温度对落叶果树休眠的影响(综述)

阐述了引起温带落叶果树休眠的主导因素是低温，一旦进入自然休眠后，需经一定的低温积累量才能解除休眠。在冬季无低温的热带亚热带地区落叶果树没有自然休眠期，仍能正常生长发育。     

利用离体培养技术打破桂花种子休眠的试验

桂花种子成熟后胚有后熟作用,胚乳中可能含有抑制胚萌发的物质,使用赤霉素和3个月的层积处理也不能促使其萌发。将桂花种子进行3个月层积处理后,进行离体培养,培养基中加入0.5 mol/L BA,1.0 mol/L BA 0.5NAA可以打破种子的休眠,促进萌发。     

肝细胞癌特异抗原的筛选

应用重组克隆表达抗原的血清学鉴定技术,从广西肝细胞癌中初步筛选出９个基因克隆,与肝癌患者及其他人血清的反应证明对肝癌有特异性。ＤＮＡ测序结果与基因库核对,发现其中７个有同源结构;２个为无同源结构的新分子。     

An interspecies conserved antigen ofPlasmodium falciparum containing clusters of asparagine residues

An interspecies conservedPlasmodium asparagine rich antigen, designated as ARK26, was isolated by immunoscreeningP. falciparum genomic DNA expression library with mouse convalescent anti-P. yeolii serum. Partial DNA sequence analysis reveals that ARK26 contains clusters of asparagines and no randomly repeated amino acid sequence motifs are observed. A 65×10³ GST fusion protein is expressed by recombinant plasmid PGEX-5X-1 (ARK26) inE. coli C strain ABLE-K. Computer programs predict that two asparagine rich regions are among the possible antigenic epitopes of p37 encoded by ARK26. Interestingly, the sequence of ARK26 displays significant similarity to yeast and several other species’ mitochondrial genes, and its possible function is discussed. Supported by a fellowship offered by International Center for Genetic Engineering & Biotechnology(ICGEB) Ma Donghui: born in 1969, Graduate student     

白皮松种子休眠研究进展

种子休眠普遍存在于高等植物中,是植物历经长期的自然选择而保存下来的一种生物学特性。白皮松(Pinus bungeana Zucc.)是中国特有种,观赏价值高,以种子繁殖为主,但种子具有深休眠特性,给苗木繁育带来一定困难。分析关于白皮松种子休眠的研究结果认为,休眠原因主要包括:种子成熟时种胚的发育状况,内、外种皮和胚乳含有种类和含量不尽相同的萌发抑制物且脱落酸类在各部位均存在并有较强的抑制能力,种皮对种子萌发的机械阻力和透水性、透气性障碍以及内源激素在种子休眠中的作用。解除白皮松种子休眠的方法主要有低温层积处理、长时间流水冲洗、植物激素浸种、化学试剂和机械处理以及环境条件处理等。     

SEREX方法在肿瘤相关抗原筛选中的应用

SEREX方法是筛选肿瘤抗原分子的一种方便且高效的方法。本文解释了SEREX的原理及方法,介绍了利用该方法所鉴定出来的肿瘤相关抗原,讨论了该方法的优缺点,阐述了改进的方法,最后对该方法的应用进行了展望。     

层积和激素处理对大旺山楂种子的生理生化影响

对栽培品种大旺山楂种子进行层积处理,并分别用200 mg/L GA3和ABA处理层积后的种子,测定层积不同阶段和激素处理种子的生理生化变化。结果表明,大旺山楂种子休眠期长,正常采收的成熟种子层积一个冬天难以解除休眠。层积处理使山楂种子的细胞膜透性增加,呼吸加强,SOD和CAT活性增加,POD,G6PDH和PAL活性降低,总糖、还原糖、可溶性蛋白质和游离氨基酸含量降低。GA3处理促进种子萌发,并使种子CAT,SOD,POD,G6PDH和PAL活性降低,而ABA处理抑制种子萌发,除了使SOD活性降低外,对其余各酶的影响与GA3的作用相反。     

Insect photoperiodism: various ways of regulating univoltinism in lacewings (Planipennia: Chrysopidae)

Summary Reproduction inTjederina gracilis adults depends on short-day followed by long-day conditions. InNineta pallida, development of overwintering first-instar larvae is retarded by short days; later on, that of second-and third-instar by long days.Nineta flava andChrysopa perla prepupae automatically enter diapause, but inN. flava, photoperiod regulates diapause eermination, and long days may retard egg laying