Studies on the Fragmented Shoot Apex of Grapevine: IV. SEPARATION OF PHENOTYPES IN A PERICLINAL CHIMERA IN VITRO

Adventitious shoots were induced on apical fragments of thegrapevine, cv. Meunier, a presumptive periclinal chimera. Thiscultivar resembles Pinot noir in essential characteristics,but is phenotypically distinguishable by the dense white matof hairs on the apex and expanding leaves (tomentose phenotype).Plants derived from apical culture were of three types: (i)phenotypically resembling Meunier, (ii) bearing tomentose leaveswith comparatively hairless sectors, and (iii) with completelynon-tomentose shoots phenotypically similar to Pinot noir. These results establish that adventitious buds of grapevineproduced by this method are multicellular in origin and arenot derived from single cells. Furthermore, it is concludedthat fragmented shoot apex culture of grapevine periclinal chimerasdisturbs the integrity of apical tissue allowing separationof component genotypes. Fragmented apex culture of such chimerasis not recommended where trueness-to-type is of prime importance.However, circumstances under which this technique may be usefullyapplied to separate chimeral genotypes are discussed. Key words: Vitis vinifera, Grapevine, In vitro, Chimera separation     

Studies on the Fragmented Shoot Apex of Grapevine: II. FACTORS AFFECTING GROWTH AND DIFFERENTIATION IN VITRO

The hormonal and nutritional requirements for the culture offragmented shoot apices of grapevine were examined. Benzyladenineat 10 µM added to the full strength Murashige and Skoogbasal medium was found to be optimal for both the initial growthof apical fragments to individual leaves, and the subsequentcapacity of these leaves to produce adventitious shoots. Serialsectioning of the site of shoot proliferation on the leavesrevealed meristematic areas at the surface of the basal swellingswith vascular connections to the underlying tissue. Using thesame culture conditions, adventitious shoots could be inducedfrom a range of grapevine cultivars incorporating several majorVitis species. Variations in the responses of the cultivarsCabernet Sauvignon and Sultana to the culture conditions aredescribed. The growth habits of plantlets derived from fragmentedshoot apices during culture and on subsequent transfer to theglasshouse are compared and discussed.     

Studies on the Fragmented Shoot Apex of Grapevine: I. THE REGENERATIVE CAPACITY OF LEAF PRIMORDIAL FRAGMENTS IN VITRO

Apical fragments of gravevine shoots cultured in a liquid mediumcontaining cytokinin each develop into leaf-like stsuctureswhich give rise to adventitious buds on transfer to solid medium.The origin of the leaf-like structures forming the first partof this procedure was examined. Microdissection of the shoot apex revealed that leaf primordialpieces regenerated into leaf-like structures in droplet culture.These leaves were regenerated directly from primordial cellswithout the need for dedifferentiation and callus formation.The implications of these results are discussed in relationto studies on leaf determination.     

杨树叶薄层培养中不定芽形态发生的细胞组织学研究

将杂种杨树(Populus nigra var.betulifolia×P.trichocarpe)NE299叶主脉用振动切片机横切成400μm或800μm的薄切片,培养在附加0.2mg/L BA和0.01mg/L NAA的木本植物培养基上。培养后,位于主脉维管束两侧中上部的维管束鞘薄壁细胞首先启动分裂。几乎同时,与其邻接的一些栅栏组织细胞也分裂,并很快形成胚性分生细胞团。主脉的愈伤组织主要由维管束鞘薄壁细胞,以及与其邻接的一些栅栏组织细胞和韧皮部的薄壁细胞分裂而来。不定芽通常发生在愈伤组织的周边区,也可以起源于维管组织结节(vascular nodules)周围的形成层状细胞。侧脉的维管束鞘细胞分裂活动很强,可不经愈伤组织直接长成不定芽。杨树叶主脉处的维管束鞘薄壁细胞在与叶肉组织相邻接的细胞中,通常含有少量较小的叶绿体,而位于背腹面的细胞中含有贮藏的淀粉。对形态发生的特定部位及其细胞进行了讨论。     

TDZ诱导花生幼叶的不定芽和体细胞胚发生的组织学观察

花生实生苗幼叶接种于MS TDZ 0.2mg/L NAA0.4mg/L诱导培养基上经诱导培养,继而转移到无激素培养基MS可获得不定芽和体细胞胚。组织学观察表明,花生不定芽和体细胞胚均起源于愈伤组织表层,不定芽为多细胞起源,而体细胞胚起源于单个胚性原始细胞。体细胞胚的发育经历多细胞原胚、球形胚、心形胚、鱼雷胚和子叶胚等时期发育成小植株。     

离体条件下条叶龙胆花芽的形成和开花条件的研究

条叶龙胆种子萌发的试管苗,通过快速大量繁殖后,转移到附加玉米素、萘乙酸、激动素及N-二甲基氨基琥珀酰胺的 MS 培养基上培养。苗端及叶腋可有大量花芽的分化,并能开出蓝紫色的鲜艳花朵,条件合适时,每朵花的花期长达4周。经显微技术鉴定,花的雌、雄器官均属正常。     

A LIGHT AND ELECTRON MICROSCOPE STUDY OF INTERLAMELLAR POLYGLUCOSIDE BODIES IN OSCILLATORIA CHALYBIA

A light and electron microscopic study of interlamellar granules in Oscillatoria chalybia was made to determine their physiological nature. Oscillatoria chalybia was cultured under continuous light in media of high nitrogen content, moderate nitrogen content and low nitrogen content. Cultures growing vigorously in a medium of moderate nitrogen content were placed in darkness for an additional 96 hr. Periodic acid-Schiffs reagent tests were made on specimens from these 4 cultural conditions. Electron microscopic studies of interlamellar granules were correlated with the cytochemical tests. It is shown that diastase digestion will eliminate the PAS-positive substance and the interlamellar granules. Conclusions are that the interlamellar granules are polyglucoside in nature and that they vary in number and size with available nitrogen, light intensity and age of culture in such a way as to indicate that they are food reserves.     

A SCANNING ELECTRON MICROSCOPE STUDY OF SURFACE FEATURES OF VIRAL AND SPONTANEOUS TRANSFORMANTS OF MOUSE BALB/3T3 CELLS

Cells of the mouse line Balb/3T3 as well as three virus-induced transformants and two spontaneous transformants grown in vitro have been studied for their topography by scanning electron microscopy. The parent cell in confluent culture closely resembles an endothelial cell in its form and in the structure of its association with adjacent cells. The tumorigenic transformants produced by SV40, murine sarcoma virus, or polyoma viruses are fusiform to pleomorphic and distinctly different from the cell of origin. They show relatively smooth surfaces except for blebs and marginal microvilli. Perhaps most surprising is the similarity they bear to one another. This is made the more singular by the very different form shown by the tumorigenic transformants of spontaneous origin. One of these, S2-4, possesses a thickened rather than the lamellar form of the parent A31 cell and is covered by long microvilli and many spherical blebs. The other, TuT₃, more closely resembles the cell of origin but shows extensive ruffling at its margins. All transformants grow without evidence of contact inhibition. The significance of the surface morphologies and the factors influencing cell form are discussed.     

EVOLUTION, DURING DIGESTION, OF THE BACTERIAL FLORA IN THE ALIMENTARY SYSTEM OF HELIX ASPERSA (GASTROPODA: PULMONATA): A SCANNING ELECTRON MICROSCOPE STUDY

The use of scanning electron microscopy (SEM) allowed a studyof the distribution of bacteria in the various digestive organsof the snail Helix aspersa Müller. The bacteria are enclosedby mucous secretions (mucous film or mucous grains) and sometimesattached on the cilia of some of the digestive walls. Accordingto the food that was given to the snails, different morphologicaltypes appeared, two of which dominated. Adult snails were fasted for 4 days, given a dehydrated artificialfood and then sacrificed at different times during digestion.The presence of bacteria may be related to the time of digestion.In fact, bacteria seem to accompany the food mass; they developmostly in the stomach and in the intestine where they may helpdigest the food. Fasting or hibernating snails do not possess bacteria in thealimentary lumen or on the digestive walls. However, the residualfaeces localized in the distal, intestinal lumen, lodge greatquantities of bacteria. From these results, the endogenous or/and exogenous existenceof the bacterial flora in alimentary system of Helix aspersais discussed. (Received 26 June 1989; accepted 16 October 1989)     

A STUDY OF IN VITRO ELECTRON TRANSPORT ACTIVITY IN MARINE PHYTOPLANKTON AS A FUNCTION OF TEMPERATURE1

The in vitro temperature inactivation of the electron transport system (ETS) activity was measured for 11 phytoplankton species. The average inactivation temperature is between 18–23 C, but exceptions with inactivation temperatures as high as 43 C were noted for a tide pool phytoplankton, Dunaliella tertiolecta Butcher. Despite differences in temperatures at which the ETS activity begins to decrease, experimental values for the energies of activation (E) of electron transport are very similar and average ca. 12 kcal/mol. The results show the necessity of applying temperature corrections to in vitro ETS activity measurements when oceanic in situ oxygen consumption is computed from ETS activity measurements. The progress of thermal inactivation of the ETS activity in phytoplankton species studied yields biphasic curves. The biphasic nature of the curves is expressed when using both relatively high and low temperature of inactivation and in more or less heat sensitive species. These curves are described in terms of microsomal and mitochondrial substrate dependence. Based on the obtained temperature response of the ETS activity, the adaption of phytoplankton species to growth temperature is discussed.     

LIGHT AND ELECTRON MICROSCOPE STUDIES OF MYCOBACTERIUM—MYCOBACTERIOPHAGE INTERACTIONS : III. Further Studies on the Ultrathin Sections

The process of multiplication of mycobacteriophage B-1 in its host cell was studied by means of an improved technic of ultrathin sectioning. The appearance of the nuclear apparatus was not altered throughout the latent period. Phage-shaped dense particles appeared about 30 minutes after infection in less dense areas neighboring the nuclear apparatus and occasionally at the margin of the nuclear apparatus. The less dense areas, which may correspond to the phage multiplication foci according to the authors' interpretation, were not filled with such arrays of fine-stranded fibrils as are seen in the nuclear apparatus. Empty phage heads could frequently be seen within and outside the lysed cells, along with the mature phage particles, at the end of the latent period. Moreover, it was indicated that empty head membranes may possibly exist within the cells during the latent period     

花背蟾蜍(Bufo raddei Strauch)眼形态发生过程中角膜上皮表面结构的扫描电镜观察

扫描电镜观察表明,花背蟾蜍眼形态发生过程中角膜上皮细胞表面形态结构的变化,大致可分三个阶段。1.从神经管期至肌肉感应期预定角膜上皮表面无明显变化;2.在心跳期和鳃血循环期预定角膜上皮表面出现较多的细胞缢束和其下细胞表面的下陷;3.在以后各期,角膜上皮中纤毛细胞的纤毛逐渐退化消失,在右鳃盖封闭期纤毛细胞全部消失。上述变化与视网膜及其中光感受器的发育分化密切相关,纤毛的退化和消失更精确地反映了这种依赖关系,似可作为角??膜上皮分化的一个形态指标。