从棉花胚性细胞原生质体培养获得植株再生

原生质体培养植株再生是进行体细胞杂交与基因工程操作的重要基础工作。近年来,国内外已有一些关于棉花原生质体分离与培养的研究报告,1986年 Firoozabady 报道从陆地棉(Ghirsutum)叶肉原生质体培养获得2—3个细胞的微克隆,1987年 Ka~-     

PEARL MILLET (PENNISETUM AMERICANUM (L.) LEEKE) AND GRAIN SORGHUM (SORGHUM BICOLOR (L.) MOENCH) ULTRASTRUCTURE

Ultrastructural features of pearl millet (Pennisetum americanum (L.) Leeke) and grain sorghum (Sorghum bicolor (L.) Moench) caryospses were investigated with thin sections of the dry, mature grain in the transmission electron microscope, and fractured kernels in the scanning electron microscope. The pericarp of those grains is comprised of three distinct layers: epicarp, mesocarp of parenchyma cells, and endocarp of compressed cross and tube cells. Mesocarp cells of grain sorghum contain starch granules embedded in a cytoplasmic matrix. The major constituent of sorghum and millet aleurone cells are aleurone grains (protein bodies) and lipid bodies. Subaleurone cells contain a much higher proportion of protein bodies than starch granules, and the protein bodies are structurally distinct from those in the aleurone. The germ scutellar ultrastructures of the two grains were similar; protein bodies, lipid bodies, epidermal cells and parenchyma cells of the germ are described.     

MORPHOLOGY AND ULTRASTRUCTURE OF EMBRYOGENIC CELL SUSPENSION CULTURES OF PANICUM MAXIMUM (GUINEA GRASS) AND PENNISETUM PURPUREUM (NAPIER GRASS)

Morphological and ultrastructural changes during the growth of embryogenic cell suspension cultures of Panicum maximum and Pennisetum purpureum have been studied. The suspensions consist almost entirely of cell aggregates of 50–75 embryogenic cells. The cell aggregates vary in size from 90–400 μm in P. maximum and from 70–340 μm in P. purpureum. Following the period of exponential growth starch grains gradually disappear and vacuolation increases. Ten to 16 days after subculture, P. maximum cells enlarge and separate from each other, and organized embryo-like structures appear. Ultrastructural studies show that the cell aggregates are made up of discrete, individual groups of 2–6 cells each. Each cell group appears to arise from a single cell and breaks away from the ‘mother group’ as cell divisions continue. The embryogenic cells are small (20 μm), isodiametric with many starch grains and contain a large nucleus with a prominent nucleolus. Extensive profiles of endoplasmic reticulum, many small peripheral vacuoles, and several amyloplasts are present. Plasmodesmatal connections exist only between cells within a cell group but not between cells of different cell groups in the large cell aggregates.     

原生质体来源的大白菜悬浮细胞系的超低温保存

原生质体来源的大白菜 Brasstca campessris var.pekinsis 悬浮细胞系在二甲亚砜的保护下,能在液氮中(-196℃)长期冻存。加入山梨醇能增强保护作用;而加入甘露糖则降低保护作用。培养基对冻存也有明显的影响。在液氮中存放的时间长短对细胞存活率没有多大影响。冻后相对活性最高可达75.4％,恢复生长快,化冻后重新悬浮培养6天,生长量可达300-500％。遮光比不遮光对恢复更有利。冻存后恢复生长的悬浮细胞,能与未经冰冻的对照一样进行原生质体分离和培养。     

A SYSTEMATIC STUDY OF PENNISETUM SECT. PENNISETUM (GRAMINEAE)

Pennisetum sect. Pennisetum includes two reproductively isolated species. Pennisetum purpureum Schumach. is a tetraploid (2n = 28) perennial species which occurs throughout the wet tropics of the world. Pennisetum americanum (L.) Leeke is a diploid (2n = 14) annual species, native to the semi-arid tropics of Africa and India, and contains three morphologically diverse subspecies. Subspecies americanum includes the wide array of cultivated pearl millets. Subspecies monodii from the Sahel of West Africa is identified as the wild progenitor of pearl millet. Subspecies stenostachyum is morphologically intermediate between subsp. americanum and monodii and includes the mimetic weeds often associated with the cultivation of pearl millet.     

与胡萝卜胚胎发生相关的胚性细胞蛋白63cDNA分离及其基因表达研究

以胡萝卜(Daucus carota L.)鱼雷形胚状体为材料,以λgt10噬菌体为载体,构建了一个含有6.0×10~8个重组子的cDNA文库。用PCR法扩增的长度为1.1kb的胚性细胞蛋白(ECP)63 DNA片段作探针,从cDNA文库中筛选出一个完整的ECP63 cDNA克隆。ECP63 cDNA核苷酸序列总长为1989bp,编码1个含569个氨基酸残基的蛋白质,分子量为62kD。以ECP63 cDNA全长作探针的Northern分子杂交结果表明,ECP63基因在胚性细胞和不同发育时期的胚状体中高度表达,但在幼苗和非胚性细胞中不表达。在转录水平上,ECP63基因在合子胚胎发生后期大量表达。     

红豆草细胞悬浮培养中体细胞胚的形成

红豆草(Ooobrychis viciaefolia Scop.)为豆科蝶形花亚科红豆草属多年生草本植物。由于营养丰富,生活力强,抗旱,耐瘠薄,适合西北干旱地区种植,是农民喜爱的牧草。有的学者已对红豆草在组织培养中体细胞胚的形成     

悬浮培养的谷子细胞的胚胎发生和植株再生(简报)

由谷子的胚性愈伤组织在附加2mg/l2,4-D和5%椰乳的UM液体培养基中建立了细胞悬浮培养,降低培养基中2,4-D的浓度,利于胚状体的形成。当液体培养中的细胞转移到MS琼脂培养基上后,通过改变激素的组成及浓度,可以促进胚性细胞团的增殖,进而再生出大量完整植株。这种通过形成胚状体而再生植株的能力,巳在该悬浮培养系中保持一年多,从由幼穗培养建立胚性愈伤组织开始,此细胞系的旺盛的再生能力至今巳保持了近三年。     

陆地棉胚性愈伤组织原生质体的制备,培养及植株再生

以陆地棉栽培品种“鲁棉６号”下胚轴的胚性愈伤组织为材料,制备并培养原生质体。采用继代培养７￣９ｄ、活力旺盛的胚性愈伤组织,在１％纤维素酶、１％果胶酶、０．７ｍｍｏｌ／Ｌ ＫＨ２ＰＯ４、２．５ｍｍｏｌ／Ｌ Ｃａ＾２＋、０．５ｍｏｌ／Ｌ甘露醇、ｐＨ５．８、３０℃的条件下,具活力的原生质体得率最高。经分离纯化后,原生质体在含有０．４５ｍｏｌ／Ｌ葡萄糖的Ｋ３无机盐、ＮＴ有机物并附加０．１ｍｇ／Ｌ,２,４－     

高分化潜能小麦胚性悬浮系的建立及保持

报道了小麦具高度植株再生潜能的优质胚性悬浮系的建立与保持方法。Ⅱ型胚性愈伤组织在改良ＭＳ液体培养基中增殖快,分散好,两周左右即可建立起优质悬浮系;在改良Ｎ６液体培养基中增殖较慢,较易形成块状结构;ＡＡ液体培养基不适于小麦胚性悬浮系的培养。长时间悬浮培养后,小麦胚性悬浮系再生能力下降,在ＮＢＤ固体培养基上培养一段时间后再转回液体培养可使其再生能力得以保持与恢复。     

火炬松胚性细胞悬浮培养物的生长参数变化

以火炬松（PinustaedaL.）成熟合子胚来源的胚性愈伤组织为材料建立了胚性细胞悬浮系,测定了其培养物的鲜重、干重、细胞体积和胚数及培养液中的pH值、电导率和蔗糖浓度等生长参数在培养过程中的变化动态。结果表明,在培养周期内,培养液中的pH值、电导率和蔗糖浓度的逐步降低与培养物的鲜重、干重、细胞体积和胚胎数的逐步增加保持一致性。在培养至18—21d,pH值、电导率和蔗糖浓度均接近或降到最低点,而胚数及细胞体积的增长都达到最高点。     

CHARACTERIZATION OF TISSUE CULTURE INITIATION AND PLANT REGENERATION IN SPOROBOLUS VIRGINICUS (GRAMINEAE)

Tissue cultures of the halophytic saltmarsh grass Sporobolus virginicus were initiated from unemerged immature inflorescence tissue. Typical graminaceous embryogenic and nonembryogenic callus and cell types were noted. Embryogenic callus was compact golden yellow. Histological evidence indicated that proliferation of the ovary tissue of the immature pistil was the source for embryogenic callus. Plants regenerated after first reducing and then eliminating auxin from the culture medium. Regeneration was observed both through the concerted development of bipolar meristems from somatic embryos and by the formation of multiple shoot meristems that were either connected through callus tissue to root meristems or which later adventitiously rooted. The main mode of regeneration appeared to be somatic embryogenesis with additional multiple shoot formation probably due to precocious germination of somatic embryos. Plants recovered from culture were acclimated to soil, grown up in a greenhouse, and planted in field plots with saline irrigation to ensure stability of salt tolerance.     

SOMATIC EMBRYOGENESIS AND PLANT REGENERATION FROM TISSUE CULTURES OF PENNISETUM AMERICANUM,AND P. AMERICANUM x P. PURPUREUM HYBRID

Immature embryos as well as explants obtained from young inflorescences of Pennisetum americanum (pearl millet) give rise to callus tissues on nutrient media containing 2,4-dichlorophenoxyacetic acid (2,4-D). A compact and pale-yellow callus that arises from the peripheral cells of the scutellum, and from the young inflorescences, undergoes further organized growth. When transferred to a 2,4-D-free medium, supplemented with indole-acetic acid or kinetin, or both, embryoids are formed in the organized areas of the callus. Embryoids show a bipolar organization with a shoot-coleorhiza (root) axis and have a coleoptile-like structure surrounded at the base by a cup-shaped structure that resembles the scutellum in texture and morphology. Embryoids show bilateral or radial symmetry and “germinate” in vitro to form plants that have been grown to maturity in soil. Similar embryogenic callus cultures have been produced from young inflorescence tissues of hybrid Pennisetum, a triploid sexually sterile hybrid of P. americanum x P. purpureum. Plants derived from these have also been transferred to soil. The regenerated plants showed normal chromosome numbers.     

CHARACTERIZATION OF FORCED SUSPENSION CULTURE OF SPONTANEOUSLY TRANSFORMED MOUSE FIBROBLASTS (B-6)

Mouse fibroblasts (B-6) were cultured on agar-coated dishes. After cells grew for 2–3 generations relatively rapidly in suspension, they began to grow very slowly (stationary phase). Electron microscopic studies showed that cells in a stationary phase developed intracellular organella: membranous structures (endoplasmic reticulum and Golgi apparatus) became manifest and the number of mitochondria increased. The specific activities of succinic-cytochrome c reductase and 5′-nucleotidase were three and five times higher, respectively, than those of cells on the dish.     

火炬松胚性悬浮细胞原生质体的分离和培养

以火炬松成熟合子胚的胚性悬浮细胞为材料分离原生质体,研究了酶液组成,渗透压稳定剂和悬浮细胞生长对原生质体产量和原生质体活力的影响。     

长江江豚脐静脉细胞体外培养的初步研究

长江江豚(Neophocaena phocaenoides asiaeorientalis)属齿鲸亚目鼠海豚科, 是世界上唯一的江豚(Neophocaena phocaenoides)淡水亚种, 主要分布于我国长江中下游干流和洞庭湖、鄱阳湖及其部分支流1—3。       

TISSUE CULTURE AND REGENERATION OF DISTICHLIS SPICATA (GRAMINEAE)

Distichlis spicata tissue cultures were initiated from mature seeds. Cultures displayed regenerable callus that was compact, white, and streaked with purple and green. Selection of compact areas at subculture established long-term, regenerable cultures. Removal of auxin and inclusion of 1 mg 1^–1 BA in the maintenance media induced regeneration. Histological sections indicate that although cells were typical of embryogenic types, regeneration was by shoot organogenesis. Regenerated plants flowered and set seed under field conditions.     

IDENTIFICATION OF LATICIFERS IN EMBRYOIDS DERIVED FROM CALLUS AND SUSPENSION CULTURES OF ASCLEPIAS SPECIES (ASCLEPIADACEAE)

Laticifers were identified in frozen sections of embryoids from callus and suspension cultures of Asclepias syriaca (common milkweed) by an indirect fluorescent antibody technique. Sections were treated with the IgG fraction of rabbit anti-latex antiserum, produced with field-collected A. syriaca latex as a source of antigens, and with fluorescein-conjugated IgG fraction goat anti-rabbit IgG. Laticifers were identified by their fluorescence in embryoids dissected from 3–4-month-old callus cultures and in embryoids from 2-month-old suspension cultures. Laticifers are not present in early globular embryoids of A. syriaca but embryoids similar in shape to late globular stage zygotic embryos possess branching laticifers typical of zygotic material. Sections on control slides, treated with whole serum or IgG fraction from whole serum, both from an uninjected rabbit, contained no fluorescent cells. No laticifers were detected with the fluorescent antibody assay in A. tuberosa embryoids.