高代回交QTL分析与水稻育种

本文对高代回交QTL分析法(advanced backcross QTL analysis,AB－QTL)的原理、步骤、适用范围以及相对于利用平衡群体进行QTL分析的优越性进行了比较。讨论了其在水稻高产育种中的应用前景。 Abstract:Advanced backcross QTL analysis method(AB－QTL),proposed by Tanksley,can deal with two matters simultaneously.One is QTL mapping and the other is to construct isogenic lines containing the QTLs mapped in the mapping population in one to two years.In this article,the principle,procedure,and application of AB－QTL are introduced.AB－QTL is also compared with mapping QTLs using a balanced population.The prospect of application of AB－QTL analysis in rice high yield breeding program is discussed.     

Possible Involvement of K^＋/Na^＋ in Assessing the Seed Vigor Index

More substances leaked from a higher-vigor seed sample than from a lower-vigor sample. This indicates that, in some cases, electric conductivity does not represent seed vigor level very well, especially for high-vigor seeds. Results from germination, germination index, leachate conductivity, and the ratio of K^＋/Na^＋ from three-seed lots of Chinese cabbage （Brassica pekinensis （Louv.） Rupr） showed that K^＋/Na^＋ correlated well with germination and germination index. The ability of K^＋/Na^＋ to indicate well changes in vigor was further supported by investigation in soybean （Glycine max （L.） Merr.） seeds and another cultivar of Chinese cabbage seeds. Thus, seed leakage of K^＋/Na^＋ can accurately indicate seed vigor, whereas the conductivity test failed to do so. Furthermore, K^＋/Na^＋ showed up bigger quantitative differences in vigor level than did the conductivity test. This findings provide a more sensitive and accurate index for the assessment of seed vigor. The mechanisms of Na^＋ and K^＋ ion transport are also discussed.     

利用SSR标记定位水稻糊化温度的QTLs

糊化温度（GT）是决定稻米蒸煮食用品质的一个重要指标。研究了以碱消值表示的糊化温度（ASV－GT）的遗传和QTL位点,选择在ASV－GT上具有显著差别的灿稻品种南特号和粳稻品种Balilla杂交,并以Balilla回交得到含有142株的回交群体,ASV－GT的测定表明,在分离群体中ASV－GT表现为双峰连续分布,说明在该群体中ASV－GT是由一主效基因控制的,并伴有微效基因的修饰,进一步用119个在双亲间具有多态性的微卫星（SSR）标记构建了全基因组的分子标记连锁图,采用区间作图法对控制碱消值的基因进行了定位分析,结果表明,位于第6染色体的qASV6-1为一主效基因,其贡献率高达87．6％,来自于亲本南特号中的等位基因可降低碱消值3．26;其余5个QTLs(qASV2,qASV3,qASV6-2,qASV9,qASV11)为微效基因,分别位于第2,3,6,9和11染色体上,双亲中都带有增效和减效等位基因。     

Genetic mapping of a new semi-dwarf gene, sd-t(t), in indica rice and estimating of the physical distance of the mapping region

Application and functional study of dwarf and semi-dwarf genes are of great importance to both crop breeding and molecular biology. A new semi-dwarf gene, sd-t(t), non-allelic to sd-1, had been identified in an indica rice variety, Aitaiyin 2. In this study the gene was genetically mapped by using an F2 population, which consisted of 474 individuals developed from a cross between Aitaiyin 2 and B30. The sd-t(t) gene was located between the RFLP markers R514 and R1408B with a distance of 1.1 cM to R514, and 4.5 cM to R1408B on chromosome 4. A physical contig covering the sd-t(t) mapping region was further constructed by screening a BAG library with R514 and R1408B as probes, and the physical distance between R514 and R1408B was estimated at approximately 147 kb. This result will facilitate map-based cloning of the sd-t(t) gene.     

皖南汉族的跖纹研究

本文分析了安徽皖南地区520例(男女各260人)汉族健康人的跖纹样本。追踪了跖纹A、B、C、D、E和P线止区,发现A、B、C、D线多止于1区;E 线主要走向13区;p三叉缺失较多,P远侧射线止区较高,而腓侧射线止区较低。母趾球纹为L>W>A。各趾间区真实花纹依次用为Ⅲ>Ⅱ>Ⅳ。足小鱼际远侧真实花纹较多,其他跖区较少。在性别、民族和人种间进行了比较,并对差异的原因进行了讨论。     

Nucleotide sequence of coat protein gene for GPV isolate of barley yellow dwarf virus and construction of expression plasmid for plant

GPV is a Chinese serotype isolate of barley yellow dwarf virus (BYDV) that has no reactionwith antiserum of MAV, PAV, SGV, RPV and RMV. The sequence of the coat protein (CP) of GPV isolate of BYDV was identified and its amino acid sequence was deduced. The coding region for the putative GPV CP is 603 bases nucleotides and encodes a Mr 22218 (22 ku) protein. The same as MAV, PAV and RPV, GPV contained a second ORF within the coat protein coding region. This protein of 17024 Mr (17 ku) is thought to correspond to the Virion protein genome linked (Vpg). Sequence comparisons of the CP coding region between the GPV isolate of BYDV and other isolates of BYDV have been done. The nucleotide and ammo acid sequence homology of GPV has a greater identity to the sequence of RPV than those of PAV and MAV. The GPV CP sequence shared 83.7% of nucleotide similarity and 77.5% of deduced amino add similarity, whereas that of the PAV and MAV shared 56.9%. 53.2% and 44.1%. 43.8% respectively. According to BYDV-GPV CP seque