大豆体细胞胚系培养及其微卫星DNA稳定性研究(简报)

植物离体培养是植物基因操作中的重要一环,也是植物个体发育研究中基因表达研究的有益参考体系。在继代培养过程中发生的遗传变异有时会使再生植株丧失优良的性状而需加以控制和避免。为此,首先需要了解培养过程中的遗传变异情况。     

Alkaline chitosan solutions

Rigid and transparent hydrogels were obtained upon pouring chitosan salt solutions into saturated ammonium hydrogen carbonate. Incubation at 20 degrees C for 5 days yielded chitosan carbamate ammonium salt, Chit-NHCO(2)(-)NH(4)(+) a chemical species that either by hydrolysis or by thermal treatment decomposed to restore chitosan in free amine form. Chitosans of different degrees of acetylation, molecular sizes and origins (squid and crustaceans) were used as hydrochloride, acetate, glycolate, citrate and lactate salts. Their hydrogels obtained in ammonium hydrogen carbonate yielded chitosan solutions at pH values as high as 9.6, from which microspheres of regenerated chitosans were obtained upon spray-drying. These materials had a modest degree of crystallinity depending on the partial acylation that took place at the sprayer temperature (168 degrees C). Citrate could cross-link chitosan and impart insolubility to the microspheres. Chloride on the contrary permitted to prepare microspheres of chitosan in free amine form. By the NH(4)HCO(3) treatment, the cationicity of chitosan could be reversibly masked in view of mixing chitosan with alginate in equimolar ratio without coacervation. The clear and poorly viscous solutions of mixed chitosan carbamate and alginate were spray-dried at 115 degrees C to manufacture chitosan-alginate microspheres having prevailing diameter approx 2 micron.     

Plate-shaped nuclear pole bodies in the monothalamous foraminiferKibisidytes sp.

Summary Cultures capable of continuous plantlet production have been established from excised, immature embryos ofSorghum bicolor and the course of development of the plantlets has been followed by light and scanning electron microscopy. Such analyzes revealed that there are two distinct methods of plantlet production. Shoot primordia and embryo-like structures arisede novo from cells of the scutellum. However, when these cultures are transferred to fresh medium a further proliferation of shoot buds occurs by the formation of axillary shoot primordia. The cultures are therefore more comparable to shoot cultures than to callus cultures. Over 300 plantlets producedin vitro have been transferred to potting compost and grown to maturity. Most plants flowered and set seed. Fifteen plants were sterile but were of normal chromosome number (2 n=20) and it is presumed that the sterility was due to segregation of restorer genes in the immature embryos used to initiate some of the cultures.Abbreviations used in the text 2,4-D 2,4 dichlorophenoxyacetic acid - MS Murashige and Skoog - NAA -Naphthalene acetic acid - 6-BAP 6-Benzylaminopurine     

Cytological Observation on Megasporogenesis and Embryo Sac Development of Regenerated Ovule in Hyacinth

The morphogenesis of regenerated ovule and cytological changes of its megasporogenesis and embryo sac development were studied. Results showed as follows: 1. the differentiation of the regenerated ovule had followed a normal process in the order of inner integument , outer integument and then funiculus. But the form of the regenerated ovules in vitro was quite different from that of ovule in vivo. Most of the regenerated ovules were orthotropous and hemianatropous , only a few were anatropous which are the same with that in vivo. 2. the megasporogenesis and the embryo sac development also had normal cytological process ,and the Polygonum type-embryo sac consisted of one egg, two synergids , one central cell and three antipodals could be seen in mature regenerated ovule. These ex-perimental results make clear that the regenerated ovule differentiated directly from explant could accomplish the complex processes of megasporogenesis and embryo sac development. By this fact ,authors infer that once the differentiation of ovule primordium, the complex biochemical programs for the megasorogenesis and embryo sac development can be controlled by the ovule itself and need no more information from flower bud and /or plant.     

Meiotic Analysis of the Regenerated Plants Derived from a Young Spike of Octoploid Triticale ×Secale cereale F1 Hybrid

The regenerated plants had high frequencies of changes in chromosome number and the pairing variation. The chromosome number was more or less variably decreased in different pollen mother cells. Most of regenerated plants were mixoploids. Some had higher frequency of homolgous chromosome pairing because double doses of rye genome had inhibited the effect of Ph gene. But, there was obvious different of chromosome pairing among regenerted plants. The difference was related to numerical chromosome change. Meiosis in a regenerant was analysed with Giemsa-C banding technigue. Partial rye chromosomes did not pair homologously or only very loosely paired. There was moderate level of wheat-wheat homologous partial pairing, however, wheat-rye chromosome pairing also occurred.     

Selection of Methionine-Resistant Variant in Onobrychis viciaefolia Scop.

The variant cell line of Onobrychis viciaefolia Scop. (ONmetr) resistant to 80 mmol/L methionine was isolated from calli which was treated with NAN3. This ONmet cell line was induced to regenerate plantlets. After growing for 6 months on a medium without selection pressure, the ONmetr cell line was still highly resistant to methionine being 5.6-fold higher than that of the wild type. The variant cell line also expressed high level of cross-resistance to ethionine which was 6. b-fold higher than that of the wild type. The contents of total methionine (Met) ,lysine (Lys) ,threonine (Thr) in ONmetr calli were 4.00,1.09,1.50-fold respectively higher than those of the wild type. The contents of total Met、 Lys、 Thr、 Ile (isoleucine) in ONmetr regenerants were-2.0, 3.5,3. 5,2. 5-fold respectively higher than those of the wild type. Two new bands appeared in SDS-PAGE profile as well as in the superoxidase isoenzymes electrophoresis pattern of the soluble proteins of ONmetr calli, thus indicated that the variant had carried the products of the changed genes.     

再生丝素固定的酶免疫传感器及其应用前景的研究

酶免疫传感器是采用再生丝素将待测抗原 (免IgG)固定在石墨电极表面 ,选用抗体 (山羊抗兔IgG-HRP)与其识别结合。利用H2 O2 将抗原抗体结合的电位响应信号放大 ,采用直接电位法检测IgG的浓度。该传感器测定IgG的最低检测浓度可达 1.2× 10 -10 mol/L ,标准曲线的线性范围在 4.1× 10 -7～ 1.2× 10 -10 mol/L ,响应时间为 15s。通过电泳的方法加速抗原抗体的识别结合 ,反应时间由原来的 90min缩短到 30min ,这在国内外鲜有报道。以固定化抗原结合酶标抗体量的多少作为检测抗原标准的新型酶免疫传感器 ,不仅在临床检测、生物医学研究领域中 ,而且在动植物疾病检测、环境监测、HLA个人身份鉴定、PC安全、物理访问 (门禁 )、军事等领域都有着广阔的应用前景。     

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.     

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     

Comprehensive molecular characterization of tissue-culture-derived Hordeum marinum plants

Summary Scuttelar calli of Hordeum marinum readily and efficiently regenerate functional plants. In order to assess genetic variability among the regenerants we employed multiple analytic tools, which included molecular and biochemical assays. Total DNA extract from regenerated plants was digested with at least two restriction enzymes and hybridized to four nuclear and six mitochondrial coding sequences, in addition to one nuclear and three mitochondrial noncoding probes. SDS-PAGE analyses of hordein extracted from seeds of regenerated plants and activity assays of -amylase were also performed. The nuclear and mitochondrial genomes of 50 regenerated plants demonstrated relative stability when assessed with coding sequences and by biochemical analyses. However, the mitochondrial noncoding probes revealed one qualitative somaclonal variant characterized by a loss of a hybridizing fragment. Moreover, changes in the methylation patterns of the rRNA genes and the nontranscribed spacer were revealed in another regenerated plant. The albino plant regenerated was characterized by a loss of three chloroplast DNA BamHI fragments.