珠三角地区几种耐荫耐旱乡土地被植物的园林应用

通过在珠三角地区的广州白云山、肇庆鼎湖山、深圳梧桐山、惠州南昆山、东莞银屏山、东莞水濂山等6处选取样方进行实地调查,并采用线性加权综合法数学模型对珠三角地区野生地被植物作综合评价。结果表明,依据植物的生活型、生境、高度等特性初步确定该地区乡土地被植物70种,重点推荐紫金牛Ardisia japonica、东方紫金牛Ardisia squamulosa、马蓝Strobilanthes cusia等8种乡土耐荫耐旱地被,其在东莞植物园的配置应用实践中,均表现出极好的耐荫性和耐旱性,且扩繁较易。     

水稻耐光氧化和耐荫特性的生理基础

用简易、有效的人工光氧化和遮荫技术对３０个水稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）种质进行筛选,鉴定出既耐光氧化又耐荫、耐光氧化不耐荫、耐荫不耐光氧化、既不耐荫又不耐光氧化等４种品种类型,并用既耐光氧化又耐荫的品种“武育粳３号”和对光氧化和遮荫均敏感的品种“香籼”进行光合特性研究。结果表明：在遮荫条件下,与对光氧化和遮荫敏感的品种“香籼”比较,“武育粳３号”的ＰＳⅡ活性差异不大,ＲｕＢｉｓＣＯ活性降     

小兴安岭不同耐荫性树种枝叶性状变异及权衡

随着植株生长,不同耐荫性树种枝叶性状对资源的响应策略存在差异。探究不同耐荫性树种在不同径级间枝叶性状变异及其相关关系,对理解植物功能性状种内和种间变异以及植物对资源的响应策略具有重要意义。以黑龙江凉水国家级自然保护区阔叶红松（Pinus koraiensis）林中不同径级（小树、中等树和大树）的喜光树种（白桦Betula platyphylla、枫桦Betula costata）和耐荫树种（春榆Ulmus japonica、紫椴Tilia amurensis、色木槭Acer mono）为研究对象,测定其出叶强度、枝横截面积、枝干重、单叶面积、总叶面积、总叶干重共6个枝叶性状。利用单因素方差（LSD）分析检验不同耐荫性树种在不同径级间其枝、叶性状是否存在显著差异;以标准化主轴估计（SMA）对不同耐荫性树种枝叶性状间相关关系进行分析。结果表明：除枝干重外,耐荫树种枝叶性状均大于喜光树种;不同耐荫性树种大树枝横截面积均最大,中等树叶面积均最小;喜光树种不同径级间枝干重、总叶干重和出叶强度无显著差异,而耐荫树种均存在显著差异。随径级增大,不同耐荫性树种枝横截面积与叶面积均呈正异速生长关系,且除耐荫树种枝横截面积与单叶面积外,均存在共同斜率;不同耐荫性树种出叶强度与单叶面积存在共同斜率为-0.51和0.47,小树和中等树枝横截面积与总叶面积和总叶干重的异速生长指数均与1存在显著差异,而大树与1无显著差异。结果表明：不同耐荫性树种在不同径级间对资源的获取策略存在差异,不同耐荫性树种小树阶段均表现出资源获取策略,大树阶段则表现出资源保守型策略。与耐荫树种相比,喜光树种表现为快速生长策略,而随着径级增大不同耐荫性树种这种差异逐渐消失,本研究结果为森林演替过程中种内和种间的相互作用提供了一个新的视角。     

基于光合系统参数建立马铃薯耐荫性综合评价体系

为构建便捷的马铃薯(Solanum tuberosum)耐荫性综合评价体系并发掘耐荫种质, 以35个马铃薯品种(系)为实验材料, 测定块茎膨大期遮荫下植株叶片叶绿素含量、光合能力和叶绿素荧光等光合参数及收获后块茎单株产量和淀粉含量等指标。根据耐荫系数, 利用主成分分析法、隶属函数法、聚类分析法和逐步回归分析法进行综合评价。通过主成分分析将马铃薯耐荫性相关的13个单项光合指标转换为6个综合指标, 代表了全部信息的87.51%。以此计算各种质的隶属函数值, 并以主成分的贡献率进行加权, 最终获得所用材料耐荫性的综合评价值(D值)。根据D值聚类分析结果将35个马铃薯分为4类, 其中Eshu10和Lishu6分别为耐荫性最强和最弱的品种。通过逐步回归分析建立了马铃薯耐荫性评价数学模型: D=0.060+0.106G_s+0.214qP+0.143NPQ。同时, 用该评价体系鉴定为耐荫性强的品种(系)在遮荫后其产量和/或淀粉含量等指标减幅均低于耐荫性弱的种质, 表明该评价体系可用于快速评价和预测马铃薯种质的耐荫性。     

基于光合系统参数建立马铃薯耐荫性综合评价体系

为构建便捷的马铃薯(Solanum tuberosum)耐荫性综合评价体系并发掘耐荫种质, 以35个马铃薯品种(系)为实验材料, 测定块茎膨大期遮荫下植株叶片叶绿素含量、光合能力和叶绿素荧光等光合参数及收获后块茎单株产量和淀粉含量等指标。根据耐荫系数, 利用主成分分析法、隶属函数法、聚类分析法和逐步回归分析法进行综合评价。通过主成分分析将马铃薯耐荫性相关的13个单项光合指标转换为6个综合指标, 代表了全部信息的87.51%。以此计算各种质的隶属函数值, 并以主成分的贡献率进行加权, 最终获得所用材料耐荫性的综合评价值(D值)。根据D值聚类分析结果将35个马铃薯分为4类, 其中Eshu10和Lishu6分别为耐荫性最强和最弱的品种。通过逐步回归分析建立了马铃薯耐荫性评价数学模型: D=0.060+0.106G_s+0.214qP+0.143NPQ。同时, 用该评价体系鉴定为耐荫性强的品种(系)在遮荫后其产量和/或淀粉含量等指标减幅均低于耐荫性弱的种质, 表明该评价体系可用于快速评价和预测马铃薯种质的耐荫性。     

深圳地区8种园林地被植物耐涝性综合评价

为高效筛选雨水花园适用植物,以香彩雀Angelonia salicariifolia等8种园林地被植物为试材,采用盆栽模拟涝渍的方法,研究不同时间淹水胁迫处理后8种植物的观赏性状及生理指标,通过主成分分析与隶属函数法对其耐涝性进行综合评价,并筛选评价植物耐涝性的有效指标。结果表明,8种园林地被植物的耐涝性强弱依次为香彩雀、水鬼蕉Hymenocallislittoralis、龙船花Ixorachinensis、朱槿Hibiscusrosa-sinensis、大花马齿苋Portulacagrandiflora、朱蕉Cordylinefruticosa、巴西野牡丹Tibouchinasemidecandra、四季海棠Begoniasemperflorens;植物叶片的相对含水量、MDA含量、相对电导率与Fv/Fm值是反映植物耐涝性的重要指标。     

假俭草的扦插繁殖

假俭草（Ｅｒｅｍｏｃｈｌｏａｏｐｈｉｕｒｏｉｄｅｓ）是禾本科多年生草本植物。具匍匐根状茎，节上分枝和生根，贴地面生长，秆斜生，草高１０—２５厘米。叶线形，总状花序单生秆顶，９—１１月抽穗开花，果期１０－１２月。假俭草主要分布在长江流域以南各省区，常生于低丘或平坦旷野和路旁。性喜阳光充足，亦稍耐荫；耐旱瘠土壤，在疏松湿润的沙质壤土上生长繁茂；终年常绿。它的分蘖能力强，生长迅速，覆盖度大，耐践踏，自然生长亦保持平展美观。据有关资料记载，ＳＯ２和Ｃｌ２对它的伤害阈值分别为２．８６ｍｇ／ｍ３×４小时和１…     

香港乡土树种幼苗在次生林下生长的研究

通过苗木移植试验,测定了２１种香港乡土树种在次生林下的成活率及生长状况。结果表明,大多数种类的幼苗具有一定的耐荫性,可在林下生长;只有极少数种类表现出极耐荫或极不耐荫,导致林下先锋树种幼苗死亡率高的主要原因是荫蔽或因荫蔽而生长不良受病虫害致死。在香港次生林演替中占优势的种类通常具有生长快、稍耐荫,或生长稍慢但耐胁迫等特点。这是对香港退化土地长期适应的结果。鸟播植物在香港次生林中占有重要地位,建议加     

岷江上游暗针叶林采伐迹地人工混交林群落结构

对四川岷江上游高山峡谷区暗针叶林采伐迹地年龄为２０－４０年的人工混交林群落结构进行了研究,结果是：（１）群落中各层次物种盖度的大小相互影响,相互制约,而林下（各）层次物种盖度的大小主要取决于其上（各）层盖度（或郁闭度）的大小,（２）人工重建的群落所能容纳的物种数及物种在群落中的分布状况主要取决于乔木物种郁工,海拔高度及经营强度。（３）群落中出现大量的耐荫植物,先锋灌丛植物已被抑制或淘汰,（４）乔木     

12种园林植物耐荫性鉴定指标的筛选

在对遮荫条件下12种园林植物的生长增量、叶片厚度、比叶面积、叶片含水量、叶绿素a＋b含量、叶绿素a,b、类胡萝卜素含量、糖含量、过氧化物酶活性、日平均净光合速率、光补偿点、表观量子效率等生理生化指标测定基础上,对各项指标进行了主成分分析和逐步回归分析,结果表明生长增量、比叶面积、叶绿素a,b、过氧化物酶活性、目平均净光合速率等5个指标对植物的耐荫性有显著影响。采用所建立的最优回归方程对供试植物进行耐荫性预测及排序的结果与栽培试验观察结果相一致,表明这5个指标可作为快捷的植物耐荫性鉴定指标。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.