Effect of Cullural Conditions on the Growth of Agrostemma githago Cells in Suspension Culture and the Concomitant Production of an Anti-Plant Virus Substance

An extract of cultured Agroxieinma githago L. cells was found to show potent inhibitory activity against plans virus infection. The effects of cultural conditions on the growth of the cell suspension and on the production of the inhibitor were examined. Since the production of substance was dependent on growth. experiments were made to improve growth. The optimum temperature was 26 to 30°C and optimum pH of the medium before autoclaving was between 5 and 7. In a medium of higher osmotic pressure, the water content of the cultured cells was lowered markedly. The growth rate in a small volume of the medium was higher than that in a larger volume at an early stage of the cultivation, but it was not changed by different inoculum sizes. The cells required thiamine and 2,4-D for growth but no other vitamins or growth regulators. The optimum level of 2,4-D was 0.1 mg/l. Higher sucrose concentration in the medium gave higher production of cell mass and of the inhibitor. However, 3% of sucrose was selected as the most economical concentration. For normal cell growth, the presence of both NH₄NO₃ and KNO₃ as nitrogen sources was required. The use of a single nitrogen source caused a long lag period or inhibition of the cell growth. KH₂PO₄ stimulated the growth when in was used in the level of 2.5 to 5 mM. The cell adhesion on the surface of the fermentor sometimes causes trouble in a large-scale cultivation. It was found that reducing the Ca²⁺ level in the medium prevented the cell adhesion and foaming remarkably. Based on the results obtained, a modified medium was established which was excellent for shortening the culture period and for efficient production of the anti-plant virus inhibitor.     

Differentiation in Lilium bulbscales grown in vitro. Effects of activated charcoal, physiological age of bulbs and sucrose concentration on differentiation and scale leaf formation in vitro

Organ differentiation and growth of tissue cultured bulbscales of Lilium auratum Lindl. was investigated. Benzyladenine stimulated bulb and bulbscale differentiation but inhibited root formation. Addition of activated charcoal to the medium negated the effect of BA on differentiation, while the growth of bulbs was markedly stimulated. Organ formation was also influenced by the physiological age of bulbs. From bulbscales of a 3-week-old bulb, a large number of bulbs and roots was formed but callus was not produced. A high sucrose concentration (90 g/1) reduced the subsequent sprouting after planting in soil. Scale leaf formation was also regulated. Sucrose (30 g/1) stimulated scale leaf formation but 90 g/1 were inhibitory.     

Differentiation in Lilium Bulbscales Grown in vitro. Effect of Various Cultural Conditions

Tissue cultures of Lilium auratum Lindl. and L. speciosum Thunb., which were derived from bulbscales, all appeared to differentiate organs. The effect of cultural conditions on the differentiation of bulblets and roots was examined. The best material for bulblet formation was bulbscales of intact or in vitro produced bulblets. The optimum temperature was 20°C and optimum pH was 6. Effect of irradiance on organ formation was not obvious but leaf emergence was stimulated. Higher kinetin concentrations stimulate the formation of numerous bulbscalcs. High NAA concentrations induce roots. On the other hand kinetin inhibits the NAA effect on root formation. A high sucrose concentration stimulated organ formation, but the number of bulblets was at a constant level in the medium containing between 10 and 90 g/l of sucrose. The formation of bulblets and their growth were stimulated at increasing strength of Murashige-Skoog's (MS) medium, but the length of roots was inhibited. Inter action of strength of MS medium and sucrose concentration was examined. High concentration of both components stimulated bulb lei growth, but the second strength of MS medium containing 90 or 120 g/l sucrose stimulated callus induction and inhibited the growth of bulblets. Maximum growth took 100 days for bulblets and about 50 days for roots. The change of fresh weight/dry weight ratio during differentiation is also discussed.     

缅甸始新世邦唐组一新的石炭兽类偶蹄类动物(英文)

描述了缅甸中始新统上部邦唐组发现的一种新的丘齿形石炭兽Myaingtherium kenyapotamoidesgen.et sp.nov.。标本为破碎的上下颌骨。Myaingtherium是一种基干石炭兽类,其大小和基本形态可以与邦唐一种小的石炭兽Anthracokeryx tenuis相对比。然而,Myaingtheri-um因具有更丘型化的齿列而与Anthracotherium和Anthracohyus在牙齿形态上更相似。在丘型齿石炭兽类中,Myaingtherium以臼齿前小尖非常退化为特点。Myaingtherium的一些牙齿特征,如具有退化的臼齿前小尖的丘型齿列和下臼齿上具有一个中间附尖,与Kenyapotaminae(最原始的化石河马)以及非洲中新世类似河马的石炭兽Kulutherium的牙齿特征相似,暗示Myaingtherium在谱系上可能与Kenyapotaminae有关。尽管需要更多的证据来检验Myaingthe-rium的谱系关系,但这个发现强化了邦唐石炭兽类在检验和理解河马-石炭兽支系的谱系关系和早期演化方面的重要性。     

A NEW SPECIES OF DICERORHINUS (RHINOCEROTIDAE) FROM THE PLIO‐PLEISTOCENE OF MYANMAR

Abstract: A skull and mandible of the new species Dicerorhinus gwebinensis sp. nov. of Rhinocerotidae (Mammalia, Perissodactyla) is described. The material is collected from the upper part of the Irrawaddy sediments (Plio‐Pleistocene) in central Myanmar. D. gwebinensis sp. nov. is morphologically more similar to the extant species D. sumatrensis (Sumatran rhinoceros) than to other species of the genus but differs from D. sumatrensis in having the comparatively shorter nasal, the more concave dorsal profile of the skull, the more elevated occiput and presence of molar crista in M3/. This is the first discovery of Dicerorhinus in the upper Miocene to lower Pleistocene of the Indian subcontinent and Mainland Southeast Asia, and fills the chronological and geographical gap of this lineage in Asia. The Dicerorhinus clade probably migrated into Southeast Asia from East Asia by the Pliocene or early Pleistocene. This hypothesis is supported by the scarcity or absence of this clade in the Neogene mammalian fauna of the Indian Subcontinent.     

RNA Species during Visual Stimulation

AS part of a programme concerned with the quality of RNA synthesized during behaviour we have carried out an experiment to detect the synthesis of qualitatively unique species of RNA during visual stimulation. Two litters of male Wistar rats were housed in a dimly lit room from 40 days of age. At 100 days four members of each litter were injected intracran-ially with 1 mCi of 5-³H-uridine and after 30 min were subjected to 90 min of visual stimulation (experimental subjects), while other rats of each litter were restrained in darkness (control subjects).     

广西崇左缺缺洞早更新世猕猴骨架化石初步报道(英文)

初步报道了缺缺洞发现的猕猴化石。新材料为一具雄性老年猕猴个体的骨架,保存了几乎完整的下颌、全部7节颈椎、9节胸椎、两侧前肢肢骨、右侧后肢部分肢骨以及绝大部分的腕(跗)骨、掌(蹠)骨和指(趾)骨。这是目前为止中国发现的最为完整的猕猴骨架化石。鉴于化石对比材料的缺乏,仅对下颌及牙齿形态进行了描述,并将之与中国已知各化石种进行了对比。由于中国猕猴属各化石种之间的系统关系尚不明确,暂将这批材料作未定种处理,更加深入的研究将另文发表。