficient plant regeneration system was developed from isolated protoplasts of Echinacea purpurea L. using an alginate block/liquid culture system. Viable protoplasts could be routinely isolated from young leaves of Echinacea seedlings in an isolation mixture containing 1.0% cellulase Onozuka R-10, 0.5% pectinase and 0.3 mol l^–1 mannitol. Purified protoplasts were embedded in 0.6% Na-alginate block at a density of 1 × 10⁵/ml and cultured in a modified MS medium containing 0.3 mol l^–1 sucrose, 2.5 µmol l^–1 BA and 5.0 µmol l^–1 2,4-D. Cell colonies were observed after 4 weeks of culture, and the protoplast-derived colonies formed calluses when transferred onto 0.25% gellan gum-solidified MS medium supplemented with 1.0 µmol l^–1 BA and 2.0 µmol l^–1 IBA. Shoot organogenesis from protoplast-derived callus was induced on MS medium supplemented with 5.0 µmol l^–1 BA and 2.0 µmol l^–1 IBA. Complete plantlets were obtained from the regenerated shoots on MS basal medium. The protoplast to plant regeneration protocol developed in this study provides the prerequisite for creating novel genotypes of this valuable medicinal species through genetic manipulation.     

甘蓝下胚轴原生质体再生植株

经纯化后,甘蓝下胚轴原生质体的产量为1．5×10⁶g^-1(Fw),采用液体浅层培养的方法进行培养。2～3d后,发生第一次分裂,第10天,统计分裂频率为6l％,5周内形成大量的细胞团和小愈伤组织,统计植板率为1．1％,把小愈伤组织转到与原生质体培养基相同激素的MS固体培养基上增殖。当愈伤组织长到3～5mm大小时,接到分化培养基上,芽分化率为46.7％．分化出来的芽长到3～4cm长时,从基部切下,插入生根培养基,两星期左右即可长成完整植株。     

诸葛菜(Orychopheagmus violaceus)叶肉原生质体培养再生植株

由诸葛菜无菌苗的叶肉组织分离原生质体,在附加0.5 mg/L BA,1.0 mg/L 2,4—D(或NAA)和9％甘露醇的MS液体培养基中作浅层培养,10d后分裂频率约45％,两周时形成大量细胞团,随后直接转到分化培养基上或逐步降低原生质体培养基的渗透压及生长素浓度,均可诱导形成大量苗或胚状体结构。转移到无激素的培养基上即可形成完整植株。     

Protoplasts as tools for plant genome modifications

We present here the application of protoplast technology in the selection and recovery of rare, spontaneous plant genome alterations. Using protoplasts as a cell cloning system allowed the detection and molecular characterization of intrachromosomal recombination events between genomic repeats. The mechanism, frequencies and the induction of intrachromosomal recombination are discussed as well as its application for genome mutagenesis.     

脱水导致的胞内溶质变化与植物耐干性的获得

植物耐干性是指许多植物个体和部分植物种子能在含水量极低的条件下存活,在回水的过程中迅速启动修复机制,细胞经重新水合修复所受损伤的能力。在脱水过程中,植物会合成和积累某些小分子物质、碳水化合物和特殊的蛋白质;在极度脱水状态下,多组分参与的玻璃化的形成和两性物质的重新分配、耐干性植物中特有的抗氧化机制都是植物获得耐干性的重要条件。复苏植物(resurrection plant)和部分被子植物种子是当前研究植物耐干性的模式材料。     

Studies on Screening Freezing-resistant Regenerated Plants from X-ray Irradiated Citrus Protoplasts

The response of cell division in the "Page" ( Citrus reticulata Blanco Ï C. grandis Osb. er. Page) protoplasts from embryonic callus to radiation challenge varied with the intensity of the X-ray dose charged. When the protoplasts were irradiated with a dose of 4128 C/kg failure of cell division was completely irreversible, those after 2064 C/kg treatment revealed low frequenee of cell division. Those after treatment with 1161 C/kg of X-ray and kept at - 11 ℃ gave off a 10.2% ~16.9% frequence of division. Some of those viable protoplasm developed into embryoids from which plantlets were regenerated. The LT50 of the leaf protoplasts in 2 of the regenerated plants was markedly lower than that in the controls.     

小麦胚性悬浮系与原生质体植株再生

普通小麦(Triticum aestivum)昌乐5号(冬性)胚性悬浮细胞系的组成成分对原生质体再生频率发生影响,此种悬浮系是由混合型愈伤组织建立起来的,建成的悬浮系中含有2—3mm的小愈伤组织和分散好的几十至上百个细胞的细胞团。分别用悬浮系中的小愈伤组织和细胞团分离原生质体进行培养。结果表明．由小愈伤组织来源的原生质体再生植株的频率显著高于由细胞团分离的原生质体的再生频率。培养基中不同成分对原生质体分裂的影响也作丁研究。     

影响花椰菜下胚轴原生质体培养和植株再生的因素

从花椰菜的无菌苗下胚轴游离原生质体经纯化后的得率为1.5～2×10~6/g FW。通过液体浅层培养、平板固体培养、双层培养和gelrlte包埋培养方法的比较,发现gelrite包埋培养法,最有利于花椰菜下胚轴的原生质体培养。纯化的原生质体用MS-1培养基培养,再生细胞的分裂频率为24％。再生的愈伤组织转到分化培养基MS-5A或MS-5B上迅速分化出苗。共获得再生植株78株,移栽到盆中生长正常,结出正常的菜花。     

克隆植物矮嵩草在刈割条件下的等级反应研究

对刈割处理下高寒矮嵩草草甸建群种矮嵩草（Kobresia humilis）构件等级中基株、分株和分蘖3个层次构件单元的数量、生物量及其变异系数的变化进行了研究。结果表明．矮嵩草株丛刈割部分和未刈割部分被测性状在处理间的差异显著性以及作构件等级间变异系数的大小均为分蘖层次〉分株层次〉基株层次。刈割后相同时期内,分蘖层次对相同处理的反应发叶生得最快,基株则最为迟缓。这说明在刈割后的相同时期内,构件等级中较外层次（分蘖层次）会发生更大的表型变异．对相同强度的刈割扰动发生反应也最快。由此证实矮嵩草在刈割条件下也同样会发生等级性反应。     

Forage and Turf Grass Biotechnology

Referee: Dr. Ian Ray, Plant Breeding and Genetics, Department of Agronomy & Horticulture, New Mexico State University, MSC 3Q, P.O. Box 30003, Las Cruces, NM 88003-8003 Forage and turf grasses are the backbone of sustainable agriculture and contribute extensively to the world economy. They play a major role in providing high quality and economical meat, milk, and fiber products and are important in soil conservation, environmental protection, and outdoor recreation. Conventional breeding contributed substantially to the genetic improvement of forage and turf grasses in the last century. The relatively new developments in genetic manipulation of these species open up opportunities for incorporating cellular and molecular techniques into grass improvement programs. For some commonly used forage and turf species, significant advances have been achieved in the following areas: (1) establishment of a tissue culture basis for the efficient regeneration of fertile and genetically stable plants, (2) generation of transgenic plants by biolistic transformation and direct gene transfer to protoplasts, (3) recovery of intergeneric somatic grass plants by protoplast fusion, (4) development of molecular markers for marker assisted selection, and (5) sequencing of expressed sequenced tags and the development of DNA array technologies for gene discovery. Although difficulties still exist in genetic manipulation of these recalcitrant monocot species, impressive progress has been made toward the generation of value-added novel grass germplasm incorporating traits such as improved forage quality. The joint efforts of molecular biologists and plant breeders make the available biotechnological methods a useful tool for accelerating forage and turf grass improvement.     

陆地棉原生质体高频率分裂及植株再生

取陆地棉品种（系）３１１８、９５５４和晋棉４号种子无菌苗的下胚轴诱导的愈伤组织,从中挑选具有分化能力的黄色颗粒状愈伤组织,建立胚性细胞悬浮培养系。以纤维素酶和离析软化酶组成的酶液,由细胞悬浮培养物游离原生质体。采用含低融点脂糖的Ｋ３基本培基包埋原生质体的培养方式,获得愈伤组织。以液体－固体－液体轮回培养法改良晋棉４号的细胞悬浮系,原生质体的植板率从２％左右提高到９％以上。在原生质体再生愈伤组织的继     

水稻原生质体再生植株及后代的性状表现

获得了粳型水稻77-170品系原生质体再生植株(R_2)6个株系的206棵后代植株。对其中96株进行性状观察和细胞学染色体鉴定,发现再生植株子代在株高、剑叶和主穗长、单株有效穗数、每穗粒数、育性、生育期等性状上都产生了变异,除株高外其他性状在第2代遗传上不稳定,染色体倍性稳定(2_n=24)。对56株再生植株子代作酯酶、过氧化物酶同工酶测定,其酶谱谱带与对照实生株相似。     

Reversion of Streptococcal Protoplasts

The reversion of protoplasts of Streptococcus faecium was examined by light and scanning electron microscopy. Regularly shaped streptococci emerged from the narrow region of large, oval protoplasts.     

Protoplasts formation inFusarium species

Formation of protoplasts from four species ofFusarium genus is described. Protoplasts were isolated from mycelium by enzymatic digestion of the cell wall in the presence of an osmotic stabilizer. The results obtained differed between the studied species. Best yields of protoplasts were obtained fromF. moniliforme (90 % cells as protoplasts).