云南“大粒水稻”对稻白叶枯病的抗性遗传

云南地方品种——云南大粒抗水稻白叶枯病菌“江陵691”,其抗性由2对具重叠作用的隐性抗性基因控制,与IR28、南粳15的显性抗病基因不等位;也与已命名的xa-5、xa-8、xa-9和xa-13 4个抗性基因也不等位。     

褐稻虱生物型变异动态监测及抗虫品种资源推荐

本文报道近十多年来广东省褐稻虱Nilaparvata lugens(Stal)生物型变异动态监测的研究结果,针对当前褐稻虱优势生物型及发展趋势,推荐优良的抗褐稻虱品种资源。监测结果表明;根据苗期抗性反应,分蘖期生存率测定,田间系统调查监测,广州褐稻虱田间种群对带有Bph1抗性基因的代表品种IR26的致害力不断增强,1992年以来抗性反应达生物型2的水平。1992～1994年在全省7个不同生态类型地区取样测定及验证试验结果表明,生物型 2已上升为广东褐稻虱田间主害代的优势种群。多年的抗性鉴定结果证实,外引品种IR56、IR50404同其对应亲本PTB33、Babawee一样,对褐稻虱的抗性稳定,已推荐用作进一步抗 性育种的优良抗源。粳籼89等23个品种能抗褐稻虱生物型1和2,可及时替代带即BPh1抗性 基因的品种。     

黄淮区粳稻抗稻瘟病基因Pi-ta、Pi-b、Pi54、Pikm的分子检测

利用水稻稻瘟病抗病基因Pi-ta、Pi-b、Pi54 和Pikm的功能标记对2016年山东省水稻中晚熟组区试、机插秧组区试的32个参试品系及连云港农业科学院科企水稻联合体黄淮粳稻区试16个品系进行了分子标记检测,结合稻瘟病抗性接种鉴定,对基因型与表型进行相关性分析。结果表明48个品种中携带Pi-ta、Pi-b、Pi54和Pikm抗性基因的品种数分别为15个、25个、26个和21个,其中鲁资稻7号、连粳14JD24含有4个基因的抗性等位基因,YS-6-6、济稻1号、D400等13个品种分别含有3个基因的抗性等位基因,临稻10号、丰稻2号、天和糯303等8个品种不含抗性等位基因。稻瘟病鉴定结果表明,48份品种中,济稻1号、圣稻072、连粳14JD24等4个品种表现中抗（MR）;临稻10、YS-6-6、圣稻053等26个品种表现中感（MS）;晶稻180、临13-105、圣稻504等15个品种表现感病（S）;H11-15、润农9号、晶稻160表现高感（HS）。Pi-ta、Pi-b、Pi54、Pikm 4个抗性基因已在黄淮区粳稻抗稻瘟病育种中得到广泛应用。其中Pikm与稻瘟病抗性综合指数存在显著相关性（r=0.477 5,P<0.01）。     

4个太湖流域粳稻地方品种抗稻瘟病性的遗传分析

以太湖流域粳稻地方品种薄稻、铁杆青、江南晚和缺儿糯等广谱、高抗稻瘟病为材料, 与高感稻瘟病品种苏御糯杂交, 获得杂交F1、F2 , 分别接种日本稻瘟病鉴别菌系北1和中国稻瘟病菌生理小种ZE3、ZG1, 根据P1、P2、F1和F2等不同世代植株的抗、感反应, 分析地方品种对不同稻瘟病菌生理小种(菌系)的抗性遗传机理。结果表明: 薄稻、铁杆青及缺儿糯对北1菌系的抗性均可能由一对显性基因控制, 江南晚对北1的抗性则可能由两对抑制基因互作控制; 铁杆青及缺儿糯对ZE3小种的抗性均可能由一对显性基因控制, 薄稻和江南晚对ZE3小种的抗性可能分别由两对显性基因和两对抑制基因互作控制; 铁杆青对ZG1小种的抗性可能是由一对显性主基因控制, 薄稻和江南晚对ZG1小种的抗性则可能由两对抑制基因互作控制。进一步将薄稻与12个日本稻瘟病菌鉴别品种杂交,用北1菌系接种不同组合的F1和F2 , 进行抗病基因的等位性测定。结果表明, 薄稻对北1菌系的抗性基因与12个鉴别品种所携带的已知抗稻瘟病基因是不等位, 将该基因暂定为Pi-bd1(t)。     

一个新的水稻叶形突变体（tll1）的遗传分析与精细定位

利用甲基磺酸乙酯（ethylmethane sulphonate,EMS）诱变粳稻品种日本晴获得了一个遗传稳定的叶形突变体thread-like leaf1（tll1）。该突变体在杭州表现为矮化、窄叶,极端时仅剩主脉,呈细丝状。将该突变体分别与籼稻品种南京6号、浙辐802和9311进行正反交配组,遗传分析表明该突变体性状由1对隐性单基因控制。通过SSR和STS分子标记对F2代分离群体进行遗传定位,将该基因初步定位在第12染色体SSR标记RM247和RM101之间。随后利用已公布的粳稻品种日本晴和籼稻品种9311的基因组序列,发展了7对有多态的STS标记,最终将该基因定位在FL13和FL14之间约94.3kb的区间内,为进一步克隆TLL1基因奠定了基础。     

一个新的水稻叶形突变体(tll1)的遗传分析与精细定位

利用甲基磺酸乙酯(ethylmethane sulphonate, EMS)诱变粳稻品种日本晴获得了一个遗传稳定的叶形突变体 thread-like leaf 1 (tll1)。该突变体在杭州表现为矮化、窄叶, 极端时仅剩主脉, 呈细丝状。将该突变体分别与籼稻品种南京6号、浙辐802和9311进行正反交配组, 遗传分析表明该突变体性状由1对隐性单基因控制。通过SSR和STS分子标记对F₂代分离群体进行遗传定位, 将该基因初步定位在第12染色体SSR标记RM247和RM101之间。随后利用已公布的粳稻品种日本晴和籼稻品种9311的基因组序列, 发展了7对有多态的STS标记, 最终将该基因定位在FL13和FL14之间约94.3 kb的区间内, 为进一步克隆TLL1基因奠定了基础。     

基因枪法转基因水稻中hpt基因稳定遗传

基因枪转化将潮霉素磷酸转移酶基因（ｈｐｔ）导入粳稻品种７７１７０,获得可育的转基因植株,研究外源基因遗传的稳定性。自交后代（Ｔ１和Ｔ２）经潮霉素筛选获得抗性植株和敏感植株,分子鉴定结果表明抗性植株带有ｈｐｔ基因,而敏感植株中没有ｈｐｔ基因存在。Ｔ１和Ｔ２代中潮霉素抗性表现为显性单基因位点的遗传方式,符合孟德尔分离规律,并得到分子鉴定结果的证实。Ｓｏｕｔｈｅｒｎ杂交结果显示,ｈｐｔ基因多拷贝整合在水     

我国东北稻区稻瘟病的研究进展

东北水稻种植区是我国粳稻的主产区,长期以来稻瘟病是生产中危害最严重的病害之一。本研究就近30年来东北稻区稻瘟病菌优势种群和优势小种变迁,主栽品种抗性进行了综述,分析了已鉴定的稻瘟病抗性基因在东北稻区的利用价值,同时对该地区稻瘟病研究存在的问题与今后的研究方向进行了讨论,以期为水稻抗稻瘟病的育种提供参考。     

稻瘟病抗性基因Pita和Pib在我国水稻主栽品种中的分布

主效抗稻瘟病基因Pita和Pib在我国很多稻区表现高水平的稻瘟病抗性,被广泛应用于我国的水稻育种和生产.但这2个基因在国内主栽品种中的分布及利用情况一直缺乏详细的资料,致使育种利用上存在着盲目性.本研究利用源于Pita和Pib基因本身的特异性分子标记,结合稻瘟病菌接种鉴定,检测和分析了我国58份水稻主栽品种(杂交稻亲本)的Pita和Pib抗性基因型.结果表明,特籼占25、佳禾早占、密阳46、测64-7等4个籼稻品种携带Pita和Pib 2个基因;籼小占等4个籼稻品种(系)和早丰9号等5个粳稻品种携带抗性基因Pita;绵恢501等5个籼稻品种(系)和粳稻品种武育粳7号、辽粳454携带抗性基因Pib.     

水稻品种条纹叶枯病抗性的研究进展

水稻条纹叶枯病是当前粳稻主产区危害最严重的病害之一,而品种抗病性的利用则被公认为是病害综合防治的根本策略.本文从抗性鉴定方法、抗性资源筛选和发掘、抗性遗传规律及抗病基因定位和抗性品种选育与抗性转基因工程4个方面,对水稻品种条纹叶枯病抗性的研究进展进行了简要综述,以期为水稻抗条纹叶枯病的育种提供参考.同时对水稻品种条纹叶枯病抗性研究的现存问题与今后的研究方向进行了讨论.     

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.