等性杂化与不等性杂化

介绍了杂化轨道间夹角公式.通过计算讨论了等性杂化与不等性杂化,明确了区分等性杂化与不等性杂化的一般原则.     

影响元素电负性的因素

在多原子分子中,元素的电负性受所连原子（或基团）、原子的杂化方式及氧化态等因素的影响而改变     

An anther-specific chalcone synthase-like geneD5 related to rice pollen development

It was shown in a previous analysis that D5 gene from rice (Oryza sativa L.) was an anther-specific gene encoding a chalcone synthase-related protein. In this study, D5 gene was found specifically expressed in tapetum cells as well as in the peripheral cells of the vascular bundle of rice anthers by RNA in situ hybridization. In order to study its function, D5 was transformed into rice in both sense and antisense directions driven by a rice Actin 1 promoter. It has been observed that the pollen grains from the antisense D5 transgenic rice plants are abnormal, indicating that D5 plays a critical role in rice pollen development.     

45S rDNA在多种植物中期染色体上的定位

应用荧光原位杂交技术首次确定了日本小檗（Berberis tkunbergii DC）、车前（Plantago major L．）、野芹菜（Sanicula lamelligera Hance）、荔枝（Litchi chinensis Sonn．）、械树（Acer buergerianum Miq．）、天目琼花（Viburnum sargentii Koehne．）、丹参（Salvia miltorrhiza Bunge．）、榆树（Ulmus pumila L．）中45S rDNA在中期染色体上的位置．根据rDNA的位点数和位置的变化,分为四种类型：①在日本小檗、车前和野芹菜中,荧光信号正好位于随体染色体的次缢痕或端部;②荔枝和械树,分别有1对和3对染色体具随体,但荧光原位杂交却检测到3对和5对染色体上具有杂交信号;③天日琼花,具有4对随体染色体,但仅住其中一对随体上显示了杂交信号;④在丹参和榆树中,有的杂交信号位于着丝粒部位或长臂的末端,杂交信号的数目成奇数．黄瓜（Cucumis sativus L．）的染色体45S rDNA信号正好位于6条染色体的着丝粒部位,这与Dal-Hoe和Hoshi等人的结果是一致的．上述结果表明：45S rDNA可以作为染色体的一个识别指标,对识别染色体的个体性具有一定的参考价值．另外还对45S rDNA位点分布的多态性进行了讨论．     

基于细胞色素b基因研究两种石鸡的渐渗杂交

大石鸡是我国特有种,分布区狭窄;石鸡为广布种;两者都是我国北方干旱、半干旱荒漠环境的指示鸟类。利用线粒体DNA细胞色素b基因标记分析了大石鸡106个、石鸡48个样品,获得大石鸡单倍型9个,石鸡单倍型13个;在大石鸡种群中发现8个个体呈现石鸡基因模式（Hap-1和Hap-2）,但是在石鸡种群中没有发现大石鸡的基因模式,确认为石鸡和大石鸡之间的渐渗杂交;确认杂交带从六盘山脉向南到陇南地区的礼县一带,杂交带长度为400km,宽度为130km。结果表明目前渐渗杂交对大石鸡种群遗传多样性影响不大,在不长的进化时期内,对增加物种多样性是有好处的。建议进行长期野外监测,以便弄清发生渐渗杂交的野外生态学数据,为物种进化研究提供参考依据。     

Primary investigation on GISH-NOR in cotton

Six loci of nucleolar organizer region (NOR) were detected in genomic in situ hybridization (GISH) of cotton (Gossypium). NOR was the characteristic of 45S rDNA but could be generated by genomic DNA (gDNA) extracted from Gossypium species as probe. With twice FISH to the same mitotic cell of G herbaceum or G hirsutum, number, position and size for NORs generated from 45S rDNA and gDNA were identified largely similar or even the same. The NORs with gDNA as probe were therefore permanently defined as GISH-NORs. GISH-NORs from G hirsutum and Graimondii mitotic images were all terminal types. Four and two GISH-NORs from G herbaceum (var. africanum) were terminal and centromere types, respectively. Six GISH-NORs in G hirsutum were chromosome mapped with two in A- and four in D-subgenomes. There were also GISH-NORs in mitotic image of G raimondii with its own gDNA as probe. From mitotic image of G herbaceum with its own gDNA as probe, GISH-NOR could not be observed but non-wholerecovery of hybridized signals was distinguished. These non-whole-recovery of hybridized signals were detected on long arm terminals of most chromosomes and especially existed in nearly half long arm of a pair of chromosomes in Gherbaceum gDNA probed itself GISH image, which may be possibly induced by low copy genes within the regions rather than inter-subgenomic segment translocations. GISH-NORs in G hirsutum mitotic images were dominantly observed when gDNAs from D and A genome species were used as probes and block, respectively, but not when the reverse probe and block gDNA from the two diploid progenitor genomes were designed. There may be two speculations to this special phenomenon: rDNA concerted evolution; content of rDNA in genome D more than genome A.     

茶树杂交种金观音与黄观音的选育及应用

选配铁观音（♀）与黄金桂（♂）杂交,从F1中分离单株,经20多年的试验研究与生产示范,育成综合性状优异的杂交种金观音（又名茗科1号）、黄观音,先后通过省级与国家级品种审定．两个杂交种适制鸟龙茶与绿茶,制优率高,黄观音亦适制红茶、白茶．花香明显,品质优异,超过黄金桂,香气与制优率均比铁观音高．茶多酚、氨基酸等生化成分和萜烯醇类及其氧化物、酯类、内酯类、酮类等乌龙茶香气特征成分含量丰富,金观音、黄观音的遗传性状分男ll趋向母本与父本．超亲优势强,产量高,比双亲平均增产20％至60％以上,扦插繁殖力、抗性与适应性强,超过双亲．开采期早,与黄金桂同期,分别比铁观音提早13d与10d左右．适宜在福鼎大白茶的适栽区域推广．     

海滨锦葵杂交后代的RAPD分析

报道了海滨锦葵植物基因组DNA的提取方法、RAPD(随机扩增多态性)-PCR(聚合酶链式反应)反应程序及RAPD标记对海滨锦葵两对组合亲本及其杂交后代进行的分子鉴定.初筛出的38个引物中有20个(52.6%)能在J2×J1组合亲本间扩增出31条特征带,初筛出的32个引物中有8个能在J3×J4组合亲本间扩增出12条特征带.组合J2×J1的8个杂交后代用OPB15引物扩增后均表现出父本J2的特征带,是真杂种;组合J3×J4的28个后代用引物OPB15扩增后,表现父本特征带的F1代个体数为24个,为真杂种,其余4个为假杂种.     

水稻矮化突变体差异表达cDNA片段的克隆与分析

利用抑制性消减杂交（Suppressive subraction hybridization,SSH）分离本实验室获得的一株水稻矮化突变体dwarf69与其野生型对照品系特光矮-2（Rryza sativa,TGA-2 indica）间表达有差异的cDNA片段,分别以dwarf69作为驱赶子,TGA-2为检测子,以及以dwarf69作为检测子,TGA-2为驱赶子建立了两个差异表达cNDA文库,分别代表在TGA-2和dwarf69中特异表达的cDNA,经反式Northern检测这两个文库共得到10个阳性克隆。     

大刍草血缘普通玉米自交系的配合力分析

以6个含有一年生墨西哥大刍草血缘的自交系为被测系,采用NCⅡ遗传交配设计对6个含大刍草血缘的玉米自交系的配合力进行研究。结果表明：亲本98—3／／（200B／大刍草）／／／98—3的单株产量GCA较高;单株产量SCA效应值最大的组合是绵714×M4,具有一定利用潜力;根据SCA效应及产量表现,将6个远缘杂交选系初步划分为4个不同类群。利用一年生墨西哥大刍草来改良普通栽培玉米自交系是可行的,但选到理想自交系的可能性较小。