冰冻保存小新月菱形藻的包埋-玻璃化法

采用包埋-玻璃化法对小新月菱形藻进行冰冻保存,探讨玻璃化溶液(PVS)配方、装载液浓度和装载时间、脱水时间以及洗涤方法对冰冻保存存活率的影响。结果表明:小新月菱形藻在0℃预冷后50%PVS2装载60min,100%PVS2脱水60min,1mol·L-1蔗糖梯度洗涤30min的条件下存活率最高,为74.1%。包埋-玻璃化法不需要特殊的冷冻设备,冰冻程序操作简单,在藻类种质的超低温保存中有较大的应用潜力。     

超低温冷冻对羯布罗香种子结构和生理生化特性的影响

为长期、稳定、有效地保存羯布罗香(Dipterocarpus turbinatus Gaertn.F.)种子,探讨了低温冷藏对种子活力、结构和生理生化指标的影响。结果表明,45%的含水量是种子的安全储藏含水量;玻璃化冷冻和缓慢冷冻对种子结构损害较大,且冷冻后的种子活力下降幅度大;快速冷冻法是种子超低温保存的最佳冷冻方式;液氮冷冻降低了种子过氧化物酶、过氧化氢酶和脱氢酶活性,提高了α-淀粉酶活性,而对丙二醛含量无显著影响。因此,超低温保存羯布罗香种子是科学可行的。     

低温保存技术在顽拗性种子种质保存中的利用

由于顽拗性种子不耐脱水且对低温敏感,常规保存方法难以达到长期保存的目的。因此,(超)低温保存顽拗性种子种质是最理想的方法。顽拗性种子的低温保存,应用较多的是玻璃化法和两步法。诸多因素影响着低温保存的成败,如种子或胚的含水量水平、溶液低温保护剂效应、降温冰冻与解冻方式、水合过程以及后培养等,这些需深入探索与解决。除顽拗性种子脱水耐性和低温敏感性机理外,植物细胞的冻害和抗冻机理也亟需探明,以便找到最佳冷冻方法,制定长期保存种质基因的最佳方案。     

五种豆科药用植物种子超低温保存技术研究

以豆科药用植物降香檀、决明、含羞草、灰毛豆和猪屎豆的成熟种子为材料,探讨含水量对其发芽率的影响,以及超低温冷冻方式对种子超低温保存的影响。结果表明,降香檀、决明、猪屎豆和灰毛豆种子发芽率均随含水量的下降而从80%左右降至20%以下,而含羞草种子含水量低于10%时,其发芽率仍在75%以上。经超低温冷冻后,五种豆科药用植物种子发芽率较对照组均有显著差异;适宜的含水量下,种子经过超低温冷冻后其发芽率与对照组差异不显著,甚至高于对照组。三种冷冻方法中,玻璃化冷冻法更适合降香檀种子的超低温保存,缓慢冷冻法更适合猪屎豆种子的超低温保存,快速冷冻法适合于决明种子、灰毛豆种子和含羞草种子的超低温保存。由此可知,液氮超低温冷冻法保存降香檀等五种豆科药用植物种子是可行的。     

脱水速率和降温速率对葡萄柚种子超低温保存的影响

以新鲜葡萄柚(Citrus paradise)种子为材料,使用3种脱水速率处理至约20%含水量,然后用饱和盐溶液平衡至10种不同的含水量,再进行简化的二步法超低温保存;同时,以经过15 ℃、50%相对湿度(RH)条件脱水至含水量约12%的葡萄柚种子为材料,使用程序降温仪进行5个降温速率和3个预冷温度的传统二步法超低温保存。结果表明,葡萄柚种子对脱水敏感,种子含水量越低,成苗率越低。而且,脱水速率越快,对种子的损伤越大,成苗率呈现75% RH>50% RH>15% RH;冷冻处理对种子有进一步的伤害,含水量6%～8%的种子超低温保存效果最佳,但脱水速率对超低温保存的种子成苗率的影响不明显。用传统二步法超低温保存葡萄柚种子,与预冷对照相比,经液氮冷冻的种子成苗率都有明显下降。在预冷对照组中,-2.5 ℃·min^-1降温速率的种子成苗率最高,在冷冻保存中-0.5 ℃·min^-1和-0.25 ℃·min^-1的降温速率最有利于超低温保存。预冷温度从-40 ℃降至-60 ℃,未超低温处理种子的发芽率降低,但超低温处理种子的发芽率提高。     

包埋-玻璃化法冷冻保存湛江等鞭金藻的研究

采用包埋-玻璃化法冷冻保存湛江等鞭金藻(Isochrysis zhanjiangensis),探讨了装载液成分和浓度、装载时间、脱水时间、洗涤液浓度及洗涤时间对超低温保存后存活率的影响。结果表明在20℃50%PVS(PVS:30%甘油(GLY) 20%乙二醇(EG) 10%二甲基亚砜(DMSO),用f/2培养基定容)装载4.5h,0℃100%PVS脱水50min,冻存24h后取出冻存管并迅速投入40℃恒温水浴中快速化冻约3min,1.0mol/L山梨醇洗涤40min条件下,湛江等鞭金藻的存活率最高,为54%。与常规的两步法和包埋脱水法相比,包埋-玻璃化法简单、快速且存活率高,在藻类种质保存中有广阔的应用前景。     

束花石斛种子超低温保存的研究

以濒危兰科物种野生束花石斛（Dendrobium chrysanthum）的成熟种子为材料,研究了PVS2植物玻璃化液对其萌发的作用,以及快速冷冻法和玻璃化法对种子超低温保存的影响。结果表明,种子的萌发率随着PVS2处理时间的延长而下降。PVS2预处理能明显地增加种子的超低温耐性。当预处理时间为15～45min时,种子的超低温耐性随预处理时间的延长而增加;当预处理时间长于60min后,种子的超低温耐性随预处理时间的延长而下降。经液氮保存后,存活的种子能萌发成为正常的幼苗。结论是经PVS2预处理45min后,成熟的束花石斛种子能成功地进行超低温保存。     

玻璃化法超低温保存蛇莓茎尖

本文采用玻璃化法对蛇莓离体茎尖超低温保存进行了初步探讨。研究了低温锻炼时间、预培养时间、预处理时间、玻璃化液处理时间和液氮保存时间对超低温保存后成活率的影响。经优化,蛇莓的最高成活率可达（42.00±2.74）%。     

螺旋藻的超低温保存法

【目的】建立螺旋藻藻种的超低温保存法,并探究该方法对不同种类螺旋藻藻种保存的适用性。【方法】采用碘量法筛选出耐低温螺旋藻藻株,通过单因素和正交试验设计对耐低温螺旋藻超低温保存法进行条件优化,并以优化后的超低温保存法对8株不同种类的螺旋藻进行保藏实验。【结果】FACHB-351为筛选出的耐低温螺旋藻藻株;优化后的超低温保存方案为:以10%蔗糖溶液做冷冻保护剂,将藻丝体密度为1.0×107 CFU/m L的藻悬液于4°C驯化72 h,再将藻液和保护剂分别在0°C预冷30 min后混匀,混匀后于0°C停留3 h,然后投入液氮保存。保藏实验结果表明,保藏6个月时除了耐低温性较差的FACHB-350、FACHB-1070、FACHB-902螺旋藻存活率为0,不能恢复生长繁殖,其它5种耐低温性较好的螺旋藻均能在一定时间内恢复正常的生长繁殖,其中FACHB-351的存活率最高,为39.33%。【结论】建立的超低温冷冻保存法可用于耐低温性较好的螺旋藻藻种的长期保存。     

藻类种质超低温保存研究概况

藻类种质的超低温保存技术已受到广泛的重视。目前已对数千种、株的淡水和海水藻类进行过超低温保存。其中 ,绝大多数藻类是采用两步冰冻法保存。影响藻类存活率的主要因素是两步法冰冻保存程序和藻类自身的抗冻性。鉴定存活率是超低温保存技术中的重要环节。由于两步法保存技术的局限性 ,玻璃化和包埋脱水法等新技术在某些藻类的种质保存中可能有较大的应用潜力。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism