18个彩色棉品系的SSR指纹分析

本研究利用SSR技术建立了18个彩色棉品系的DNA指纹图谱,在110对SSR引物中筛选到10对扩增效果较好的引物,应用其中的4对构建了18个彩色棉的分子检索模式图。同时用这10对引物对18个彩色棉进行了聚类分析,对它们的亲缘关系作了初步探讨。     

芦荟组织培养研究进展

本文首先对芦荟植物做了简单介绍,之后对芦荟的组织培养状况进行了概述,最后提出了对芦荟组织培养的一点看法。     

云计算安全探讨

随着云计算的广泛应用,云计算安全问题逐渐凸显出来。文章首先阐述了云计算安全相关概念,并对云计算安全特征进行了分析,然后对云计算安全的体系架构进行了介绍,并对云计算安全的关键技术和发展趋势进行了分析。     

稀土元素对酥梨叶片氮、磷、钾及其同化能力的影响

本文报道了稀土元素对酥梨叶片中氮、磷、钾含量,叶绿素含量及其光合效率的影响。结果表明,稀土元素有效地促进树体对氮、磷、钾的吸收。其中对磷的促进作用更显著。同时,增加了叶绿素含量,提高了光合强度。从而,提高了果实产量和品质。     

海南地衣多样性考察及其资源研发前景

文中对中国海南岛地区地衣多样性进行了考察并对其资源研究与开发提出了建议。笔者对生物多样性的概念做了阐明;对于考察中的有关地衣资源做了简报,对地衣多样性及其资源的研究与开发及其三大存取系统进行了论述。报道了海南地衣138种,其中中国新记录种14种。     

海洋酸化对蟹类影响的研究进展

人类活动排放二氧化碳引起了海水碳酸盐平衡体系变化和pH下降, 最终导致了“海洋酸化”。海洋酸化对蟹类产生了从表观到分子的多重影响。文章在总结海洋酸化对各种蟹类生长发育、生理与代谢、表型和行为等方面影响的基础上, 对其影响的机理展开了讨论, 并对控制海洋酸化及其对蟹类的影响研究提出了意见和建议。     

稀土元素对酥梨叶片氮、磷、钾及其同化能力的影响

本文报道了稀土元素对酥梨叶片中氮、磷、钾含量,叶绿素含量及其光合效率的影响。结果表明,稀土元素有效地促进树体对氮、磷、钾的吸收。其中对磷的促进作用更显著。同时,增加了叶绿素含量,提高了光合强度。从而,提高了果实产量和品质。     

鸟类对城市化的适应

城市生态系统是以人为主导的复杂系统,当前的高速城市化进程对包括鸟类在内的城市区域动物施加了广泛的选择压力。从鸟类对城市环境的主动适应角度,归纳了国内外城市鸟类生态学研究中有关鸟类对城市化的适应研究,探讨了城市化进程中城市鸟类行为、生理指标以及种群基因结构的适应性变化。基于遗传的数量效应,研究认为某些鸟种对城市环境的适应已经上升到进化层次,同时还对城市化导致鸟类新物种形成的可能性进行了探讨。最后,对鸟类对城市化适应的研究前景提出了展望。     

一种提高微生物发酵单位的新优化控制策略

微生物发酵过程对技术进行控制和优化,对微生物发酵单位的经济利益和质量都具有重要的作用。在传统的微生物发酵过程中,为了提高工作的效率和质量,注重对菌种方面的选择。但是,随着我国生物信息技术的不断发展,对其领域进行了一系列的研究,并对微生物发酵过程进行了优化。本文对一种提高微生物发酵单位新优化控制进行了分析和阐述,并提出了一些建议,以此促进我国微生物研究领域的长远发展。     

湖南汉族、侗族16对遗传性状的调查

本对湖南汉族、侗族的16对遗传性状进行了调查。计算出了每对性状的出现率及除扣手和交叉臂外的14对遗传性状的基因频率,分别析了民族间和性别间的差异,同时还分析了惯用手,扣手、交叉臂之间的关系。     

Anatomical Studies of Regeneration after Ringing of Eucommia ulmoides

The trunk of Eucommia ulmoides Oliv. following ringing about one meter in length, could regenerate new bark without significantly affecting the tree growth. Such regeneration process differed from that following partial stripping in other trees as has been reported previously. After ringing in Eucommia ulmoides, there was primarily a proliferation of xylary mother cells and partly remained cambium cells forming a cork layer which led to the establishmant of a more or less normal complete periderm. At the same time the xylary ray cells near the surface dilated and proliferated until they extended across in continuity with the neighbor rays. No callus formation by the rays emerged from the surface was observed. Among the ray cells following multiplication, some immature xylary elements were also visible. Simultaneously, some immature xylary elements lying internal to region of the dilated and coalesced ray cells gradually transformed into new cambium. Due to the fact that initially part of the xylary ray cells was not completely differentiated, it seemed that some of the remained xylary rays separated the newly formed cambium zone into many segments. Three to four months after ringing, new cambium activity proceeded periclinally so as to establish a complete ring of cambium zone. Subsequent differentiation of newly formed cambium followed the normal pattern of vascular tissue development in this plant.     

STEM ANATOMY OF PARTHENIUM ARGENTATUM,P. INCANUM AND THEIR NATURAL HYBRIDS

Guayule (Parthenium argentatum Gray) contains rubber in the parenchymatous cells of stems and roots. Stem anatomy of P. argentatum is described along with that of P. incanum H.B.K. (mariola). Anatomy of these species differs significantly. Phloem rays in both species increase in width by cell division and expansion; however, the increase observed in mariola is less as compared to that in guayule. Axial xylem parenchyma in guayule is generally a two-cell strand as compared to the fusiform axial xylem parenchyma observed in mariola. Vascular ray cells and cells of the pith region of guayule are parenchymatous, whereas those of mariola are sclerenchymatous. As a result of introgression between guayule and mariola, three forms of guayule exist in the native stands of Mexico. Morphological differences between these guayule plants have been described previously. The stem anatomy of these three groups of plants differ importantly. Group I guayule plants, least introgressed by mariola, have taller rays with the cells of pith region and vascular rays parenchymatous. Group III plants, highly introgressed by mariola, have a few to many cells of vascular rays and pith with lignified secondary walls and shorter rays. Many of the anatomical characteristics of group II plants, somewhat introgressed by mariola, are intermediate between group I and III plants.     

毛青藤茎的发育解剖学研究

毛青藤茎顶端的原生分生组织由原套和原体组成,其行生细胞形成初生分生组织──原表皮、原形成层和基本分生组织。初生分生组织的衍生细胞分化形成茎的初生结构,包括表皮、皮层、维管束和髓。随着茎的继续发育,维管形成层开始活动,由束中形成层产生次生韧皮部和次生木质部分子,而束间形成层仅产生薄壁组织细胞形成宽的射线。在原生韧皮部筛管分化成熟的过程中,韧应部外方仍保留1—2层原形成层细胞,以后,它们分裂为多层纤维原始细胞,在次生结构形成时,这些细胞的细胞壁加厚,形成初生初皮纤维。茎始终未产生用皮。     

Chlorophyll distribution in the stems and trunk of beech trees

The distribution of chlorophyll was examined in cross-sections of 2- and 6-year-old stems as well as in the bark of the stump trunk of beech trees, utilising chlorophyll autofluorescence. The investigations were conducted using a confocal microscope. The tests carried out on 2 – 6-year old stems showed a large presence of chlorophyll in the bark, in primary and secondary rays as well as in the pith, but smaller amounts in wood parenchyma cells. There was no chlorophyll in the cork, sclerenchyma: in wood in vessels, tracheids and fibers. A reduction in the chlorophyll content in 6-year-old stems was not observed. In the bark of the trunk, chlorophyll was found in large amounts directly under the cork and in vestigial amounts in the primary phloem.     

Differentiation of the ray system in woody plants

The regulation of vascular ray differentiation has received limited attention, despite the fact that vascular rays constitute an important part of the secondary body of plants. In this paper we review developmental aspects of the ray system and suggest a general hypothesis for the regulation of ray differentiation and evolution. In studies of ray differentiation, two basic factors should be taken into consideration: 1) the normal gradual increase in ray size in relation to age, distance from the pith, and distance from the young leaves; and 2) the influence of wound effects on the size, structure, and spacing of rays. The relationships between the rate of cambial activity and secondary xylem differentiation are not clearly understood. There are contrasting results on the relationships between ray number and rate of radial growth. The rate of radial growth (= rate of cambial activity) is not the regulating mechanism of ray characteristics. Bünning (1952, 1965) proposed that rays are distributed regularly in the tissue, as the outcome of an inhibitory influence expressed by them. However, Bünning’s hypothesis contradicts a basic feature of the vascular ray system, namely, fusion of rays. Detailed histological studies of the secondary xylem revealed that proximity to and contact with rays plays a major role in the survival of fusiform initials in the cambium (Bannan, 1951, 1953). Such evidence led Ziegler (1964) to suggest that since the cambium is supplied predominantly via the rays, this is an effective feedback regulative system for an equidistant arrangement of the rays. The hypothesis that rays are induced and controlled by a radial signal flow seems to be the best explanation for the structure and spacing of rays. The formation of a polycentric ray—a special case of “ray” initiation inside a vascular ray—supports the idea that radial signal flow occurs within the rays (Lev-Yadun & Aloni, 1991a). This idea is also supported by findings fromQuercus species in which aggregate rays in the xylem disperse naturally in branch junctions and, following partial girdling, leave a longitudinal narrow bridge of cambium and bark as a result of enhanced axial signal flow (of auxin and other growth regulators) (Lev-Yadun & Aloni, 1991b). The longitudinally elongated shape of rays is their response to axial signal flows (mainly the polar auxin flow). Two methods have been used to study the evolution of the ray system: 1) statistical studies of the relationships between vessel and ray characteristics in many species, when vessel characteristics were the evolutionary standard, and 2) comparison of ray characteristics in fossils originating from several geological eras. We suggest that evolution of the ray system reflects changes in the relations between radial and axial signal flows.     

Comparative wood anatomy of Andromedeae s.s., Gaultherieae, Lyonieae and Oxydendreae (Vaccinioideae, Ericaceae s.l.)

The wood anatomical structure of 11 out of 13 genera from four tribes of the Vaccinioideae, namely Andromedeae s.s. , Gaultherieae, Lyonieae and Oxydendreae (Ericaceae s.l. ), is described using light and scanning electron microscopy. Several features of the secondary xylem support the tribal classification based on molecular data: arrangement of vessel-ray pitting, height of multiseriate rays and the shape of the body ray cells. Oxydendreae are clearly defined from the other representatives by various wood anatomical features. Gaultherieae can be distinguished from Lyonieae by differences in vessel perforation plates, vessel-ray pitting, height and structure of multiseriate rays, and occurrence of prismatic crystals, but the wood of Andromedeae s.s. is similar to Gaultherieae. Moreover, Andromedeae s.s. , Oxydendreae and Vaccinieae are characterized by their pith structure, whereas considerable variation in the pith cells is found in Lyonieae and Gaultherieae.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 161–179.     

濒危植物海南风吹楠营养器官解剖结构特征

该研究采用石蜡切片和光学显微技术,对海南风吹楠营养器官的解剖结构及其对环境的适应性进行了探讨。结果表明:海南风吹楠为典型异面叶,叶片中脉发达,中部分化出髓,上表皮外侧具角质层,内侧具1层内皮层,下表皮外侧无角质层,有气孔器分布,气孔器为双环型,略下陷;栅栏组织3~4层细胞,海绵组织4~6层细胞。茎的初生结构中表皮轻微角质化,维管束为外韧型,8~10个初生维管束围绕髓排列为1轮;茎的次生结构中,表皮外部角质层加厚,维管柱紧密排列连成环状,次生韧皮部和次生木质部发达,形成层细胞3~5层。根的初生结构中表皮细胞外壁加厚,外皮层细胞体积大,形状不规则,内侧具1层形成层,内皮层具凯氏带,初生木质部为多原型,呈辐射状排列。根的次生结构中木栓层细胞5~6层,木栓层内侧具1层木栓形成层,栓内层细胞3层。海南风吹楠营养器官具有一定耐阴和耐旱结构特征,同时与其生活的热带雨林沟谷中高温荫湿的环境相适应。     

STRUCTURALLY PRESERVED FOSSIL PLANTS FROM ANTARCTICA. I. ANTARCTICYCAS,GEN. NOV., A TRIASSIC CYCAD STEM FROM THE BEARDMORE GLACIER AREA

Silicified stems with typical cycadalean anatomy are described from specimens collected from the Fremouw Formation (Triassic) in the Transantarctic Mountains of Antarctica. Axes are slender with a large parenchymatous pith and cortex separated by a narrow ring of vascular tissue. Mucilage canals are present in both pith and cortex. Vascular tissue consists of endarch primary xylem, a narrow band of secondary xylem tracheids, cambial zone, and region of secondary phloem. Vascular bundles contain uni- to triseriate rays with larger rays up to 2 mm wide separating the individual bundles. Pitting on primary xylem elements ranges from helical to scalariform; secondary xylem tracheids exhibit alternate circular bordered pits. Traces, often accompanied by a mucilage canal, extend out through the large rays into the cortex where some assume a girdling configuration. A zone of periderm is present at the periphery of the stem. Large and small roots are attached to the stem and are conspicuous in the surrounding matrix. The anatomy of the Antarctic cycad is compared with that of other fossil and extant cycadalean stems.     

5种甘草根和根状茎的解剖学研究

５种甘草根和根状茎的比较解剖学研究表明,成长根都由周皮和维管组织构成,种间差异主要表现在木栓层和细胞层、韧皮纤维束和排列和轮数、导管分布频率、射线形成以及初生木质部在根中央的星散分布状况等方面;成长根状茎都由周皮、维管组织和髓构成,与根相比较根状茎具厚的木栓层、长而粗的导管分子稿的导管分布频率,不同种根状茎之间韧皮射线的形态和裂隙的有无以及髓、韧皮部含单宁细胞的数量、导管内含物等方面也存在一定差异     

The comparative stem and root anatomy of Goniothalamus andersonii, G. macrophyllus, G. malayanus and G. velutinus (Annonaceae) from the peat swamps of Sarawak

The stem and root anatomy of G. andersonii, G. macrophyllus and G. velutinus from the peat-swamps of Sarawak is compared. Sufficient anatomical differences exist to differentiate the four species. The main distinguishing anatomical features between the stems are the cork cells, the nature and relative quantity of cortical sclereids and the presence or absence of lignified pith parenchyma. In differentiating between the roots of G. andersonii, G. macrophyllus and G. malayanus. the principal features are the cork cells and the relative quantity of cortical sclereids. In addition, the medullary rays of G. macrophyllus root in transverse sections are noticeably broader in the xylem towards the phloem than those of the other species.