Life history traits and mechanisms of endangerment inRanalisma rostratum

Ranalisma rostratum (Alismataceae) is an endangered aquatic plant, and now there is only one population existing in China. In its natural habitat, Huli marsh in Chaling, Hunan province, the best growing plants have been observed at microsites where the water depth is 5∼10cm, and the plants grow in emergent form.R. rostratum reproduces asexually or sexually. The recruitment of asexual propagules into population is a very important way to maintain the natural population size. Although seed production does not appear to limitR. rostratum, restricted dispersal of propagules and seeds, low seed viability, low germinability, slow growth of seedlings under all conditions, and habitat loss due to agriculture appear to be more important reasons for the endangerment of this plant. Supported by the national Natural Science Foundation of China Wang Jianbo: born in 1964, Ph. D, Associate professor     

长喙毛茛泽泻的研究进展

综述了国家一级保护野生植物长喙毛茛泽泻的生物学特性,生殖生物学,生态学及其致濒机制和保护措施等方面的研究进展.     

The expression of Quox-1 gene in the embryo development ofAndrias davianus

Two set ofAndrias davidanus fertilized eggs and its seedlings were got by means of artificial reproduction. The sections of the embryo ofAndrias davidianus were made by histological method. The expression of homologous sequences of Quox-1 gene has been studied by immunohistochemical method with special antibody. Results show that the expression of homologous sequences of Quox-1 gene was detected in the epidermis of blastula and gastula. The highly expression was investigated in the epidermis at the neural tube phrase and the tail bud stage. Deng Fengjiao: born in October, 1954, Associate Professor     

不同施肥时期新春二号小麦胚胎生长发育研究

本文研究新春二号小麦胚胎在新疆的生长发育特性.结果表明,整个胚胎发育经历22天时间,处于小麦灌浆时期.不同施肥时期对胚胎发育进程影响不明显,但对胚胎中、后期的生长有明显影响.胚乳亦与胚同步增长,并呈正相关.且不同施肥时期对胚乳的影响较胚明显.     

紫荆种子成熟过程中种皮和胚乳超微结构观察

为探讨紫荆种子成熟过程中种皮结构和胚乳细胞内含物的变化,对不同成熟期紫荆种子的种皮和胚乳分别进行了扫描电镜(SEM)和透射电镜(TEM)观察。扫描电镜观察发现:在紫荆种子发育初期,种皮表面出现孔状结构; 随着种子的逐渐成熟,种皮表面气孔消失,蜡质开始形成并逐渐加厚,种孔和种脐也逐渐开裂。从种皮的纵切面可以看出,种脐部位栅栏层形成较早,为单层细胞结构。花后105 d可观察到由种脐沿种子表面延伸的输水管道,花后135 d时,输水管道内出现由种脐沿种皮延伸至种子另一端的管胞群。种子发育成熟时,种子中间部位的种皮由外到内依次为角质层、栅栏层和薄壁细胞层,角质层主要由蜡质及其他覆盖物组成,栅栏层则由单层紧密排列的长柱状厚壁的大石细胞构成。角质层和栅栏层的这种结构可能是影响紫荆种子种皮透性进而引起休眠的原因之一。透射电镜观察发现:紫荆种子发育初期,胚乳细胞内存在大液泡,但脂滴与高电子致密物质数量较少。随着种子的不断成熟,线粒体、内质网、高尔基体等细胞器逐渐形成,胚乳中营养物质的代谢速度较快,之后这些细胞器又逐渐降解消融,脂滴和高电子致密物质则不断增加,说明随着种子的发育,胚乳内大分子贮藏物质不断积累,物质代谢活动降低,种子逐渐进入休眠期。     

Analysis for the dorsalization potency of the animal blastomeres of the 16 cell stageXenopus embryo

The dorso-ventral axis ofXenopus embryo is established after fertilization. Blastula stage blastomeres acquire different identities as they have inherited different maternal materials which distribute radial symmetrically along the animal vegetal aixs in the full-grown oocyte, and are rearranged by the cortical rotation triggered by fertilization. The vegetal blastmeres demonstrate the different dorsalization potencies in the previous transplantation experiments. The data of blastomere explanting and RT-PCR analyzing indicate that the dorsal ventral bias also exists among the animal blastomeres even during the early blastula stage.     

The internal structure of Early Cambrian fossil embryo <Emphasis Type="Italic">Olivooides</Emphasis> revealed in the light of Synchrotron X-ray Tomographic Microscopy

Countless fossil embryo Olivooides and the hatched larvae, juveniles and adults （the latter two kinds are Punctatus） are recovered by means of acid maceration from the fine-crystalline to medium-crystalline phosphatic limestone and phosphatic micrite of Early Cambrian Kuanchuanpu Formation at the Shizhonggou section, near Kuanchuanpu Village, Ningqiang County, Shaanxi Province, China. Using the technique of Synchrotron X-ray Tomographic Microscopy, the 3D internal structure of Ofivooides and Punctatus is reconstructed. The morphological and statistic analyses are also given to the stellae structure of Ofivooides and Punctatus, which indicates that this structure is a result of adaptive evolution to a lifestyle of fast-attaching after hatching, probably with the function of mucilage secretion. The internal structure of Punctatus is described and discussed. The ovum-like structure, a common internal feature of Punctatus, is considered as the taphonomic structure, rather than eggs or other biological structure. This structure is thought to be formed after the burial of the animal and before or during the mineralization. The original internal structure of Punctatus is assumed to be tabulae-filled, with soft body grown on them.     

濒危植物-半日花(Helianthemum songaricum)的双受精作用及胚和胚乳发育

运用石蜡切片法,对半日花Ｈ．ｓｏｎｇａｒｉｃｕｍ的受精过程,胚及胚乳发育进行了初步观察．受精前,一个助细胞解体,另一助细胞宿存．精核与极核的融合早于精核与卵的融合．受精极核不经过休眠过程,经多次分裂形成核型胚乳．胚乳游离核于球胚晚期开始细胞化．种子成熟后无胚乳．胚胎发育属柳叶菜型．胚柄由一纵列细胞组成并于球胚晚期开始退化．胚的发育经历球形原胚、心形胚、鱼雷形胚及成熟胚各时期．     

诺丹冰草（Agropyron desertorum CV．nordan）的胚和胚乳发育

观察了诺丹冰草胚和胚乳的发育过程．一般合子第一次分裂为横分裂，但偶见有斜分裂，形成顶细胞和基细胞．顶细胞纵分裂，基细胞横分裂，胚胎发生属紫宛型．一个助细胞于受精前解体，宿存助细胞生存到椭圆形胚期．丝状器具强的ＰＡＳ正反应．反足细胞于受精后增殖并保留到多细胞原胚时消失且无多糖反应．核型胚乳，胚乳细胞化开始于多细胞原胚期．成熟胚乳细胞中具许多大的淀粉粒．种子有胚乳．发现有原胚的移位及胚囊中缺少胚的现象．     

麻疯树胚乳cDNA文库的构建与分析

以等质量比的不同发育阶段的麻疯树（Jatropha curcas L.）胚乳为材料构建麻疯树胚乳cDNA文库.初级文库滴度为1.5×106 Pfu/mL,重组率为99.7％,插入片段大小为0.4～4 kb,平均约1 kb.全长基因的比例达到20％.推测的蛋白质序列种类主要包括贮存蛋白相关、转录表达调控相关、脂肪酸合成相关及信号传导相关等同源基因序列.编码功能基因的类型与分布情况同Joseph A White等构建的蓖麻胚乳cDNA文库基本一致,个别类型如贮存蛋白合成相关基因的比例相比较低,信号传导     

水稻胚乳淀粉积累及其结构研究进展

从水稻胚乳的发育,胚乳淀粉的积累、胚乳淀粉细胞的生化变化及其对稻米品质的影响和胚乳淀粉细胞结构与稻米品质的关系综述了水稻胚乳淀粉积累及其结构研究进展。     

中华稻蝗（Oxya Chinesis Thunberg）胚胎发育过程中耗氧率变化的研究

用ＳＫＷ－３型华氏呼吸仪对中华稻蝗（ＯｘｙａＣｈｉｎｅｓｉｓＴｈｕｎｂｅｒｇ）卵发育过程中的耗氧率进行了测定研究（培养条件：恒温２５℃），并同步用染色法研究了胚胎形态的变化．结果发现，中华稻蝗卵发育的耗氧率曲线形状在种内，特别是同一居群内具有一定的稳定性，但总的耗氧量在不同的地区、甚至在同一地区不同的采集条件下均有明显的变化     

玉米种子基因组DNA提取及RAPD分析

采用了两种不同DNA提取方法(常规法及改进法)从玉米Zea mays种子的胚和胚乳中分别提取基因组。结果表明，在两种不同的提取方法中，改进法比常规法有提取的DNA纯度高、RNA含量少、DNA降解少等优点。无论从胚和胚乳中提取的DNA都可以满足RAPD的要求。为玉米RAPD，分子标记，品质鉴定等研究提供可行的依据。     

不同水分条件对3种蕨类植物配子体形态发育的影响

研究了不同水分条件对3种不同演化地位的蕨类植物(海金沙(Lygodium japonicum)、水蕨(Ceratopteris thalictroides)、狗脊(Woodwardia japonica))的配子体形态发育的影响.结果表明:1)随着水分的增加,海金沙、水蕨和狗脊孢子的萌发速率加快,丝状体的长度增长; 2)在缺水条件下,配子体易发育成雄性配子体,而在水分充足条件下,配子体易发育成两性配子体或雌性配子体; 3)次生假根的形态及毛状体的数量等受到水分条件的影响; 4)孢子萌发类型、配子体发育类型及成熟原叶体和毛状体的形态结构是相对稳定的性状,可作为蕨类植物分类鉴定的依据.     

栽培年限对走马胎生长及有效成分含量的影响

本文研究不同栽培年限对走马胎（Ardisia gigantifolia Stapf.）生长、生物量及有效成分含量的影响,拟为走马胎药材应用和采收提供科学依据。以1-5年生走马胎植株为试验材料,用全株挖掘的方法测算其生物量,用紫外分光光度计检测其有效成分。结果表明：走马胎株高、基茎及各器官的生物量随栽培年限延长呈显著（P<0.05）增加趋势,生物量增量由大到小依次为根、茎、叶;根、茎生物量增速最快出现在第4年,最慢在第5年。栽培年限可显著影响走马胎各器官的生物量分配比（P<0.05）,其中根比重为0.30-0.51,普遍高于茎、叶,且最大值出现在第4年。走马胎有效成分含量总体呈现根>叶>茎的趋势;3年生植株各器官的总皂苷含量最高,1年生茎、叶的总酚、总黄酮含量最高,2年和4年生根的总酚、总黄酮含量最高。综上,走马胎最佳药用部分为根系,栽培3-4年采收比较合适。