用于筛选直链淀粉含量为中等的籼稻品种的分子标记

用PCR AccⅠ分子标记检测方法 ,检测了来自不同地区的 6 3个栽培水稻品种 (系 )蜡质基因第 1内含子剪接供体 1位碱基是G或是T。另外 ,还测定了这些水稻成熟种子的直链淀粉含量。结果显示该位置是G碱基的水稻品系成熟种子中直链淀粉含量均高于 2 0 % ,该位置是T的均低于 18%。在杂交育种过程中 ,这一分子标记可用于预测水稻植株种子的直链淀粉含量。对高直链淀粉含量的水稻亲本与中等直链淀粉含量的水稻亲本之间 5个籼型杂交组合F2 群体的分析表明 ,蜡质基因第 1内含子 1位碱基是G或是T与水稻种子中直链淀粉含量的高或低是紧密连锁 ,共同分离的。这些结果表明PCR AccⅠ分子标记检测方法可用于选育中等直链淀粉含量的籼稻新品系     

籼型杂种稻米品质性状的数量遗传分析

应用新近提出的ｐ＾＋ｑ＾＋ｐｑ交配设计的种子性状遗传表达鉴别方法,分析了籼型水稻３个不育系和１０个恢复系配组的３０个杂种Ｆ１植株上的Ｆ２种子及其亲本的９个稻米品质性状。结果表明：（１）粒长、粒宽、粒重、糙米率和完整精米率５个性状在Ｆ２米粒间没有发生遗传分离,它们的遗传受二倍体母体基因型（Ｆ１植株）控制。（２）垩白率、直链淀粉含量、糊化温度和胶稠度４个性状则在Ｆ２米粒间有极显著的遗传分离,帮主要受三     

甘蓝型油菜和芥菜型油菜种间杂交研究

甘蓝型油菜与芥菜型油菜杂交研究结果表明,杂交结实力与杂交组合方式以及参与杂交的亲本材料有关,以芥菜型油菜作母本的杂交结实力高于以甘蓝型作母本的组合：芥×甘杂交组合的平均结实数／花为 ２．６４ 粒,而甘×芥杂交组合的平均结实数／花为 ０．１０ 粒。芥甘杂种一代形态特征和生育期介于双亲之间,甘芥杂种一代不表现整齐的中间类型,株间差异明显;总体来看,芥甘杂种一代与双亲回交的结实力（０．４０,０．２１）低于甘芥杂种一代与双亲回交的结实力（３．３０,１．７４）,无论是芥甘杂种一代还是甘芥杂种一代,用甘蓝型油菜作父本回交的结实力高于用芥菜型油菜作父本回交的结实力,但也有个别回交组合出现例外,不表现上述规律。 Ｂ Ｃ１ 代种子当年播种出苗率低（１８．５％ ）,群体株间性状差异明显,生育期极不一致。芥甘杂种一代与甘蓝型油菜亲本第二次回交,其平均结实数／花较回交一代提高 １．０８ 粒, Ｂ Ｃ２ 代种子当年播种出苗率仍较低,但较对应的 Ｂ Ｃ１ 代稍有提高,群体中出现趋回交父本性状但雄性育性彻底退化的植株。芥甘杂种一代自由授粉所得 Ｆ２ 群体是一个变异极为丰富的遗传群体。     

从农艺性状和分子标记鉴定一个水稻三倍体x二倍体F2群体的遗传稳 …

一自然发生的三倍体水稻材料与二倍体杂交,在Ｆ２代获得了一个稳定群体。群体形态表现,农艺性状分析和微卫星标记三个方面的研究表明：该杂交Ｆ２群体确系两个亲本的杂交的杂交后代。在杂交后有重组发生并迅速纯合,因而在形态上和遗传上呈现稳定性。对水稻中出现的这种早代稳定现象的利用和途径发生机制进行了探讨．     

籼爪交水稻F_2群体的蒸煮食味品质研究

分析了籼型高直链淀粉恢复系CG133R与糯性爪哇稻22号杂交衍生的F2群体的蒸煮品质变异及其与淀粉粘滞性特征间的相关性,以及F2群体颗粒结合淀粉合成酶(Wxa基因)和可溶性淀粉合成酶(SSⅡ-3基因)主效基因的遗传。结果表明:蒸煮品质指标和RVA谱特征值在F2群体中广泛分离,其中变异最大的是消减值,其次为胶稠度、直链淀粉含量。高直链淀粉材料各理化指标与RVA谱特征值的相关性不显著;RVA谱特征值在中、低直链淀粉含量和糯稻群体中与各理化指标存在显著或极显著相关;在中、低直链淀粉材料中,RVA谱特征值与糊化温度(GT)也存在显著或极显著相关。用Wxa基因和SSⅡ-3基因的分子标记检测到这两个基因在F2群体中存在偏分离,分别指向两个亲本类型。除高直链淀粉材料外,可以通过RVA谱特征值来辅助筛选优质水稻品种。     

丁香属植物有性杂交试验的研究初报

１９８８－１９８９年在哈尔滨市第三苗圃进行了丁香属（Ｓｙｒｉｎｇａ Ｌ．）植物种间（内）杂交试验。结果表明：⑴不同杂交组合的亲和性差异很大,在试验的１８个杂交组合中有５个杂交组合得到了发育正常的杂种Ｆ１代种子,但结实率不同,其中以白丁香与洋丁香为亲本的杂交组合,无论是正交或反交,杂种Ｆ１代的结实率均达８６％以上,表现出较高的亲和力。而以重瓣洋丁香为母本,白丁香为父本和杂交组合,杂种Ｆ１代结实率仅有     

作物杂种后代基因型值和杂种优良的预测方法

本文提出了利用作物亲本和Ｆ１预测杂种后代基因型值和杂种优势的统计分析方法。该方法运用加性－显性遗传模型,分析双列杂交试验资料,用ＭＩＮＱＵＥ（１）法估算方差分量以及预测遗传效应值。由加性和显笥效应预测值可进一步预测Ｆ１,Ｆ２,ＢＣ１,ＢＣ２,等不同世代的基因型值,在预测Ｆ１群体平均优势和 群丛超亲优势的基础上,可以推导出其它各世代的杂种优势。提出了预测杂种后代保持超亲优热世代数的简单公式,根据杂交组合Ｆ１群体平均优势和双亲相对遗传差异,便可预测该组合能的生产上直接利用的世代数。以棉花六个品种完全双列杂交试验资料为例,分析了各组合Ｆ１和Ｆ２的 基因型值、超亲优势和保持５％超亲优势的世代数。     

云南软米直链淀粉含量的遗传分析与基因定位

以低直链淀粉( 软米)品种毫木细与高直链淀粉品种桂朝2号杂交F2代分离群体为试验材料,研究水稻低直链淀粉含量的遗传规律和基因定位。结果表明,软米品种毫木细直链淀粉含量受一个隐性主效基因/QTL控制,该基因位点（QTL）与糯性基因(wx)为非等位。除主效QTL外,可能还有微效基因的作用。用SSR标记检测到该主效基因/QTL位于11号染色体上RM224附近,LOD值为15.4,可解释的表型变异率为32%。     

超甜玉米种子萌发物质利用性状杂种优势及亲子回归关系分析

为阐明超甜玉米(Zea mays L.var.saccharata Bailey)亲本对F_1种子物质利用性状遗传效应,研究了19份自交系和其测配的10个杂交组合的杂种优势及亲子回归关系。结果表明,超甜玉米自交系及F_1种子的淀粉含量、蛋白质含量、脂肪含量、百粒重、种子物质动用量和种子物质利用率差异较大,10个杂交组合中亲本和F_1种子的淀粉含量、脂肪含量、百粒重均存在显著差异。F_1种子淀粉含量和百粒重均表现出正向超亲优势,即近高亲本遗传;而F_1种子的蛋白质含量、脂肪含量、种子物质动用量和种子物质利用率为近低亲本遗传。聚类分析和杂种优势分析表明,性状差异较大的FH14、Q26、GT22、GT2等亲本测配的杂交组合在种子百粒重或种子物质利用率等性状上具有较强的超亲优势。回归分析表明,母本对F_1种子的淀粉含量、百粒重有负效应,对种子物质动用量和种子物质利用率有正效应;父本对种子淀粉含量有负效应,对种子物质利用率有正效应。     

籼稻转反义蜡质基因后代的直链淀粉含量测定和纯系选育

通过根癌农杆菌介导将反义蜡质基因导入籼型雄性不育保持系龙特甫B中,获得30个PCR检测为阳性的转基因植株,其中,28个为Southern检测阳性。T1种子直链淀粉含量测定结果表明,有21个转基因植株比龙特甫B明显下降,下降幅度为3％-13％,并在部分转基因植株的种子中观察到蜡质状籽粒;对6个转基因植株进行了不同世代的直链淀粉含量测定,在L3和L5的T4代中,选择到直链淀粉含量分别为15．9％和8．4％的纯合株系,经凝胶电泳测定,WX蛋白量明显降低,并与直链淀粉含量下降表现一致。以L3-1-1-1(15．9％)和L5-8-2-1(8．4％)纯合株系为亲本,分别与龙特甫A进行成对杂交和回交,并测定了F1和B1F1种子直链淀粉含量,以L3-1-1-1作亲本的F1为21．4％,B1F1为17．1％;以L5-8-2-1作亲本的F1为13．6％,B1F1为9．3％,结果表明：在不育系的转育过程中,以中低直链淀粉含量的转基因纯合株系为亲本,能有效降低F1和B1F1的种子直链淀粉含量。     

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.