芦苇胚性愈伤组织的形成及植株的再生

以芦苇种子为外植体,其愈伤组织的诱导率最高。叶鞘和叶片不发生脱分化。培养基中最合适的蔗糖浓度为4%。维生素 B 类、肌醇对愈伤组织的生长起促进作用。而酵母提取物对愈伤组织的诱导和生长具有明显的抑制作用。这种抑制效应,将随酵母提取物浓度的提高而增大。愈伤组织的继代培养,随培养基中2,4-D 浓度的提高,其平均鲜重明显降低。脱分化培养基中2,4-D 浓度对胚性愈伤组织的诱导形成具有一定的相关性。胚性愈伤组织经30代继代培养依然具有90%的分化频率,只是每块愈伤组织的分化苗数减少。反之,非胚性愈伤组织则完全丧失形态发生的能力。对两类愈伤组织进行扫描电镜的观察,发现其表面结构有很大差异。其过氧化物酶、酯酶同工酶谱以及可溶性蛋白的含量均有明显的差别。     

石刁柏胚乳愈伤组织的诱导及植株的再生

石刁柏已形成细胞的幼嫩胚乳,接种在附加有不同浓度的生长素(NAA)和细胞分裂素(BA)的 MS 培养基上,获得了愈伤组织。愈伤组织的诱导频率随生长素的浓度不同而异,可达65.9—83.1%。将胚乳愈伤组织转移到降低了生长素浓度或只含有低浓度生长素的分化培养基上,可陆续分化芽、根、芽丛和少量胚状体,个别的芽和胚状体能发育成小植株。切取1.5—5cm 长的芽,接种在诱导根的培养基上,或在 IBA50ppm 溶液中浸泡2小时,转移到 MS 基本培养基上,部分芽能生根形成完整植株。     

用薄层色谱分离提纯单半乳糖和双半乳糖双甘油酯

本文选择两种溶剂体系,用两次单向薄层层析,从小麦抗寒与不抗寒品系天然橡胶胶乳分离提纯出6种单半乳糖和双半乳糖双甘油酯。并比较了它们的疏水侧链的脂肪酸组成。小麦糖脂疏水侧链脂肪酸的不饱和指数远大于天然胶乳糖脂。抗寒品系胶乳糖脂疏水侧链脂肪酸不饱和指数大于不抗寒品系。双半乳糖双甘油酯疏水侧链脂肪酸不饱和指数均大于其单半乳糖糖脂。     

Microbial desulphurization of heavy oils and bitumen

Most oil producing countries have extensive reserves of heavy oil and bitumen. As easily accessible sources of conventional crudes decline, these reserves will become more important in supplementing the energy requirements. Heavy oil and bitumen are highly viscous and contain 3 to 6% sulphur. These objectionable quantities of sulphur must be removed before being acceptable as refinery feedstock. This paper addresses the potential of biological desulphurization of heavy oil and bitumen. The aerobic and anaerobic processes to remove organic as well as inorganic sulphur have been reviewed. To date, most studies were performed with model substrates, particularly dibenzothiophene (DBT) in a synthetic medium. Early work concerned with the isolation of microorganisms, identification and characterization of intermediate metabolites, and the development of growth media. No commercially viable process has emerged since the engineering details of the process have not been addressed conclusively. Due to high utility and catalyst cost conventional hydrodesulphurization processes are reported to be uneconomic in case of high sulphur oils. Microbial desulphurization, on the other hand, appears to be promising due to the inherent low energy requirement. This process may become more attractive by the application of genetically modified bacteria and improvements in bioreactor design.     

Advances in the molecular biology of plant seed storage proteins

Plant seed storage proteins were among the first proteins to be isolated (20); however, only recently, as a result of using molecular biology techniques, have the amino acid sequences of many of these proteins been determined. With the accumulation of amino acid sequence data for many vicilin-type storage proteins much has been learned concerning the location of conserved amino acid regions and other regions which can tolerate amino acid sequence variation. Combining this knowledge with recent advances in plant gene transfer technologies will allow molecular biologists to correct (by using amino acid replacement mutations) the sulfur amino acid deficiency inherent to bean seed storage proteins. The development of more nutritious soybean and common bean seeds will be of benefit to programs involving human and animal nutrition.     

Molecular biology of Philadelphia chromosome in chronic granulocytic leukaemia and acute lymphoblastic leukaemia

In classical t(9;22) translocation, as observed in chronic granulocytic leukemia (CGL), a hybrid DNA unit is produced, including a rearranged PHL gene, previously known as bcr (breakpoint cluster region) plus the translocated c-abl gene from chromosome 9: a hybrid bcr-abl protein, p210 is formed, with increased tyrosine kinase activity. Such DNA rearrangement, with a p210 protein synthesis, is also found in cases of Philadelphia-positive acute lymphoblastic leukemia (ALL), but in apparently similar cases the bcr gene is not rearranged, and a novel p190 abl-related protein can be found; c-abl rearrangement has also been observed.It is thus established that correlations between cytogenetic and molecular events can be found in CGL and ALL, as in other haemopoietic malignancies: translocation and possible rearrangement of the c-abl oncogene seem of particular importance in this case.     

寄生于蚊类的罗索线虫属一新种——郴州罗索线虫(嘴刺目:索科)

作者等于1984年8月以来在湖南南部郴州市郊区水田中采到一种寄生于三带喙库蚊(Culex tritaeniorhynchus)幼虫胸内的索线虫,自然感染率较高,寄生较普遍。经鉴定属于线虫纲(Nematoda)嘴刺目(Enoplida),索科(Mermithidae),罗索属(Romanomermis)的一新种。文中量度除标明外,均以μm为单位。     

广东和广西条鳅亚科鱼类及一新属三新种描述(鲤形目:鳅科)

为了编著我国的鱼类志,作者于1984年10月至12月在广东和广西两省(区)采得一批条鳅亚科(Noemacheilinae)鱼类标本,经鉴定有三属五种,其中有一个新种,即稀有条鳅Noemacheilus rarus sp. nov.。另有一个新属和两个新种:间条鳅属Heminoemacheilus gen.nov.、郑氏间条鳅Heminocmacheilus zhengbaoshani,sp.nov.和叉尾平鳅Oreonectes furcocaudalis sp.nov.,分别由中国科学院动物研究所郑葆珊研究员和暨南大学郑慈英副教授、中国科学院水生生物研究所张卫同志提供的。根据我们的采集和原有的记载,广东和广西两省(区)的条鳅亚科鱼类共四属九种,现整理如下:     

有壳变形虫在我国第四纪古环境研究中的意义

有壳变形虫在我国第四纪地层中广泛分布,常见种有旋匣壳虫、无棘匣壳虫、针棘匣壳虫和砂壳虫未定种等。作为能在低pH环境下抗溶蚀的原生动物,它们在缺乏钙质化石的地层中是特别有用的环境标志。在我国,有壳变形虫在沿海平原与陆架海区是辨认海相、陆相和海陆过渡相沉积的宝贵标志。此外,有壳变形虫对于营养水平、沉积速率和其它环境参数反应灵敏,是第四纪地层古湖泊学的潜在指示化石。但是为了将有壳变形虫用于我国古湖泊学研究,需要对其现代分布进行定量的研究。 本文描述了一个新种,即亚洲鸟嘴虫Hoogenraadia asiatica。