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。     

Flavonoids as superoxide scavengers and antioxidants

The superoxide anions scavenging activity and antioxidation of seven flavonoids--quercetin, rutin, morin, acacetin, hispidulin, hesperidin, and naringin--were studied. The superoxide anions were generated in a phenazin methosulphate-NADH system and were assayed by reduction of nitroblue tetrazolium. The scavenging activity ranked: rutin was the strongest, and quercetin and naringin the second, while morin and hispidulin were very weak. The concentration values yielding 50% inhibition of lipid peroxidation in mouse liver homogenate were in order of 10(-6) M for quercetin, rutin, and morin; and of 10(-5) M for acacetin and hispidulin, while naringin and hesperidin had no antioxidative action. In comparison with the antioxidative and scavenging activities of flavonoids, there are no correlations.     

小麦—天兰偃麦草—黑麦三属杂种花粉植株诱导条件的研究

研究表明,三属杂种处于单核中晚期阶段的花粉最适于诱导形成愈伤组织。低温预处理对促进三属杂种花粉愈伤组织的诱导有一定的作用。利用以马铃薯提取物为基础物质的马铃薯-Ⅱ培养基作诱导培养基,其愈伤组织诱导与分化的频率比目前两个较好的合成培养基要高。同一个三属杂种F_1春、秋播种植株之间在形成愈伤组织的能力上有较大的差异,秋播材料形成愈伤组织的能力明显高于春播材料。F_(?)杂种植株诱导愈伤组织和分化植株的频率均比F_1杂种明显提高。     

坛紫菜原生质体的发育研究

用2％的海螺酶和1％的纤维素酶混合,将坛紫菜叶状体的4种不同细胞类型即:营养细胞、根丝细胞、精子囊和果孢子囊,分别解离成原生质体,并研究了这些不同部位和不同生长时期。细胞的生长、发育途径。由根丝细胞分离的原生质体能长成新的叶状体;由早期中部营养细胞分离的原生质体,有70％长成新的叶状体,其余的发育成精子囊和果孢子囊。再生叶状体在室内培养,能正常成熟。由精子囊和果孢子囊分离的原生质体,即精子细胞和果孢子细胞不能再生叶状体。前者形成新的精子囊放散精子,后者形成新的果孢子囊,放散果孢子发育成丝状体。晚期紫菜与早期紫菜比较,再生叶状体的数量显著减少,而发育成精子囊和果孢子囊的数量则大大增多。     

诱导小麦-天兰偃麦草-黑麦三属杂种花粉植株的研究

以法国六倍体小黑麦为母本,分别与普通小麦(Triticum aestivum)和天兰偃麦草(Elytrigia intermedia of Agropyron glaucum)的杂交后代中的中间类型3号和5号杂交。由此获得的三属杂种F_1性状介于亲本之间,兼有三属亲本类型的特征,呈中间类型。用马铃薯-Ⅱ培养基培养三属杂种F_1的花药,诱导花粉愈伤组织。将所获得的愈伤组织转入190-2培养基进行分化,已成功地诱导出一批三属间杂种花粉植株,并用Giemsa显带技术鉴定花粉植株的染色体组组成。     

Gene amplification at a locus encoding a putative Na+/H+ antiporter confers sodium and lithium tolerance in fission yeast.

We have identified a new locus, sodium 2 (sod2) based on selection for increased LiCl tolerance in fission yeast, Schizosaccharomyces pombe. Tolerant strains have enhanced pH-dependent Na+ export capacity and sodium transport experiments suggest that the gene encodes an Na+/H+ antiport. The predicted sod2 gene product can be placed in the broad class of transporters which possess 12 hydrophobic transmembrane domains. The protein shows some sequence similarity to the human and bacterial Na+/H+ antiporters. Overexpression of sod2 increased Na+ export capacity and conferred sodium tolerance. Osmotolerance was not affected and sod2 cells were unaffected for growth in K+. In a sod2 disruption strain cells were incapable of exporting sodium. They were hypersensitive to Na+ or Li+ and could not grow under conditions that approximate pH7. The sod2 gene amplification could be selected stepwise and the degree of such amplification correlated with the level of Na+ or Li+ tolerance.     

The reconciliation behavior of golden monkeys (Rhinopithecus roxellanae roxellanae) in small breeding groups

Observations were made following 130 spontaneous aggressive incidents in two small breeding groups of captive golden monkeys (Rhinopithecus roxellanae roxellanae). Participants were observed both during the first 10 min following these incidents and during matched control observations. An increased contact rate was observed between opponents following the aggressive incident. Post-conflict contacts were characterized by a number of behavior patterns: open mouth, rapid grooming, embrace, and crouching. Adult males played an important role as mediator in agonistic disputes among females: males intervened in 93.6% of female fights. It is speculated that this intervention behavior is related to the species' organization into one-male units.     

湘中、湘东地区早籼稻耐土壤潜育性评价

我国南方稻区的主要低产稻田是潜育性稻田,约有一亿亩。挖掘其“潜在生产力”,种植耐潜育性土壤逆境胁迫能力较强的水稻品种,则是简便、经济而有效的重要途径之一。本文就几个早籼稻品种(组合)对潜育性稻田的生态适应性进行了较系统的观测,并初步提出了耐潜育性的几个鉴定指标,诸如根系生长量和幼穗分化期根系氧化力;分蘖早期茎蘖增长速率;分蘖后期单株干物质产量;乳熟期剑叶片过氧化氢酶活性GDI和光合强度等。上述鉴定指标,综合应用于水稻品种生态适应性和耐潜育性育种研究,有助于提高水稻抗逆性育种的效率。