虎耳草炭疽病病原菌鉴定

【目的】从虎耳草炭疽病病斑分离病原菌,并对病原菌进行鉴定。【方法】采用柯赫氏法则对从病斑组织块分离的病原菌进行验证,通过形态学结合多基因分子系统学方法对病原菌进行鉴定。【结果】从虎耳草炭疽病病斑分离到2株菌株(菌株号:LPSU 20120244、LPSU 20120251)。2株菌株孢子均无色,无隔,直、圆柱状,菌株LPSU 20120244孢子(11-25)μm×(5-9)μm,菌株LPSU 20120251孢子(15-25)μm×(5-7)μm。多基因分子系统树中,2株菌株分别与喀斯特炭疽菌(Colletotrichum karstii Y.L.Yang,Zuo Y.Liu,K.D.HydeL.Cai)和江西炭疽菌(C.jiangxiense F.LiuL.Cai)模式菌株聚为一支,支持率均为100%。【结论】形态学及多基因分子系统学分析表明菌株LPSU 20120244为喀斯特炭疽菌,菌株LPSU 20120251为江西炭疽菌。     

HPLC法测定槟榔中的多酚类物质

采用高效液相色谱法对槟榔中的多酚类物质进行分析.用甲醇提取槟榔中的多酚类物质,并依次用石油醚、乙酸乙酯、正丁醇萃取,萃取物经抽真空浓缩,流动相定容,高效液相色谱法测定.分析结果表明:槟榔幼果较槟榔成熟果中所含的多酚种类和数量少,槟榔成熟果中果仁的多酚种类和数量都远较皮中多;槟榔的甲醇提取物乙酸乙酯萃取部分中所含的多酚种...     

海南岛中部山区槟榔植株金属元素的吸收积累及交换作用

本文研究了海南岛中部山区不同生境、不同品种的槟榔植株对6种金属元素的选择吸收积累和交换作用。结果表明槟榔植株对元素的吸收积累量、变化范围和交换作用差异明显 ,均为海南槟榔>云南槟榔>泰国槟榔 ;种间金属元素含量水平以A1>Zn>Cu>Ni>Mo>Pb为列 ;同种槟榔不同部位金属元素的吸收积累量差异程度不一 ;至于槟榔植株与土壤中元素的交换作用 ,以中北部沟谷产的槟榔吸收量 (127.25ug.g-1,48.44% )最高 ,东南部山地居中 ,西南部低丘偏低些。     

海南岛不同生态型槟榔脯氨酸累积与抗逆性

不同生态型槟榔总的、淳离基酸含量均以砂丘槟榔〉旱生槟榔〉沟谷槟榔,滨海槟榔,而脯氨权平均含量２．５２～３．７４ｍｇ．ｇ＾－１ＤＷ三亚、屯昌试区槟榔含量为前两者分别高达２．４７８～２．６０倍,３．８０～４．２８倍,２．２５～２．４１倍,３．４３～３．９８部,不同品种槟榔的脯氨一,则以海南槟榔高于泰国槟榔,云南榔１９．４４％、３１．３４％,其中果实增长比例最大,在不同生境中,生于地碱地的槟榔显著高于非     

芒果炭疽菌研究进展

芒果炭疽病是芒果生长期和采后贮藏期的主要病害之一,严重影响芒果的产量和品质。本文从芒果炭疽病的症状、病原菌分类鉴定、生物学特性、侵染特性及致病机理等方面进行综述;针对芒果炭疽病症状复杂、我国芒果炭疽病病原菌未获详细而系统的研究,指出全面了解我国芒果炭疽病的病原菌种类及优势种群,明确我国芒果炭疽菌的致病力强弱,有助于研究该病的发生流行规律,为抗病材料的选育和抗病品种在田间的合理布局提供参考。提出对我国芒果炭疽菌的抗药性进行系统监测分析,可防止或减缓芒果炭疽菌对杀菌剂抗药性的产生,从而有效减少化学农药的用量,为研究芒果炭疽病绿色防控新策略、新方法和新药剂奠定基础。     

海南与市售槟榔等中药材中重金属含量比较研究

本文用石墨炉原子吸收分光光度法测定了海南与市售槟榔等六种中药材中的铅元素含量 ,用原子荧光法测定了其中砷、汞元素的含量 ;通过对海南与市售槟榔等六种中药材 (槟榔、益智仁、砂仁、巴戟天、丁香及肉豆蔻 )中铅、砷、汞含量的比较研究 ,说明海南生态环境的优良是实现中药材GAP种植 ,生产绿色中药材的最佳环境     

菠萝蜜黑腐病病原菌的形态学与分子鉴定

为明确菠萝蜜黑腐病的病原菌和分类地位,本研究从海南保亭地区采样,经过田间调查、菌株分离纯化和致病性鉴定,以形态学特征为基础,结合病原菌的ITS序列和EF1-α序列,联合两基因建立系统发育树,最终鉴定该病害的病原.结果 显示:病原菌LTHD006菌丝生长速度快,初期白色絮状,较薄,后期菌丝开始变黑,菌落也开始致密,且与Lasiodiplodia theobromae (ID:CBS175.26)聚为一个分支,支持率为100％,最终将菠萝蜜黑腐病的病原菌鉴定为可可毛色二孢(Lasiodiplodia theobromae).该病害在国内为首次简略报道,研究结果为菠萝蜜黑腐病发病规律和防治的进一步研究提供理论基础.     

浅谈植物炭疽病

自２００１年美国纽约的“９·１１”事件后,又接二连三的发生了邮寄炭疽热病菌孢子的恐怖事件,致使全美国再次陷于十分恐慌的状态。为什么人们对炭疽热病如此惧怕呢？这是由于炭疽菌的致病力极强,感染后潜伏期短,发病急以及病死率高等特点。炭疽菌不仅能感染家畜和人类,而且还可使植物染病,只不过它们感染的病原菌不同而已,其中引起人畜炭疽病的病原菌叫炭疽杆菌（Bacillusanthracis）,而植物炭疽病的病原菌则为一类真菌,即指由黑盘孢目中的炭疽属（Colletotrichum）真菌的有性世代所引起的病害的统称。以往也曾有些人使用侵染植…     

禾谷炭疽菌磷脂酰肌醇转移蛋白生物信息学分析

目的:禾谷炭疽菌侵染玉米、小麦等农作物引起的炭疽病,给各国农业生产造成了巨大经济损失。植物病原菌在对植物侵染、定殖、扩展等致病过程中,细胞信号转导起着重要的作用。磷脂酰肌醇转移蛋白(PITP)参与众多生理生化过程,并在细胞信号转导过程中发挥重要作用。本研究为深入开展禾谷炭疽菌PITP的功能研究打下坚实的理论基础,同时,也为进一步开展其他炭疽菌的研究提供重要的理论指导。方法:基于酿酒酵母中已经报道的5个典型PITP序列,对炭疽菌属蛋白质数据库进行Blastp比对以及关键词搜索,并通过SMART保守结构域分析。结果:明确禾谷炭疽菌存在3个典型的PITP,同时,明确上述蛋白疏水性、细胞信号肽、跨膜区结构、亚细胞定位以及二级结构等情况。结论:与其他物种中9个同源序列进行遗传关系比较分析,该菌与希金斯炭疽菌亲缘关系较近。     

海南岛兴降地区某些药用植物中的微量元素

本文研究海南兴隆地区12种不同类型药用植物微量元素的生物吸收系数(Ax)及其含量水平变化特性,结果表明不同科、属、种植物对同一元素的吸收量差异显著,以Mg>Al>Fe>Mn>Zn>Cu为序;同属不同品种植物在不同生境中对微量元素的生物吸收系数各有差别,海南槟榔(Ax 0.30×10-6、12.51×10-6)>泰国槟榔(Ax 0.29×10-6、11.59×10-6)>云南槟榔(Ax 0.27×10-6、11.56×10-6),元素间吸收量相比以Mo>Zn>Cu>Mn>Ni为例;同种植物不同器官微量元素的吸收量也是不同的,例如巴戟天的含量以根(218.48×10-6)>叶(115.19×10-6)>茎(113.02×10-6)。植物与土壤中元素含量消长变化关系密切,相比之下,植物中Fe、Mn、Zn含量均高于Cu、Pb、Ni。绞股蓝(189.26)>巴戟天(169.04)>益智(161.70)>槟榔(155.88)。     

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.