不同生境区稻田节肢动物群落相似性分析

根据不同生境区稻田节肢动物群落系统调查结果,应用组平均聚类分析法及主成分分析法,讨论节肢动物群落的相似（相异）性问题。结果表明：生境条件及管理措施的差异对群落的结构影响较为明显,不同生境区的稻田节肢动物群落,都能在一定距离取值时聚合成一类,而水稻品种对此影响较小。主成分分析结果由二维图表达已基本满足要求。结果说明大八镇生境区稻田节肢动物群落与岗列镇生境区稻田节肢动物群落差异较大,分别列于两个极端。海陵镇生境区稻田介于两者之间,而与岗列镇生境区稻田节肢动物群落重叠。与聚类分析结果有所差异。这可能与主成分分析法损失部分信息有关。     

低营养条件下Paclobutrazol(PP333)对黄瓜去顶幼苗直接形成花芽的影响(简报)

植物开花机理是生物学中的一个基本问题,多年来人们进行过许多的研究,积累了大量的事实,然而对开花的机理仍然还不甚清楚。因而在利用原有实验系统的同时,有必要寻找更多简单,又便于分析的实验系统。Jullien等报告离体培养的大豆子叶节能直接产生花芽。我们在建立离体培养黄瓜子叶直接单独形成雄花或雌花的实验系统的过程中,发现黄瓜幼苗去除顶芽后在子叶节处也能直接形成花芽。这一现象有可能用于深入研究各营养器官和花启动间关系等问题,定将     

水稻自然生长趋势的数学模型和动态分析

本研究以随机过程理论为基础,应用数理方法,在分期播种的基础上,提出了一个受遗传特性控制的水稻各生物学参量自然生长趋势的数学模型。并进行了重复验证,得到了不同生育时段各生物学参量的生长速度（一阶导数）和生长速度的变化率（二阶导数）,揭示了水稻生长的基本规律。并结合实测资料,通过相关分析,得到影响各生物学参量的关键气象因子,将水稻生长的研究建立在定量的基础上,有利于更加合理地采用各项高产栽培和农田管理措施。     

Topography of short portal vessels in the rat pituitary gland: a scanning electron-microscopic and morphometric study of corrosion cast replicas

We applied scanning electron microscopy combined with imaging and morphometric techniques to analyze the dorsal topography and morphology of short portal vessels linking the capillary beds of the pituitary neural and anterior lobes in adult male albino rats. The pituitary microvasculature was replicated by intracarotid injection of Batson's No. 17 compound producing plastic casts that were advantageous for comprehensive morphometric analyses using an imaging device. The analysis revealed the existence of two types of portal vessels having quantitatively different morphological properties. The bilateral venular plexus of 3–4 vessels located at the base of the infundibular stalk (each venule measuring 300 m in length and 32 m in diameter) appears to be the major part of the short portal system in the dorsum of the rat pituitary gland. Narrower capillary-like shunt vessels (6.8 m in diameter), of about the same length as the venules, were situated throughout other subregions of the intermediate lobe cleft. The short portal vessels of both types made direct anastomoses with the capillary networks in the neural and anterior lobes. The neural lobe capillaries were twice as numerous (1324 per mm²), and only half as wide (6.2 m), as the sinusoidal capillaries in the anterior lobe (density of 637 per mm²; diameter of 13.7 m). The topographical position of the portal venular system suggests that the caudolateral subregions of the pituitary neural and anterior lobes have a functional relationship dependent on rapid interlobe transfer of neurohumoral factors such as hormones via the portal blood. This process appears to be supplemented throughout the rest of the cleft between the two lobes by a small number of capillary shunts that supply the epithelial cell lobules of the intermediate lobe in situ. The findings collectively indicate that this portal system provides a constant stream of neurohumoral information that is shared moment-by-moment between the pituitary neural and anterior lobes.     

Ar^＋,远红外激光,γ射线单一及复合处理水稻的诱变效果

用Ar~+、远红外两种激光和~(60)Co—r射线单一或复合处理两个籼稻品种的干种子,分析和比较了不同处理对水稻的当代生物学效应及处理二代的变异频率。结果表明,两种激光对当代的几个性状均表现为刺激效应,并有减轻,射线辐射损伤的作用,复合处理二代的变异频率和变异类型数明显高于相应的单一处理。说明复合处理是提高激光育种效果的有效方法。     

几种药物对HL-60细胞的诱导分化作用及其过程中蛋白激酶C活力分布的变化

本文就HHT、RA、WB_(852)对HL-60细胞的诱导分化作用及此过程中PKC活力在细胞胞浆部分及膜溶脱部分的变化进行研究。结果表明,在适当的用药浓度下,从细胞生长抑制情况、形态学观察及NBT还原能力测定判断,三种药物对HL-60细胞有明显的诱导分化作用。PKC活力分布变化的研究结果表明,用药组细胞胞浆部分酶活力有不同程度的下降,尤在用药早期(约6h以前)下降显著;而膜部分PKC活力则表现上升、或下降,或活力相差不大的结果。暗示在信息传递过程中起核心作用的PKC对不同的胞外刺激可能采取不同的应答方式。PKC的作用可能主要发生在信息传递的早期。     

Release of Prostaglandin E2 by Human Mononuclear Cells Exposed to Heat-Killed Salmonella typhi

Human mononuclear cells pre-labeled with [³H]arachidonic acid were shown to release metabolites following in vitro addition of heat-killed Salmonella typhi (HKST). The amount of label released was significantly higher than that seen with live S. typhi (LST). Addition of increasing amounts of HKST resulted in an increased release of metabolites. Enzyme immunoassay of the culture supernatants revealed that the bulk of the metabolite released was prostaglandin E₂ (PGE₂). Leukotriene B₄ (LTB₄) and leukotriene C₄ (LTC₄) were not detectable in the culture supernatants. The significance and implications of these results are discussed.     

Identification of a genomic region linked with sex determination of Undaria pinnatifida (Alariaceae) through genomic resequencing and genetic linkage analyses of a segregating gametophyte family

Different from the traditional knowledge about kelp, three sexual phenotypes (female, male, and monoecious) exist in the haploid gametophytes of Undaria pinnatifida. However, the sex-determining mechanisms remain unknown. Genetic linkage mapping is an efficient tool to identify sex-linked regions. In the present study, we resequenced a segregating gametophyte family based on the male genome of U. pinnatifida. A high-density genetic linkage map was constructed using 9887 SNPs, with an average distance of 0.41 cM between adjacent SNPs. On the basis of this genetic map and using the composite interval mapping method, we identified 62 SNPs significantly linked with the sexual phenotype. They were located at a position of 67.67 cM on the linkage group 23, corresponding to a physical range of 14.67 Mbp on the HiC_Scaffold_23 of the genome. Reanalysis of the previous specific length amplified fragment sequencing data according to the reference genome led to the identification of a sex-linked genomic region that encompassed the above-mentioned 14.67 Mbp region. Hence, this overlapped genomic range was likely the sex-determining region. Within this region, 129 genes were retrieved and 39 of them were annotated with explicit function, including the potential male sex-determining gene-encoding high mobility group (HMG) domain protein. Relative expression analysis of the HMG gene showed that its expression was higher in male gametophytes during the vegetative phase and monoecious gametophytes during both the vegetative and gametogenesis phases, but significantly lower in male gametophytes during the gametogenesis phase. These results provide a foundation for deciphering the sex-determining mechanism of U. pinnatifida.